1 MEETING
2 OF THE
3 SCIENTIFIC REVIEW PANEL ON TOXIC AIR CONTAMINANTS
4 CALIFORNIA AIR RESOURCES BOARD
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6
7
8
9
10 SOUTH SAN FRANCISCO CONFERENCE CENTER
11 255 SOUTH AIRPORT BOULEVARD
12 SOUTH SAN FRANCISCO, CALIFORNIA
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14
15
16
17
18 WEDNESDAY, APRIL 22, 1998
19 9:00 A.M.
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21
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24 Janet H. Nicol
Certified Shorthand Reporter
25 License Number 9764
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1 APPEARANCES
2 MEMBERS PRESENT:
3 Dr. John Froines, Chairman
Dr. Paul D. Blanc
4 Dr. Craig Byus
Dr. Gary Friedman
5 Dr. Anthony Fucaloro
Dr. Stanley Glantz
6 Dr. Peter S. Kennedy
Dr. Hanspeter Witschi
7
8 REPRESENTING THE CALIFORNIA AIR RESOURCES BOARD:
9 Mr. Manjit Ahuja
Mr. Donald Ames, Assistant Chief
10 Mr. Robert Krieger, Associate Air Pollution Specialist
Dr. Michael Lipsett
11 Mr. Peter Mathews, Office of the Ombudsman
Mr. Kirk Oliver, Staff Counsel
12 Mr. Ralph Propper
Ms. Genevieve Shiroma, Chief, AQMB
13
14 REPRESENTING THE OFFICE OF ENVIRONMENTAL HEALTH HAZARD
ASSESSMENT:
15
Dr. George Alexeeff, Chief, Air Toxicology & Epidemiology
16 Dr. John Budroe, Staff Toxicologist
Dr. Stanley Dawson, Staff Toxicologist
17 Dr. Melanie Marty, Senior Toxicologist
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1 INDEX
2 PAGE
AGENDA ITEMS:
3
1 Review of report: Proposed Identification of 1
4 Diesel Exhaust as a Toxic Air Contaminant,
February 1998
5
Adjournment 224
6
Certificate of Reporter 225
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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1 P R O C E E D I N G S
2 ACTING CHAIRMAN FROINES: I'd like to call the
3 meeting to order. I think we have a long day ahead of us
4 and the sooner we get started, the better.
5 I should say that we have one logistical issue to
6 deal with, and that is that I think it's important for all
7 the panel members to be able to attend the discussion.
8 And as you can see and know, Jim Seiber was not
9 able to be with us because he's in the Netherlands.
10 But we have one further conflict, which is that
11 Paul Blanc has to go up to UC San Francisco to give a talk
12 at noon.
13 So I would propose that we take a lunch break at
14 11:45. Paul can get up to San Francisco, his talk runs
15 until 12:30, and he promises that he'll be back by 1:00
16 under pain of death and burning.
17 So if that's okay with everybody else, we can do
18 that.
19 Bill, is that okay with you?
20 I think that given the logistics of lunch, that
21 might make sense anyway. So 11:45 to 1:00 will be our
22 break.
23 So we'll try and go as far as possible this
24 morning. Although Genevieve and George have said that they
25 have a fairly extended period of description of most recent
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1 events.
2 And so I think that without my taking time to make
3 any other comments, we all are deluged with loads of
4 material, and the one thing I will say is that you do have
5 draft findings which I put together, and I wanted to make
6 everybody on the panel aware that I tried to make those
7 findings very simple. I tried to make those findings by and
8 large reasonably straightforward in the hopes that the panel
9 would then make subsequent modifications.
10 So I wasn't trying to write anything like a final
11 draft at all. I was simply trying to put something together
12 that we would have to work from. So please take that as a
13 draft in process.
14 DR. BLANC: John, is this on? Can people hear me?
15 How about now?
16 Well, John, I'll talk loudly.
17 Could you map out for us what, in broad terms,
18 what the agenda is today? Because appropre of your comment
19 on the draft findings, what I would suggest is that after
20 whatever initial presentation the staff has for us that we
21 actually use your very useful draft as a kind of template or
22 guideline for how we can structure our discussion, because I
23 found that your draft was so useful that I can just see
24 going through it point by point and coming to closure as a
25 group on each of the various subparts of it as a way of
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1 organizing our discussion, if that would be acceptable to
2 the other panel members.
3 ACTING CHAIRMAN FROINES: For those that are
4 confused, since I developed two drafts, you need to know
5 what he's talking about. He's talking about the draft where
6 I went through some of the definitional issues.
7 DR. BLANC: No. I actually mean the draft of your
8 findings.
9 DR. FUCALORO: He's talking about the 22 points.
10 DR. BLANC: I would just go through the 22 points.
11 I think we can refer to the other memo as needed when we
12 come to questions of definitions and what our charge is, but
13 I just found your draft findings so useful that it would
14 probably be a good way to structure our focus discussion.
15 ACTING CHAIRMAN FROINES: Well, I think that
16 that's an interesting suggestion.
17 Normally what's happened in the past is that after
18 the presentation is made by staff of our ARB and OEHHA and
19 during that time there are always questions that can be
20 raised of the staff during their presentations, but then in
21 a sense it reverts to the panel itself.
22 Normally what we have done is say under Part A
23 Tony will be the lead replacing Jim Seiber for this meeting
24 and what Tony would then do is make any comments that he
25 chooses to make and then he would then ask for comments from
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1 panel members around the room.
2 If you're suggesting that rather than go around
3 the room, we go through the document on Part A during that
4 time, that's another way of doing it. So we should decide
5 that pretty quickly.
6 DR. BLANC: Well, that's why I bring it up right
7 at the start, because I think it would sort of guarantee
8 that at the end of the day we had given a balanced amount of
9 time and had a draft, a modified draft document, that would
10 be our product at the end of the day.
11 But I guess I would ask Tony if you would feel
12 comfortable with the first half if, let's say, the first ten
13 points for example address some of the key areas of the
14 salient features of that part of the document and then you
15 actually reviewed the -- or coordinated the discussion on
16 the health, so I would assume that the points 11 through 22
17 or the 11 through 19 or so of your draft document would, you
18 know, since you formulated it that way.
19 ACTING CHAIRMAN FROINES: If we did that, what
20 that then means is that we go through and say Stan has a
21 point that's not in the document that he can raise that at
22 an appropriate time.
23 DR. BLANC: Yeah.
24 DR. FUCALORO: Since you have more experience in
25 these sort of things I'll do whatever you wish. I can
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1 handle it either way.
2 ACTING CHAIRMAN FROINES: What do others feel?
3 DR. GLANTZ: I actually think that's a good idea
4 because often the findings get kind of rushed at the end of
5 the meeting, and this way we would focus on the findings.
6 And, I mean, I think, though, there are -- I do
7 have a few comments on the actual document, the report, that
8 I think we would want to have.
9 I think what we maybe ought to do is follow Paul's
10 suggestion. Probably in the context of that discussion
11 there will be some changes to the report brought up, but
12 then after we've done that, to just go through the report
13 with anything anybody hasn't talked about to make sure that
14 because we are approving the report too, and as well as
15 issuing the findings, so we want to make sure everybody is
16 happy with the report.
17 I think it's a good idea, actually.
18 ACTING CHAIRMAN FROINES: Peter -- probably
19 shouldn't have put Peter and Hanspeter next to each other,
20 because every time we turn that way, one or the other is
21 going to answer.
22 Well, that seems, unless there's dramatic
23 disagreement, it seems to me we're going to go that way. I
24 think it will work fine. It will help, if -- this is such
25 an immense document what we need to do is to try to organize
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1 how we approach it so we can systematically get through in a
2 reasonable period of time with significant depth to the
3 discussion. I think that's important that we have the level
4 of depth that's required for making the determination.
5 So having worked on these internal matters,
6 Genevieve, if you could introduce yourself and others.
7 And so that -- everybody does have the staff --
8 the two documents that I prepared, right?
9 DR. GLANTZ: One document?
10 ACTING CHAIRMAN FROINES: One was the definitional
11 one and one was the findings.
12 DR. GLANTZ: Is the definitional one this e-mail?
13 ACTING CHAIRMAN FROINES: Yes.
14 And we will also be making available to you this
15 morning two other documents that I received this morning.
16 They are both from the National Institute for Occupational
17 Safety and Health, and they both represent new risk
18 assessments that have been conducted by NIOSH and are going
19 to be published in the July issue of the American Journal of
20 Industrial Medicine. So we'll have that as another risk
21 assessment approach, and I'll get Peter to work on that.
22 I don't think there's any other -- everybody has
23 the Allan Smith document, because that was in the comments,
24 I believe. And that's a very nice document and I hope we
25 have it as some discussion point, because anything that
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1 helps simplify any of these discussions I think is to our
2 advantage.
3 So anyway, Genevieve.
4 MS. SHIROMA: Thank you. Good morning,
5 Dr. Froines and members of the panel. My name is Genevieve
6 Shiroma. I am chief of the Air Quality Measures Branch at
7 the Air Resources Board.
8 My branch is responsible for implementing the
9 toxic air contaminants identification program, specifically
10 the exposure portion.
11 With me is Robert Krieger of my staff, who is lead
12 on the exposure assessment for diesel exhaust.
13 In accordance with AB 1807, toxic air contaminate
14 statutes, we are here today to seek, along with the staff of
15 the Office of Environmental Health Hazard Assessment, to
16 seek your approval of the February 1998 draft report
17 proposed identification of diesel exhaust as a toxic air
18 contaminant.
19 We will present an overview of the report,
20 summarize the public comments received and we will also be
21 proposing a number of revisions to the report for your
22 assessment.
23 Now, this is an outline of today's presentation.
24 I'll start out with a short introduction, and then we'll
25 move on to an overview of the report.
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1 Robert will give a short overview of the Part A
2 exposure assessment.
3 Dr. George Alexeeff, with the OEHHA, will present
4 the overview of the Part B health risk assessment.
5 Now, following that, Robert will then summarize
6 the comments that we received on Part A and our proposed
7 revisions.
8 Then Dr. Melanie Marty with OEHHA will summarize
9 the Part B comments and present proposed revisions.
10 Now, as you know, we have a comprehensive -- we
11 have a comprehensive air toxics program in California. The
12 toxic air contaminant program was established by AB 1807 in
13 1983. The program is a two-phased program.
14 ACTING CHAIRMAN FROINES: Can I interrupt you
15 before we start?
16 MS. SHIROMA: Yes, you may.
17 ACTING CHAIRMAN FROINES: Because when you went
18 through all that, a little signal went off in my ear. And
19 this reflects to George and Melanie.
20 The panel has had the benefit of reading the
21 responses to the comments and so hopefully you can keep, you
22 can address the most important comments in a reasonably
23 efficient fashion, because I think that the panel needs to
24 have a lot of time to discuss these things and so -- and the
25 panel is very active and so the -- we should try and keep
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1 the time for -- to go over things that people have already
2 hopefully read to some minimum and if there's ever any
3 question, the panel can reraise issues, the panel is not
4 precluded, but I think we also need to make sure we move
5 along at a reasonable pace.
6 MS. SHIROMA: That's fine. We'll keep it succinct
7 and brief.
8 Again, just for an overview on the program, I have
9 the definition of a toxic air contaminant up on the screen.
10 The program is a two-phased program.
11 A toxic air contaminant is defined in the law as
12 an air pollutant which may cause or contribute to an
13 increase in mortality or in serious illness or which may
14 pose a present or potential hazard to human health.
15 The first phase of the program is the risk
16 assessment or the identification phase.
17 The second phase is the risk management phase
18 where the need for an appropriate degree of control of a
19 toxic air contaminant is assessed.
20 As you know, we are in the first phase, the
21 identification of diesel exhaust as a toxic air contaminant.
22 Now, for the benefit particularly of the new SRP,
23 the newer SRP members, we thought at this point we'd have
24 Kirk Oliver with our office of legal affairs, just briefly
25 describe each of our responsibilities under the statute.
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1 Now, Kirk has been delayed in traffic, and so I
2 will just briefly go over the items that he wanted to
3 outline for you and then he will be here eventually. If you
4 have questions, he'll be here to answer questions.
5 ACTING CHAIRMAN FROINES: I just want to make one
6 comment, that that definition I made available to the panel.
7 I left one piece out. I just want to read it so that
8 everybody has it in the back of their mind.
9 And that is it's section E under 39650. It says
10 that while absolute and undisputed scientific evidence may
11 not be available to determine the exact nature and extent of
12 risk from toxic air contaminants, it is necessary to take
13 action to protect public health.
14 I think that needs to be seen within the context
15 of the definition as well.
16 DR. GLANTZ: Genevieve, if Kirk will ultimately
17 get here, why don't you get on with the science and he can
18 talk about the law when he gets here.
19 MS. SHIROMA: That would be fine.
20 One of the things that he wanted to make real
21 clear is that the ARB indeed is responsible for the exposure
22 part of the science, the OEHHA on the health part of the
23 science, and that OEHHA by the statute is required to
24 provide a range of risk.
25 And also to indicate whether or not there is a
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1 threshold below which no adverse health effects are
2 expected.
3 And then you, the SRP, are responsible for
4 reviewing the report for sound science.
5 John, is that satisfactory with you?
6 ACTING CHAIRMAN FROINES: All right.
7 MS. SHIROMA: Okay. Then the next slide is just a
8 list of the criteria we use for prioritization. It really
9 is the first step of looking at entering a compound into the
10 program. We look at things like potential risk to public
11 health, the exposure, usage in California, persistence.
12 DR. FUCALORO: Excuse me. Just for clarification,
13 this prioritization is for those substances that you
14 currently have in the pipeline to consider, so this is
15 the --
16 MS. SHIROMA: That's right. In previous meetings
17 we've presented a list of several hundred substances that we
18 continually prioritize.
19 The next one shows a flow chart of the process.
20 Once we have selected a compound, we begin the process of
21 producing the report. Very key part is that they're
22 distributed for public review and comment with public
23 workshops where interested parties can discuss the issues
24 with both the staff and the Scientific Review Panel members.
25 After that we then go through looking at the
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1 comments and revising the report accordingly.
2 We then submit it to you as we have.
3 Here is Kirk.
4 And go through a process of seeking your approval.
5 If you approve the report and you develop
6 findings, which are then submitted to the Board, we then put
7 out a hearing notice for a 45-day comment period, and then a
8 Board hearing to take formal action to identify the
9 substance.
10 Our Board simply determines in a regulatory format
11 is this substance a toxic air contaminant and adds that then
12 to the regulation.
13 Then at that point, the second phase, the
14 right-hand side of the flow chart begins where the risk
15 management phase begins where the degree of control is
16 reassessed.
17 Now, the next slide shows the types of criteria we
18 took into consideration when we entered diesel exhaust back
19 in 1989, in that the potential for non-cancer and cancer
20 health effects, widespread exposure in California, the
21 International Agency for Research on Cancer designation as a
22 probable human carcinogen, US EPA had begun its evaluation
23 of diesel exhaust health effects and overall method of
24 criteria for the definition of a toxic air contaminant at
25 that time.
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1 Now, this next slide is a chronology just showing
2 that again since 1989 there has been an extensive effort to
3 go through a thorough public and scientific process.
4 Couple of items to note.
5 In January of 1996 the OEHHA, the ARB, the Health
6 Effects Institute, National Institute of Occupational Safety
7 and Health, World Health Organization and US EPA sponsored a
8 human health study workshop.
9 October of '97 the ARB and OEHHA staff provided
10 you, the panel, with an overview of the report and the types
11 of comments we were receiving on the May draft.
12 And then on February 23rd we released this report.
13 In March you held a meeting with invited
14 scientists.
15 Overall the draft report has been through three
16 comment periods, three public workshops, and the staff have
17 participated in numerous individual meetings with interested
18 stakeholders.
19 Now, at this point we can move on to the overview
20 of the report.
21 And, again, Kirk Oliver is here for questions.
22 I'm going to now turn the presentation over to
23 Robert Krieger. After Robert we'll hear from Dr. Alexeeff.
24 Robert is going to give you, again, a short
25 overview of the exposure assessment portion of the report.
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1 DR. GLANTZ: Since Kirk just showed up, do you
2 think it would be worth him just briefly saying what he was
3 going to say?
4 MS. SHIROMA: Yes, I do, actually think it would
5 be worth it.
6 ACTING CHAIRMAN FROINES: No more than five
7 minutes.
8 DR. GLANTZ: Yeah, briefly.
9 MR. OLIVER: Thank you, Dr. Glantz and Dr. Froines
10 and members of the panel. And I apologize for being late.
11 The traffic in this area, as you know, is very heavy, and
12 was so today.
13 And I promise I can get through this in less than
14 five minutes, so let's get going on it.
15 The AB 1807 identification statute is quite clear
16 on the responsibilities of the ARB, OEHHA and the Scientific
17 Review Panel.
18 Primarily the ARB is to prepare a report in a form
19 which may serve as the basis for regulatory action regarding
20 the formal identification of the substance.
21 In doing this, the ARB staff is required to
22 consider research and monitoring data, emissions inventory
23 data, information on estimated actual exposures to
24 substances based on geographic and demographic data, and on
25 data derived from analytical methods that measure the
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1 dispersion and concentrations of substances in ambient air
2 and in indoor environments, as well as ambient conditions.
3 The OEHHA staff, at the request of ARB, is
4 required to evaluate the health effects of and prepare
5 recommendations regarding a substance, considering all
6 available scientific data, including but not limited to
7 relevant data provided by the ARB, the State Department of
8 Health Services, the Occupational and Safety and Health
9 Division of the Department of Industrial Relations, the
10 Department of Pesticide Regulation, international and
11 federal health agencies, private industry, academic
12 researchers and public health and environmental
13 organizations.
14 The OEHHA evaluation must assess the availability
15 and quality of data on health effects, including potency,
16 mode of action and other relevant biological factors of the
17 substance.
18 The OEHHA evaluation is also required to contain
19 an estimate of the levels of exposure which may cause or
20 contribute to adverse health effects.
21 Where it can be established that a threshold of
22 adverse health effects exists, the estimate shall include
23 both of the following factors. One, the exposure level
24 below which no adverse health effects are anticipated; and,
25 two, an ample margin of safety which accounts for the
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1 variable effects that heterogeneous human populations
2 exposed to the substance under evaluation may experience,
3 the uncertainties associated with the applicability of the
4 data to human beings and the completeness and quality of the
5 information available on potential human health exposure to
6 the substance.
7 However, in cases where there is no threshold of
8 significant health effects, the OEHHA is required to
9 determine the range of risk to humans resulting from current
10 or anticipated exposures to the substance.
11 The report compiled by the ARB and contributed to
12 by OEHHA shall be made available to the public and must be
13 formally reviewed by you, the Scientific Review Panel.
14 You're required to review the scientific
15 procedures and methods used to support the data in the
16 report, the data itself and the conclusions and assessments
17 on which the report is based.
18 Your panel is required to submit its written
19 findings to the ARB on this report within a specified time
20 frame.
21 If you, the panel, determine that the health
22 effects report is not based upon sound scientific knowledge,
23 methods or practices, the report shall be returned to the
24 ARB, and the ARB with OEHHA is required to prepare revisions
25 to the report, which have to be resubmitted to you for
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1 re-review.
2 Within ten days of the receipt by the ARB of your
3 findings that the report does meet the legal requirements,
4 the ARB staff is required to prepare a hearing notice and
5 propose regulations for the proposed identification of the
6 substance under review by you.
7 That ends my summary of your various
8 responsibilities.
9 Are there any questions you have now?
10 MR. KRIEGER: Thank you, Kirk.
11 Thank you, Genevieve.
12 Good morning, Dr. Froines and members of the
13 panel.
14 Right now I'd like to give you a brief
15 presentation on the Part A exposure assessment.
16 Our Part A was also contributed, I'd like to also
17 note, that Part A was contributed by the other divisions
18 within the Air Resources Board, Monitoring and Laboratory
19 Division, the Technical Support Division, the Research
20 Division, Mobile Source Division, and our Stationary Source
21 Division.
22 I'll begin my overview of Part A with the
23 properties of diesel exhaust.
24 As you know, diesel exhaust is a complex mixture
25 of thousands of gases and fine particles emitted by internal
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1 combustion engines.
2 Some of the components are known human
3 carcinogens, like arsenic and benzene.
4 It also includes over 40 substances that have been
5 identified as toxic air contaminants and by the US EPA as
6 hazardous air pollutants. Over 90 percent of these
7 particles are less than one micron in diameter.
8 This overhead shows the 40 compounds that are
9 federal hazardous air pollutants and have been identified by
10 the Air Resources Board as toxic air contaminants. 17 of
11 these also have IARC, or International Agency for Research
12 on Cancer, designations.
13 This slide shows the sources of emissions of
14 diesel exhaust in California. The majority of these
15 emissions, as you can see, come from on-road motor vehicles.
16 To characterize exposure to diesel exhaust, we use
17 particulate matter concentrations. To estimate
18 population-weighted average outdoor concentrations of diesel
19 exhaust, PM 10, we use receptor modeling techniques which
20 include chemical mass balance results from several studies,
21 ambient PM 10 monitoring network data, and the 1990
22 emissions inventory.
23 From the results of this analysis, we estimated
24 that Californians in 1990 were exposed to a
25 population-weighted average outdoor concentration of three
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1 micrograms per cubic meter.
2 We have also estimated in 1995 and future year
3 outdoor average concentrations.
4 These future concentrations, important to note,
5 take into account the measures and control measures by ARB
6 that have been adopted to date.
7 In December of 1993 we conducted a study to
8 determine near-source concentrations near a Long Beach
9 freeway. The results indicate that near-source
10 concentrations may be up to three times that of outdoor
11 ambient air concentrations.
12 This slide gives you an indication of what other
13 researchers have done to measure outdoor atmospheric
14 concentrations of diesel exhaust PM.
15 The comparison shows well with those of other
16 researchers.
17 We estimated the outdoor population-weighted
18 concentration in a model to calculate indoor and total air
19 exposures. This model, the California population indoor
20 exposure model, accounts for the amount of time spent
21 indoors and outdoors.
22 The model was developed under contract to ARB to
23 improve estimates of population exposures to toxic air
24 contaminants. The model uses relevant data, such as
25 distributions of California building air exchange rates,
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1 activity patterns data, and air concentrations of diesel
2 exhaust particles as inputs to develop indoor and population
3 exposure estimates across all environments.
4 The estimated average indoor exposure is in 1990
5 to be two micrograms per cubic meter and the average total
6 air exposure, including outdoor and indoor, to be 2.1
7 micrograms per cubic meter.
8 We have also done the comparable analysis for the
9 indoor and total exposure analysis for 1995 and 2010 as
10 shown in the overhead.
11 Now I want to address some of the findings of the
12 CE-CERT study, or the College of Engineering Center for
13 Environmental Research and Technology at the University of
14 California at Riverside.
15 I will provide some background on the purpose of
16 the study and then a brief summary of the results.
17 To address the effects of diesel fuel composition,
18 we have on the toxic exhaust --
19 ACTING CHAIRMAN FROINES: Excuse me. Is the
20 average population-weighted average for Southern California
21 3.6 micrograms per cubic meter?
22 MR. KRIEGER: Yes, that's the outdoor average.
23 ACTING CHAIRMAN FROINES: What's the range?
24 MR. KRIEGER: The range of exposures for outdoor
25 concentrations goes from .2 to 3.6.
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1 ACTING CHAIRMAN FROINES: That can't be an average
2 then.
3 MR. KRIEGER: That's not an average.
4 ACTING CHAIRMAN FROINES: What's the range?
5 What's the distribution look like?
6 MR. KRIEGER: Within the South Coast?
7 ACTING CHAIRMAN FROINES: Yes.
8 MS. SHIROMA: We'll look that up.
9 MR. KRIEGER: We'll look that up for you.
10 ACTING CHAIRMAN FROINES: I'm particularly curious
11 because of your RCL, because if you're up to 3.6 and heading
12 towards five, you're starting to get to another number.
13 MR. KRIEGER: In order to make the best use of the
14 study designed for the CE-CERT study, a technical advisor
15 committee was formed, which included members from the Engine
16 Manufacturers' Association, oil refiners, ARB and OEHHA
17 staffs.
18 The study design designated the testing of one
19 heavy duty diesel engine that represents the majority of the
20 market share in California. They tested this on three
21 fuels, the pre-1993 regulation fuel, low aromatic and an
22 alternative formulation fuel.
23 The engine was tested using the US EPA's
24 heavy-duty diesel transient federal test procedures.
25 Multiple samples collected during multi-day testing for each
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1 of three fuels was done.
2 To maximize the resources available and to address
3 the overall goal and purpose of the study, CE-CERT met
4 several objectives. They quantified a number of items,
5 including the criteria pollutants as you can see; size
6 fraction characteristics of the PM 2.5 and PM 10; carbonyl
7 analysis; elemental and organic carbon analysis; particle
8 and gas phase PAH and nitro-PAH, nitrosomorpholine analysis.
9 They also determined the mutagenicity and an attempt to
10 quantify the dioxins for methods development.
11 Testing was conducted from December 1996 to
12 January 1997.
13 The final draft report was approved by the ARB's
14 research screening committee on April 3rd, 1998.
15 The results showed that the emission reductions in
16 both PM and NOx, oxides and nitrogen, from the use of new
17 reformulated fuel meets ARB's predictions set forth in the
18 1988 diesel fuel regulation.
19 While the mass has been reduced, the chemical
20 composition of the exhaust, per milligram per brake
21 horsepower per hour, from the old and new diesel fuels are
22 similar.
23 DR. FUCALORO: Excuse me. I read the CERT report
24 and that doesn't seem to be the case. I would just look at
25 some of the graphs, and they seem to be quite different in
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1 certain compositions.
2 I can give you a page 67, for example. If you
3 look at that, the weighted total between the pre '93, the
4 low aromatic and the reformulated and --
5 DR. GLANTZ: What page?
6 DR. FUCALORO: Page 67. That's one. There's
7 several others. But it seems to be some significant
8 difference in some of the components, many of which are
9 known to be toxins.
10 MR. AMES: Dr. Fucaloro, this is Don Ames, with
11 the ARB staff.
12 Let me first take a shot at this.
13 And that is what we were attempting to do is look
14 at the toxic air contaminants that Robert mentioned earlier.
15 There are 40 known toxic air contaminants in diesel exhaust
16 and one of the issues raised to us years ago by some
17 industry representatives was the question if you would find
18 these same toxic air contaminants in the old fuel exhaust
19 and the new fuel exhaust or would many of them disappear?
20 So part of the objective of this study was to look
21 at that fingerprint and see if the relative proportion when
22 you account for the reduced mass from the exhaust of the new
23 fuel, would you have the same relative proportion of those
24 40 toxic air contaminants.
25 And a general answer is, yes, although there are
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1 some exceptions, but, yes, we largely found those toxic air
2 contaminants to be present with the new fuel exhaust as well
3 as the old fuel exhaust, and so that's the general answer.
4 But when you look at individual species you may
5 find some slight differences, and we have some staff from
6 our research division if you want to get into more details.
7 ACTING CHAIRMAN FROINES: I had a question about
8 that, because when I looked at the data, there are some
9 chemicals that I look at closely because I think they're so
10 particularly dangerous, and one of them is 1,3-butadiene,
11 which I think is the most toxic of everything, and it seems
12 to me when I looked at it, it seems as though the
13 1,3-butadiene went up rather than going down, and that's an
14 important issue.
15 DR. FUCALORO: It goes up from 1.8 to 2.46
16 milligrams per braking -- for, I don't know, BHP, what does
17 the B stand for?
18 MR. KRIEGER: Brake horsepower.
19 DR. FUCALORO: It's units of energy, right? Power
20 times time, right? So per joule. It goes up in that case.
21 Same with benzene as a matter of fact, even the
22 low aromatic, which I don't know if that's correct, but the
23 low aromatic fuel has a higher benzene emission than the
24 higher aromatic fuel. Unless I'm reading this wrong.
25 MS. SHIROMA: I'd like to introduce Manjit Ahuja
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1 and Ralph Propper from our Research Division, who were the
2 contract monitors for the CE-CERT report.
3 MR. AHUJA: Yes. As your question is quite valid,
4 the fuel, the low aromatic fuel is a combined fuel and it is
5 not a commercial fuel. It is used for research purposes.
6 And, yes, we did find that the benzene went up and
7 1,3-butadiene did go up in fact quite significantly.
8 But if you were to go and take a basket of
9 fuel-outs from commercial outlets, it may be different than
10 what we have found here.
11 MR. AMES: One thing we'd like to point out is
12 that when you do a toxic air contaminant weighted factor and
13 you multiply potency times mass for each of those toxic air
14 contaminants, we do see a benefit to the new fuel, a
15 reduction in potential cancer risk from the exhaust relative
16 to the brake horsepower and that's one important point for
17 the average fuel that's out there.
18 DR. FUCALORO: Well, I was going to say, just look
19 at page 74, Table 30, and in terms of a fingerprint just
20 looking at the numbers, I think you can see that there is
21 quite a difference in the composition of the organics that
22 are listed in this table from the three fuels, the pre '93,
23 I understand the low aromatic is not a fuel that's available
24 to the public, and the reformulated blend, you can see
25 rather significant differences.
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1 And that's why I'm just wondering about the
2 statement that the diesel chemical composition, and I guess
3 you mean diesel exhaust chemical composition fingerprint is
4 same in the old and the new. I was not clear what you mean
5 by the new. Do you mean the low aromatic or the
6 reformulated?
7 But in either case, I think that one could see
8 that there's a difference and that can be somewhat
9 misleading, that statement, in my view. Now, maybe I'm
10 wrong and you can correct me if I am.
11 ACTING CHAIRMAN FROINES: I think that the other
12 question that I have is on this list, some of the compounds
13 go up and some go down. And what's missing here on this
14 particular list are the nitro-PAHs, which I take as being
15 some of the most important.
16 And also it doesn't -- isn't able to address the
17 degree of nitrousation that could occur under conditions of
18 atmospheric chemistry.
19 So I think we want to move on past the CERT thing
20 so we may need to go back and not focus so much on detail.
21 I think we're going to need to have some sort of the
22 conclusory sense of what the implications are.
23 Clearly, I would conclude one thing and that is
24 that a great deal of more research is needed to look at the
25 composition of diesel fuels and their combustion products
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1 over the next few years, and I think that that's something
2 we probably would all agree on.
3 But I think what Tony and I are sort of getting at
4 is the take-home lesson isn't entirely clear here.
5 DR. GLANTZ: I just wanted to clarify something.
6 My understanding, and I mean I'm not the chemist
7 here, but my understanding is what you were saying and what
8 the CERT study was saying is that the new fuels produce less
9 total emissions, but that the distribution of different
10 compounds within, per unit mass of emission was similar. I
11 mean, is that -- is that what you meant?
12 MR. AMES: That's correct. Because we wanted --
13 DR. FUCALORO: I understood it that way. My
14 statement is predicated on that understanding that the --
15 because this is per unit energy and the fact that
16 distribution is dissimilar in some ways and of course it's
17 how dissimilar is becomes perhaps their definition of what
18 similar is different than mine.
19 I would think for example for
20 2,3,5-trimethylnaphthalene the pre '93 diesel fuel had 283
21 micrograms per unit energy that they do, and the low
22 aromatic had 15. So 15 to 283 seems to be quite a different
23 ratio, but maybe I'm reading it wrong and that's all.
24 I certainly don't want to hold us up.
25 ACTING CHAIRMAN FROINES: I have one question that
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1 has to do with bioavailability. What's the relative
2 particle size, aerodynamic diameters of these different
3 fuels? Because clearly if the particles get smaller, then
4 you have more bioavailability potentially and so you can
5 have a greater risk rather than a lesser risk.
6 MR. PROPPER: We didn't find any significant
7 difference in the particle size in these fuels.
8 However, when we planed the study it was before
9 the great concern about the ultrafine particles arose. So
10 that we only looked at larger size cuts like one micron, 2.5
11 micron.
12 I would like to add in response to Dr. Fucaloro,
13 you're quite right, the major difference that we did see in
14 the target analytes between the new and the old fuel was in
15 the volatile PAHs, and this is consistent with the fact that
16 the newer fuels contain much less volatile PAHs in the fuel.
17 And for the three fuels you find quite consistent
18 correlation between the amount of PAH in the fuel and the
19 amount of volatile PAH submitted.
20 I'd like to add, though, that the main toxic
21 concern has been with the more particle phase PAHs like
22 benzo(a)pyrene, although it still is good to see those
23 numbers go down in the volatile PAHs.
24 MR. KRIEGER: One more to add about the size of
25 the particle too, and the study showed that 98 percent of
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1 the particle is less than 2.5 microns. The majority is
2 confirmed with what we said in our report.
3 Back on the question on the exposure of the South
4 Coast Air Basin, the upper end is 4.5 micrograms per cubic
5 meter.
6 ACTING CHAIRMAN FROINES: I shouldn't ask this
7 question.
8 When you have the 4.5 days, do you also have a lot
9 of nitrogen oxides in the air on those days?
10 Let it go. It's not about --
11 DR. GLANTZ: Genevieve, the chair has withdrawn
12 the question.
13 MS. SHIROMA: We'll go on with the presentation.
14 ACTING CHAIRMAN FROINES: Don't worry about it.
15 You know what I'm worried about. The higher the
16 PAH stage, the higher the nitro-PAH days.
17 Let's go.
18 MR. KRIEGER: Bullet No. 4, the mutagenicity we
19 found is lower in the new fuel. The results indicate that
20 the most mutagenic fraction for the PM is an unidentified
21 fraction from the fractions containing PAH and nitro-PAH.
22 However, the differences are not statistically significant
23 since the study was not robust enough. They tested one
24 engine on three fuels.
25 DR. FUCALORO: It's 55 percent, mutagenicity is
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1 now 55 percent. And it may not be significant, I certainly
2 didn't do the statistics, but it is significantly lower, am
3 I correct? I mean, I meant significantly not in a
4 mathematical -- it is appreciably lower?
5 MR. KRIEGER: Yes.
6 MS. SHIROMA: For the data set for the study, and
7 the data set of itself, but looking at making some sort of
8 broad brush conclusion, okay, that's what Robert is
9 referring to.
10 MR. KRIEGER: I think you're correct. Not on a
11 mathematical sense, statistically, but from appearance, yes,
12 yes, it is.
13 ACTING CHAIRMAN FROINES: I have done tens of
14 thousands of Ames tests over the years, and so I know this
15 one pretty well. And I think saying that it's lower is
16 fine, but I think one has to be careful and we'd have to
17 look -- were they doing direct mutagenicity or oro chloro
18 induced S9 fractions?
19 DR. FUCALORO: Both. The S9, plus they did it
20 both, with and without. Am I correct?
21 MR. PROPPER: Yes. They did both kinds, and there
22 are somewhat different result, but not drastically different
23 results between whether they did the plus S9, plus S9. They
24 also used vapor phase and particle phase.
25 I'd like to point out that the bulk of the
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1 mutagenicity was in fractions more polar than contained in
2 the nitro or PAHs. We don't know what's in those.
3 ACTING CHAIRMAN FROINES: The bulk of the
4 mutagenicity was, say that again?
5 MR. PROPPER: Was in fractions more polar than
6 those that contain the nitro-PAHs and also obviously the
7 PAHs.
8 DR. FUCALORO: The seventh fraction?
9 MR. PROPPER: Yes, that's correct.
10 ACTING CHAIRMAN FROINES: Well, I think it's
11 important to say that the mutagenicity was low, but
12 mutagenicity goes down by a factor of two is almost
13 inconsequential and for the most part, so I think what it
14 suggests is that we need to do more work to carry it
15 further.
16 I think it's good findings and important findings,
17 but I think it does suggest the need for further follow-up.
18 MR. KRIEGER: Fifth bullet on dioxins.
19 The study detected dioxins in both old and new
20 fuels, but could not be quantified.
21 However, the method development for collecting
22 these dioxins was improved and it goes back to the statement
23 Dr. Froines made, overall the study points to a need for
24 additional research on more engines and under various
25 operating conditions and fuels.
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1 In summary, diesel exhaust is a complex mixture of
2 gases, vapors and fine particles, with the majority as fine
3 particulate matter.
4 As the CE-CERT study indicates, it remains a
5 complex mixture after reformulation with the same toxic
6 substances.
7 Most of the emissions of diesel exhaust, PM 10,
8 are from on-road motor vehicles.
9 ACTING CHAIRMAN FROINES: It also is important to
10 realize what the atmospheric conditions you're operating in,
11 because within that particular context we're concerned with
12 different health effects. There's a clear evidence for
13 acute health effects, respiratory effects associated with
14 diesel exhaust and so that part of the question is is the
15 relationship between the technology, the fuel and the
16 emissions and the health effects that you're interested in
17 learning about.
18 And I think we want to be careful to not always
19 have everything be part of some sort of tyranny of cancer,
20 so that we're not only looking at one kind of end point as
21 we evaluate this data, and that's what tends to happen.
22 MR. KRIEGER: In summary and to conclude, the
23 population-weighted average outdoor diesel exhaust
24 concentrations decreased from three micrograms per cubic
25 meter in 1990 to 1.7 microgram per cubic meter in 2010.
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1 Near-freeway concentrations of diesel exhaust PM
2 10 were found to be up to three times that of ambient
3 concentrations.
4 MS. SHIROMA: Sorry to interrupt, Robert.
5 Dr. Froines, just to note that when you were
6 asking about the range of concentrations that didn't account
7 for this near-source scenario where near the, in this
8 particular case it was the Long Beach freeway, the
9 concentrations were found to be up to three times higher
10 than the ambient.
11 MR. KRIEGER: Finally, we have considered a
12 person's daily activity and exposures to different
13 environments to estimate for 1990 an average total air
14 concentration of 2.1 micrograms per cubic meter.
15 We have done an additional analysis to estimate
16 for 1995 the average total air concentration of 1.5
17 micrograms per cubic meter.
18 At this point --
19 DR. FRIEDMAN: I'm a little confused about the
20 first item, which says that the concentration will be down
21 to 1.7 in 2010, and that's already lower than that in '95.
22 I'm not clear how those two fit together.
23 MR. KRIEGER: The 1995 estimate is a total air
24 exposure estimate. That includes weighted concentration
25 from indoor and outdoor exposures. So the estimate of 1.5
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1 includes within that outdoor concentrations the exposure to
2 indoor air as well. It's not a 24-hour outdoor exposure.
3 It's an integrated time-weighted exposure.
4 MS. SHIROMA: The number --
5 DR. BLANC: The number you're referring to is for
6 a target for outdoor, which is higher than indoor, and this
7 number includes -- is something between the mean for outdoor
8 and the mean for indoor, because it's an average 24-hour
9 exposure.
10 DR. FRIEDMAN: I see.
11 How did you arrive at the 1.7 for 2010? Did you
12 sort of do an extrapolation of the current trends?
13 MR. KRIEGER: Extrapolation of the current trends.
14 That takes into account all the controlled measures and
15 future control measures that have been adopted to date in
16 our emissions inventory.
17 ACTING CHAIRMAN FROINES: Everybody is so
18 comfortable in this room. We're going along at this kind of
19 rolling pace. I think we ought to create a little more
20 tension and move on in a more less rolling pace.
21 I want to ask, it seems to me if in fact you get
22 threefold increases in measurements near freeways, or at
23 least in the few freeways you've looked at, does that
24 represent something we should look more into?
25 I mean, are people who live near freeways having
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1 quite significant exposures to diesel in California? We
2 live in a state of freeways, after all.
3 MS. SHIROMA: Should you approve the report,
4 should the Board identify diesel exhaust as a toxic air
5 contaminant, then during the risk management phase, we at
6 the ARB will be looking further into refining that estimate
7 and then also looking at whether something else can be done.
8 MR. KRIEGER: At this point I'd like to turn the
9 presentation over to Dr. George Alexeeff, of the Office of
10 Environmental Health Hazard Assessment, to give an overview
11 of the Part B report.
12 ACTING CHAIRMAN FROINES: Welcome, George.
13 DR. ALEXEEFF: My name is George Alexeeff. I'm
14 deputy director for Scientific Affairs of the Office of
15 Environmental Health Hazard Assessment in the California
16 EPA.
17 ACTING CHAIRMAN FROINES: Have we congratulated
18 you on this promotion?
19 DR. ALEXEEFF: Well --
20 DR. FUCALORO: You received my card, haven't you?
21 DR. ALEXEEFF: Yes, thank you.
22 DR. GLANTZ: I guess the question is when you say
23 can we congratulate him, does that mean is it proper or is
24 he glad he was promoted?
25 DR. ALEXEEFF: Somehow I'm still on this hot seat,
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1 so I don't know what has changed.
2 MS. SHIROMA: It's gotten hotter.
3 DR. ALEXEEFF: In any case, I'll be presenting a
4 review summary of the key issues in the health risk
5 assessment report for diesel exhaust called Part B.
6 And the last time I made a presentation before the
7 panel was on October 16th, and on that day we came to the
8 panel with five major issues that were being raised in the
9 comments, and we seeked your advice on how to address some
10 of those issues and we have --
11 DR. BLANC: Sought.
12 DR. ALEXEEFF: Sought, thank you.
13 So we have implemented your comments or
14 suggestions in this version here. And I'll touch upon those
15 as I go through the presentation.
16 Also as you see here these are the major topics I
17 will be discussing. Some of these topics are more
18 contentious than others. The ones of greatest interest,
19 both in terms of the commentators, and I think in terms of
20 the discussions we had last month, are the human
21 occupational studies and the cancer quantitative risk
22 assessment. So I'll go in greater depth for those, but I
23 felt it's important to sort of give a complete picture.
24 Also, as you know, this document is very
25 technical. There's a lot of information in here, and I have
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1 the relevant experts on each of those topics here present,
2 so as issues come up we can have them come up and answer
3 those questions.
4 Okay. First, in terms of the human acute --
5 actually, I'm going to make one more comment before I start
6 on this.
7 Now, we have reviewed the scientific literature
8 and all the comments up until, essentially just about this
9 point. As mentioned, Dr. Froines even presented us with
10 some information from the Federal Register this month. In
11 February of '98, couple months ago, US EPA came out with
12 their health assessment of diesel exhaust, so this document
13 we have here is very current.
14 First is the human acute non-cancer health
15 effects. There are increased symptoms of eye, throat and
16 bronchial irritation. There's increased physiological
17 symptoms such as headache, nausea and vomiting. There have
18 been reports of immunological activity based on elevated
19 IgE, altered T-cell cytokine levels, hyperresponsive nasal
20 eosinophils, and enhanced immunological reaction to common
21 allergens.
22 Most of this information was obtained actually as
23 a result of comments made by the panel in October, and a lot
24 of these reports were published in 1996, '97, '98.
25 Also have been some occupational case reports
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1 suggesting asthma.
2 Unfortunately, we can't really quantify the
3 exposure concentrations that cause these results.
4 Next slide.
5 There's also been some corroborative animal
6 studies done where we have either inhalation or direct
7 application in the respiratory tract which induced airway
8 changes, lung function changes, increased susceptibility to
9 lung infection, and also a number of reports suggesting
10 immunological activity based upon, again, elevated IgE,
11 altered circulatory cytokines, eosinophilic infiltration and
12 inflammation of the airways.
13 So that's the acute summary.
14 With regards to the chronic non-cancer summary,
15 again this information has not been considered that
16 controversial in terms of what we've reviewed and what we've
17 proposed.
18 In terms of chronic non-cancer health effects for
19 the humans, there are some occupational exposure studies
20 that suggest some respiratory effects, but the data are
21 insufficient to calculate a reference level.
22 Instead, we've taken the same route as US EPA and
23 the World Health Organization using animal data, and in this
24 case there's an inflammatory and histological changes in the
25 lung reported above 460 micrograms per cubic meter in the
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1 rat exposed for 30 months. That's the basis of our study.
2 And the next slide it just shows how we did our
3 calculations. We used what's called benchmark dose
4 approach, which is kind of a new approach that's used in
5 non-cancer risk assessment where instead of simply taking
6 the no-effect level, you extrapolate to some percent
7 response. And in this case you can see under the column
8 with analysis percent response was either 1, 5 or 10 percent
9 response.
10 And we used two different models, a probit and a
11 Weibull. You can see the benchmark concentration is then
12 treated like a no-effect level in the rat.
13 And then an uncertainty factor is added and our
14 uncertainty factor in this case would be 30, and then you
15 come up with reference levels in the range of 3 to 21, or 2
16 to 21.
17 But that's the basis of our non-cancer risk
18 assessment.
19 The next slide sort of compares with what we did
20 with other agencies.
21 US EPA has had in their IRIS database and also
22 they've reiterated it in their most recent 1998 February
23 document, a reference concentration of five micrograms per
24 cubic meter. It's based upon the same chronic
25 histopathological changes in the female rat.
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1 And the World Health Organization also conducted a
2 series of analyses similar to the kind of thing I just
3 showed you. They had a range of two to 14 micrograms per
4 cubic meter.
5 I also wanted to point out that US EPA also has a
6 PM 2.5 standard, a 15 micrograms per cubic meter, because
7 there was some questions as to how the standard relates to
8 these results.
9 And as I mentioned, our approaches come up with a
10 range of two to 20.
11 So consequently we're recommending to agree or go
12 along with what US EPA presented to come up with a reference
13 level of five micrograms per cubic meter.
14 ACTING CHAIRMAN FROINES: That's assuming a
15 threshold and a 30-fold safety factor?
16 DR. ALEXEEFF: Yes. It's a 30-fold safety factor,
17 assuming a threshold.
18 DR. WITSCHI: How did you come to the 30?
19 DR. ALEXEEFF: The 30, okay, the 30 is broken down
20 into two parts. Usually when we're extrapolating from
21 animals we consider differences between the animal species
22 and the humans. And sort of the first step is to consider a
23 tenfold uncertainty factor.
24 Now, in this particular case there is also some
25 data in the monkey suggesting that although it's not as
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1 quantitative as this rat data, suggesting that maybe the
2 species are not that different in terms of response.
3 So in this case we only used a threefold
4 uncertainty factor to go from the rat to the humans.
5 And then the other part of the uncertainty factor
6 is the interspecies differences or differences within the
7 human population. And again the standard approach is to
8 start with ten, and we stuck with ten, and so did US EPA.
9 The reason for that is ten sort of represents kind of the
10 average, healthy individual and -- I'm sorry. You start
11 with the average healthy individual and then you want to
12 also add a factor of ten to protect those that might be
13 susceptible in terms of asthmatics or other chronic
14 respiratory diseases. So we stuck with a factor of ten in
15 this case. So that's the basis of the 30.
16 ACTING CHAIRMAN FROINES: George, have you found
17 that all the sport utility vehicles that are produced after
18 the year 2000 are diesel vehicles and if you found that near
19 freeways that diesel levels are very high, so you were well
20 above your five, how do you assess the range of risk? This
21 is in a sense a threshold value. How do you define dose
22 response? How would you determine the number of people who
23 might be at risk at seven, 10, 20, 50 and a hundred?
24 DR. ALEXEEFF: Well, if the 30-fold factor ends up
25 being a fairly large assumption in this case, and if we go
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1 back one slide or -- one slide, John, you can see that the
2 benchmark concentration you see one, five and ten percent
3 response. So you can see that the one percent response is
4 about three. This is in the rat, though. Okay. And so,
5 you know, and then the five percent response would be a
6 little bit higher.
7 So what one, you know, the best one could do with
8 the data would be to make some sort of correlation with this
9 information. But then the uncertainty ends up being this
10 30-fold uncertainty factor.
11 DR. GLANTZ: George, I don't see where when you
12 said the one percent is three. I don't understand.
13 DR. ALEXEEFF: I'm sorry. One percent results in
14 a number of .17, and then divide by 30.
15 ACTING CHAIRMAN FROINES: For people who don't
16 know about the benchmark, they're essentially extrapolating
17 from data points where you have information.
18 DR. GLANTZ: No, I understand that. It's just I
19 don't understand when you have the one, five and ten
20 percent, are those -- is the one percent, .175 percent is
21 .59 and ten percent is --
22 DR. ALEXEEFF: Yes. I'm sorry. That column B and
23 C in terms of simplifying the slide, that's actually
24 milligrams per cubic meter, because we're kind of -- the
25 concentration that we started with was much higher, so we're
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1 kind of going down. It's actually there .17 milligrams per
2 cubic meter or 170 micrograms per cubic meter.
3 There's a small time adjustment which actually
4 results in the actual number change in terms of the
5 conventions of the exposure in the rat.
6 ACTING CHAIRMAN FROINES: Why don't you go ahead.
7 I want to take a little time on this, because
8 you're required to make estimates of risk and this does
9 constitute your estimate of risk for non-cancer respiratory
10 effects. And I want to make sure that everybody is aware
11 that there are more numbers in this document than simply the
12 numbers associated with lung cancer risk.
13 DR. ALEXEEFF: Now, in a practical matter,
14 Dr. Froines, the way it would work or the way it does work
15 when we have a reference concentration and there is some
16 exposure and we're trying to compare it with that reference
17 concentration, we use what's called kind of a hazard index
18 approach. So if the concentration is below that five, we
19 feel that there is no issue of concern at all. That's the
20 basis of the approach.
21 Now, if it's above the five, we feel there's an
22 increasing chance of some concern, so it's not -- it's
23 simply sort of reflecting kind of in terms of our procedures
24 where we would start, you know, having some concerns and
25 depending on -- the concern that we have is in part based
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1 upon how large the uncertainty factor is. So in this case
2 the uncertainty factor is relatively large. So like a
3 factor, like a value of six or something like that would not
4 be of great concern in terms of the uncertainty, but a value
5 of 50 would then of course be of concern.
6 ACTING CHAIRMAN FROINES: All right.
7 DR. ALEXEEFF: Now, I'd like to briefly review the
8 genotoxicity. And the genotoxicity itself I don't consider
9 that to be a very controversial issue in a sense, but there
10 is this related issue of the bioavailability of this
11 genotoxicity. And I'll be getting into that, but I thought
12 I should just briefly go through the genotoxicity
13 information.
14 I presented almost the same slides in October.
15 ACTING CHAIRMAN FROINES: Go quickly then.
16 DR. ALEXEEFF: Whole diesel exhaust and diesel
17 extracts were reported mutagenic in bacterial assays.
18 Particles and extracts of diesel exhaust were reported
19 mutagenic in mammalian cell assays. We have diesel exhaust
20 extracts reported to be mutagenic in cultured human
21 lymphoblasts.
22 Mutagenicity per microgram was not significantly
23 different between the new and the old fuels. We had some
24 discussion about the information is basically preliminary.
25 Diesel exhaust extracts induced chromosomal
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1 aberrations in mammalian cell assays, but most of the
2 results were negative in vivo.
3 The particles in extracts induced sister chromatid
4 exchanges in mammalian cell assays and the results in vivo
5 are mixed.
6 Now, treatment of mammalian cells in vitro have
7 resulted in an increase in the DNA adduct formation.
8 And rats and monkeys exposed to whole diesel
9 exhaust demonstrated an increase in DNA adducts formation
10 and their increased levels of DNA adducts have been found in
11 some workers exposed to diesel exhaust.
12 Now, in terms of bioavailability, the DNA adduct
13 work that I just mentioned is very difficult work and there
14 are some uncertainties in that work and some differences of
15 opinion.
16 But I'll briefly go through why we feel that there
17 is evidence, and we our provide this in the report, why we
18 think there is evidence that the genotoxicity in the
19 particles is bioavailable, even from a mechanistic point of
20 view, aside from the cancer impact.
21 The particles, when the particles are dispersed in
22 simulated pulmonary surfactant, there exhibited similar
23 genotoxic activity to regular diesel exhaust extracts in
24 vitro.
25 The reported adduct formation in rats and monkeys
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1 exposed to diesel exhaust are supportive, but there have
2 been, as I mentioned, some questions of these results in
3 literature, but we feel that it is supportive.
4 Rat tissue exposure to diesel exhaust induced
5 unscheduled DNA synthesis, and so when I say diesel exhaust,
6 I'm saying it's a difficult experiment to develop where you
7 are actually exposing an in vitro study to diesel exhaust,
8 and that's why I mentioned that.
9 DNA adducts associated with some occupational
10 exposures to diesel exhaust, there are some urinary
11 metabolites of polycyclic aromatic hydrocarbons found
12 following exposure to rats to diesel exhaust. Also urinary
13 metabolites of polycyclic aromatic hydrocarbons have been
14 associated with some occupational exposures to diesel
15 exhaust. Thus, the genotoxic components of diesel exhaust
16 particles appear to be bioavailable, but more study in this
17 area would be useful. We think this would be a great area
18 to continue doing more research.
19 DR. BLANC: George, I have a question, just a
20 process question for you.
21 And we have a printout of your slides.
22 I think because this goes over material that is
23 available to us in the report, I think if you will simply
24 highlight briefly any areas where you believe the data
25 you're presenting this morning represents a significant
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1 change or advancement on the February draft document, I
2 think that would be a more useful approach, because I think
3 the panel is familiar enough with much of what you're going
4 over that it's really not productive, I think, to go into
5 this level of detail.
6 DR. ALEXEEFF: Okay. I'd be happy to.
7 ACTING CHAIRMAN FROINES: George, I was going to
8 say, remember, that we've seen it in October, we saw it in
9 March, we've read the document, and I think we need to move
10 so that we can be more active participants. So, for
11 example, I would just leave out the animal cancer data.
12 DR. ALEXEEFF: Fine.
13 ACTING CHAIRMAN FROINES: And Melanie is going to
14 have to be very short on the comments, I think.
15 DR. MARTY: I am very short.
16 ACTING CHAIRMAN FROINES: Because I think
17 otherwise people are going to -- does everybody agree with
18 that?
19 DR. FUCALORO: I agree.
20 I have a question on some of this, I'll certainly
21 pipe up.
22 DR. ALEXEEFF: I think one thing that's worth
23 noting in terms of animal cancer findings is the result in
24 the US EPA report. So I just bring your attention to that
25 quote in there. No sense reading me quotes, but I'll just
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1 bring your attention to that.
2 DR. GLANTZ: What quote is that?
3 DR. ALEXEEFF: It's their findings about the issue
4 of mice. The US EPA feels that the mice data is also an
5 important consideration in the animal carcinogenicity.
6 Now we'll get to the cancer epidemiology slide.
7 As we mentioned before, we reviewed many studies.
8 I just want to emphasize that there seems to be some
9 confusion from time to time that we've looked at many
10 studies, including those of not just railroad workers, but
11 also truck drivers, dock workers, transport workers,
12 equipment operators, to name some.
13 The next slide.
14 And we assess the quality of this information both
15 qualitatively and quantitatively. We've gone through the
16 what's considered the Bradford Hill criteria in terms of
17 consistency, possibility for bias and chance, evidence of
18 exposure response, temporality, biological plausibility.
19 The issue of causality has been one that remains
20 in the comments, so it's important to take this into
21 account.
22 So the key issue here is that there's a lot of
23 consistency. We feel the explanation in terms of bias or
24 chance is unlikely. Evidence of exposure response is sort
25 of the weak point.
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1 Getting back to the strength of the findings, it's
2 a fairly weak association, about a 40 percent increase.
3 Temporality association is appropriate and the
4 biological plausibility, we think, is definitely there.
5 And on the next slide this is from the document.
6 Smoking-adjusted studies of diesel exhaust exposure in lung
7 cancer, and in this list again there are in addition to
8 railroad worker studies, there is also truck drivers, dock
9 workers, equipment operators.
10 And you can see the consistency by looking at just
11 the midpoint. Some of the studies are not statistically
12 significant. The far -- the point on the far right is the
13 result of the meta-analysis, the all smoking-adjusted value.
14 And then if we go to the next slide.
15 DR. FRIEDMAN: George, there was a point in the
16 middle with very narrow confidence bounds. Was that a
17 meta-analysis too or -- that is a very large study. I think
18 it was Pfluger.
19 DR. ALEXEEFF: I can't recall.
20 DR. FUCALORO: It's almost identical to the
21 meta-analysis.
22 DR. ALEXEEFF: Which, can you read that?
23 DR. FRIEDMAN: Pfluger, 1994.
24 DR. ALEXEEFF: The question, Dr. Lipsett, was from
25 Dr. Friedman, was that an actual meta-analysis or was it
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1 actually a study of workers?
2 And I think that was the question you were asking;
3 right?
4 Dr. Michael Lipsett.
5 DR. LIPSETT: It is from one of the studies that
6 was part of the meta-analysis. The summary estimate is over
7 at the far right of the graph.
8 DR. FRIEDMAN: Was it a huge study, is that why
9 the confidence levels are so narrow?
10 DR. LIPSETT: Okay. It was -- it wasn't a huge --
11 it wasn't necessarily a huge study. It was about 1300
12 people.
13 DR. FRIEDMAN: Well, I mean, this is not a real
14 important point, but I just wonder if there's not mistake in
15 putting -- because it just doesn't seem right that a study
16 would have such narrow confidence limits.
17 DR. LIPSETT: I can certainly check it on the
18 spreadsheet, but we did have an error-checking procedure in
19 terms of data entry, and having a couple people look these
20 things over. I don't think it's a mistake.
21 DR. FRIEDMAN: By the way, I appreciate, I think
22 the previous version had this expressed as logs of relative
23 risk, and I appreciate that you made that change to actual
24 relative risk. I think it's much more understandable now.
25 I just have one minor suggestion that I don't
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1 think should hold up our approval. I think that perhaps in
2 the next version that although you now don't have it
3 expressed in logs, you should still use a log scale, because
4 it's -- you're talking about a multiplicative type of
5 situation.
6 And then the confidence limits would be
7 symmetrical. In other words, from .5 to 1 should be the
8 same distance as from 1 to 2, and 2 to 4, and so on.
9 DR. LIPSETT: Okay.
10 ACTING CHAIRMAN FROINES: Go ahead, George.
11 DR. ALEXEEFF: And this slide just simply
12 quantitates that the point on the far right side, it's 1.44
13 using a fixed effects model, and 1.43 using a random effects
14 model. And this is again the smoking-adjusted values taken
15 from the studies that took -- that adjusted for smoking.
16 The next slide.
17 And again in the human cancer findings, the early
18 findings by IRAC had limited evidence. US EPA, in their
19 most recent document, has moved further than that and is now
20 saying that the human evidence is highly suggestive of an
21 association, and it's just short of being labeled as a known
22 human carcinogen.
23 And the next slide mentioned before about HEI and
24 WHO's conclusions, that they do see a weak association, weak
25 meaning about a 40 percent increase. And at the same time
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1 HEI feels that their conclusions should be always couched by
2 the fact that they feel the uncertainties and confounders
3 prohibit the use of this information for quantitative risk
4 assessment. And that is a difference of opinion, but I just
5 like making that clear.
6 ACTING CHAIRMAN FROINES: Is that true in Aaron
7 Cohen's chapter?
8 DR. ALEXEEFF: I don't think Aaron Cohen's chapter
9 specifically addresses application of this to quantitative
10 risk assessment, but it could very well be.
11 Okay. In terms of our conclusion, our conclusion
12 and our document is that the epidemiologic studies provide
13 evidence of a consistent and causal relationship.
14 The next slide.
15 Now, I'd like to -- this is pretty much the issue
16 of greatest contention, concern, both in the comments and by
17 people looking at our document, how we did the quantitative
18 risk assessment, what we used, so I'm going to go through it
19 and also try to put it in a little bit of perspective.
20 First of all, Kathy Hammond, Dr. Hammond, made a
21 presentation last month to the panel discussing the
22 exposures of different worker groups, all the way from heavy
23 equipment operators, truck drivers, bus drivers, railroad
24 workers.
25 And she presented to the panel this range, this
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1 exposure range of 5 to 500 micrograms per cubic meter. She
2 felt that that kind of covered the whole range. And that's
3 in the slides that she provided.
4 At the same time in October the panel had asked us
5 to think about using this meta-analysis information somehow
6 in a risk assessment. And we felt that we -- that it could
7 be used to give us a sense of the total bracket of risk, but
8 not necessarily the range of risk that we would propose,
9 primarily because the exposure range in all those different
10 occupational groups is such a broad range.
11 You can see that it brackets the risk from about
12 1.3 in 10,000, to 1.3 in 100. So that's kind of like the
13 conceptual approach that we were using that basically the
14 meta-analysis and the total range of exposure that it's
15 possible in the studies, what would the range of risks kind
16 of be or the bracket of the risk.
17 We did an in-depth evaluation of two railroad
18 worker studies. One is the Garshick case control and the
19 other is the Garshick cohort data.
20 It's the Garshick cohort data that's had all this
21 extensive discussion and re-evaluation.
22 And, again, the primary source of uncertainty that
23 we feel exists is the exposure data in these worker studies.
24 In the next slide what we did is we considered
25 various scenarios of exposure to try to bracket what's the
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1 possible range of exposure of these workers, again to get a
2 full breadth of what the range of risk could be, because our
3 primary responsibility is to come up with a range of risk.
4 The first, I presented this slide in the October
5 meeting, but I think it bears repeating, because it can get
6 to be a little bit confusing.
7 The first slide is what's called, what we're
8 referring to as a block exposure pattern. That's just
9 assuming constant exposure from 1959, and that is how the
10 Garshick studies are constructed, just assuming constant
11 exposure.
12 Later on in 1991 it was suggested that the
13 dieselization that occurred from the mid '40s to '59 be
14 taken into account, and so a ramping kind of approach came
15 into fruition.
16 And in the bottom, number C, that is what we are
17 referring to as a roof pattern, and roof is just descriptive
18 of a picture, and that takes into account the rate of
19 dieselization, plus the improvements in engine design and
20 engine efficiency that occurred after 1959.
21 We have both some anecdotal information in these
22 railroad worker studies, as well as some information that we
23 received from the Engine Manufacturers' Association and
24 received it from the, I think, the Railroad Workers'
25 Association, or some railroad association that was studying
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1 engine design. So we know that there has been some
2 improvement in the emissions.
3 DR. WITSCHI: I have a question with regard to
4 this.
5 The way this looks superficially is if these
6 people are in pristine air and then from '59 all of a sudden
7 they are exposed to diesel, do we have -- that's probably
8 not true. I mean, they were working in railroad yards and
9 there must have been considerable other things around before
10 diesel came along. Do we have any idea about what was
11 around before diesel came along or still together with
12 diesel?
13 DR. ALEXEEFF: Well, yes, there's two issues here.
14 One is dieselization that was occurring, so if we
15 went with the top diagram, which we do not in our report,
16 but if we went with the top diagram it would not take into
17 account the diesel exposures that occurred before '59, so we
18 actually support the bottom diagram, number C.
19 But what you're saying is other compounds in the
20 air that would be contributing to risk and exposure, okay.
21 And that is definitely would be a concern in any of these
22 exposure studies, other confounders.
23 Part of it is taking into account not in terms of
24 the response, but at least in the exposure in the way that
25 Dr. Hammond and others subtracted out some of the other
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1 things that they were in the air, and particular
2 environmental tobacco smoke and other -- there's other
3 background concentrations of particulate matter that are
4 subtracted out in the calculations.
5 Now, in terms of whether there is some other
6 substance or component in the air which is causing the
7 disease, some of the studies try to take some issues into
8 account. For example, I think one of the Garshick studies
9 tried to take into account asbestos.
10 But, you're right, this is an issue of
11 uncertainty.
12 DR. WITSCHI: What about steam engines? They were
13 pretty dirty.
14 DR. ALEXEEFF: Yes, I agree.
15 So you do have that confounding.
16 In a sense you have other exposures which are not
17 taken into account, but what you try to do, and I can
18 have -- well, maybe I should have Dr. Lipsett explain how
19 the study designs of these epi studies try to focus on the
20 diesel exhaust component in terms of their structure.
21 Did you want to make any comment?
22 ACTING CHAIRMAN FROINES: I will say, George, just
23 one comment, as a person who is an exposure assessor in
24 occupational epi studies, that it seems clear to me that if,
25 one, if you put together a group of industrial hygienists
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1 who do this kind of work, like Bob Spear or Steve Rappaport
2 and Tom Smith and others, I think the roof model makes the
3 most sense. It makes the most sense for two reasons.
4 One of which was in 1970, when the OSHA act was
5 passed, people's attention to chemical exposures became much
6 more heightened and it's very clear that during that decade
7 of the '70s to the '80s, as a uniform phenomenon, exposures
8 went down.
9 So I think it's one could argue about the slope of
10 the decline, but I think it's clear that there was a decline
11 in exposure.
12 And so it seems to me that using the ramp with
13 then a flat exposure is probably going to estimate what was
14 one of the most health, occupational health conscious
15 decades in the last hundred years, and so that I think the
16 roof model tends to reflect what the industrial hygiene
17 community would recognize during that decade more than you
18 might otherwise realize.
19 DR. LIPSETT: I just wanted to add a couple
20 things.
21 First, a correction to what I said before to
22 Dr. Friedman. I haven't read this particular paper in many
23 months and went back, I was looking at the wrong thing when
24 I indicated there was that. There was actually well over a
25 million person years of exposure involved in that one study
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1 and that will explain why the confidence interval is so
2 narrow.
3 So I hope that allays your concern about an error
4 in that.
5 DR. FRIEDMAN: Thank you.
6 DR. LIPSETT: One of the other things, though,
7 with respect to steam engines is apparently one of the main
8 concerns that took place during the steam engine era was
9 asbestos exposure when these things were overhauled and the
10 number of the railroad studies did try to take that into
11 account where they had information about exposure to
12 asbestos during that period of time.
13 And then with respect to the emissions from the
14 steam engine, in at least one of the railroad studies found
15 the investigators did try and look at the effects of that
16 separately by using certain brackets on the time of exposure
17 and found that the relative risk from that was not -- I mean
18 it wasn't substantially greater than what you would see from
19 the diesel exposures occurring later.
20 That's not very helpful. The data are pretty
21 sparse, basically.
22 ACTING CHAIRMAN FROINES: Is there any data within
23 the studies on mesothelioma, which would be indicative of
24 confounding by asbestos?
25 DR. LIPSETT: Yeah, I think there was in at least
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1 one of the studies, but again it's been many months since
2 I've read most of these studies and I --
3 ACTING CHAIRMAN FROINES: But it's not something
4 that you feel was a major issue?
5 DR. LIPSETT: No.
6 DR. KENNEDY: That was not generally recognized
7 before 1948, so it would be hard to come up with anything
8 before that.
9 ACTING CHAIRMAN FROINES: He's looking at people
10 who are dying later. The Selecoff stuff is in the early
11 '60s, so there's from the '60s on there's a consciousness
12 about mesothelioma. So I would guess that they would --
13 DR. KENNEDY: I thought the question relates to
14 the awareness of mesothelioma and a time context. It was
15 not described by Selecoff until around 1950.
16 ACTING CHAIRMAN FROINES: He's saying that for the
17 pre-diesel period, that there was asbestos, people might not
18 have recognized it.
19 DR. LIPSETT: There's one study, though, the one
20 Finnish study, that seemed to have a lower risk for lung
21 cancer and it did find a substantially increased risk for
22 mesotheliom in the train engineers that they looked at. It
23 was severalfold increase in mesothelioma.
24 ACTING CHAIRMAN FROINES: That in your study or
25 your meta-analysis?
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1 DR. LIPSETT: Is that paper? It is included in
2 the meta-analysis, but the mesothelioma is not, just the
3 lung cancer.
4 ACTING CHAIRMAN FROINES: But it becomes a clear
5 confounder then.
6 Let's go, George.
7 DR. ALEXEEFF: We agree with you, Dr. Froines,
8 that the roof pattern is the most appropriate.
9 Now, this table is taken from the document and you
10 can see, I'd like to just explain what this table represents
11 because this ends up being sort of the crux of a lot of the
12 discussion or concern. And again I have Dr. Dawson here if
13 we have any specific questions on the derivation of these
14 numbers.
15 First of all, just to point out we have risk
16 estimates that are derived both from the case control study
17 as well as the cohort study, and it's the cohort study that
18 has had a lot of additional concern and a lot of the
19 discussion of the comments refers to results of the cohort
20 study.
21 Now, you can see in that column of different
22 scenarios. Now, scenario A refers to the ramp pattern. All
23 the other scenarios refer to that roof or that peak shaped.
24 So it's just something to point out.
25 The ramped pattern has the highest risk, because
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1 it ends up being the lowest exposure. Okay. Because it
2 doesn't come back down. So that's something to keep in mind
3 as to whether or not the ramp pattern is appropriate to keep
4 in the range of risk.
5 So the other scenario is B, C, D and F are all
6 scenarios on the roof pattern, but the differences have to
7 do with what Dr. Froines mentioned about the slope of that
8 roof pattern.
9 No. E, which has the lowest risk, has the highest
10 peak. It goes all the way up to 500 micrograms per cubic
11 meter in 1959, and then it goes all the way down to 50
12 micrograms per cubic meter. It has the -- it presumes the
13 highest exposure of the railroad workers, and therefore
14 results in the lowest risk.
15 And then the others, B, C and D represent
16 modifications of those peak levels.
17 And we think that from B through E we've pretty
18 much captured the information that Dr. Hammond presented
19 last month in terms of what are the possible -- what's the
20 possible range of exposure that could have occurred in terms
21 of these workers here.
22 And also Dr. Hammond suggested that this
23 information could be applied to both the case control, as
24 well as the cohort study, the exposure information, and that
25 is what we have done here.
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1 Now, the other thing is --
2 DR. BLANC: George, one of the modeling
3 assumptions that's missing from this table, and may be
4 confusing to other people, is that the block pattern is
5 missing, which gives yet the highest estimated risk, and the
6 risk value of 2.4 times 10 to the minus 3rd, which it
7 doesn't appear here, is in fact based on the block
8 assumption; is that correct?
9 DR. ALEXEEFF: Correct. Yes. If one chose to
10 make a calculation based upon the block diagram, as
11 Dr. Blanc indicated, there would be slightly higher risk.
12 It would go above the A value or above the scenario A, be
13 somewhere around 2 to 3. So it increases it.
14 DR. BLANC: In fact, isn't that the risk number
15 that's cited later in the document?
16 DR. ALEXEEFF: Yes. There are other
17 investigators, and I'll mention that on my next slide or so,
18 sort of putting it into context, numbers that have come out
19 of the study using the block diagram. That's basically the
20 approach they use. They used a constant exposure from '59,
21 so it makes for a slight higher risk.
22 DR. BLANC: What I guess I'm trying to say,
23 wouldn't it be useful for this table, depending on how this
24 table would be used, to at least have in the legend or
25 underneath the table, the clarification that is not listed
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1 here is the block scenario, which would yield for the case
2 control a value of X and for the cohort a value of Y?
3 DR. ALEXEEFF: What we want this -- what we would
4 like this table to show is the range of risks being
5 proposed.
6 And Dr. Froines at the last meeting suggested that
7 we have an additional table, which shows all the risk values
8 calculated by various investigators. So I will mention that
9 and I think that's one proposal is to add.
10 We have the information in the document, but
11 because the text can be difficult to sort of wade through,
12 it was suggested we put it in a table. So I think that
13 might be where it could be clarified.
14 ACTING CHAIRMAN FROINES: Let me make my point
15 here, and I feel extremely strongly about that.
16 And, Paul, I think what you're asking for is
17 exactly what I want in the end, which is a full table that
18 covers all the risk assessments that have been done, and put
19 in some sort of orderly form so people can read it. I mean,
20 putting things in a table is supposed to make things easier,
21 not harder.
22 But for example, in a previous slide, you've
23 already shown a risk assessment. You've shown Michael
24 Lipsett's meta-analysis and Kathy Hammond's, and estimates
25 of exposures that occur, and you've come up with numbers
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1 from that.
2 And so that is a value that's already been done.
3 That's separate from the Garshick data.
4 DR. ALEXEEFF: Correct.
5 ACTING CHAIRMAN FROINES: And I want everybody to
6 see that in fact, and we're going to come to this when I get
7 into the NIOSH data later, that we have some very strong
8 risk assessments that have been conducted that are not only
9 linked to the Garshick information. I want to show the
10 breadth of the risk assessments so people have some sense of
11 the complementarity between them and have a sense of how
12 people approach them.
13 So these are railroad workers and NIOSH workers on
14 truckers and so on and so forth.
15 DR. GLANTZ: My understanding, I agree that there
16 are places that you just get bogged down in this report, and
17 my understanding is that nobody thinks the block pattern is
18 a realistic exposure pattern.
19 DR. BLANC: Well, that's what the EPA is using for
20 their risk estimate.
21 DR. GLANTZ: Oh, really?
22 DR. BLANC: Of course, one question that is a
23 really minor one, but I was just curious, maybe, Mike, you
24 have the answer to this, if we have a number of 2.4 using
25 the cohort -- using, I'm sorry, the case control data and
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1 the block assumption, and EPA has a value of 2.0, I'm just
2 wondering maybe Dr. Dawson can comment why there's that
3 slight mathematical difference, since I assume that's a
4 modeling using all the same assumptions.
5 ACTING CHAIRMAN FROINES: But also, Paul, we can
6 have in the table the EPA estimates again to show the
7 ranges.
8 DR. BLANC: I think they are in essentially that's
9 what this Table 3 is, which I guess George is going to get
10 to.
11 ACTING CHAIRMAN FROINES: Well, I don't think it
12 has the EPA data in it. Maybe it does.
13 DR. GLANTZ: If I can just maybe finish a point I
14 was trying to make, and maybe I should drop it, but I was
15 going to suggest that the discussion of the block pattern be
16 just dropped in the report, because I think it's confusing.
17 DR. BLANC: Well, I wouldn't, because I think you
18 want to show that you've addressed and related to the other
19 risk estimates that are out there.
20 ACTING CHAIRMAN FROINES: If EPA has it, we can
21 put it in a table and have a footnote that says based on a
22 block.
23 DR. GLANTZ: Okay.
24 ACTING CHAIRMAN FROINES: Now, the other thing is
25 that there's one thing that George and I talked about and
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1 the panel can discuss it later, I don't think we have to
2 discuss it right now, but the EPA document used a unit risk
3 value of 2 times 10 to the minus 3, and we have no values
4 that have more than two places past the decimal. It might
5 be useful to get rid of anything past the decimal and just
6 go with the number.
7 DR. BLANC: Well, they --
8 ACTING CHAIRMAN FROINES: Like 7.0 to 7.6, how we
9 want to deal with that. Do we want to just treat that as 7
10 and go with it?
11 But let's not take that up right now. We're
12 thinking about it.
13 DR. WITSCHI: But I have problem with the Table 3
14 and with the next two slides that George is going to show,
15 because if you -- it gives a so-called overview about the
16 different risk estimates. There were only two sets of data
17 those different estimates were derived from.
18 The one is the comparative mutagenesis studies,
19 which is always the same set of data is looked at it another
20 way, and the other one are the railroad workers, and they
21 also looked at it in different ways.
22 The need, the important thing is the paucity of
23 data, but there are numerous way to look at those data.
24 But this doesn't exactly confirm that the database
25 is assumed. Just because you can manipulate it in very
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1 different ways does not necessarily mean the different
2 analyses confirm each other and strengthens the evidence.
3 ACTING CHAIRMAN FROINES: I think that's an
4 important point, Peter.
5 Let's come back to it when we go around the panel
6 and talk about that as a substantive issue, because one
7 could make the opposite argument that there is consistency
8 within the data and that's good, and that the approaches
9 that have been taken are different approaches.
10 The meta-analysis is not based on the railroad
11 worker study. The NIOSH data is not based on the railroad
12 worker study. So we have more than -- we have at least
13 three risk assessments based on different data sets.
14 So let's come back to that.
15 DR. WITSCHI: Wait a second here. This table says
16 for this meta-analysis, says based on smoking-adjusted
17 pooled railroads.
18 DR. BLANC: Well, relative risk, not railroads.
19 DR. WITSCHI: Relative risks.
20 DR. BLANC: Yes, that's fine.
21 Also, Hanspeter, it's important that you note that
22 in fact these relative -- I'm sorry, these risk estimates
23 are not based, even the ones that cite Garshick, are not
24 based all on the same studies, they're based two different
25 studies. One is a case control study and one is a cohort
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1 study. So I would actually differ with your interpretation
2 that it's a different analysis of the same data, because
3 it's analyses of different data and data obtained with a
4 fundamentally different methodological approach, and
5 therefore coming up with similar estimate ranges using two
6 different studies, albeit in the same general work
7 population, using very different methods of obtaining the
8 data are quite supportive, one of the other.
9 So, actually, I wouldn't agree with your comment
10 in that regard.
11 ACTING CHAIRMAN FROINES: It's an important point,
12 and let's come back to it.
13 DR. BLANC: I think that, Dr. Dawson, you were
14 going to just clarify for me that 2.0 versus 2.4. I don't
15 think this will take you very long.
16 DR. DAWSON: Well, I'll try to be precise.
17 I'm Stan Dawson.
18 First of all, the US EPA number is based on
19 McClellan's analysis of the case control.
20 DR. BLANC: Right. Case control study.
21 DR. DAWSON: Right. And he's making two
22 assumptions there about the level of concentration which he
23 considers to be constant from 1959 to 1980. And the two
24 assumptions are 125 micrograms per cubic meter and 500.
25 Now, the higher risk number, of course, comes from
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1 the 125, so that's where that came from.
2 Now, we do not -- that's just -- and this report,
3 in the previous report, we used that number, the previous
4 draft last year.
5 But in this report we do not use that number at
6 all. We simply go back to the Garshick case control slope
7 result, and put in our -- an extended block scenario.
8 Now, it goes back from seven years prior to 1959,
9 because we think that it's really more like a ramp than a
10 simple block, but it has the same cumulative area under the
11 curve, the same cumulative exposure as the area under the
12 curve, as that particular block, and the block is more
13 logical for a duration analysis, which is what Garshick's
14 case control study, how that was analyzed.
15 So, anyway, we put that extended block in and then
16 did the basic calculation up there in A, which gives you
17 this same number that you get if you used the ramp, and then
18 I did the ratioing process to get all those other numbers
19 out, simply erasing the area under the curve of each
20 scenario compared to that original block.
21 ACTING CHAIRMAN FROINES: The people doing the
22 video want to take a break, but I'd like George to go
23 through your next -- can you get through the risk
24 assessments and we need to take a break.
25 DR. ALEXEEFF: Yeah. I'd be happy to. It's not
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1 that much further in terms of just putting in perspective.
2 If you look at the next slide, and I put a
3 handout -- I broke it down into two pieces so that it would
4 show up on the overhead, but this is the handout in the
5 back.
6 And also I think the panel members should have
7 this handout, which just lists various reports that have
8 reported unit risks, and also includes the numbers that
9 constitute our range are listed in bold.
10 So you can see the top, and there's the method
11 description.
12 The first three are this comparative potency
13 analysis, where one is comparing the potency of diesel
14 exhaust relative to some other carcinogens.
15 And then the other first epidemiologic analysis is
16 the one that Dr. Smith presented and slightly refined, he
17 presented it was last month.
18 And then it's -- then you can see ours in bold.
19 If you go to the next slide, John.
20 Now, I've added the information in red there from
21 the -- just to let you see that this is information that
22 probably could be added. It's in the -- came in the Federal
23 Register this month. There's a survey of ranges from
24 Dr. Stayner, and that goes from one in -- you know, right
25 there you can see the range there.
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1 And then there's a new study which is in press by
2 Dr. Steenland, at NIOSH, on US truck drivers, and reports
3 that range, or that value there.
4 And I put it, it's sort of in the middle -- those
5 numbers are kind of overlapping our range somewhat.
6 And then you can see further down in the non-bold,
7 other studies. There's the railroad workers, London
8 transport workers, US EPA's slight modification use of the
9 McClellan data, and then our bracketing approach that we
10 used on the bottom.
11 So it gives you a sense as to where the
12 calculations we did can kind of be placed with other
13 calculations that will be done, just on the human data or
14 some variation of the human data. This does not include the
15 animal data.
16 ACTING CHAIRMAN FROINES: So it looks to me like
17 at the widest range you're running 1.3 times 10 to the minus
18 2 up to what?
19 DR. ALEXEEFF: Roughly 2.6 times 10 to the minus
20 5. It's on the previous slide.
21 DR. FUCALORO: It's not on this one. It's on the
22 previous one.
23 ACTING CHAIRMAN FROINES: So we're running, what?
24 DR. ALEXEEFF: About 2 in 100,000.
25 ACTING CHAIRMAN FROINES: 2 times 10 to the minus
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1 3.
2 DR. ALEXEEFF: 2 times 10 to the minus -- no, the
3 smallest number is roughly 2.6 times 10 to the minus 5.
4 Okay. That's the smallest risk.
5 And then the largest risk is -- well, there's 2 to
6 the minus 3, and then there's the bracketing which goes even
7 further.
8 ACTING CHAIRMAN FROINES: Which is?
9 DR. ALEXEEFF: 1.3 times 10 to the minus 2.
10 DR. GLANTZ: Yeah, but you know if you limit
11 yourself to the epidemiological studies, which I think this
12 is the more cautious thing to do, then the range is even
13 narrower. It's around 2 times 10 to the minus 4 to around 2
14 times 10 to the minus 3.
15 ACTING CHAIRMAN FROINES: Which epidemiology
16 study?
17 DR. GLANTZ: If you just look at all of them.
18 I'm looking at the table.
19 The comparative potency, I think the epidemiologic
20 analysis is going to be more -- there's more or less
21 uncertain than the comparative potency analyses and if you
22 just look at the epidemiological studies, the range of unit
23 risk is about an order of magnitude, and we're just
24 eyeballing it from around 1 or 2 times 10 to the minus 4 to
25 around 2 times 10 to the minus 3.
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1 ACTING CHAIRMAN FROINES: George, I mean, Stan, I
2 think that's a point to take up, which is whether or not to
3 use the comparative potency, and I tend to agree with you
4 that those are less solid than the other studies we have
5 before us.
6 So let's hold that. We've got a couple of topics
7 we want to hold.
8 So, George, is this -- but I think the important
9 issue here is that we see a range of values, we see a range
10 of approaches and we see a range of populations that have
11 been under study. So this gives us in a sense the landscape
12 on the quantitative risk assessment issue for us to then
13 talk about as part of our deliberations. This gives us a, I
14 think, a wider picture than what we had in the documents
15 that only listed basically the Garshick report.
16 DR. BLANC: Can I ask a question about the
17 Steenland data that have just -- are just coming out or in
18 press, in the American Journal of Industrial Medicine? In
19 addition to the quantitative risk estimate derived from that
20 study, does that study have a relative risk estimate that is
21 not previously been calculated on that cohort or did they go
22 back to data that has already produced a relative risk for
23 lung cancer that has already been incorporated into the
24 meta-analysis?
25 Maybe Mike can answer that question, Mike Lipsett.
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1 DR. ALEXEEFF: I think maybe during the break we
2 can check.
3 DR. BLANC: Okay.
4 ACTING CHAIRMAN FROINES: George.
5 DR. ALEXEEFF: And this last slide just, I think
6 it's on the key points with regards to the requirements in
7 the statute. There is the reference concentration for
8 non-cancer chronic exposure of five micrograms per cubic
9 meter.
10 We're supposed to make a statement whether or not
11 we were able to identify a threshold, and obviously we
12 identify a threshold for the non-cancer effects. We're
13 unable to identify a threshold for the carcinogenic effects.
14 And then the bottom point simply is the range of risk based
15 upon our epi studies in that table, Table 1-1.
16 DR. FUCALORO: Just a clarification.
17 DR. WITSCHI: I have a question.
18 DR. ALEXEEFF: This is the range. It's in the
19 current document. Later on we're going to suggest we have
20 some revisions that might modify that range slightly, but
21 this is what's in the current February document that went
22 out.
23 DR. BLANC: So can you just -- can you explain to
24 me again the 1.3 times 10 to minus 4 conforms to the number
25 that I had seen previously, the 1.5 times 10 to the minus 3
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1 is slightly lower than the 2.4 times 10 to the minus 3. Can
2 you just explain to me again, I think I've lost a step here,
3 where we discarded some of the more potent estimates that
4 were somewhat above 2.0.
5 DR. ALEXEEFF: That is simply a correction from, I
6 think the 2.4 you're referring to is what the previous
7 version -- oh, I'm sorry. Yeah. We're going to be making a
8 proposed correction based upon actual comments submitted
9 which adjusted the 2.4. And Dr. Marty will be explaining
10 that.
11 DR. FUCALORO: So the Table 2 reports it as 1.3
12 times 10 to minus 4, to 2.4 times 10 to the minus 3, and
13 that's the accurate --
14 DR. ALEXEEFF: I'm sorry. That is going to be a
15 proposed correction. So this is the range that's actually
16 in the document, and then you have a proposed correction on
17 that range.
18 DR. WITSCHI: I have a question.
19 What are we doing with the McClellan study from
20 '89, because that's he repeatedly retracted it.
21 DR. ALEXEEFF: Right. We are not using the
22 McClellan study in our calculations at all. But US EPA is,
23 so we simply included it in that table. US EPA is using it,
24 we are not using it.
25 DR. WITSCHI: I'm wondering whether we even should
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1 mention it, because clearly somebody said that was wrong. I
2 don't know that we can use this.
3 DR. BLANC: Well, I disagree pretty strongly with
4 saying that. I think it's important to recognize what the
5 US EPA is going to be doing as long as it's put in the
6 proper context, which is this document does.
7 DR. WITSCHI: I'm not talking about the US EPA.
8 DR. BLANC: But US EPA is actually basing their
9 risk estimate on the McClellan analysis of the Garshick case
10 control data, and therefore it would be silly of us to
11 completely ignore what the EPA is doing. It should be given
12 a nod, as it is in this document.
13 And maybe I misunderstood your comment, but your
14 comment was let's just not even mention the McClellan
15 analysis, but that, I think, would be inappropriately naive.
16 DR. GLANTZ: Would it be okay to just in the
17 table, the fourth through the bottom line is the McClellan
18 risk number, which if Hanspeter says it's been retracted,
19 couldn't that just be deleted, because if you go down
20 further, the second from the bottom line is the citation to
21 US EPA.
22 ACTING CHAIRMAN FROINES: See --
23 DR. GLANTZ: I'm just reacting to the comment.
24 ACTING CHAIRMAN FROINES: We all know Roger, and
25 if Roger has published a paper with findings in it and we
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1 review the science within the paper, right? That's our job.
2 Sometimes we don't like that science and sometimes we do.
3 Sometimes we're critical. Sometimes we accept it.
4 But we always interpret every paper we read.
5 That's our job as scientists. No paper is read as though
6 it's God's truth. The way science works is to be critical.
7 We have every obligation to take a paper that
8 Roger wrote and be critical of it. We may decide that it's
9 irrelevant. We may decide that it's a great paper.
10 But we do have the option, and I would argue the
11 responsibility, to look at Roger's paper and make a
12 determination on the adequacy of the science.
13 And I think we have to do that as scientists,
14 because we all do it to each other when we review papers all
15 the time, and I think it's our obligation to do that.
16 And if we simply say that Roger withdraws his
17 paper, he can withdraw his paper, but it doesn't mean we
18 don't get to read it and judge it. We respect him, he's a
19 great scientist, so it's not as though we're saying that
20 what he's doing is incorrect.
21 But I think we still have the obligation to
22 evaluate the data that's in that document.
23 DR. FRIEDMAN: George, the bottom, the
24 epidemiologic analysis listed at the bottom of the table,
25 that's the one that's based on the meta-analysis. Could you
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1 explain why you didn't take -- put that in bold and include
2 that as one of your primary risk estimates?
3 DR. ALEXEEFF: Yeah. There's probably a couple of
4 reasons we did not include it.
5 One is we were simply using it to sort of get a
6 sense as to what's the total possible ballpark landscape.
7 So it's a fairly broad range of exposure of five to 500
8 applied to the various occupational cohorts.
9 I think if one wanted to really do it rigorously,
10 you'd probably want to, you know, choose various exposures
11 for the various subcohorts and apply them, which we did --
12 which we did not do. But it was just sort of set the
13 landscape.
14 ACTING CHAIRMAN FROINES: George, but that's wrong
15 at one level, isn't it? Because you have taken a wide range
16 and you have looked at the data and you do have a range that
17 runs over a factor of a hundred, which is quite consistent
18 with everything else we've done.
19 Therefore, the fact that you're bringing in the
20 meta-analysis, making an estimate of the range of exposures,
21 if we want to after this is all over, we can go back and
22 look at that range of exposures more carefully and tighten
23 it down and give it some other numbers.
24 But this actually seems to me to be very useful.
25 It's saying we're not -- we're going to look at what the
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1 exposures were known to be and we're going to take a range
2 of those exposures, and we're going to see how it turns out
3 within the context of the meta-analysis.
4 And I frankly think that that -- I don't know if
5 this was what Gary was saying -- but I think that that one
6 meta-analysis risk assessment linkage is actually very
7 valuable.
8 DR. FUCALORO: I'm not sure. You don't mean that
9 this -- you're talking about the last entry here? I'm not
10 sure that's the meta-analysis, if I understood what that
11 means, but rather a range of analysis -- a range of values
12 that you've seen. I think the meta-analysis you're talking
13 about is in the slide you showed previously, the graph, and
14 which had a rather narrow range of uncertainty.
15 DR. BLANC: No, no. Let me explain what they did,
16 because then if I didn't understand it, then you'll know
17 that other people didn't understand it.
18 They did a meta-analysis that gave a relative risk
19 of 1.4, let's say, for the confidence intervals.
20 They know from epidemiologic data that the
21 absolute range of exposures in the various occupational
22 studies was a low of five micrograms per cubic meter and a
23 high of 500 micrograms per cubic meter. And then they went
24 through an algebraic calculation and said let's assume that
25 everybody in all of those studies was exposed to only five
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1 micrograms per cubic meter, and that gave a relative risk of
2 1.4, what would the cancer potency be.
3 And then they said, well, now let's assume that
4 everybody was exposed to 500 micrograms per cubic meter,
5 what would be the cancer potency. So if everybody was
6 exposed to such a high level to get a relative risk of 1.4,
7 then you would get that low level of 1.3 times 10 to minus 4
8 and if everybody was exposed to five, then you'd get -- and
9 that's why the brackets are actually kind of absurd in a
10 sense, because -- and that's why you were so cautious to use
11 the word brackets, but I think there's an easy solution for
12 this problem, which would make it more consistent with all
13 the other confidence interval based data that you presented,
14 which is to make an assumption that the mean exposure was
15 250 micrograms per cubic meter, come up with an estimate of
16 what the standard deviation about that mean of 250
17 micrograms per meter is, and then give us 95 percent
18 confidence intervals for what the upper and lower bounds
19 would be of the cancer potency factor, assuming not the zero
20 percentile, but the fifth percentile, the 95th percentile,
21 and assume that the exposures were normally distributed,
22 even though that's probably not true.
23 And at least then you would get something that
24 would be somewhat less than 1.3 and up to the 10 to the
25 minus 4 and -- it will be narrower on both sides and if you
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1 want to model it with instead of normal distribution, Possan
2 distribution or something, which might even be -- have a
3 narrower peak and lower slopes, that might even be better.
4 What do you say, Stan?
5 DR. GLANTZ: I don't know if we want to have them
6 do it, because I don't think it's going to change.
7 DR. BLANC: It's not going to change the bread and
8 butter of this --
9 DR. GLANTZ: I think it's a good idea. And I
10 think it will confirm -- I think what that will probably end
11 up doing is giving you a range of risk very similar to what
12 they got from the Garshick data, which would strengthen the
13 case. I don't know that we'd want to hold the report up --
14 maybe they can do that at lunch.
15 ACTING CHAIRMAN FROINES: Stan --
16 DR. GLANTZ: They keep saying they're smart.
17 ACTING CHAIRMAN FROINES: Stan and Gary and Paul,
18 I want to emphasize the value of that is that it is -- it's
19 not entirely independent, but it is a different way of
20 looking at the risk assessment and to the degree that
21 there's concern about the reliance on Garshick, this is
22 another piece of evidence that we can use as part of looking
23 at this overall picture, and I think it's extremely
24 valuable.
25 DR. GLANTZ: Maybe they can do it over lunch.
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1 They have a laptop computer.
2 ACTING CHAIRMAN FROINES: We don't have to worry
3 about getting the exact numbers out before we make
4 determinations. We all understand what Paul is talking
5 about. But it's the idea, I think.
6 DR. GLANTZ: Yeah. I think it's a good idea.
7 DR. BLANC: Because I do think that having a level
8 of 1.3 times 10 to the minus 2, which is so low, or so high,
9 depending on the language you want to use, it undermines the
10 utility of it.
11 So rather than doing something -- because we all
12 know that the exposure over all of those occupations was not
13 as low as five micrograms.
14 ACTING CHAIRMAN FROINES: The five is a bad
15 number. As we saw in Allan Smith's where he is up around
16 80, 60 to 80, that makes -- that's a more realistic number.
17 DR. FRIEDMAN: I think that, just to emphasize
18 what was said, that all these studies are estimates that are
19 listed in bold are all derived from the Garshick data,
20 either cohort or case control, and there's so much
21 contention about that, that it would be nice to have
22 something else that you did in bold too as another good
23 estimate.
24 ACTING CHAIRMAN FROINES: Well, that's also, Gary,
25 why I wanted to -- and we spent the morning getting the two
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1 papers from NIOSH where two new risk assessments studies,
2 one on truckers has been done, so it gives us a new data set
3 entirely to look at.
4 And, again, the numbers are all turning out to be
5 pretty much the same, but it's nice to have different
6 sources of information to help confirm.
7 DR. BLANC: As an occupational health physician, I
8 do have to say that the video people have now gone beyond
9 the time that you promised them.
10 ACTING CHAIRMAN FROINES: Well, I was actually
11 trying to squeeze --
12 DR. FUCALORO: Don't talk squeeze.
13 ACTING CHAIRMAN FROINES: I was hoping to get
14 through to 11:30 and breaking for lunch. You guys think you
15 can make that?
16 DR. BLANC: Can you go to 11:30 and break for
17 lunch?
18 ACTING CHAIRMAN FROINES: I knew what I was doing,
19 but I knew I was on tender ground here.
20 DR. BYUS: I'll be glad to run the camera.
21 ACTING CHAIRMAN FROINES: George, you want to try
22 to finish off in ten minutes?
23 DR. ALEXEEFF: I'm done with my presentation.
24 ACTING CHAIRMAN FROINES: Okay. I have a question
25 then for the panel.
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1 DR. ALEXEEFF: Unless you wanted -- we haven't
2 discussed comments.
3 ACTING CHAIRMAN FROINES: No, I think that we're
4 at a place now where we have to make a decision, and I would
5 argue that after lunch we go to the findings, which is going
6 to get us into the substance of the panel can take up a lot
7 of these issues, and maybe we won't take up the comments or
8 that we do take up the comments. My only concern about
9 taking up the comments is that it goes on for a very long
10 period of time, we're going to start having less time for
11 the panel's discussion.
12 And so however you want to do it.
13 DR. GLANTZ: Why don't we give Melanie ten minutes
14 to talk about the key comments, and then we go to 11:30 and
15 the key -- because I mean there was a lot of important stuff
16 in the comments.
17 ACTING CHAIRMAN FROINES: Can you do that?
18 Stan, let me act -- in the role of the chair, let
19 me -- how much time do you think you need on the comments?
20 DR. MARTY: Well, if you'd ask me that last night,
21 I would have said a half an hour, but I think I can buzz
22 through this in ten minutes.
23 ACTING CHAIRMAN FROINES: If you can do that and
24 then that means that we won't go to comments until later
25 with Genevieve.
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1 DR. GLANTZ: You're using up Melanie's time.
2 MS. SHIROMA: OEHHA will go first then and then
3 ARB with summary of comments and response and our proposed
4 revisions. For the ARB portion it's maybe five minutes'
5 worth of -- everyone has been mailed --
6 ACTING CHAIRMAN FROINES: If we start at 1:00
7 o'clock we'll be finished with comments completely by 1:15,
8 1:20, 1:30? I really want to get us on to the substance of
9 this.
10 DR. GLANTZ: Let her do the comments.
11 ACTING CHAIRMAN FROINES: I understand. But I'm
12 not talking about Melanie. I'm talking about ARB right now.
13 MS. SHIROMA: Yes. Ours is very brief, short.
14 ACTING CHAIRMAN FROINES: So we will start at 1:00
15 on the dot, and we will be finished with comments at 1:15,
16 and then we'll start going around the table.
17 DR. MARTY: I think that the fastest way is for me
18 not be get up there with overheads and just to talk about
19 it, so that's what I'm going to do.
20 Essentially, we have grouped the comments by
21 underlying theme in order to talk about them today and to
22 stress the major substantive issues.
23 And I'd like to report that none of the issues
24 raised in the latest comment period are new. Some of the
25 details might be a little different, but the underlying
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1 issues are the same that we have responded to in the past
2 Part C documents in May '97 and again in February '98, and
3 also in the responses to comments that we sent to you folks
4 last week.
5 There were comments concerning causality. The
6 commentators questioned how OEHHA could come to the
7 conclusion that epidemiological evidence supports a causal
8 link between exposure to diesel exhaust and the lung cancer.
9 And I think George went over that briefly earlier.
10 HEI made the comment that because of uncertainties
11 around whether there's a dose response can be estimated, the
12 extent of bioavailability in the small size of relative
13 risks, that they could not come -- that it made it difficult
14 for them to come to that conclusion.
15 And OEHHA has assessed causal inference using
16 standard criteria. The consistency of the findings is
17 there. The great majority of the epi studies find an
18 association.
19 The small magnitude of risks is offset by the
20 number and the diversity of occupations for which those
21 relative risks were found, and the consistency of the
22 findings from study to study.
23 We did analyze whether the possibility that the
24 findings could be due to bias or to chance, and our analyses
25 found that it is not likely to account for the effect.
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1 There is modest evidence of exposure response
2 based on the duration of exposure.
3 The temporality of the associations is such that
4 there's sufficient time elapsed between the start of
5 exposure and lung cancer in most studies.
6 And lastly there is biological plausibility.
7 There are mutagens and known human carcinogens and
8 respiratory tract carcinogens in diesel exhaust and diesel
9 exhaust does cause lung cancer in animal models.
10 And finally the HEI themselves report in their own
11 diesel exhaust document that the studies they reviewed
12 suggests an exposure to diesel exhaust in a variety of
13 occupational circumstances is associated with small to
14 moderate relative increases in lung cancer occurrence and/or
15 mortality.
16 These elevations do not appear to be fully
17 explicable by compounding due to cigarette smoking or other
18 sources of bias. Therefore, at present, exposure to diesel
19 exhaust provides the most reasonable explanation for these
20 elevations.
21 We had comments on causality, but I don't think
22 it's worth going over them at this point.
23 The other issue that was raised by several
24 commentators again hits on the bioavailability of the
25 genotoxins present on a particle phase.
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1 And their main points were that only extracts of
2 diesel exhaust particles are mutagenic, that the DNA adduct
3 data are not conclusive and therefore do not support
4 bioavailability, and that no enzyme induction was seen in
5 the chronic studies, and no immunological responses were
6 seen in animals, indicating a lack of bioavailability.
7 And our response to that is as was mentioned
8 previously, that while it is true that many of the studies
9 used diesel extract, diesel exhaust extract, and those were
10 positive mutagenicity studies, whole diesel exhaust also
11 induced mutation and four strains of salmonella and diesel
12 exhaust particles suspended in simulated physiologic fluids
13 were mutagenic in salmonella and also in mammalian cell
14 assays.
15 And I'd like to point out that the bioavailability
16 argument does not apply to the vapor phase genotoxins that
17 are present, which include low molecular weight PAHs and
18 nitro-PAHs, 1,3-butadiene, formaldehyde and a host of
19 others.
20 We did talk briefly about the DNA adduct data. I
21 don't think I need to go over that again, but we believe
22 that although there is some noise in the data it does
23 support bioavailability.
24 In terms of the lack of enzyme induction, they're
25 referring to the cytochrome P4 50 monoxygenates drug
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1 metabolizing enzyme system. It is true that it was not
2 noted to be induced in the long-term bioassays. However,
3 induction of AHH activity over baseline is not required for
4 PAH metabolism.
5 The levels of PAH experienced by the lung cells
6 may be insufficient to induce enzyme activity, but
7 sufficient to produce genotoxicity.
8 There is evidence that macrophages can activate
9 benzo(a)pyrene coated on diesel particles and release the
10 metabolites to the surrounding medium.
11 And there are many recent studies showing
12 immunological responses to diesel exhaust particles.
13 Issues were raised about the uncertainty in the
14 occupational exposure estimates. I think we've really
15 covered that. I think it's safe to say that we believe that
16 bounding of our exposure reconstruction in the document is
17 such that it's unlikely that any of the exposures were lower
18 than our lower estimates or higher than our highest
19 estimates. And I think we stand by that.
20 It also was brought up that the extrapolating
21 downwards from occupational exposures to ambient levels, and
22 that extrapolation really is not unduly large if you're
23 familiar with risk assessment in general. It's on the order
24 of 10 to hundredfold, depending on what measurements you're
25 talking about.
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1 And other identified TACs had extrapolations up to
2 10,000-fold. We don't think that's really an issue.
3 Commentators brought up the issue that we're
4 assuming a linear nonthreshold model and we could have been
5 using other models.
6 The reason we chose the linear nonthreshold model
7 is the presence of the many genotoxic compounds in the
8 theory that the linear nonthreshold model is appropriate for
9 genotoxic mechanism of carcinogenicity.
10 There is not an evidence for a threshold effect in
11 humans. And particle overload is not evident in the workers
12 and we don't think it's an issue in terms of modeling the
13 dose response from epidemiological data.
14 We got some comments that Dr. Crump keeps getting
15 negative dose response curves.
16 There's a couple of reasons we think that is the
17 case.
18 One is that Dr. Crump treats clerks and signalmen
19 as if they were exposed to diesel exhaust, and we do not,
20 per the report in the Garshick study, which indicated that
21 those individuals were looked upon as unexposed to diesel
22 exhaust.
23 So I think that that is a big reason why we get
24 different analyses, different results of our analyses than
25 Dr. Crump.
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1 In addition, there is some collinearity problems
2 using cumulative exposure and counter year variables in the
3 same regression, doesn't provide reliable estimates of the
4 slopes because cumulative exposure is nearly proportional to
5 calendar year once you exclude the clerks and signalmen,
6 which was done in Dr. Crump's analyses.
7 Dr. Crump also pointed out that in our latest
8 attempts to account for exposure prior to 1959, which gets
9 back to the ramp and roof models, assumes that all workers
10 had that additional exposure prior to 1959.
11 And he also points out an error which resulted in
12 gaps in exposure in our program.
13 It is true that we assume that all those
14 individuals had exposure prior to 1959, but the correction
15 we realize was not going to be a perfect correction. We
16 just wanted to indicate that these exposures occurred and to
17 adjust the slope estimates to account for those additional
18 exposures.
19 We also corrected the error pointed out and reran
20 the model and this resulted in a small increase in the unit
21 risk estimate.
22 There's a few other issues raised on the modeling,
23 but I don't think it's worth going over them right now.
24 I did want to note that Dr. Kyle Steenland from
25 NIOSH forwarded as a comment an abstract of a manuscript
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1 that he is publishing, and we just heard a little bit about
2 that, and he has an estimate that is on the order of 8 times
3 10 to the minus 4, right into the 10 to the minus 3 range as
4 a unit risk.
5 ACTING CHAIRMAN FROINES: Stayner is mining, and
6 Steenland is truckers.
7 DR. MARTY: Right. Dr. Duncan Thomas also was
8 communicating with Stan Dawson and sent a number of
9 comments, and Dr. Thomas presented at the March 11th SRP
10 meeting. He sent a number of comments supporting the
11 conclusion that lung cancer effects of diesel exhaust -- or
12 that lung cancer and diesel exhaust relationship is causal.
13 He gave us lots of positive comments, which I
14 probably should go through, but calls our meta-analysis
15 outstanding.
16 And he also was happy that we started -- we used
17 the Garshick case control and welcomed the reanalysis of the
18 Garshick cohort data.
19 He did express difficulty that the multistage
20 model where the last stage is considered to be the active
21 stage is biologically implausible, but when we run the
22 model, the model itself suggests that the final stage is
23 acted upon by diesel exhaust.
24 And in a preliminary analysis the fit of the model
25 with first stages dependent on diesel exhaust exposure is
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1 much more poorer than the fit of the model with the final
2 stage being acted upon by diesel exhaust.
3 And then I should probably finally mention that
4 the California Trucking Association commented that OEHHA
5 missed an Australian study, which would disprove our
6 association between within diesel exhaust exposure and lung
7 cancer risk. That's pointed out in a number of studies in
8 our document.
9 And OEHHA's reviewed that study now as a technical
10 report from the Australian government.
11 The study is conventional cohort investigation
12 intended to examine all causes of mortality. It is not
13 specifically a study of lung cancer or of diesel exhaust.
14 And there were actually a number of problems,
15 technical problems, with the study, which was designed to be
16 a preliminary study anyhow.
17 There was not a minimum period of employment for
18 the coal miners to be in the cohort. They mixed coal miners
19 from underground mines and above-ground mines. They had
20 difficulties tracking the miners' work experience.
21 Most importantly the average age of the cohort was
22 between 40 and 50 years old, which is really not old enough
23 to be examining these individuals for incidence of lung
24 cancer.
25 And 30 percent of the cohort had been in the
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1 industry less than ten years, so we didn't have enough
2 exposure time lapsing.
3 And also the report included deaths in the first
4 ten years of the cohort experience, which just adds noise to
5 the cancer analysis.
6 And finally the SIR for lung cancer for the entire
7 cohort, while appearing to be lower than the general
8 population, was actually not statistically significant.
9 Does anyone want to discuss individual points or
10 want me to touch on other things that you've read in our
11 response to comments?
12 DR. BLANC: I just want to say in terms of the
13 coal mining study, particularly such a hubbub was made about
14 it, I found it verging on the absurd that you even had to
15 respond to that. It was not germane and it was not
16 appropriate for analysis of any kind of cancer risk, let
17 alone diesel-related lung cancer risk.
18 So I think you're completely on safe ground by
19 disposing of that in short order.
20 And in fact the summary document upon which that
21 published paper was based, itself acknowledges that the
22 study cannot be used to address cancer risk because the
23 latency period is insufficient to evaluate cancer in that
24 cohort.
25 ACTING CHAIRMAN FROINES: Gary.
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1 DR. FRIEDMAN: I just want to add too that I was
2 very disturbed by some of the comments that said that your
3 group was biased, that you started out with a forgone
4 conclusion and just tried to prove it.
5 And I think that that's not true at all, and I
6 think those, that kind of comment is totally inappropriate.
7 I know your group has worked very hard to respond
8 to all the comments to really do an objective analysis, and
9 I think that people who make comments like that should
10 realize that they're just not appropriate. They're
11 ad homonym arguments which have no role in a scientific
12 discussion.
13 DR. GLANTZ: I just also, I thought you guys did a
14 very very fine job of responding to the comments. I mean,
15 there's a huge volume of them. They were very all -- they
16 were covering a wide variety of issues and I thought the
17 responses were really strong.
18 I have a couple of things I want to suggest, based
19 on the comments, but overall I think you just did an
20 exceptionally good job on it.
21 DR. MARTY: Thank you.
22 ACTING CHAIRMAN FROINES: I think when you look at
23 the US EPA document and you compare it to ours, it's really
24 very impressive, given that we're operating as a state
25 agency, in contrast to the federal government.
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1 And I can say, having been the longest term member
2 of the panel, that this is in fact the best document that
3 I've ever seen from OEHHA and ARB. It's really quite an
4 extraordinary document, I think.
5 And then with that, we'll break, because in the
6 afternoon it gets -- we start to go at the document a little
7 harder. Get the good news first.
8 We're going to start at 1:00, folks, because I
9 want to get everybody's energy going so we can get through
10 here today.
11 (Thereupon the lunch recess was taken.)
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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1 A F T E R N O O N S E S S I O N
2 ACTING CHAIRMAN FROINES: I'm calling the meeting
3 to order.
4 The tension level in this room is much too low.
5 We expected about 500 truckers here. That didn't
6 materialize, and now everybody is so relaxed we can't move
7 anything forward.
8 So for better or for worse, whatever way we're
9 headed, let's move it along.
10 That requires Stan Glantz taking a seat.
11 And Genevieve and her people up here.
12 Tony is going to start with the findings.
13 Come on, Paul. We give you $100, we expect every
14 minute of your time.
15 What we want to do is to integrate comments on
16 Part A and Part B as we go through the findings. So you
17 guys are going to have to be creative, nonlinear, of course.
18 We're about to pass around the most recent NIOSH
19 information on risk assessment, which you won't have had a
20 chance to read, but that is literally hot off the presses.
21 And it has the advantage of being miners and truck
22 drivers, so it's not same old, same old.
23 DR. GLANTZ: We were discussing the origins of why
24 Hanspeter thought RR meant railroad.
25 DR. BLANC: That's because Stan is often trying to
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1 railroad people with his epidemiologic --
2 DR. GLANTZ: No, no.
3 ACTING CHAIRMAN FROINES: So we're ready to go.
4 Tony, could you take us through each section of
5 the first half of this?
6 DR. GLANTZ: Wasn't Genevieve going to talk about
7 their response to comments first?
8 ACTING CHAIRMAN FROINES: Who?
9 DR. GLANTZ: Genevieve.
10 ACTING CHAIRMAN FROINES: They will, but we're
11 going to move this so we can finish this today.
12 DR. GLANTZ: I'm fine.
13 ACTING CHAIRMAN FROINES: And we have had the
14 comments to read and Genevieve and Melanie know that as we
15 move forward here, where there are comments that are germane
16 to the findings, they will bring them in.
17 If there's new science, then somebody needs to
18 tell us about that, but I've been listening to this stuff
19 for nine years now, and I'm not hearing a lot of new
20 science.
21 DR. GLANTZ: Okay.
22 ACTING CHAIRMAN FROINES: Lot of mathematicians,
23 but that's about it.
24 DR. GLANTZ: Well, let's go.
25 DR. FUCALORO: Okay. I'm new to this, and was
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1 called -- pressed into service because Jim Seiber had to be
2 out of the country, legitimate reasons, as far as I know.
3 And I have to report on Part 1 or Part A.
4 I'm just going to read something that Jim
5 suggested, some suggested language to be added to our
6 findings to see whether or not you agree with it.
7 After that I guess we can throw it open to the
8 discussion to respond to this.
9 ACTING CHAIRMAN FROINES: Usually we go around the
10 room and get comments.
11 We're now in the Part A findings, everybody, so
12 we're going to go around the room and get comments on the
13 Part A findings.
14 DR. FUCALORO: People can respond to this or make
15 any other statements they wish to make regarding Part A.
16 Let me read what Jim has written.
17 He said, although there is evidence that diesel
18 exhaust is carcinogenic, particulate matter concentrations
19 in California's estimated total population, air exposure has
20 decreased significantly from 2.1 plus or minus .8, he has
21 grams here, but micrograms per meter cubed in 1990, to 1.5
22 in 1995, and estimated values of 1.2 for 2000 and 1.1 for
23 2010.
24 Also very recent ARB-sponsored studies by UC
25 Riverside and UC Davis scientists show significant
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1 reductions in concentrations of some carcinogenic components
2 and a reduction of specific mutagenic activity in exhaust
3 from modern diesel engine running on either reformulated or
4 low aromatic fuels of the types introduced in California in
5 1993.
6 Thus the trend in reducing particulate matter and
7 carcinogenic components in diesel exhaust emitted in
8 California is positive.
9 SRP recognizes the improvements made to date and
10 encourages further studies aimed at documenting and reducing
11 the toxic potential of diesel exhaust as emitted to
12 California's air environment.
13 I would say that that's not clear from what I
14 heard today that the carcinogenic activity of diesel exhaust
15 has been reduced, but it might have been reduced in these
16 new fuel formulations, and so the last sentence still
17 obtains, it seems to me, encouraging further studies aimed
18 at documenting and reducing the toxic potential of diesel
19 exhaust as emitted to California's air environment.
20 So with that, I would go around the table and see
21 what people think.
22 ACTING CHAIRMAN FROINES: You've made a
23 presentation. Do you want to respond to that?
24 MS. SHIROMA: Yes. Just to help direct the
25 discussion, I think that we have touched on Dr. Seiber's
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1 points in your number five, also number nine, and number 10.
2 Now, in light of his comments, you may wish to add
3 more specificity, but I think the three topic areas are
4 covered, the estimated ambient total exposure, the
5 acknowledgement that the current regulations will reduce,
6 are anticipated to reduce that total exposure, and then the
7 CE-CERT analysis.
8 DR. FUCALORO: Right.
9 Of course in No. 10 I would argue, and you can
10 tell me if you agree with this, with the removal of the
11 sentence which says the results indicates that diesel
12 exhaust from the new fuel tested contained at the same
13 relative portions of toxic air contaminants as the old fuel.
14 I don't think that's quite accurate. I don't
15 think it changes any of our conclusions regarding diesel
16 exhaust as a toxic air contaminant.
17 I'm just not sure from the data, unless you can
18 convince me otherwise, that that's true.
19 MS. SHIROMA: And we are focusing on the toxic air
20 contaminant subset of the mix, but we could suggest that you
21 consider that the exhaust for the new and the old contain
22 the same constituents.
23 DR. FUCALORO: I think that's fair to say.
24 MS. SHIROMA: Okay.
25 DR. FUCALORO: I think that's fair to say, they
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1 do.
2 MS. SHIROMA: Contain the same toxic air
3 substances as the old fuel. Take out the phrase relative
4 portions of?
5 DR. FUCALORO: Right.
6 MS. SHIROMA: So the sentence would read the
7 results indicate that the diesel exhaust for the new fuel
8 tested contain the same toxic air substances as the old
9 fuel.
10 DR. FUCALORO: Yes.
11 And I think in some ways that's accurate, but in
12 union with the next sentence, maybe you need some other
13 sentence in there which says, or something added to that
14 sentence, although, perhaps, perhaps at different
15 concentrations. So then that makes sense at the next
16 sentence which says further research will be helpful to
17 quantify the amounts of specific compounds emitted for a
18 variety of engine technologies, operating cycles and fuel,
19 to better characterize any differences between old and new.
20 MS. SHIROMA: So then we will add in -- and I
21 think that's --
22 DR. KENNEDY: I don't mean to talk out of turn,
23 but are not the differences in new fuel more complex simply
24 than their carbon components? We're talking particle size,
25 which is really an unknown. We've got some balancing
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1 forces.
2 I think that to make a summary statement that
3 reflects only these components is really not doing justice
4 to the changes, although I certainly would agree that we are
5 all in favor of continued investigation into what these
6 differences mean in terms of our safety.
7 DR. GLANTZ: I actually was going to suggest we
8 just delete No. 10. I think especially with the changes
9 that we're making now, I don't see what it really adds to
10 the findings. Everyone is always in favor of more research
11 and better fuel and all that. I mean --
12 DR. FUCALORO: Well, I think in this case the
13 reason for putting it in, this is I'm speaking for Jim on
14 this, I think I agree with this, is that the composition of
15 diesel exhaust probably does change, not only the amount,
16 but the composition does change. It's different than, say,
17 benzene, which is one compound, but this is a mix of
18 compounds, a heterogeneous mix in terms of phases, that we
19 have to be very careful to note that the change may be good
20 and may be bad, and we have to -- and continuing research
21 would ensure that study continue.
22 DR. GLANTZ: Okay.
23 ACTING CHAIRMAN FROINES: You have a sentence that
24 you two can agree that will be in there?
25 MS. SHIROMA: I think we're very close. I was
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1 going to suggest that perhaps a sentence that we're
2 suggesting on ES-11, the executive summary on page 11, to
3 add in the CE-CERT. We have a sentence saying -- it's
4 labeled as E-11 in the revisions to the February 23rd
5 report, and Peter just handed that around.
6 DR. FUCALORO: Read it.
7 MS. SHIROMA: A comparison of the milligram to
8 milligram per cubic meter emission profiles using the three
9 different fuels showed the presence of the same toxic
10 substances in a similar distribution of toxic substances,
11 but with a few substances showing much different emission
12 rates.
13 It then goes on to mention that in addition,
14 higher mutagenic activity was observed in both the particle
15 and vapor phase.
16 ACTING CHAIRMAN FROINES: That would be enough, I
17 think. Let's not -- these are findings and we're going --
18 we're not going to take the executive summary and make it
19 into findings. These have to be simpler. So I would accept
20 a sentence, but --
21 DR. BLANC: Let me suggest a phrase reflecting
22 what everyone has said.
23 The sentence would now read in point 10, the
24 results indicate that diesel exhaust from the new fuel
25 contains the same toxic air contaminants as the old fuel,
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1 although there are concentrations and other components may
2 differ. Period. Further research, blah-blah-blah.
3 ACTING CHAIRMAN FROINES: I want to have further
4 research in there.
5 DR. FUCALORO: I do too.
6 DR. BLANC: Would that phrase be --
7 ACTING CHAIRMAN FROINES: That's fine.
8 DR. FUCALORO: We can't call Jim Seiber, but I
9 think that reflects his --
10 ACTING CHAIRMAN FROINES: If he gets a trip to the
11 Netherlands, he doesn't -- we don't have to check with him.
12 He made the trip after this thing was scheduled.
13 Give it to somebody who can be more responsible
14 than me.
15 That was good, Paul.
16 MS. SHIROMA: That will do it.
17 DR. FUCALORO: That works.
18 MS. SHIROMA: That works.
19 ACTING CHAIRMAN FROINES: I don't think -- I would
20 oppose putting in this mutagenic activity in. One, it
21 wasn't statistically significant and, two, it was change of
22 a half, and if you're a mutagenesis person going for a
23 change of a half doesn't really mean very much.
24 DR. GLANTZ: Could I just as a point of
25 information, are the findings, the draft findings you handed
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1 out today, the same as the ones that were faxed around
2 yesterday?
3 MS. SHIROMA: Yes.
4 ACTING CHAIRMAN FROINES: This is just a working
5 document.
6 DR. GLANTZ: I just want to make sure, because I
7 read those and didn't read this.
8 DR. FUCALORO: I guess with that issue resolved,
9 as near as I can tell, it seems to, we can go around the
10 room now and gather the comments from various panel members
11 on Part A.
12 So I would ask Craig to --
13 DR. BYUS: I have no comment. I agree with these
14 changes. I think it's perfectly fine.
15 ACTING CHAIRMAN FROINES: You're on 1 through 10.
16 DR. FUCALORO: 1 through 10, which is Part A.
17 ACTING CHAIRMAN FROINES: Check your notes and see
18 what you have.
19 DR. BYUS: I like the findings, virtually all of
20 them.
21 DR. FUCALORO: 1 through 10.
22 DR. BLANC: I have a question.
23 Vis-a-vis comments that were made, why did
24 somebody make a big deal about whether we said it was gases
25 and fine particles, as opposed to saying gases and vapors
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1 and fine particles? Maybe our lawyer would say why that --
2 that was lost on me as to what the -- it seemed to be a big
3 deal to somebody, and I couldn't figure out exactly why.
4 Do you remember that comment?
5 ACTING CHAIRMAN FROINES: When I see comments like
6 that I tend to go by them pretty fast, because I think
7 they're --
8 DR. BLANC: I thought it had some legal
9 implication as well.
10 DR. FUCALORO: There is a scientific distinction.
11 DR. BLANC: That I know.
12 MR. KRIEGER: Dr. Blanc, I'd like to try to
13 address that.
14 Legal issue, I don't think that's the problem.
15 I think it was quoted in one part of our text as
16 being gases, vapors, particles, and another part of our text
17 it was quoted as gases and particles.
18 Diesel exhaust is a mixture of gases and
19 particles. The particles there's phases, you have a solid
20 phase and you have a vapor phase, so the confusion over the
21 terminology is what spurred that comment.
22 DR. BLANC: I only brought that up in terms of the
23 very first paragraph. It was a nonissue, it didn't matter
24 to me.
25 DR. FUCALORO: Now, Craig, you're completed?
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1 DR. BYUS: I'm fine.
2 DR. FUCALORO: Paul, do you have any other
3 comments regarding the first ten conclusions?
4 DR. BLANC: Well, I wonder why John hasn't said
5 anything here. I guess you say it later about the
6 nitro-PAHs. So it's in the second -- it's in point 2, but
7 it's not in point 1, except PAH derivatives includes the
8 nitro-PAHs, I assume.
9 John, do you see what I'm talking about?
10 ACTING CHAIRMAN FROINES: Under 2?
11 DR. BLANC: Under 2 you specifically mention PAH
12 derivatives such as nitro-PAHs, but in paragraph one you
13 just say PAHs derivatives.
14 ACTING CHAIRMAN FROINES: No. Because paragraph
15 one is intending to focus on gases.
16 Paragraph two is intended to focus on
17 particle-bound chemicals.
18 There was a clear distinction made there.
19 You notice that in paragraph one we're talking
20 about products of incomplete combustion, gases, fractions,
21 includes all those, and the PAHs that we're talking about
22 there are things like naphthalene that are basically vapors,
23 in a vapor phase or gaseous phase.
24 Then you go down to two and you're talking about
25 the particle bound organics.
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1 MS. SHIROMA: Dr. Froines, maybe some of the
2 confusion is maybe this is just a typo and you paste and
3 click and so forth. Last sentence on No. 1 says some of the
4 gaseous components are and it includes arsenic and nickel.
5 And perhaps that's where some of the confusion is.
6 Perhaps that was meant to be moved.
7 ACTING CHAIRMAN FROINES: Well --
8 DR. BLANC: Yeah.
9 ACTING CHAIRMAN FROINES: I had wanted to put in
10 the list of carcinogens identified, and that would have been
11 under three, and that didn't get in. It was on a slide here
12 today, but it never made the text, and I wanted it to be
13 spelled out. So I would just as soon take out that last
14 sentence of one, but I wanted it included under three.
15 MS. SHIROMA: And it would be more generic. Some
16 of the components --
17 DR. BLANC: Get rid of the word gaseous then, is
18 what she's saying. So then it should read some of the
19 components of diesel exhaust, such as benzene, formaldehyde,
20 1,3-butadiene, arsenic and nickel are suspected or known to
21 cause cancer in humans, and that entire phrase then should
22 be moved to be the last sentence in point No. 3.
23 ACTING CHAIRMAN FROINES: Yeah. The only thing I
24 didn't like about this was -- it's okay.
25 DR. BLANC: Would that be acceptable?
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1 ACTING CHAIRMAN FROINES: I would add chromium in
2 there. Add chromium in. But there are other --
3 DR. BLANC: Well, you said some.
4 ACTING CHAIRMAN FROINES: Here's my point. This
5 is about the gaseous phase and some of the constituency --
6 DR. BLANC: But clearly arsenic is not in a
7 gaseous form.
8 ACTING CHAIRMAN FROINES: Wait. Sure it is. If
9 nickel and arsenic are in a gaseous form, then chromium is
10 too.
11 DR. BLANC: Not as a fume?
12 ACTING CHAIRMAN FROINES: That's part of the
13 problem with this.
14 My problem was that I wasn't so sure we should
15 have the metals in here as gases.
16 DR. BLANC: Wouldn't that solve the problem if you
17 get rid of the word gases, and just say some of the
18 components?
19 ACTING CHAIRMAN FROINES: That's right. It saves
20 that.
21 But the point is I would rather have a section
22 under three where we actually list the carcinogens found in
23 diesel exhaust. And that wasn't done when I asked for it to
24 be changed.
25 So we list a few compounds here that in essence
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1 referred to the gaseous aspect of it.
2 DR. BLANC: Well, let me ask you then, if you were
3 going to add other things that you felt were nongaseous, so
4 that we avoid the argument of arsenic and nickel, you would
5 include there PAHs and nitro-PAHs, or what else, what would
6 be missing?
7 ACTING CHAIRMAN FROINES: No. Because those
8 aren't --
9 DR. BLANC: What would be missing from there,
10 assuming that we added chromium?
11 ACTING CHAIRMAN FROINES: You see what you've got,
12 we've created an apples and oranges problem here. We start
13 out talking about gases.
14 DR. BLANC: Well, I think it's confusing to talk
15 about those perhaps, then.
16 I mean is it that important to you that we talk
17 about those detailed gases. Your real point is that they're
18 carcinogens. So then doesn't it make more sense --
19 ACTING CHAIRMAN FROINES: I would take out -- I
20 think we should just take out that sentence and have the
21 carcinogens listed under three.
22 DR. BLANC: Yeah, that's fine.
23 ACTING CHAIRMAN FROINES: Then it's in its
24 proper --
25 DR. BLANC: That's what I am suggesting,
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1 essentially.
2 ACTING CHAIRMAN FROINES: So we take out the last
3 sentence of one, and add a list of carcinogens that are
4 under three.
5 DR. FUCALORO: And I'm given to understand that
6 arsenic and nickel are probably organometallic type --
7 ACTING CHAIRMAN FROINES: No, no. There's --
8 DR. FUCALORO: I'm wrong about that? Nickel is in
9 what form just --
10 ACTING CHAIRMAN FROINES: It's a fume. It's a
11 fume. And that's why it was incorrect actually to list it
12 as a gas, because you just have to decide what you think is
13 the relationship between a gas and a fume.
14 DR. FUCALORO: I see.
15 DR. GLANTZ: Are you saying that what we would be
16 doing then is like in No. 3 saying there are many
17 carcinogens in diesel exhaust, and then list the ones that
18 are listed in the report?
19 ACTING CHAIRMAN FROINES: Yeah. Irrespective of
20 their gases or particle base.
21 DR. FRIEDMAN: I would suggest, though, that when
22 you do that, since that statement in No. 3 says possible,
23 probable, et cetera, that you distinguish, because someone
24 might conclude that 16 of the 17 are just possible. So I
25 think that you should set a definite, the probable and
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1 possible each listed separately.
2 ACTING CHAIRMAN FROINES: Right.
3 DR. BLANC: One other thing that would make it
4 clearer to the reader, because this was something that
5 confused me, I understand it now, but you've explained your
6 intent, would be actually since you want one section to be
7 about gases and the next one to be about particulates,
8 that's the intent, right? It would actually be clearer that
9 that's what you were doing if that's what we were doing if
10 point No. 1 was one sentence only, which was diesel exhaust
11 as a complex mixture of gases and fine particulates emitted
12 by diesel fuel internal combustion engine. And point two
13 would start the gases fraction is composed of, and then
14 everything else would be one number higher.
15 That would make it clearer, because the very first
16 sentence is what confused me, since that was a lead-in
17 sentence to talk about gases and fine particles. I never
18 would have realized it --
19 ACTING CHAIRMAN FROINES: How about another
20 suggestion, because I don't quite agree.
21 How about if we have 1 A, B?
22 DR. GLANTZ: I think you should have two.
23 ACTING CHAIRMAN FROINES: I think 1, 2 and what is
24 now 2 will become 3?
25 DR. GLANTZ: Yes.
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1 DR. BLANC: Yeah.
2 DR. FUCALORO: I think so. Because it lays out
3 the -- one says they're both gaseous and particulate, and
4 two and three and give you the gases and --
5 ACTING CHAIRMAN FROINES: That's fine. I don't
6 like one-sentence paragraphs.
7 DR. BLANC: I don't like bullet intros to
8 paragraphs that then don't talk about what the bullet intro
9 says.
10 DR. FUCALORO: Now that we handled these comments
11 on style, let's get back to the science.
12 DR. BLANC: John, I have one other, this is
13 actually just a very very minor thing.
14 In the former paragraph six, the very last
15 sentence, the sentence says it also excludes other routes of
16 exposure to diesel exhaust, such as ingestion and dermal
17 absorption, from deposition of diesel exhaust.
18 I almost wondered if there was a word missing
19 there or was that -- I wasn't sure what that comma was
20 supposed to make me --
21 DR. FUCALORO: As an extra comma.
22 DR. BLANC: Does that comma really need to be
23 there?
24 The dermal -- well, my question is is both the
25 dirt got the diesel from deposition and the dermal
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1 absorption is from deposition, right? So the deposition
2 refers to both of those things?
3 DR. KENNEDY: That sentence excludes other routes
4 of exposure to diesel exhaust from deposition to diesel
5 exhaust. That's the --
6 DR. GLANTZ: The deposition of diesel exhaust
7 should be deleted.
8 DR. FRIEDMAN: Change it to exposure to deposited
9 diesel exhaust, such as ingestion of dirt and dermal
10 absorption.
11 DR. BLANC: Yes. That would be clearer.
12 DR. GLANTZ: Can I say one other thing about that
13 one?
14 There were some stuff in the public comments about
15 the problems of water, of compounds from diesel getting into
16 water, and then being, you know, drank or drunk, or
17 whatever.
18 And you can correct my grammar, Paul.
19 I think it would be just worth just mentioning
20 that, that there's another of the things that we're
21 excluding is diesel exhaust that gets in through the water
22 supply.
23 There were two letters in the public comments, or
24 more than two, there was a bunch, talking about that. One
25 was from the Bay Area Water Control District, or something.
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1 You're looking very blank, John.
2 ACTING CHAIRMAN FROINES: No. I'm waiting for you
3 to make some recommendation.
4 DR. GLANTZ: I would just recommend, and you have
5 a list here where you're saying it also includes other
6 routes of exposure to diesel exhaust such as ingestion of
7 dirt, water and dermal absorption.
8 DR. FUCALORO: And I'd like to take the lead here,
9 because I think Gary had a sentence that I think can
10 incorporate your suggestion. So if you can repeat --
11 DR. FRIEDMAN: I just suggested taking off from
12 deposition of diesel exhaust and putting in the word
13 deposited before diesel, before diesel exhaust. So I'm not
14 sure how that would quite encompass Stan's concern.
15 DR. BLANC: All you have to do is insert the word
16 water after dirt. Dirt, water, and dermal absorption.
17 DR. FUCALORO: Why can't you have deposition?
18 DR. KENNEDY: The really key question here is not
19 necessarily the source, but the route of exposure, which is
20 the sentence. So routes of exposure include ingestion and
21 dermal absorption, and that's it. And you can eat it, you
22 can drink it, you can roll in it, and sort of there.
23 Beating the horse.
24 ACTING CHAIRMAN FROINES: Peter, where are you
25 making --
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1 DR. KENNEDY: The same sentence, that excludes
2 other routes of exposure as -- meaning noninhalants, to
3 diesel exhaust, such as ingestion and dermal absorption.
4 Period. End of discussion, end of sentence. It implicitly
5 includes any form of ingestion.
6 DR. BLANC: Dirt or water.
7 MS. SHIROMA: Gentlemen, along those lines,
8 Melanie was reminding me that crop ingestion is also another
9 key example. These were meant to be examples, but
10 Dr. Kennedy --
11 DR. GLANTZ: I like what Genevieve is suggesting.
12 ACTING CHAIRMAN FROINES: I'm still trying to get
13 it.
14 Such as ingestion of dirt?
15 DR. KENNEDY: Just ingestion.
16 DR. GLANTZ: Ingestion and dermal absorption,
17 period.
18 ACTING CHAIRMAN FROINES: Got it.
19 DR. KENNEDY: Source of the contamination is not
20 important. It's the route of it. It's the route of
21 application.
22 ACTING CHAIRMAN FROINES: Got it, Genevieve?
23 MS. SHIROMA: Got it.
24 DR. GLANTZ: The sentence would read it also
25 excludes other routes of exposure to diesel exhaust such as
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1 ingestion and dermal absorption, period.
2 That's what you were suggesting; right?
3 ACTING CHAIRMAN FROINES: You done?
4 DR. GLANTZ: I think that's fine.
5 DR. FUCALORO: Is there any other comment on this
6 issue?
7 If there isn't, we get back to Dr. Blanc who --
8 DR. BLANC: No. That's it.
9 DR. FUCALORO: You're finished with your comments?
10 MS. SHIROMA: Pardon me, Dr. Fucaloro. Sorry to
11 interrupt.
12 Just a protocol comment. Kirk has indicated for
13 members of the audience that there are extra copies of the
14 material that you're looking at now on the table.
15 And then also Kirk is reminding that the other SRP
16 members are now back from lunch and have been for some time,
17 just for the record, since we reconvened.
18 DR. FRIEDMAN: I have nothing to add on this part.
19 DR. FUCALORO: Good.
20 We'll go around to Dr. Glantz.
21 DR. GLANTZ: I'm happy now.
22 DR. FUCALORO: I'm sorry. I didn't hear you.
23 DR. GLANTZ: I have nothing more.
24 DR. FUCALORO: Nothing to add.
25 DR. WITSCHI: I was wondering, the first sentence,
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1 you describe the diesel engines --
2 DR. FUCALORO: I'm sorry. What you are looking
3 at?
4 DR. WITSCHI: No. 2. The first sentence, does it
5 still adequately describe new types of diesel engines?
6 DR. FUCALORO: That's a good question.
7 I guess, I certainly don't know the answer to that
8 and would call upon members of the ARB.
9 DR. WITSCHI: I recently talked to Joe Mauderly
10 and he told me, this isn't a quote, but when they did the
11 first diesel studies with the '81 engine they had, they had
12 to dilute the smoke to get about eight milligrams per cubic
13 meter. And they repeated the studies in '86 or '88 and the
14 new engine, and they just could use what came out of the
15 tailpipe for getting the same particle loads they had in the
16 previous study. And if he was going to use a modern today
17 engine, he would have to concentrate what they were coming
18 out of tailpipe.
19 So I'm really wondering with this statement that
20 release of particles at the rate of about 20 times greater
21 than from gasoline fueled vehicles if this is still true
22 with modern technology.
23 DR. FUCALORO: Go ahead.
24 MR. KRIEGER: Dr. Witschi, the 20 times greater
25 comes from at least the most recent study that we're aware
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1 of which examines early 1990 engines, and that was from
2 actually the World Health Organization report. That 20
3 times calculation came from that.
4 In our report we mentioned, and like you said,
5 it's true, the older engines have greater amount of
6 particles than the gasoline, they just didn't catch up in
7 technology yet, but we mention it's a 50 to 80 times greater
8 in the report, but generally it's 20 times a good number
9 right now for the current technology.
10 DR. WITSCHI: But the greatest, they way this
11 reads, this is a one-dimensional statement in a
12 multidimensional world.
13 DR. FUCALORO: How would you suggest changing it
14 or would you suggest eliminating it? I mean, you're
15 obviously critical of the statement. Can we modify it?
16 DR. WITSCHI: Well, this is clearly something that
17 has changed over times, and probably is going to change over
18 times too.
19 And in this describing diesel exhaust, those
20 changes that have been accomplished and those changes which
21 are going to occur should be acknowledged. As I said,
22 otherwise it becomes a one-dimensional statement, which does
23 not reflect reality.
24 DR. BLANC: Well, I have a suggestion that I think
25 that would address that.
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1 Part of that is covered in the later points, but
2 in terms of making it clearer, because later points are made
3 about the changing technology and so forth, but I think the
4 addition of the following phrase at the end of the first
5 sentence would perhaps address your concern, such that it
6 would read now at the very end of the sentence, on an
7 equivalent fuel energy basis, based on technology currently
8 in use, period.
9 DR. WITSCHI: I'm not so sure about current. He
10 said 1992. We have 1998.
11 DR. BLANC: Based on technology in use, widely in
12 use as of 1992.
13 DR. WITSCHI: Well --
14 DR. BLANC: I think --
15 DR. WITSCHI: There is an additional problem
16 there, and this is not only the progress in engine
17 technology, but the other problem of not as many changes in
18 the fleet as we could expect from changing technology.
19 Because many of these old clunkers, which are emitting more,
20 are still around, actually too many of them.
21 DR. BLANC: You're saying for many, it's more than
22 20?
23 DR. WITSCHI: Yeah.
24 DR. BLANC: I think the number 20 reflects an
25 average of old technology and new technology.
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1 DR. WITSCHI: What it's bothering me is this first
2 sentence simply doesn't describe the situation. It's much
3 more complex, and which eventually is coming to judge health
4 effects have to consider to some extent.
5 MS. SHIROMA: May we offer some suggested
6 language? And then Dr. Witschi's comment.
7 Again, the suggestion is one of the main
8 characteristics of diesel exhaust is the release of
9 particles at a relative rate of 20 times or greater than
10 from gas fuel vehicles, depending on -- dependent on the age
11 and operating conditions of the vehicles, because that's
12 essentially what the WHO report indicated, that it could be
13 up to 80 times, depending on the age and operating
14 conditions of the older --
15 DR. WITSCHI: I would agree with extrapolating
16 back up to 80 or whatever it is, but I'm not quite so sure
17 about the 20.
18 DR. FUCALORO: Do you want to avoid any specific
19 quantitative term or we can put in a hedge word, many
20 multiples of that from gasoline-powered vehicles. Would
21 that be better for you?
22 DR. WITSCHI: It might. I'm still not --
23 DR. FUCALORO: In some ways it seems to me in
24 reading the remainder of that paragraph, that first sentence
25 isn't that important to mention gasoline-fueled vehicles. I
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1 mean, except to mention that there's -- to indicate that
2 there's a large fraction of the exhaust is particulate
3 matter in diesel powered.
4 And then the second sentence the particles are
5 mainly aggregates of, and that's specific to diesel fuel.
6 So maybe that's the approach once you take that
7 it's recognized that a good portion of diesel exhaust is in
8 the form of particulate matter.
9 Then the particles are mainly aggregates, and so
10 on.
11 DR. FRIEDMAN: I think, though, that the
12 comparison with gasoline is worthwhile because people are
13 saying, there had been some comments, you know, why are you
14 picking on diesel exhaust, why don't you pick on all
15 exhaust.
16 So I find that some kind of comparison, whether
17 it's 20 times or something indicating a much larger rate of
18 particle formation --
19 DR. FUCALORO: But his point, of course, is that
20 the absolute quantitative amount is such a difficult thing
21 to nail down, because there are older vehicles, newer
22 vehicles, changes since 1990 something, whenever you had the
23 last measure. So one could then also say that it is a --
24 that the particulate matter is a large portion, much higher
25 than in gasoline-powered vehicles.
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1 ACTING CHAIRMAN FROINES: Why don't you just
2 say -- excuse me. Why don't we just say which is the
3 release of particles greater than from gasoline-fueled
4 vehicles on an equivalent fuel basis?
5 DR. FRIEDMAN: Would it be fair to say
6 considerably greater?
7 DR. BLANC: I would actually say at least in order
8 of magnitude greater, because even -- you know, even if
9 you're not happy with 20, I think that they --
10 DR. FUCALORO: At the minimum.
11 DR. BLANC: Ten is certainly giving you even more
12 of a fudge factor downward. So I would say that if we said
13 at least in order of magnitude it would put things in the
14 range that we're talking at a minimum.
15 ACTING CHAIRMAN FROINES: Let's do that.
16 DR. WITSCHI: The other thing is that might be a
17 bit off the wall, but the emphasis on particles puts
18 everything we think is bad about diesel, the particles, and
19 that's a fact I'm not convinced of.
20 DR. BLANC: I don't think that starting with
21 paragraph one gives that impression.
22 DR. WITSCHI: Okay.
23 DR. FUCALORO: It talks about both particles and
24 the vapor phase and this particular paragraph has to do with
25 the particulate matter.
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1 DR. BYUS: I think we do have to make some
2 comparison with the gasoline engine. Everyone accuses us of
3 picking on diesel. I mean, this is the reason. It's
4 explained in detail.
5 I would be in favor of using the word markedly
6 more, instead of just tenfold. I don't think you can put
7 any number. But I would say markedly more, and then leave
8 it at that.
9 I mean, you could say even that there has been a
10 number of attempts to improve the emissions of diesel
11 engines. Everybody knows this. If we want to put something
12 in the findings, because they have, I mean, later on they
13 mention it. But I would say just markedly more particles.
14 ACTING CHAIRMAN FROINES: I want to go back and --
15 DR. FUCALORO: Can I get closure on this?
16 Do you think do you have the wording that
17 represents that?
18 MS. SHIROMA: Yes. One of the main
19 characteristics of diesel exhaust is the release of
20 particles at a markedly greater rate than from
21 gasoline-fueled vehicles --
22 DR. FUCALORO: On an equivalent fuel basis.
23 MS. SHIROMA: On an equivalent fuel energy basis.
24 DR. FUCALORO: Does everyone find that acceptable?
25 ACTING CHAIRMAN FROINES: I thought it was -- is
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1 the release or particles at least in order of magnitude
2 greater than from gasoline-fueled vehicles?
3 DR. FUCALORO: That was the previous suggestion by
4 Paul. But Craig has said -- wants to go to back to the less
5 quantitative statement and used the word markedly greater.
6 My own preference, I don't have a preference. I
7 think both are fine, as far as I can tell, but so I'm
8 willing to accept either one, but if any of you --
9 DR. FRIEDMAN: Is there any concern that it could
10 be less than tenfold greater?
11 Hanspeter, is it --
12 DR. WITSCHI: Yeah. According to what some people
13 telling me is that today's 1998 diesel engines approximate
14 internal combustion engines with regard to what's coming out
15 of the tailpipe.
16 DR. FRIEDMAN: Then I guess I would stick to
17 markedly.
18 DR. FUCALORO: Then I go with Craig.
19 DR. WITSCHI: It's something that really would
20 have to be checked into.
21 ACTING CHAIRMAN FROINES: I think we should draw
22 this to closure.
23 DR. FUCALORO: I think we have.
24 Do we all agree on Craig's wording, that is to say
25 markedly greater? Okay.
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1 ACTING CHAIRMAN FROINES: I want to go back to one
2 for a second, where we say volatile hydrocarbons, aldehydes,
3 et cetera.
4 I want to have it changed to be volatile organics
5 such as aromatics, butadiene, benzene, formaldehyde as
6 example, because volatile hydrocarbons is not a sufficient
7 descriptor of the gaseous compounds.
8 You can say, you can include hydrocarbons, but I
9 think we need to show that there are other volatile
10 hydrocarbons, aromatics, alkenes, such as volatile
11 hydrocarbons, alkenes, aromatics, aldehydes and low
12 molecular weight polycyclic or aromatic compounds.
13 DR. FUCALORO: Any comments on that suggestion?
14 If it's -- if not, if it's been recorded, we'll
15 move on.
16 ACTING CHAIRMAN FROINES: Peter, you done?
17 DR. WITSCHI: I'm done.
18 ACTING CHAIRMAN FROINES: Everything?
19 DR. FUCALORO: We have another Peter.
20 ACTING CHAIRMAN FROINES: One through ten.
21 DR. KENNEDY: I have one small change, since we're
22 talking levels of comfort.
23 On the last line, become trapped into is
24 grammatically incorrect. I would suggest trapped within the
25 small airways and alveoli of the lungs. Anatomically, small
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1 airways is a better term.
2 DR. FUCALORO: I'll defer to your knowledge on
3 that.
4 ACTING CHAIRMAN FROINES: Go ahead.
5 DR. FUCALORO: Did you record that?
6 Any comment on that?
7 I come back to you, John, do you wish to make any
8 comment?
9 This is your construct, so I guess maybe you're
10 pleased with that.
11 Okay. Again, this is my first go-around at this
12 sort of thing.
13 Are my duties completed or do I need to --
14 ACTING CHAIRMAN FROINES: You're done.
15 DR. FUCALORO: I'm done. Thank you.
16 ACTING CHAIRMAN FROINES: Thank you very much.
17 Okay. Now, we'll get down to the hopefully
18 easiest part of the discussion. We want to go over now the
19 health effects associated with diesel exhaust.
20 I am the lead, so I'll take the lead on going
21 through it.
22 I just want to say that as far as I was concerned,
23 the document dealt, as far as my reading, with both animal
24 and human acute effects of diesel. The document deals with
25 chronic, again animal and human effects of diesel. The
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1 document deals with immunologic effects, animal and human.
2 It has some discussion of mortality of non-cancer effects.
3 It deals in animals and humans with respect to genotoxicity.
4 It addresses bioavailability, which is a very important
5 issue.
6 I should say that we're doing a lot of work now on
7 chromium where we're finding in fact that particles are not
8 bioavailable, and so in some cases with some substances you
9 have real significance with respect to carcinogenicity.
10 And finally, the document deals with lung cancer.
11 Now, I've left out some other categories, like
12 reproductive effects, developmental effects, bladder cancer,
13 because those the document concluded there was not
14 sufficient evidence, although it may have hints of evidence
15 to focus health effects discussion on those.
16 So that the ones, the list I just went through,
17 represent those effects, those health effects that the
18 document addresses that they consider significant within the
19 context of identifying diesel exhaust as a toxic air
20 contaminant.
21 So we have the obligation now to determine
22 whether, in terms of finding this as a toxic air
23 contaminant, whether or not the State has met the burden of
24 proof or the quality within the context of those subject
25 areas.
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1 So it seems to me that perhaps one of the first
2 things we can address within the context of the health
3 effects part of the findings is those areas where we --
4 there is evidence for health effects.
5 And I'll go around the room and I'll start with
6 Craig Byus again and come back to finish with Tony.
7 DR. BYUS: Yeah. I have minimal comment on this
8 as well. I find after the last meeting I had all the issues
9 I had cleared up and I think it's written quite well in
10 terms of the in vitro and in vivo data. I'm very pleased
11 with it.
12 ACTING CHAIRMAN FROINES: We love those kinds of
13 comments.
14 DR. FUCALORO: The author loves those type of
15 comments.
16 DR. BLANC: One of the things that struck me
17 throughout those discussions in the focus on the
18 carcinogenic issues associated with diesel exhaust has been
19 the relative back burner that non-cancer risk has had to
20 take, and it's partly driven by the requirements for
21 quantitative attempts and quantitative risk assessment, I
22 realize, and how that kind of risk assessment gets even more
23 complicated dealing with non-cancer outcomes.
24 I believe that even absent any evidence of
25 carcinogenicity, which is overwhelmingly convincing for
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1 this, that this would be a toxic air contaminant on the
2 basis of its non-cancer health-related effects.
3 I don't think we need to say that explicitly, but
4 what I would like to see, I think, in the current number,
5 14, which will I guess change to 15 as all the numbers get
6 inflated by one, is a statement which might say something
7 like it should be recognized that this reference exposure
8 level may need to be lowered further as quantitative data
9 emerge on the potential adverse non-cancer effects from
10 diesel exhaust in the future.
11 ACTING CHAIRMAN FROINES: Paul, can you say that
12 again slowly. It should be recognized that --
13 DR. BLANC: It should be recognized that this REL
14 may need to be lowered further as quantitative data emerge
15 on potential adverse non-cancer effects from diesel exhaust.
16 Because I think this is an area --
17 ACTING CHAIRMAN FROINES: To be lowered further?
18 DR. FUCALORO: I would get rid of the word
19 further, wouldn't you, Paul.
20 DR. BLANC: Lowered, okay, as quantitative data
21 emerge on potential adverse non-cancer effects from diesel
22 exhaust.
23 ACTING CHAIRMAN FROINES: So that would be added
24 to 14?
25 DR. BLANC: Yeah, the end of it.
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1 ACTING CHAIRMAN FROINES: I don't see anybody
2 standing up and protesting.
3 DR. BLANC: This is also just a question about are
4 we discussing all the rest of the points?
5 ACTING CHAIRMAN FROINES: Yes.
6 DR. BLANC: Or just the points related to --
7 because there's some summary points at the end.
8 ACTING CHAIRMAN FROINES: Well, I think what we
9 should do is we should be going through the points that you
10 have in your head as things you want to address. As we get
11 all around and there are points that are not yet addressed
12 we should take that up then.
13 But you can only do what you can do, and others
14 will presumably raise other points and then we'll have to go
15 back and look at the document overall.
16 DR. FUCALORO: What Paul was just suggesting that
17 items 20 through 22 are a summary.
18 ACTING CHAIRMAN FROINES: We'll have to go back to
19 those.
20 DR. BLANC: Okay.
21 ACTING CHAIRMAN FROINES: So in a sense we're
22 trying to deal with everything in a sense leading up to
23 that.
24 DR. BLANC: Right.
25 ACTING CHAIRMAN FROINES: If everybody agrees with
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1 everything that leads up to that, then that pretty much
2 makes those last points they follow presumably, but we'll
3 see.
4 DR. BLANC: Okay.
5 DR. FRIEDMAN: I thought that these were very well
6 done, but I have one suggestion for the item that's
7 currently numbered 16.
8 There's a sentence that seems to be trying to
9 combine two ideas and it sounds like a non sequitur.
10 OEHHA analyzed the lung cancer findings for
11 consistency and found that the association was unlikely to
12 be due to chance.
13 I think that should be, if I understand it
14 correctly, it should be restated that OEHHA found the lung
15 cancer findings to be consistent and found that the
16 association was unlikely to be due to chance.
17 There's two different things going on there.
18 ACTING CHAIRMAN FROINES: OEHHA found the lung
19 cancer findings --
20 DR. FRIEDMAN: To be consistent.
21 ACTING CHAIRMAN FROINES: And found the
22 association was unlikely due to chance?
23 DR. FRIEDMAN: Right.
24 DR. FUCALORO: Making it a compound sentence.
25 DR. FRIEDMAN: There's two things.
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1 My only concern now with that change, and I don't
2 have a better suggestion at this point, is there's the
3 found, findings and findings. There's too many -- maybe you
4 can say concluded, OEHHA concluded that the findings were
5 consistent.
6 DR. FUCALORO: I find it to be fine.
7 DR. GLANTZ: Actually, though, these are really
8 our findings, not OEHHA's findings, so I would suggest that
9 we leave OEHHA out of it and just say the lung cancer
10 findings are consistent and unlikely to be due to chance.
11 DR. FRIEDMAN: That will be fine.
12 ACTING CHAIRMAN FROINES: Lung cancer findings are
13 consistent and the association --
14 DR. GLANTZ: Is unlikely to be due to chance.
15 ACTING CHAIRMAN FROINES: Is unlikely to be due to
16 chance.
17 You have to remember that Stan is pretty good at
18 this kind of thing, for those of you who don't remember the
19 lead day.
20 DR. GLANTZ: Halloween.
21 DR. FRIEDMAN: That's all I have.
22 ACTING CHAIRMAN FROINES: Okay. Stan, we never
23 assume that you will have quite the succinctness that Gary
24 and Paul --
25 DR. GLANTZ: I just have a couple of things.
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1 No. 16, I think the last sentence of No. 16 should
2 be moved to No. 15.
3 And then in No. 18 -- well, let me, just before I
4 comment on No. 18, I think that the --
5 ACTING CHAIRMAN FROINES: You're saying that the
6 last sentence in 16 should --
7 DR. KENNEDY: Is not a epidemiologic study. It's
8 animal information.
9 ACTING CHAIRMAN FROINES: Good.
10 DR. GLANTZ: Belongs with No. 15.
11 DR. KENNEDY: Can I expand on that just a moment?
12 Because I think there are a lot of conflicting
13 animal data, even though this is clearly positive, and is
14 there any responsibility to note that there are
15 species-specific differences or that any issue of
16 transference of mechanism needs to be considered?
17 It gets a little messy, but I think it is the
18 responsible thing to do.
19 ACTING CHAIRMAN FROINES: Peter, were you going to
20 say something about that?
21 DR. WITSCHI: No. Well, I really -- no, I don't
22 think so.
23 First of all, we have only three animal species
24 where this thing has really been tested, out of one -- which
25 one, the hamster, never gets lung cancer from any
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1 inhalation. So that's the one thing.
2 DR. KENNEDY: Mice where this doesn't really
3 happen --
4 DR. WITSCHI: In mice it does happen, yes, in
5 some, but the evidence is not all that good and all that
6 consistent.
7 ACTING CHAIRMAN FROINES: It would be interesting,
8 because I feel that the mouse issue is unresolved. I think
9 there are definitely positive studies, and it's very
10 dangerous to take a well-constructed animal study,
11 specifically with mice, and find positive results and then
12 draw a conclusion that there's no evidence in mice.
13 I think that if we went back and did similar
14 studies with mice it would end up being positive. But I'm
15 not arguing that.
16 So I think mice is one of the missing areas in
17 this whole toxicologic investigation, but we're stuck with
18 the data that we have, so we could say further animal
19 research is relevant, but nobody is going to want to do it.
20 So one could say something about -- you could say
21 although the mechanisms by which diesel exhaust induces lung
22 cancers in the rat are not certain, but there may be some
23 species specificity associated, but then we are making -- we
24 as a panel are making a decision about a mechanism and this
25 is a bit more neutral.
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1 I'm not sure the panel wants to make that --
2 DR. WITSCHI: I'm not sure what you mean.
3 ACTING CHAIRMAN FROINES: What I'm saying is if we
4 say something, if we hint anything about overload or
5 Mikaylas Menton clearance processes or any of that, we're
6 actually entering into the discussion of the mechanism, and
7 it seems to me that we probably don't want to do that.
8 And if you're the person that's shaking your head
9 no, then I'm happy, because you're the most knowledgeable in
10 that respect.
11 DR. WITSCHI: Because if you're going down that
12 route, you're going to find out that mice are unique too,
13 the way they handle butadiene.
14 ACTING CHAIRMAN FROINES: I think Peter and I
15 agree on one thing in the world, and that is butadiene is an
16 important chemical.
17 DR. BLANC: Dr. Kennedy, I'm not sure where we are
18 at this point. There's been some back and forth.
19 Are you satisfied with just moving the sentence as
20 is?
21 DR. KENNEDY: I am --
22 DR. BLANC: Do you still want to say something
23 additional?
24 DR. KENNEDY: I'm happiest with just moving it up.
25 And maybe the mechanism by which diesel exhaust
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1 induces lung tumors is not certain. One could simply remove
2 that clause.
3 DR. WITSCHI: Could we just add results of
4 inhalation bioassays in the rat and with lesser certainty in
5 mice have demonstrated the carcinogenicity.
6 ACTING CHAIRMAN FROINES: Say it again, Peter.
7 DR. WITSCHI: Results of inhalation bioassays in
8 the rat and with lesser certainty in mice have demonstrated
9 the carcinogenicity of diesel exhaust in test animals.
10 DR. KENNEDY: I'm happy with that.
11 DR. FUCALORO: If you put in the phrase with test
12 animals.
13 ACTING CHAIRMAN FROINES: Read it to me again.
14 I'm sorry.
15 DR. WITSCHI: Result of inhalation bioassays in
16 the rat and with lesser certainty in mice have demonstrated
17 carcinogenic potential of diesel exhaust in animals.
18 ACTING CHAIRMAN FROINES: You want to keep the
19 sentence about mechanism in still?
20 DR. BLANC: No. He wanted to delete those.
21 DR. BYUS: Is everybody convinced then that
22 diesel, all -- I mean that the diesel exhaust
23 carcinogenicity in rats cannot be explained by the particles
24 alone? That's the question.
25 ACTING CHAIRMAN FROINES: Wait. Let me just deal
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1 with the factual.
2 Peter, are you taking out --
3 DR. WITSCHI: Take out the second sentence.
4 DR. BYUS: You see what I'm saying, I like the
5 idea of the uncertain mechanism in a sense what we're
6 saying, I mean my interpretation of that data was that much
7 of the carcinogenicity, I would say much, not at all, but
8 much of it in the animal data, the rat data, is explained by
9 particle overload and the particles themselves, not
10 necessarily. And so that eliminate diesel exhaust as being
11 positive, simply the particles at very very high doses.
12 ACTING CHAIRMAN FROINES: I don't think the
13 evidence --
14 DR. BYUS: That's what I'm asking everybody.
15 ACTING CHAIRMAN FROINES: I think what happens
16 sometimes in science is that people want a hypothesis to
17 work out to be the correct hypothesis, so the research that
18 gets done gets emphasized in that area.
19 There's a lot of research on animals that hasn't
20 been done. So in a sense what Joe Mauderly, who is a very
21 fine scientist, has done, though, has focused his research,
22 thereby leaving a bunch of questions unanswered.
23 So the role of more semantic cell mutation, the
24 role of nitro-PAH carcinogenicity as is yet unresolved. It
25 may not be important. It may be important.
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1 I think it's important.
2 DR. BYUS: So do I.
3 ACTING CHAIRMAN FROINES: I think there are others
4 that do.
5 So I think what we have now is we have a body of
6 literature which is holding a place, but it doesn't mean
7 it's holding the answer. It's just holding the place.
8 And so I'm not ready to say, yes, because you've
9 got titanium dioxide and carbon and diesel and they all look
10 about the same, that therefore the answer that follows is
11 true. I don't agree with that.
12 And I think what we're going to see as we go
13 forward is that both mechanisms are going to be playing a
14 role.
15 DR. BYUS: I agree with you.
16 What I'm asking you is does the animal data in
17 rats demonstrate that diesel exhaust is a carcinogen?
18 That's what we're saying, does it demonstrate it?
19 And I'm not sure that it demonstrates it.
20 ACTING CHAIRMAN FROINES: I think two things.
21 One, I think there is one piece, one biological
22 issue that's important, and that is that diesel produces
23 cancers in mice, it appears, in rats and in humans.
24 Now, you can go through each one of those and find
25 reasons why any one of them are not true, but I think that
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1 you have to take seriously the fact that you have three
2 species that have cancer from a similar exposure.
3 That, by itself, is important, I think, whatever
4 the single species arguments and all that.
5 But that doesn't -- just one more point.
6 So but put that aside.
7 All I'm saying is with respect to the rat it
8 appears that the mechanism of the carcinogenicity in the
9 lung of the rat could change depending upon the dose that
10 the rat receives. And that is the high dose may have a
11 mechanism different than what you might find at a low dose.
12 DR. WITSCHI: Address your concern about has it
13 been demonstrated, I mean if you look at carcinogenesis, and
14 particularly inhalation assays in general, the diesel is
15 really almost the only confounder. We have gotten almost
16 identical results in at least three or four or five
17 different labs. In all those labs they produced lumps and
18 to me it has unequivocally --
19 DR. BYUS: But some of the particles, that's the
20 point. And this is the point, clearly.
21 So you're then you have to say is it the particles
22 or is it the diesel exhaust itself with the carcinogens.
23 You can't ignore that when you say demonstrate.
24 That's what I'm getting at. That why I'm trying to say is I
25 liked your attempt at qualifying that statement with the
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1 mechanism. In a sense now we take that mechanism statement
2 out, we're -- I mean, I'm less comfortable with it in a
3 sense.
4 I agree with everything you say, but I just I
5 think you can't get away from that point. It could be the
6 particles themselves. The animal experiments, could it all
7 be explained by particles, that's -- I'm not sure that it
8 couldn't be, but certainly in rats it could be.
9 DR. WITSCHI: Well, you --
10 DR. BYUS: The other animals I'm less sure.
11 DR. WITSCHI: If you listen carefully to Joe, he
12 never said that he doesn't believe diesel does the cancer,
13 probably one of those mechanisms Joe alluded to.
14 All he said really was this particular mechanism
15 or because it's a particular mechanisms which produced
16 apparently those lumps in rat, we should not use this for
17 the human situation. That's all he says. He never said
18 that he didn't believe diesel was not carcinogenic.
19 ACTING CHAIRMAN FROINES: In fact he does. He was
20 asked at a meeting I chaired and in fact he acknowledged
21 that it was a carcinogen.
22 So that then we also have the issue going back to
23 our favorite chemicals of things like benzene, formaldehyde,
24 acetaldehyde, butadiene, that there are things besides
25 particles that people breathe that do cause lung cancer, and
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1 so it's entirely possible that when you're breathing all
2 these gaseous compounds that are carcinogens, they may be a
3 source of cancer that does not have anything to do with
4 overload.
5 DR. BYUS: I have no doubt. I have no doubt about
6 that, but I'm saying the data -- all I'm saying the data as
7 it's done in the rats could all be explained by the
8 particles.
9 ACTING CHAIRMAN FROINES: Well, let's go back to
10 the action item, as opposed to a discussion item.
11 Would you prefer we left in that phrase because --
12 DR. BYUS: Yeah, I like -- but I'll --
13 ACTING CHAIRMAN FROINES: We can leave it in
14 unless anybody strongly objects.
15 DR. FRIEDMAN: Could you point it out again. I've
16 lost it.
17 ACTING CHAIRMAN FROINES: It says the sentence now
18 reads --
19 DR. FRIEDMAN: What item is this?
20 ACTING CHAIRMAN FROINES: Item 16, page four.
21 Results of inhalation -- and it's been moved up to
22 15. Results of the inhalation bioassays in the rat and with
23 lesser, something, certainty in the mice, have demonstrated
24 the carcinogenicity of diesel exhaust in animals, although
25 the mechanisms by which diesel exhaust induces lung tumors
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1 in the rat are not certain.
2 DR. WITSCHI: Actually you should really just, to
3 be honest in saying the mechanisms by which diesel exhaust
4 induces lung tumors in animals.
5 ACTING CHAIRMAN FROINES: Okay.
6 DR. WITSCHI: Remains uncertain.
7 ACTING CHAIRMAN FROINES: That's better.
8 DR. FRIEDMAN: Doesn't that agree with you, Craig?
9 DR. BYUS: It does. That's why I liked it in
10 there. I don't disagree with what everybody is saying, I
11 just want to make sure that we don't -- it is important.
12 ACTING CHAIRMAN FROINES: Back to you, Stan.
13 DR. GLANTZ: In No. 18 -- before I comment on the
14 change, I think we should make there, one change I think
15 should be made to Part B of the report is that in Chapter 7
16 the quantitative risk assessment, I really think the
17 assessment based on animal data gets in the way of the
18 report.
19 Several of the commenters took exception to it.
20 And we don't use it in the end and I think it's
21 very confusing.
22 And what one thing I would suggest is that the
23 part that the sections in Chapter 7 that deal with the
24 animal risk assessment be moved to an appendix to get them
25 out of the way.
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1 And that the animal risk assessment numbers that
2 are in the figure, I think it's figure 7-10, be taken out of
3 that figure.
4 I think if OEHHA wants to present the results of
5 the calculations for people's information that's -- I don't
6 have a problem with that, although -- but I really think it
7 makes the report hard to follow.
8 And I think the criticisms of the use of the
9 animal numbers that came in and the comments were well
10 taken, especially since the human data, I think, is better.
11 So having made that suggestion, I would change No.
12 18 by deleting the first two sentences.
13 ACTING CHAIRMAN FROINES: Wait, wait, wait.
14 Are you suggesting, are you making a
15 recommendation before you get to 18?
16 DR. GLANTZ: Yeah.
17 ACTING CHAIRMAN FROINES: That the animal stuff
18 gets moved to an appendix.
19 DR. GLANTZ: The animal stuff in Chapter 7.
20 ACTING CHAIRMAN FROINES: George, what do you
21 think?
22 DR. ALEXEEFF: It's okay.
23 DR. FUCALORO: It's my impression that the animal
24 material was in that chapter historically because I think
25 you were using those data for your risk assessment, then
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1 when you decided not to, the material remained in that
2 chapter. I think it should be set aside, perhaps in an
3 appendix.
4 DR. GLANTZ: I wouldn't be that unhappy to see it
5 disappear entirely.
6 ACTING CHAIRMAN FROINES: Anyone disagree with
7 that move?
8 DR. KENNEDY: No. I think it's a good idea.
9 ACTING CHAIRMAN FROINES: Peter is a plus. Peter
10 2 is a plus. And then plus. And then there's clearly
11 support from the non --
12 DR. BLANC: Well --
13 DR. GLANTZ: I'm not saying delete it.
14 DR. BLANC: No, no. I think that the appendix
15 proposal is more useful.
16 And in the same vein, the last iteration of the
17 draft document appeared before the EPA February '88
18 document, and I wonder -- '98 document -- I would wonder
19 whether or not in that same appendix you could then comment
20 on the EPA mouse-based risk guesstimation as a -- you can
21 put that in there too, and then you would at least be
22 alluding to that. I don't feel strongly about that.
23 ACTING CHAIRMAN FROINES: That's a good idea. I'd
24 support that.
25 DR. BLANC: By the way, I think that's another
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1 reason why it's good to get mice into that other phrase that
2 we put them in, because after all, being used by the --
3 ACTING CHAIRMAN FROINES: George, you know what's
4 being said?
5 DR. MARTY: EPA's lower end of the range.
6 DR. ALEXEEFF: There's just one clarification.
7 We don't believe there is a mouse-based risk
8 estimate in the US EPA document. It is a rat-based --
9 DR. BLANC: Is that an error then in their text?
10 DR. FUCALORO: I thought they said rat-based, but
11 I could be wrong.
12 ACTING CHAIRMAN FROINES: Well, Stan --
13 DR. GLANTZ: I'd like to say, because we want to
14 approve the report today, and I don't want to get
15 something -- open up a substantive thing which could then
16 cause trouble, if it's an editorial change that the chair
17 can approve on the panel to put a comment in on the EPA
18 report, I don't care one way or the other.
19 But I think the important point is to move the
20 stuff in Chapter 7 dealing with animal-based risk assessment
21 into an appendix and make it clear, as several of the
22 commenters suggested, that this is being presented for
23 information and comparison purposes with other studies, but
24 the risk assessment doesn't use the animal.
25 ACTING CHAIRMAN FROINES: George, listen. You and
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1 Stan stop doing that. The action item is that you're moving
2 the material on animals into Chapter 7.
3 DR. GLANTZ: No.
4 ACTING CHAIRMAN FROINES: Into the appendix.
5 DR. GLANTZ: The animal material in Chapter 7.
6 ACTING CHAIRMAN FROINES: Let me do this. I can
7 do it fine.
8 The second thing we would like you to do is to
9 look at the EPA risk assessment and look at the discussion
10 of the mouse data and whether it's included in the risk
11 assessment.
12 If there's particularly relevant information that
13 you think is worth commenting on, then do so in that
14 appendix.
15 And if you think there are major policy or science
16 questions that need to come back to the panel, do so, but
17 try and not do that.
18 DR. GLANTZ: No, no.
19 I would like to amend -- no, no. I would like to
20 say if there are major policy or scientific issues, don't
21 put them in the report. I don't want to have to go back
22 and --
23 ACTING CHAIRMAN FROINES: Well, those of us who
24 believe in mice are more oriented towards having it in there
25 if we can. So, George and I will communicate on this and
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1 we'll communicate and if we need a -- if it --
2 DR. GLANTZ: I would say if it has to come back --
3 if it can be done and it's simply an editorial thing, that I
4 don't care.
5 But I think if it's something of sufficient
6 magnitude that would have to come back to the panel, I would
7 argue not to put it in.
8 ACTING CHAIRMAN FROINES: I think that if we find
9 something that's significantly important it should come back
10 to the panel, because we would rather not somebody on the
11 outside sue us and force us to do the same thing.
12 Let's handle it appropriately. And I guarantee
13 that 95 -- 99 percent of the chance is that you'll never see
14 it again.
15 DR. GLANTZ: Okay.
16 DR. FRIEDMAN: If it has to come back to the panel
17 will there have to be another public comment period?
18 ACTING CHAIRMAN FROINES: Yeah. You guys are
19 escalating, aren't you?
20 DR. GLANTZ: I think that if you can --
21 ACTING CHAIRMAN FROINES: We can handle this.
22 We'll make a recommendation.
23 DR. GLANTZ: I will accept what you're suggesting
24 with the caveat that if it has to come back to the panel,
25 you won't do it.
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1 MS. SHIROMA: Could I get a clarification on this?
2 From listening to the discussion it sounds like
3 you would like the information moved in Chapter 7 to the
4 appendices, and then to add some clarification on what the
5 US EPA did?
6 ACTING CHAIRMAN FROINES: No. To review what US
7 EPA did and determine if there's any information that would
8 be germane to that section.
9 DR. GLANTZ: Actually, I don't like that, because
10 I want -- I think there's a point where you have to finish.
11 And what I'm -- and I think that's just a
12 different point.
13 What I'm -- what I want to do -- and this is
14 getting off the point talking about mice and rats. What
15 I -- the reason I'm making the suggestion is because I want
16 to make it very clear that the risk assessment is based on
17 the human data. And I really think the animal-based risk
18 adjustment just gets in the way. The human data are
19 clearer, the human data are more germane to humans, the
20 quantitative risk assessment is simpler.
21 ACTING CHAIRMAN FROINES: But wait. Let me speak
22 to that. I think it's very --
23 DR. GLANTZ: I'm not saying delete it from the
24 report.
25 ACTING CHAIRMAN FROINES: Come on, Stan, let me
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1 finish.
2 I think you're right in every respect, except for
3 the fact that major mechanistic issues, specifically around
4 interspecies variability, has been raised.
5 There is some quite important scientific issues
6 that diesel has raised around animal testing.
7 If there is something in the EPA document that
8 helps illuminate that issue, then I think as a matter of
9 science we have an obligation to incorporate that.
10 And it may be more troublesome, but I think this
11 is not simply a regulatory process. This is a risk
12 assessment where we try and look at all the data and we try
13 and look at how the data and animals relates to humans.
14 And I think that by simply saying the human data
15 is better is to misunderstand some of the complexities of
16 the mechanistic issues around the animals.
17 So I would still argue that if there's something
18 in there that's useful, it could be put in, and if it -- and
19 I suspect it won't have to come back, because it can be done
20 as a quote. It could be kind of done as a quote from the
21 EPA document. It's not something that George is going to
22 write some new creative thing from. So it shouldn't be a
23 problem at all.
24 DR. GLANTZ: Okay. Then I will stop.
25 Getting back to No. 18, what I would do then is I
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1 would delete the first three sentences of the paragraph and
2 then so that the first sentence of the paragraph would read,
3 there are data from human epidemiological studies of
4 occupationally exposed population which are useful for
5 quantitative risk assessment.
6 And then I would delete everything down to where
7 it says based on a variety of exposure scenarios. The range
8 of resulting estimates of cancer risk, and then I would
9 insert in parentheses, upper 95 percent confidence interval,
10 or whatever it was you had on the slide, which was clearer.
11 And then I would delete the last sentence, because
12 I think that the Table 3 that you provided, which while very
13 interesting, should be incorporated into the report, not the
14 findings.
15 And I think you should incorporate that Table 3
16 into the report with the other additions that you showed us
17 today, the Steenland study and other study.
18 And then I would add a reasonable point estimate
19 of the unit risk is 4 times 10 to the minus 4.
20 So the paragraph would read --
21 ACTING CHAIRMAN FROINES: I'm sorry. Could you go
22 over your changes.
23 DR. GLANTZ: First three sentences are out.
24 And then the next sentence stays.
25 And then beginning with --
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1 DR. BLANC: Which is the next sentence?
2 DR. GLANTZ: The next sentence which says there
3 are data. That stays.
4 And then from on balance down to where it says
5 population due to diesel exhaust, I would delete. It's the
6 third-from-the-bottom line.
7 DR. FUCALORO: Including population, including the
8 sentence in which that --
9 DR. GLANTZ: Yeah. I would delete everything down
10 to where it says based on a variety.
11 And then after cancer risk, in parentheses, I
12 would put, 95 percent upper confidence interlevel, or
13 however it was on the slide they showed.
14 And then I would delete the last sentence and add
15 the sentence, a reasonable point estimate of the unit risk
16 is 4 times 10 to the minus 4.
17 ACTING CHAIRMAN FROINES: Are you subtracting out
18 a comparison of estimates of risk can be found in Table 3?
19 DR. GLANTZ: Yeah. I would take that out.
20 ACTING CHAIRMAN FROINES: No. I disagree strongly
21 with that.
22 DR. GLANTZ: Table 3, I think that should go in
23 the report. I mean --
24 ACTING CHAIRMAN FROINES: I see. You're saying --
25 DR. GLANTZ: I think Table 3 should be in the
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1 report.
2 ACTING CHAIRMAN FROINES: No. I think it should
3 be in the report and I think it should be in our findings.
4 Because our findings show the range of risk assessments that
5 have been conducted, and I think I'm going to present this
6 to the Board and I want to have that table in front of me,
7 because I want to show them the breadth of -- it doesn't do
8 any harm to have a table that shows the breadth and the
9 scope of the risk assessments.
10 DR. GLANTZ: All right. I just think -- all
11 right.
12 I mean, but in any event it should be in the
13 report.
14 ACTING CHAIRMAN FROINES: No doubt.
15 DR. GLANTZ: With those other two studies. I
16 think it gets in the way here, but I'll defer to you.
17 ACTING CHAIRMAN FROINES: So you're at the crucial
18 point.
19 DR. GLANTZ: No. 18 would read the following.
20 There are data from human epidemiological studies
21 of occupationally-exposed populations which are useful for
22 quantitative risk assessment. Based on a variety of
23 exposure scenarios, the range of resulting cancer -- or
24 resulting estimates of cancer risk, parentheses, 95 upper
25 confidence interval, is 1.3 times 10 to the minus 4, to 2.4
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1 times 10 to the minus 3, Table 2. A reasonable point
2 estimate of the unit risk is 4 times 10 to the minus 4. A
3 comparison of estimates of risk can be found in Table 3, if
4 you really want it.
5 DR. BYUS: You better say lung cancer.
6 DR. GLANTZ: Yeah, lung cancer. I agree with
7 that.
8 ACTING CHAIRMAN FROINES: George, before we get
9 into the more difficult question, when we go through and
10 have Kyle Steenland's and Stayner's document and Kathy
11 Hammond's work with the meta-analysis and Allan Smith's
12 work, those are four new pieces of information, does the
13 range of risk stay to be to these values or will they
14 include any of the -- will those all fall within this range
15 or does the range change based on those four values?
16 DR. ALEXEEFF: They all fall within the range.
17 ACTING CHAIRMAN FROINES: They do.
18 DR. ALEXEEFF: Yes. Based on what was suggested
19 earlier for in terms of the -- we did preliminary
20 calculations following Dr. Blanc's suggestion, and that
21 would stay within the range.
22 ACTING CHAIRMAN FROINES: So that with Allan
23 Smith, Kyle Steenland, Les Stayner, Allan Smith, those four
24 new values that are not based on Garshick, they're not based
25 on Garshick, they would all stay within this range as you've
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1 defined it. That's a yes or no question.
2 DR. ALEXEEFF: The answer is yes.
3 ACTING CHAIRMAN FROINES: The answer is yes?
4 DR. ALEXEEFF: Yes.
5 ACTING CHAIRMAN FROINES: You're comfortable with
6 that?
7 And you understand what I'm now saying is that the
8 range of risk in our Table 3, the range of risk that we list
9 will include those values?
10 DR. ALEXEEFF: Right.
11 ACTING CHAIRMAN FROINES: And we will be -- we
12 will see that they are similar? George?
13 DR. ALEXEEFF: Uh-huh.
14 ACTING CHAIRMAN FROINES: And that you can put a
15 sentence in to say these four values taken with the Garshick
16 data are essentially internally consistent.
17 I'm trying to get a weight of evidence here. Do
18 you understand I'm trying to --
19 DR. ALEXEEFF: Yes.
20 ACTING CHAIRMAN FROINES: I'm trying to show it's
21 not all Garshick.
22 DR. BLANC: Can you tell me, following up on
23 John's comment, if you use the value of 250 micrograms in
24 the algebraic calculation based on the pooled relative risk
25 of 1.4, what that midpoint is?
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1 DR. ALEXEEFF: Yeah. The new point would be 2.6
2 times 10 to the minus 4.
3 DR. BLANC: Would be that value.
4 ACTING CHAIRMAN FROINES: Okay. But I'm not --
5 wait. I'm coming to you. But I want to make sure that I'm
6 clear.
7 DR. ALEXEEFF: Yes, you're clear. What you're
8 saying is if we consider our range of risk, which is the
9 range that we calculated using essentially -- well, first
10 starting with the two railroad worker studies. Now if we
11 also consider the work, the revised estimate from the
12 meta-analysis, plus the Steenland study, plus the Stayner
13 information, plus Allan Smith's calculation, are those
14 numbers all falling with our estimated range of risk, and
15 the answer is yes.
16 ACTING CHAIRMAN FROINES: Yes.
17 And then I want you to put a sentence in that
18 draws attention to that, that you have railroad worker
19 studies and coal miners and you have meta-analysis and you
20 have railroad workers, you have a wide range of industries
21 and occupations which have been done by different people and
22 have come out with consistent, which appears to be
23 consistent, results and that you take that as being
24 meaningful.
25 DR. ALEXEEFF: Yes.
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1 ACTING CHAIRMAN FROINES: Because I think that
2 there has been a lot of concern expressed about the
3 overemphasis on the Garshick study, and here you have a
4 wonderful opportunity to show how whether it be coal miners
5 or truck drivers or railroad workers or the meta-analysis
6 covering all the studies, that you have reasonably
7 consistent results based on solid methodology. And I think
8 that's very worth drawing attention to.
9 Now I'm finished. I'm finished. And I'm now
10 going to go to what -- to Stan's issue, which I take it is
11 controversial.
12 DR. GLANTZ: No.
13 DR. ALEXEEFF: Before you do that, I'd like to
14 discuss a couple other issues related to that.
15 ACTING CHAIRMAN FROINES: Okay. I think that that
16 also means that you can consider dropping out or putting in
17 an appendice or doing something with some of those risk
18 assessments that are based, that are a little bit softer.
19 DR. GLANTZ: Wait. I had the floor.
20 DR. ALEXEEFF: I think -- let me just clarify one
21 thing. We have this table. The table that we're calling
22 Table 3. Okay.
23 And it sounds to me what you're suggesting is that
24 we have a Table 3 with this information.
25 At the same time our range of risk table, which
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1 would supplement that by adding this other study
2 information, is that correct? Or is it simply we're talking
3 about Table 3 and pointing to this Table 3? Let me just
4 make sure we're talking about -- are we actually altering --
5 because the way we have explained our range of risk is look
6 at this table, here's the calculations. So Table 7-10 as
7 example or 1-1, if you're looking at the executive summary.
8 So one possibility would be to add this other
9 information as part of the range of risk.
10 The other one is simply to use it as an adjunct
11 table and point to it. And I guess that's the only
12 distinction I'm not clear on.
13 DR. GLANTZ: If I could, what I think you should
14 do is the former. That what I'd like is that in the table
15 in the main text and in the figure, I think it's Figure
16 7-10, that you could take out the animal.
17 DR. MARTY: 7-4.
18 DR. GLANTZ: 7-4. You should take out the animal
19 stuff and add in these other couple of estimates, the four
20 estimates that John has talked about.
21 And the -- it won't change the summary statement
22 here at all.
23 And I think now we're basing things on a much
24 broader set of information. And so that's -- and I think
25 the report and the executive summary needs to be revised is
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1 appropriate to make that point.
2 I don't think it should be just be an adjunct of
3 it. It should be viewed as consistent with all the other
4 stuff that's in there.
5 DR. ALEXEEFF: So we would be revising Table 3,
6 plus we would also be revising in our document our Table
7 7-10 or 1-1 where we actually have our risk range. Is that
8 what the suggestion is? I just want to make sure I
9 understand.
10 DR. GLANTZ: That's what I would suggest. But
11 also there is that figure in there with the --
12 DR. ALEXEEFF: Plus the figure, right. Make the
13 figure consistent with the table, I think is what you're
14 suggesting.
15 ACTING CHAIRMAN FROINES: Peter is next.
16 DR. WITSCHI: I expressed earlier some concerns
17 about that limited database. Some of them have been
18 alleviated. But those two papers we just got by Steenland
19 and by Stayner, have they to be appeared in the peer review
20 literature, have to be published as such?
21 DR. BLANC: One is in the press in the American
22 Journal.
23 DR. WITSCHI: One is in press? Both are. Okay.
24 ACTING CHAIRMAN FROINES: Both are press.
25 DR. WITSCHI: So they have undergone peer review?
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1 DR. ALEXEEFF: No, actually let me -- I'm not
2 hundred percent sure on the Stayner, maybe you can -- but
3 the Steenland is in -- the Steenland article is in press.
4 Okay.
5 And actually let me just clarify one other point
6 regarding the Steenland.
7 So is Stayner too, right.
8 Regarding the Steenland paper, Dr. Blanc asked a
9 question whether or not this was a new relative risk and if
10 it was included in our meta-analysis.
11 So the answer is that the relative risk used in
12 the Steenland paper is the one -- is in our meta-analysis
13 already. It's the 1990 relative risk.
14 What is new in the Steenland paper is the exposure
15 analysis of the truck drivers and coming up with a unit risk
16 value. That is what's different and new. But the relative
17 risk is the one that's published.
18 DR. BLANC: What was it, 1.3?
19 DR. ALEXEEFF: That I can't recall. I can't
20 recall what that relative risk was. But it's in that --
21 ACTING CHAIRMAN FROINES: Can I say, these numbers
22 are not to be used in the table until we -- I mean, we need
23 to get clearance from the journal and from the authors to
24 incorporate them into our document, so there could be a time
25 gap. We can't take and we can't quote these. This is not
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1 to go to the press. We can't -- these are -- one of them is
2 in the Federal Register, but I think that these are
3 documents that are about to emerge.
4 DR. GLANTZ: I think you should check with them,
5 but it's not -- the fact is they provided them in press
6 things and I mean --
7 ACTING CHAIRMAN FROINES: I'll work that out.
8 Don't worry about it.
9 DR. GLANTZ: Well, anyway, so the other change I
10 would make to Table 3 is first three lines about the
11 comparative potency. I would take that out.
12 ACTING CHAIRMAN FROINES: Wait. I can't --
13 DR. FUCALORO: Excuse me. Where were you now?
14 DR. GLANTZ: I'm back at Table 3.
15 ACTING CHAIRMAN FROINES: Can we go back to your
16 point, though. As much as you would like it to go by
17 unnoticed, I think --
18 DR. GLANTZ: We can come back, but I'd like to
19 just try and finish making the points. We can go discuss
20 that.
21 Just to finish the point of focusing things on the
22 human data, in the Table 3 I think the comparative potency
23 lines of that should be removed.
24 I thought that argument was -- I mean, it's back
25 to animals. I think it's not as strong and it just confuses
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1 matters, so I would like that deleted from Table 3.
2 ACTING CHAIRMAN FROINES: I've lost it.
3 DR. GLANTZ: Table 3 has a bunch of different
4 epidemiological -- the summary results of --
5 ACTING CHAIRMAN FROINES: You want to take out the
6 three comparative potencies?
7 DR. GLANTZ: Yeah.
8 ACTING CHAIRMAN FROINES: Keep them in the text,
9 George.
10 DR. GLANTZ: You can keep it in the report, but
11 take it out of the table.
12 ACTING CHAIRMAN FROINES: I think the other thing
13 I want to take out, I want to be responsive to Peter
14 Witschi, and that is we have McClellan in here twice, one of
15 which is a EPA quote, one of which is our quote of him. I
16 would argue that I would support Peter and take out ours,
17 and since we have this same thing as the EPA document quote.
18 Peter, you agree?
19 DR. WITSCHI: Yes.
20 DR. ALEXEEFF: Take out whose?
21 ACTING CHAIRMAN FROINES: There's no sense having
22 the same risk assessment in twice.
23 DR. GLANTZ: The fourth from the bottom, the
24 McClellan railroad workers, delete that from the table.
25 DR. ALEXEEFF: We didn't use it in our risk
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1 assessment, so I think it should be deleted, because we
2 took -- he wrote us a letter asking us not to use it, and we
3 did not. So putting it in the table would suggest that we
4 did, and it would be confusing.
5 DR. BLANC: Can we come back to your suggestion
6 that the best point estimate is four? I'm sorry --
7 DR. GLANTZ: I didn't say best. I said a
8 reasonable point estimate.
9 DR. BLANC: A reasonable point estimate. 4 times
10 10 to the minus 4?
11 DR. GLANTZ: Yes.
12 DR. BLANC: Could it -- it would be useful for me
13 to hear you state to me why you think that's the most
14 reasonable number.
15 DR. GLANTZ: Because when you look at -- the way I
16 came up with that number was when if you look at figure 7-4,
17 which is the results of all of the different analyses, and
18 there are all kinds of different assessments or exposures
19 assessments, that seemed about the middle of it.
20 And I was actually struck in reading this at how
21 insensitive the unit risks were to the presumed exposures.
22 And it seemed to me that a reasonable number to
23 use, because people are going to want to know what we would
24 suggest and we've spent years looking at this is the middle,
25 and four is in the middle, and I talked with George about
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1 this, and he -- that was a number they came up with too.
2 DR. FRIEDMAN: These upper 95 percent confidence?
3 DR. GLANTZ: Yes.
4 DR. FRIEDMAN: Well, then I wouldn't use the
5 term -- you can use the term, but not point estimate,
6 because that will -- people get confused because they think
7 of that as not as the confidence limit.
8 DR. GLANTZ: Well, then just say a reasonable
9 estimate of the unit risk. Yeah. I'm happy with that. In
10 fact, that's what I had originally written. Just say a
11 reasonable estimate of the unit risk is. It's not even
12 saying it's the best one, but it's a reasonable one.
13 ACTING CHAIRMAN FROINES: Paul, in seven minutes I
14 want to take a break.
15 DR. BLANC: Well, I want to say two things in
16 response to that.
17 One is I think that's an excellent idea that we
18 say what we think a reasonable estimate is.
19 Secondly, I think that we should not have a
20 reasonable estimate which is lower than the lower 95 percent
21 confidence level of the various -- of any of the various
22 models that we're suggesting are potentially viable.
23 There were in the series of roof models, I don't
24 have the table in front of me, one of the roofs, you know
25 that A, B, C, D thing, do you have that handy? Can you just
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1 put that up?
2 DR. ALEXEEFF: The numbers?
3 DR. BLANC: The numbers.
4 DR. ALEXEEFF: Or the pictures?
5 DR. BLANC: The numbers.
6 DR. ALEXEEFF: Melanie will put that up.
7 DR. BLANC: First of all, the estimate that's
8 going to -- that I've written -- that I wrote down earlier,
9 that came out of Steenland is 7.7 times 10 to the minus 4th.
10 DR. ALEXEEFF: Correct. That's the number that we
11 had.
12 DR. BLANC: Did I get that correct?
13 So we would be below their estimate for that.
14 And then some of these -- some of the lower 95
15 percent estimates of these models are also above 4 times 10
16 to the minus 4th.
17 So I think to be consistent, I'm not trying to
18 split hairs, but I think we should go up slightly more than
19 that in order not to be inconsistent with our own 95 percent
20 modeling on the lower end. I think we're obliged to be
21 above the lower end of 95 percent confidence intervals and
22 some of these model assumptions, albeit not in -- so I think
23 you're in the ballpark, but I think it needs to be up a bit
24 higher.
25 DR. ALEXEEFF: Can I clarify a couple points on
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1 this?
2 One is the four, I think that that's what Stan is,
3 Dr. Glantz is referring to is the geometric mean of our
4 previous upper 95 percent confidence limits. So it is a
5 geometric mean of the upper bounds.
6 DR. FUCALORO: May I ask you a question? Is this
7 a standard procedure to get the geometric mean?
8 DR. ALEXEEFF: We've often calculated a geometric
9 mean, yes. But it's not --
10 DR. FUCALORO: Then if we use that number, somehow
11 I think Stan has some point here he's trying to get is that
12 we should have a number that we can quote rather than just a
13 range. I think that's his motivation.
14 But then maybe instead of using the word
15 reasonable, let's just say how we arrived at the number. It
16 was the geometric mean between the limits of the range, or
17 something like that.
18 DR. ALEXEEFF: Right. There's two points on that.
19 In the past what we have done, as we have often
20 found a single study or a value that we felt was the most
21 compelling and that is what we suggested in the range of
22 risk.
23 In this case the view is more of an overall review
24 of all the information.
25 In the past we've had a geometric mean. That is
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1 not necessarily to say it's the best value. We tried to be
2 clear in the document that we're saying it's not necessarily
3 the best value. It just gives a sense of where the -- when
4 you have a table of numbers like this, where the balance
5 point is.
6 DR. FUCALORO: I understand that. And I'm saying
7 by just stating exactly how you arrived at that number, I
8 think that on the face of it explains it.
9 Now, whether or not someone says why did you do
10 that, well, you can say ask Stan, or ask you.
11 But the question is that if there is a statistical
12 methodology which comes to the best value, let's hear it and
13 let's use it.
14 But if there is none, but some sort of policy or
15 some sort of practice of using the geometric mean, let's
16 state that we did and use that.
17 I would say that even in this case, there's
18 probably less meaning to that number because it is a mixture
19 as opposed to an individual compound, and a mixture that
20 whose composition may change over time.
21 So this number probably has less impact or less
22 importance.
23 However, if Stan thinks that that number somehow
24 makes it convenient to people to state something, I'll go
25 along with that, but let's just state what it is and not put
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1 too much confidence in that number for the reasons I state.
2 DR. BLANC: Well, I want to correct something.
3 First of all, I had see the table briefly before
4 and I now realize that it wasn't the two sides of the 95
5 percent. The one is the upper and other is the best
6 estimate. So from that point of view, I'm sorry for
7 bringing that up.
8 But I wonder how the 4 times 10 to the minus 4th
9 changes when you plug in not just these numbers in your
10 best, but you add the Steenland and all that. I just want
11 to make sure that we're not -- because we are going to come
12 out lower than Steenland's estimate that way. He's at 1.7.
13 He's at -- I'm sorry. He's at 7.
14 DR. ALEXEEFF: Steenland's value is 7.7 times 10
15 to the minus 4.
16 DR. BLANC: We're proposing --
17 DR. FUCALORO: The geometric mean is not 4, it's
18 5.5.
19 DR. ALEXEEFF: Correct. Yeah. There's a point to
20 make here and that is, as we indicated, there were some
21 suggested changes in a couple of these calculations,
22 particularly the numbers like in the scenario A. So if you
23 look at scenario A, that number is different slightly from
24 the value that's in the document, because of comments that
25 came in. So it would end up being slightly higher, about
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1 5.5, 5.6.
2 DR. FUCALORO: 5.58. But if you want one
3 significant figure you get to 6, which is in very close
4 agreement with --
5 DR. ALEXEEFF: On the other hand, if we included
6 the Stayner information and the Steenland information as the
7 table, do we have to recalculate the geometric mean again,
8 is all I'm referring to.
9 ACTING CHAIRMAN FROINES: Why don't you leave them
10 out.
11 DR. GLANTZ: Well --
12 ACTING CHAIRMAN FROINES: Leave them out.
13 DR. GLANTZ: Of what? You just said to put them
14 in.
15 The only point, what I would suggest doing in
16 light of this discussion is the following.
17 I don't think we need to talk about the geometric
18 mean in the findings, but I think it should be explained in
19 the report. Okay.
20 And I think what you should do is just correct
21 these numbers, as you just said, add in these other four
22 points, compute the geometric mean, round it to one or two
23 digits, probably one, and then use that number, and then it
24 will be around five, four or five, six.
25 DR. FUCALORO: Geometric mean from a set of
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1 findings.
2 DR. GLANTZ: Make it clear how you did it.
3 DR. FUCALORO: I actually did it from the two
4 extremes. That's how I came up with 5.6. But if there are
5 more data you can --
6 DR. GLANTZ: As Tony said, the difference between
7 six and seven and five isn't that much in this context. But
8 I think what is important is to give people some guidance as
9 to what we think a reasonable estimate of the unit risk is,
10 because I don't think we should take the highest upper 95
11 percent number because that's, you know, I just think that's
12 biased. And nor do I think we should take the lowest one.
13 And this will give us a reasonable middle estimate.
14 And so you can explain, put a little section in
15 the report or a paragraph at the right place explaining how
16 you came up with it, and then put the appropriate number in.
17 DR. FUCALORO: Then you can worry about defending
18 it.
19 DR. BLANC: Well, I just want to say again, I
20 completely agree it's not that I objected to saying what we
21 thought it was. I just thought it was obtuse to me how that
22 number had been arrived at, and it didn't seem to be totally
23 consistent with all the data.
24 DR. GLANTZ: Okay.
25 DR. BLANC: And I would say that when you go
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1 through this exercise of generating this number, which is
2 going to be in the ballpark of between 1.5 and -- I'm sorry,
3 between 4 and 8 times 10 to the minus 4th, that what you
4 take the -- if you do it on the basis of taking some kind of
5 mean of these numbers, I don't think each of the various
6 models should be weighted such that you have 15 different
7 things going at the model. Take a mean of those four
8 different roof models. Take a mean of the other roof and
9 ramp models from these various data. Otherwise you're
10 overweighting things from one data set and one approach.
11 So I think you can take the average of your
12 various roof models, the average of your various ramp
13 models, the average for the cohort for the case control. Do
14 you follow what I'm saying?
15 DR. ALEXEEFF: Yes.
16 DR. BLANC: And then average those averages with
17 your other sources, the one from the 1.4 meta-analysis
18 relative risk based on a mean of 250 micrograms, the one
19 from Steenland, et cetera.
20 DR. GLANTZ: It will probably come out the same as
21 what Tony just did, but I think that's the correct
22 procedure.
23 DR. FUCALORO: Whatever you do, be prepared to
24 defend it, defend your method.
25 DR. ALEXEEFF: I think what we will do is we'll
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1 combine -- we'll average the values based upon the studies,
2 so we'll average the case control values, average the cohort
3 study values. I think that's the most defendable. And just
4 say this is our average from that and average from that and
5 then we can average with the other values.
6 DR. GLANTZ: Geometric average.
7 DR. ALEXEEFF: Geometrically, yes.
8 DR. FUCALORO: Keep away from value-laden terms
9 like reasonable and that sort of thing. That would be my
10 suggestion. You can --
11 DR. ALEXEEFF: I think we would just leave it
12 as -- we already have a discussion that it's a geometric
13 mean and we'll just explain that.
14 DR. FUCALORO: Exactly.
15 DR. GLANTZ: The reason I picked reasonable was I
16 was trying to avoid the word best.
17 DR. BLANC: I think for this kind of report, for
18 this kind of document, the word reasonable is fine.
19 I think, Anthony, you were referring more to what
20 they should say in the full-blown --
21 DR. GLANTZ: So anyway that's what I would
22 suggest.
23 And that's -- and I have a few little odds and
24 ends things in the report, which I think are more editorial
25 that I can give them later.
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1 DR. FUCALORO: I just want to pass by for your
2 consideration changing the wording on the sentence which
3 begins based on a variety of exposure scenarios, and I'm not
4 exactly sure I know what that means, the range of resulting
5 estimates.
6 Is this what is meant by that? Maybe I'm wrong.
7 The estimated range of the lung cancer unit risk
8 factors determined from the epidemiological studies is?
9 DR. GLANTZ: That would be much better. I like
10 that better.
11 DR. FUCALORO: Did you get it?
12 MS. SHIROMA: Could you repeat that?
13 DR. FUCALORO: I'll just bring it over there.
14 DR. GLANTZ: Why don't you read it for everybody.
15 I think that's much better than the way it reads.
16 DR. FUCALORO: The estimated range of the lung
17 cancer unit risk factors determined from the epidemiological
18 studies is, then put in the value.
19 DR. ALEXEEFF: We would want to insert in there
20 that upper 95 percent confidence intervals.
21 DR. FUCALORO: That's what Stan is suggesting. I
22 think we all approved that.
23 ACTING CHAIRMAN FROINES: Okay. Stan, I want to
24 take a break for the stenographer, and so if you have other
25 points that are relatively minor you can just give them to
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1 George or Melanie.
2 DR. GLANTZ: That's what I'll do. I'll just give
3 them to them.
4 ACTING CHAIRMAN FROINES: And so we're then going
5 to go next to Peter and Peter for -- and Tony, but he's
6 getting all his shots in. He's not hiding over here. I was
7 recognizing that.
8 So let's take a break. What we'd like to do is
9 then go to Peter and Peter and back to me and Tony and then
10 hopefully we can wrap up. I would like to try to wrap up by
11 4:00 o'clock if we think we can do it. Everything is going
12 so smoothly, it would seem like we can.
13 (Thereupon a short recess was taken.)
14 ACTING CHAIRMAN FROINES: No yawning. Okay.
15 We've moved on from Dr. Glantz and we're now
16 taking comments from Dr. Witschi.
17 George.
18 DR. ALEXEEFF: Just as a comment, we've looked
19 through that EPA report again. We haven't found a mouse
20 value, although they discuss mouse studies. So we don't
21 suspect we're going to find one calculated on the mouse
22 data.
23 ACTING CHAIRMAN FROINES: That makes everybody
24 happy except me, because I still believe the mouse is
25 positive.
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1 Peter.
2 DR. WITSCHI: Okay. I have a substantial problem
3 with assigning a unit risk diesel exhaust particles.
4 First of all, it's usually unit risk is associated
5 with properties of specific compounds, and as far as this
6 list is concerned, we have a mixture.
7 The second one, if you look at Table 2 the unit
8 risk value for diesel exhaust is pretty close to the one of
9 inorganic arsenic or benzo(a)pyrene or nickel or butadiene,
10 out of which all those compounds are probably just present
11 in traces of micrograms per cubic meter.
12 So having a unit risk of the mixture is the same
13 as the defined compounds. Somehow I would like to know what
14 it is in diesel then that makes it as potent as the other
15 agents are.
16 The third problem I have is what we are doing,
17 particularly if you look at point 19, the 200 to 3,600
18 additional cancer cases. We are taking something which
19 probably happened in the 1950s and 1960s, and this is
20 increased rates of lung cancer. We are multiplying this by
21 measurements we took in the '80s and more often than not,
22 those measurements are surrogates for diesel. Most of the
23 time they are just separate particle without having been
24 identified exactly as diesel.
25 And from this then we make projections for the
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1 year 2000 and beyond. And this involves many many
2 assumptions and many many uncertainties.
3 And frankly it's just too much for me. There are
4 too many assumptions and there are too many uncertainties to
5 come down and give a cancer potency to diesel.
6 Particularly if you look at this thing in a
7 different way. This document has given us a hypothesis and
8 the hypothesis is that diesel causes lung cancer in men, and
9 that's a hypothesis that's testable, without having any
10 numbers.
11 I know it's beyond the scope of this panel, but
12 the way this happened, this could be test is by really
13 substantially reducing exposure of the general public to
14 diesel by dealing with all of those heavy polluters which
15 are still around, and by really cutting down on reduction on
16 emissions. And in other words to see whether diesel causes
17 lung cancer is a testable hypothesis, and we should test it.
18 That's all I have to say.
19 ACTING CHAIRMAN FROINES: Well, break it in two
20 pieces.
21 The first question derives from your concern about
22 establishing a unit risk value, and the second concerns the
23 actual cancer estimate of 200 to 3600, which is actually not
24 based on a single unit risk estimate, it's based on a taking
25 the two unit risk assessments and calculating them directly.
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1 DR. WITSCHI: I understand this, but this does not
2 change the principle. It does not change the principle.
3 ACTING CHAIRMAN FROINES: Okay. And so why don't
4 we have a discussion about the unit risk issue first. And I
5 don't know the best way to have it.
6 You've expressed two points of view.
7 DR. WITSCHI: Well, I also would like still to go
8 by 36653 -- 9654 E, that while absolute and undisputed
9 scientific evidence may not be available to determine the
10 exact nature and extent of risk from toxic air contaminants,
11 it is necessary to take action to protect public health.
12 In other words, to me it seems we can take action
13 to protect public health in the absence of a unit risk,
14 because a unit risk might not be scientifically as sound or
15 defensible as it is for example for individual compounds.
16 And the other one in the particular case we do not
17 need, because the evidence is just too good.
18 ACTING CHAIRMAN FROINES: Here's a legal matter.
19 We meet our obligation as a panel by either adopting a unit
20 risk or by accepting the range of risk. Our obligations are
21 met in either case. We are under no requirement that says
22 we must have a specific unit risk value.
23 Now, we have, with the exception of lead, we have
24 always had a unit risk value.
25 So that the real issue is does the panel feel that
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1 the data before it in their report justifies establishing a
2 unit risk value. I think that's the question before us.
3 DR. GLANTZ: Well, I think since I suggested it,
4 yes.
5 And I agree with you that we should do No. 18 and
6 No. 19 and discuss those separately.
7 But the fact -- I don't agree with Hanspeter. I
8 think the evidence in front of us that diesel exhaust is a
9 lung carcinogen is very strong.
10 DR. WITSCHI: That's not what -- you heard me
11 wrong.
12 DR. GLANTZ: Hang on. Let me just finish.
13 I think that the evidence that we have that it is
14 a human carcinogen is exceptionally strong, and of all the
15 reports I've been on, worked on, on this committee, this is
16 one of the most thorough, more compelling, best cases, and I
17 think that the -- so the fact that there is a risk is, to
18 me, is certain as you can ever be in these things.
19 The reason that I suggested that we specify a
20 reasonable estimate is because the fact is that that's going
21 to happen as the discussion moves forward, and we've spent
22 the last several years looking at this going to endless
23 workshops, and I think that the idea of taking the geometric
24 mean of these different estimates is a very reasonable way
25 to come up with a suggested number.
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1 The thing that has struck me in reading the report
2 in terms of the human stuff is that how little scatter there
3 is actually and how little variability there is in the
4 estimates when you cut it many different way in the
5 meta-analysis. And I'm glad that we have decided to give
6 the meta-analysis more emphasis, because I actually think
7 that's more compelling than just hanging everything on one
8 of the Garshick or the two Garshick studies.
9 And I think that the thing that struck me is how
10 relatively insensitive the unit risk, the sort of the unit
11 risk estimate is, and I think that if -- that we are better
12 positioned to come up with a recommended value than anybody
13 else who has been in the process so far.
14 And every other report that we've done, we've come
15 to that conclusion, often based on much much much less
16 information and many more assumptions than are necessary
17 here.
18 The only real assumptions that are made are, you
19 know, which of these different exposure profiles is the
20 reasonable one to assume. And what the staff have done is
21 widely bracketed all possible things that would be
22 reasonable. And we're taking something that's in the middle
23 of that.
24 And so I think we're in fact making many fewer
25 assumptions in doing this than we have, you know, everything
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1 else we've looked at since I've been on the panel.
2 DR. WITSCHI: Well, I'm not -- that's okay. I
3 mean, I never said it's not a carcinogen.
4 DR. GLANTZ: Yeah, I know.
5 DR. WITSCHI: I found actually among all the
6 things, those estimates and whatever it was, actually I
7 found Allan Smith's approach much more compelling than all
8 those assumptions and certainties and guesstimates that came
9 from developing the formal risk assessment, because that's
10 somehow I personally can relate to. That makes sense.
11 DR. GLANTZ: Well, you're not going to get
12 argument out of me.
13 But it comes out with about the same number, about
14 5 times 10 to the minus 4, 6 times 10 to the minus 4.
15 DR. WITSCHI: That's okay.
16 DR. GLANTZ: Okay.
17 DR. WITSCHI: I would be fine with. I just said
18 the unit risk is for a mixture is something I have a problem
19 with.
20 Take it only from Allan's standpoint, taking only
21 that ratio of 1.4 without then bringing exposure into the
22 game is, to me, much more convincing than starting to say
23 going into all this particles, they make the carcinogens out
24 there, so on and so, ramp, no ramp, proof and all these
25 kinds of things. To me, this one here is much more simple.
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1 ACTING CHAIRMAN FROINES: To you that would be
2 acceptable?
3 DR. GLANTZ: You come up with the same number both
4 ways, though, you know.
5 DR. FUCALORO: Well, I think as to be somewhat of
6 a diplomat in this, I mean, one could also put another item
7 in which points out Allan's approach and demonstrate that it
8 comes out to about the same number.
9 I think, though, it points to something, you have
10 another point here that I think is well taken, and when I
11 tried to get in earlier, maybe I can be more explicit about
12 it now, I admittedly will mix risk assessment and management
13 and I know that there's a fire wall between the two by law,
14 but allow me this for the moment.
15 Now, risk assessment and risk management use two
16 factors that they're interested in. One is a risk factor
17 and an exposure level. Normally for single compound toxins
18 all -- once the risk factor has been established, the only
19 thing one is concerned about is exposure level, trying to
20 reduce that using the best available technology.
21 While in this case I would argue that one has to
22 monitor also the risk factor, because the nature of diesel
23 exhaust will change with time. And I think that perhaps
24 wording that recognizes that, if it does not exceed our
25 authority, and I'm not sure I know if it does, would be
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1 something that might find its way in our recommendation,
2 something saying that we recognize that not only does
3 exposure level have to be monitored, but also risk factor,
4 because that may be a changing number.
5 And what even confounds it more, and I think
6 Peter, Hanspeter will agree with this, is the number of
7 older diesel engines, you have newer ones, and so on, I
8 mean, it's a pretty complicated number to get at, but maybe
9 it can be arrived at with reasonable methodology.
10 ACTING CHAIRMAN FROINES: Well, I need help here.
11 DR. BLANC: Well, let me see if I can step in.
12 I think that Dr. Witschi's trepidations are
13 understandable from a philosophical point of view,
14 representing your philosophical approach to this, but I
15 don't think they are consistent with the charge of the
16 committee or of the process as it has gone forward over very
17 many months and I don't think there is any linguistic way to
18 satisfy your trepidation.
19 And I think that you're going to have, in the end,
20 just beg to differ with the conclusions of the panel,
21 because I don't think that taking out the risk estimation is
22 a viable option.
23 And really my question to you is what form would
24 you like your trepidations to be voiced?
25 DR. WITSCHI: Okay. Say that again, what form?
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1 DR. BLANC: What form would you like your
2 trepidations to be voiced in? Because they are too global
3 to be addressed in the document, in our finding itself.
4 DR. WITSCHI: That's very simple.
5 The risk assessments saw the light of the day by
6 the famous benzene decision, where something just could not
7 be considered to be a carcinogen without demonstration of
8 adequate risk, which happened in 1983.
9 The language and presumably the mandate of the
10 committee, at least what it says here, also goes back to
11 1983.
12 Now we have 1998, and we have much more
13 information. We know much more about carcinogenesis, we
14 know much more about human carcinogenesis, and my contention
15 is why going through all these difficult things and coming
16 up with a number, which is fraught with so many
17 uncertainties, when we are dealing with something we know
18 it's a human carcinogen and can do something about it
19 without even having creating a number which is based on many
20 many assumptions. It's that simple.
21 DR. FUCALORO: In other words, you just don't
22 think we need to report a risk factor?
23 DR. WITSCHI: Right.
24 DR. FUCALORO: I mean, that's what you're saying
25 and you're using the language in the law which allows for
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1 that to happen?
2 DR. WITSCHI: Yes.
3 DR. FUCALORO: I understand that.
4 DR. BLANC: I understood that that was your
5 comment.
6 I'll come back and say again that is not going to
7 be the prevailing view on this committee, I do not believe.
8 Then I am trying to find some way at the same time
9 to take into account your trepidations while we move forward
10 with our work.
11 DR. WITSCHI: We do not have to be unanimous.
12 DR. BLANC: What's that?
13 DR. WITSCHI: We do not have to be unanimous in
14 adopting the findings.
15 The only thing I'm taking issue with is nothing
16 else but point 18 and 19 in the findings. And it's going to
17 be the prerogative of the chairman how he's going to phrase
18 the question.
19 My disagreements to those two points would in no
20 way preclude me voting for diesel exhaust being a toxic air
21 contaminant. It clearly fills the criteria.
22 So I leave it up to the imagination of Dr. Froines
23 eventually to come up having listened to me, to come up with
24 an appropriate question.
25 DR. FUCALORO: In other words, I think you are
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1 clear, he can phrase the motion such that you're given the
2 freedom to vote that it is a toxic air contaminant, but not
3 force you to vote for the number that's the item 18.
4 DR. WITSCHI: Yes.
5 ACTING CHAIRMAN FROINES: I would prefer if we
6 could come to a unanimous agreement among the ourselves. I
7 think it would be better for the panel.
8 DR. BLANC: Let me come at this a different way,
9 then, or ask the question a different way.
10 If we at the end of the day take this memorandum
11 as we've modified it through various comments, and we say we
12 would now -- we would like the record to show that the panel
13 has reached a consensus on this memorandum, and I turn to
14 you and said I know that you're not thrilled with certain
15 aspects of this because of deeper philosophical beliefs
16 about how one goes about calculating risk, or whatever,
17 however I say it, but can you live with this as a whole,
18 despite whatever trepidations you have? Would your answer
19 be yes, I can live with as a whole?
20 DR. WITSCHI: I really don't think that that's not
21 so much philosophy, it's what I think is some criteria
22 applied to science. I probably have -- I cannot live with
23 that unit risk for diesel exhaust.
24 DR. BLANC: Well, then, John, I think at that
25 particular difference on that particular point is, with all
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1 due respect, probably irreconcilable and what the options
2 are either simply to state that we've achieved consensus
3 except on one point where there was one member of the panel
4 who dissented from the view on this one point, or some other
5 mechanism for noting that, but I don't believe that you're
6 going to achieve consensus on point 18, or whatever.
7 ACTING CHAIRMAN FROINES: And we haven't taken a
8 vote on this principle, so it's not clear what the consensus
9 is.
10 But the other matter, let me go back to Stan,
11 though, or to the other panel members. We have a range of
12 cancer risk of 1.3 times 10 to the minus 4, to 2.4 times 10
13 to the minus 3. The 4 is already, but there's been no
14 disagreement about. What do we benefit by coming out with a
15 specific number?
16 DR. GLANTZ: Well, the reason that I think we
17 should do is that we've always done it and I think --
18 ACTING CHAIRMAN FROINES: That's not true.
19 DR. GLANTZ: Well, except for lead, which was a
20 report that was mired in political problems.
21 ACTING CHAIRMAN FROINES: But let me preface it by
22 saying, at one point I wrote a document and I sent to all of
23 you and said that we have an obligation under the law to
24 define a range of risk.
25 DR. GLANTZ: Right.
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1 ACTING CHAIRMAN FROINES: We have no obligation
2 under the law to define a unit risk value.
3 DR. GLANTZ: Well, I understand.
4 ACTING CHAIRMAN FROINES: Let me finish. Let me
5 finish, because I just want to make a point.
6 One of the things that we all agree on here is
7 that further research is necessary, especially with respect
8 to the relationship between the nature of the diesel
9 particulate -- diesel exhaust with railroads and what people
10 are currently driving down the street today.
11 DR. FUCALORO: In their Mercedes.
12 ACTING CHAIRMAN FROINES: In their Mercedes.
13 And we know that we need to look to see is the
14 risk now similar to what we saw with coal miners or truckers
15 or railroad workers sometime back.
16 So that I think that there is some benefit to not
17 giving the South Coast Air Quality Management District a
18 bright line. And that part of that is what concerns me.
19 And that is that are we prepared in here to say
20 that we are sufficiently confident with what we are doing
21 that the bright line is what we really want to come out.
22 DR. BLANC: Stan, maybe I'm confused.
23 Dr. Witschi, maybe I misunderstood your
24 trepidation.
25 Is your trepidation only with giving a reasonable
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1 best estimate, that you don't have any problem with saying
2 what we think the range of risk is?
3 I took your comment, I think, maybe too globally.
4 DR. FUCALORO: I took it the same way he did. I
5 thought you had a problem with the range also.
6 DR. WITSCHI: No. It's just this -- it's now a
7 bit difficult.
8 As I said, Allan Smith did the same thing, which I
9 think is much more plausible.
10 DR. BLANC: As a best estimate?
11 DR. WITSCHI: As a best estimate, because he does
12 not go through all the assumption about ramps, plateaus,
13 roofs and all those --
14 DR. BLANC: Well, then that I do have -- I'm
15 sorry. I misunderstood you. I thought you had a much
16 deeper philosophical scientific global difficulty.
17 Well, then what I would suggest is that we,
18 instead of going through the exercise that we suggested
19 before of taking the geometric mean of all the estimates,
20 you just gives us the point estimate that would come from
21 assuming midlevel, 250 microgram per cubic meter value of
22 diesel and the 1.4 relative risk, and you're going to come
23 up with a value that's going to be 5.2 times 10 to the minus
24 4th, and I can -- I'd be very happy with that if you would
25 be happy with that.
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1 DR. GLANTZ: Would you be happy with that?
2 DR. WITSCHI: Yes.
3 DR. GLANTZ: I'm happy with that.
4 DR. FUCALORO: I'm ecstatic.
5 DR. GLANTZ: Okay.
6 DR. BLANC: That's fine.
7 DR. GLANTZ: Let's stop.
8 DR. BLANC: Let's stop right there.
9 ACTING CHAIRMAN FROINES: Wait, wait. We're not
10 done yet. We aren't done.
11 One, we haven't got to Dr. Kennedy yet. And he's
12 sitting there with a bombshell.
13 DR. GLANTZ: Wait. One point I want to just make,
14 at the risk of talking after we've reached consensus, I mean
15 the reason that I'm --
16 ACTING CHAIRMAN FROINES: Stan, this is like
17 you're asking those people last week --
18 DR. GLANTZ: Okay. I'll shut up.
19 ACTING CHAIRMAN FROINES: Can we go back to
20 another --
21 DR. GLANTZ: Let the record record that the staff
22 are giggling.
23 ACTING CHAIRMAN FROINES: Peter has raised a
24 second substantive issue, which I think we now have to
25 address, and that is that he's raising a question about No.
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1 19, in which he's concerned about the -- why don't you
2 restate it, because I may state in incorrectly.
3 DR. WITSCHI: Well, this is again one of those
4 things which then can be looked at in different way. To
5 some people this calculating numbers are going to look like
6 real, to some people they're going to look like acceptable,
7 to others they are not going to look acceptable -- not
8 acceptable.
9 Whereas I think the evidence we have on diesel is
10 that clearly exposure of people to diesel is not acceptable.
11 DR. FUCALORO: I'm sorry?
12 DR. WITSCHI: Is not acceptable. Not just for the
13 cancer --
14 ACTING CHAIRMAN FROINES: What I hear you saying
15 is that using this 200 to 3600 is based on a railroad worker
16 study of some time ago and it may not reflect the actual
17 risk in say Los Angeles today, so by putting these values in
18 may overstate the risk. Does that --
19 DR. WITSCHI: Or understate the risk.
20 ACTING CHAIRMAN FROINES: Or understate.
21 The question is how can we best approach this
22 issue?
23 DR. WITSCHI: Why do we need -- that's really my
24 point, why do we need to convey to anybody that we have
25 to -- we are going to count bodies. And we know about
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1 something is here, it's bad and something against it can be
2 done, regardless of how many bodies.
3 DR. FUCALORO: Your suggestion is to eliminate 19?
4 DR. WITSCHI: Yes.
5 ACTING CHAIRMAN FROINES: Stan.
6 DR. GLANTZ: Well --
7 ACTING CHAIRMAN FROINES: I have a feeling that
8 Peter is agreeing with that. Or are you just acknowledging?
9 DR. KENNEDY: I'll say my piece. No, I agree.
10 DR. GLANTZ: I just consulted with the staff, and
11 I need to slightly amend my agreement with the previous
12 point, after prefacing it with I'm willing to throw away 19
13 to get 18 the way I want it, because I agree with Hanspeter,
14 I don't think it's the point 19 is particularly necessary.
15 The problem I have with just basing it on Allan
16 Smith's number, that gives us the absolute bottom of the
17 range we've got from all the other studies. And I think
18 that, while I agree with you, in fact I was talking to
19 Melanie at the break, that after he does the back of the
20 envelope calculation that comes out very close to what they
21 did after years of analysis, I think that I would feel more
22 comfortable with something that's closer to the middle of
23 the plausible range, rather than at the bottom of it.
24 I was under the impression the Smith number came
25 out closer to the middle.
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1 ACTING CHAIRMAN FROINES: Oh, come on.
2 DR. FUCALORO: It comes out to 5 times 10 to the
3 minus 4.
4 ACTING CHAIRMAN FROINES: These numbers --
5 DR. GLANTZ: 5 times 10 to the minus 4.
6 DR. FUCALORO: I better verify that.
7 DR. GLANTZ: If it comes out 5 times 10 to the
8 minus 4, I'm happy. I just --
9 ACTING CHAIRMAN FROINES: None of it's correct
10 anyway.
11 DR. GLANTZ: Well, don't say that.
12 ACTING CHAIRMAN FROINES: It's a risk assessment.
13 DR. GLANTZ: I know, but, thanks, you just got
14 yourself sued.
15 ACTING CHAIRMAN FROINES: None of this is real.
16 DR. ALEXEEFF: Let me just make a --
17 MS. SHIROMA: None of it is precise.
18 DR. ALEXEEFF: If I can just make a comment.
19 If we rounded, if we used 250 micrograms per cubic
20 meter as was suggested, all we have to do is in his -- in
21 Dr. Smith's equation, is substitute 250 for 67, so you can
22 see if you did that it's divisible by about four. So the
23 number, if you round to one digit, would be 1 times 10 to
24 the minus 4, just so you know what the number is, which is
25 at the bottom of our range.
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1 ACTING CHAIRMAN FROINES: Well, let's go with
2 that.
3 DR. WITSCHI: Well, you know, that's we've gone
4 through risk hazard identification, we have done some risk
5 management, what about risk communication. I mean, the
6 coming up with something rather than giving a risk -- let me
7 finish. To like the calculation is the potency factor and
8 so on, but Allan Smith essentially says look in people who
9 are exposed to rather high amounts of diesel, so and so much
10 was added to their, what they would had gotten anyway in
11 lung cancer, and we should have learned a lesson from there,
12 and if we do some very simple calculations, then if what
13 people are exposed to on the street, so and so much is going
14 to add to their burden. And that's much more easy to
15 understand than any --
16 DR. GLANTZ: Right. But the difference is that I
17 think that we have a lot -- we do have a lot more
18 information than just that one calculation.
19 And I mean you have Kyle Steenland's work, which
20 is -- he's very very meticulous. It came out around seven
21 or eight.
22 And I just think we should pick something that's
23 near the middle, and not at the bottom. I mean, at one
24 level to me we're talking about 10 to the minus 3, to 10 to
25 the minus 4, and that's a fairly narrow range.
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1 But I just think based on having spent a lot of
2 time studying this and working and trying to understand the
3 differences between all these different competing analyses,
4 and why different people got different numbers, and reading
5 all of these studies, I think the bottom of the plausible
6 range, which is lower than the real number is likely to be,
7 and I think the top of the plausible range is higher than
8 the real number is likely to be. And I think that if we
9 just specify that range, then what's going to end up
10 happening is that certain people are going to come in and
11 argue for the low end and other people are going to argue
12 for the upper end, based largely not on any grand
13 philosophical or scientific reasoning, but their political
14 positions.
15 What I'd like to see us say is that we're giving
16 you a range, but we think the most reasonable number is
17 something in the middle, because I think if you look at all
18 the studies and if look at all the different --
19 ACTING CHAIRMAN FROINES: George --
20 DR. GLANTZ: Of the two Garshick studies under a
21 wide variety of assumptions, they tend to cluster in the
22 middle. And I think we want to draw attention to that.
23 And so I just think to say we're going to rely on
24 one back-of-the-envelope calculation that gives you the
25 bottom end of the risk, even though I'm very sympathetic
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1 with the calculation, I think it really strengthens the
2 whole rest of the argument, I just think we should be
3 picking a number somewhere in the middle.
4 If you don't want to do a geometric mean, I mean
5 the four number I came up with was from staring at the
6 graph, that highly quantitative method, and George, it
7 turned out, got the same thing.
8 DR. BLANC: Let me make -- I was taking an
9 arithmetic mean between five and 500, which is probably also
10 too primitive, so if you take the mean value that Allan
11 Smith took, which was 67, so it's not the arithmetic mean
12 between this low of the bracket of five and the top of 500,
13 then I think the value that was arrived at was 3 times 10 to
14 the minus 4th, which is very close to your four times --
15 DR. GLANTZ: I would be satisfied with that.
16 DR. FRIEDMAN: How about, would you be satisfied
17 with not giving a number, but just saying we think that the
18 true risk is probably somewhere in the middle?
19 DR. GLANTZ: No. I think we need to give them a
20 number that we think is reasonable.
21 DR. BLANC: I think 3 times 10 to the minus 4th,
22 which is the number --
23 DR. GLANTZ: I'm happy with that.
24 DR. BLANC: -- based on I guess 67 micrograms per
25 meter. Do I have that number right, people from --
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1 DR. MARTY: Allan Smith's was 5 times 10 to the
2 minus 4, based on 67 micrograms per --
3 DR. FUCALORO: Microgram per meter cubed, right.
4 DR. BLANC: And he arrived at 67 as a kind of mean
5 value based on -- where did 67 come from?
6 DR. ALEXEEFF: The 67 actually is basing it on the
7 railroad worker information, using the Woskie data where you
8 have a background level of -- well, approximately 80
9 something, 83, it's subtracting out the other -- the
10 non-diesel background and you come to 67.
11 DR. BLANC: Does that seem like a reasonable mean
12 for all of the pooled various occupations that we looked at,
13 some of which were clearly much higher than that and some of
14 which were lower than that, in your --
15 DR. FUCALORO: It only has to apply -- it needs to
16 apply to the finding that there's a 40 percent increase in
17 background lung cancers. So to use other data you'd have to
18 look at what that increases. So he's using .4 over 20,
19 assuming that that's increase from 1 over 20, which is the
20 incidence of lung cancer in the general population; right?
21 So that's an extra .4, and that .4 over 20 is
22 equal to the risk factor times the exposure, and if the
23 exposure is 67, .4 out of 20 increase, then you come up with
24 this number that you find acceptable.
25 DR. GLANTZ: Is 3 -- that's fine with me.
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1 ACTING CHAIRMAN FROINES: I want to stop
2 everybody's discussion, and I want -- I want one of the four
3 of you, or whoever, to express to me the justification and
4 the basis for the number that you're now proposing.
5 And it has to be said very clearly, because what
6 you're saying to every citizen of California is that through
7 a rigorous scientific process we have established what we
8 consider to be the best value for diesel exhaust risk with
9 respect to lung cancer.
10 DR. GLANTZ: Okay. Let me, as the first --
11 ACTING CHAIRMAN FROINES: Go on the record --
12 DR. GLANTZ: I'll try to express it on the record.
13 Okay.
14 The way that I would prefer to -- I think that we,
15 having spent years working at this, going to multiple
16 workshops and spending more time than I care to add up
17 reading all of this stuff, are the best-positioned people to
18 make a recommendation of what a reasonable number would be.
19 I did not say it's the best number, although I
20 actually think it is. I'm happy to use the word reasonable.
21 The range of risk estimates that have come out of
22 this entire exercise, whether you look at the Garshick data,
23 the two Garshick data sets, under a variety of assumptions
24 of exposure patterns, which are reasonable, if you look at
25 the Allan Smith back-of-the-envelope calculation, if you
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1 look at the Steenland studies and the other new studies, the
2 results to me are remarkably consistent, yielding risk
3 estimates in the range of 10 to the minus 4, to 10 to the
4 minus 3.
5 I think, however, that it is unlikely that we are
6 in either of the upper or lower end of that range, and that
7 if you look at figure -- at the figure in the report, which
8 shows the effects of the different exposure models that are
9 used, you'll see that most of them cluster around the middle
10 of that range.
11 And so to me the procedure which I think is the
12 best one to use is the one that got suggested of computing
13 the geometric mean of these different estimates, because I
14 think that's the one which is most likely to come out near
15 what the actual number really is.
16 Now, if all the mathematical gyrations which are
17 involved in doing that bother Hanspeter sufficiently that he
18 wants to stay with a simpler thing, if those come out about
19 the same, I'm not going to make an issue of it because I
20 don't think the difference between three and four or four
21 and five isn't that much to me.
22 My concern is that we not come in with a number
23 that's at the bottom of the range, because I think that's
24 unlikely to be the correct number.
25 ACTING CHAIRMAN FROINES: Let me stop. You
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1 make -- you're talking to The Los Angeles Times, The San
2 Francisco Chronicle, you're explaining why you have selected
3 this value, and in two paragraphs why this is the best
4 value.
5 DR. GLANTZ: Want me to try it again?
6 ACTING CHAIRMAN FROINES: If you can't do it,
7 somebody else should, but it has to be clear.
8 DR. GLANTZ: Let me try one more time, John.
9 And that is that there is -- there is a certain
10 amount of uncertainty associated with these different risk
11 estimates, due to all the stuff we've been discussing
12 obsessively.
13 And when you look at the range of risk estimates
14 that you get, some of that uncertainty is going to bias the
15 estimate up and some of it's going to bias the estimate
16 down.
17 And I think the most reasonable estimate is in the
18 middle. And that's why I'm suggesting we say that, not that
19 it's at the bottom or the top. And to me the middle is
20 around 4 times 10 to the minus 4.
21 That's where I came up with that number.
22 ACTING CHAIRMAN FROINES: Peter.
23 DR. GLANTZ: So that's how I would explain it to
24 The LA Times, who is sitting back there.
25 ACTING CHAIRMAN FROINES: Can you speak to that?
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1 DR. WITSCHI: The way I see it, I might be naive
2 with that one, but what you're looking at for coming in the
3 ranges four or five data set bases, the two Garshick
4 studies, the Steenland studies --
5 ACTING CHAIRMAN FROINES: Meta-analysis.
6 DR. GLANTZ: The meta-analysis.
7 DR. WITSCHI: Well, yes, and those --
8 DR. GLANTZ: I don't think that's what we just --
9 I'm sorry.
10 DR. WITSCHI: Well, the way I see the other one,
11 Allan Smith's estimate, is based on very broad data sets, 30
12 or so studies, so the database is much broader than yours,
13 the 30 to 40, and fewer assumptions. That's how I would
14 justify it, we came to this number. It's a broader database
15 and fewer assumptions.
16 ACTING CHAIRMAN FROINES: George, what are the two
17 numbers?
18 DR. ALEXEEFF: Okay. The number varies depending
19 upon --
20 ACTING CHAIRMAN FROINES: No, I didn't ask you for
21 the number varies -- I asked you for --
22 DR. ALEXEEFF: Five or one.
23 ACTING CHAIRMAN FROINES: What?
24 DR. ALEXEEFF: You asked what the two numbers
25 were.
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1 ACTING CHAIRMAN FROINES: His number is what?
2 DR. ALEXEEFF: Five.
3 ACTING CHAIRMAN FROINES: 5 times 10 to the minus
4 4.
5 DR. ALEXEEFF: Yeah. I'm sorry. Are you talking
6 about the geometric mean number?
7 ACTING CHAIRMAN FROINES: I'm talking about the
8 number that he just said is the best number that --
9 DR. ALEXEEFF: We chose the geometric mean, we
10 haven't done the calculation yet, but it would be about
11 five.
12 ACTING CHAIRMAN FROINES: 5 times 10 to the minus
13 4.
14 What is Peter's number?
15 DR. ALEXEEFF: Hanspeter would be 5.
16 ACTING CHAIRMAN FROINES: Unless I'm mistaken --
17 DR. ALEXEEFF: If we use Allan Smith's exact
18 calculations, it would be five. If we use 250, it would end
19 up being one. Okay. That's --
20 DR. WITSCHI: I could live with two things. One
21 is with Allan Smith's estimate, and the other one by some
22 addendum that a point estimate is not good enough, you
23 really have to consider ranges.
24 DR. GLANTZ: We have given them the range, too.
25 I'm not saying -- wait, so you're saying if we did Allan
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1 Smith's just the way he did it, it would also be five?
2 DR. ALEXEEFF: Yes.
3 DR. GLANTZ: Then there's nothing to disagree
4 about. Then we agree, it should be five. Because whether
5 you do it the simple-minded way or the unsimple-minded way,
6 you get the same answer, which means it's probably right.
7 ACTING CHAIRMAN FROINES: Here's what we're going
8 to do.
9 You two are going to work -- you two -- excuse me.
10 You two are going to work with Hans and Stan and the four of
11 you are going to come up with a number, and the two of them
12 are going to write the specific language that will go in
13 here to go with that language.
14 DR. GLANTZ: No.
15 ACTING CHAIRMAN FROINES: No, no, no. We're going
16 to try and get this done.
17 DR. GLANTZ: You mean right now? Okay.
18 ACTING CHAIRMAN FROINES: We're not going to
19 necessarily do it right now. We can agree that the number
20 is going to be in the middle and we'll have to agree that
21 the language will get --
22 DR. GLANTZ: You're making this too complicated.
23 I think we just agreed.
24 ACTING CHAIRMAN FROINES: No, no. But you don't
25 understand is I'm trying to get this process through, one.
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1 Secondly, I'm trying to get a justification that
2 will go to the Air Resources Board that when it's written
3 down they will understand it and say, yes, that makes sense
4 to me.
5 DR. GLANTZ: But let me try and tell --
6 ACTING CHAIRMAN FROINES: I don't want you to try
7 to say it anymore.
8 DR. GLANTZ: John, you're making it --
9 ACTING CHAIRMAN FROINES: I want you to sit down
10 and write it.
11 DR. GLANTZ: Well, no. I think that we've said
12 it. There's two different ways you can do this.
13 One way is to take the Allan Smith simple
14 approach, which with his numbers which leads you to an
15 estimate of 5 times 10 to minus 4, right?
16 ACTING CHAIRMAN FROINES: Right.
17 DR. GLANTZ: Just listen to me.
18 ACTING CHAIRMAN FROINES: Stan, I've heard this
19 twice. You're missing the point.
20 DR. GLANTZ: No, I'm not missing the point.
21 You're missing the point.
22 The other thing is that you can go through this
23 other process that was described, which is more involved,
24 and gives you the same answer. So it doesn't matter.
25 MS. SHIROMA: Dr. Glantz, I think that what the
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1 chair is referring to is at times as we've dealt with
2 substances, the chair directs a subcommittee to come up with
3 the exact language over the next few days type of thing,
4 that is then passed around to the panel members before the
5 chair signs it. I think that's all he's --
6 DR. GLANTZ: I don't think we should put this in
7 the findings. It's too technical. I think if we want to
8 add something to the report explaining this that would be
9 okay.
10 ACTING CHAIRMAN FROINES: Excuse me, but the issue
11 of the quantitative risk assessment has been the most
12 debated element of this entire process. If you're going to
13 put in a range of risk and a unit risk value, you're going
14 to say as part of that, what the justification of it was.
15 Otherwise, I'm not going to send it forward,
16 because it has to be stated clearly to the Air Resources
17 Board the basis of our decision.
18 DR. GLANTZ: But, you see, I think --
19 ACTING CHAIRMAN FROINES: Stan, don't argue with
20 me. That's the way it's going to be. It's got to be
21 written in a coherent, clear way, so that it is effectively
22 justified for the body politic and for the Air Resources
23 Board in particular.
24 I'm sorry. That's the way it has to be.
25 Now, you can go sit out in the hall now and the
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1 two of you can write it, but we're going to get it written
2 before this thing goes forward.
3 DR. GLANTZ: We'll do that now, because I think we
4 need to do that before we leave. We'll go write it.
5 ACTING CHAIRMAN FROINES: George has the numbers,
6 I think.
7 I want everybody to understand why I sound a
8 little bit dogmatic.
9 DR. BLANC: No, I think --
10 DR. BYUS: You're absolutely correct.
11 DR. FRIEDMAN: We understand.
12 DR. BLANC: You don't have to convince us.
13 DR. KENNEDY: Say no more.
14 DR. BLANC: I think that we're trying to preserve
15 consensus in a difficult situation where people hold
16 different points of view, and it's challenging because some
17 of those points of view are so fundamentally different than
18 the process mandates that it does provide an inherent
19 conflict.
20 ACTING CHAIRMAN FROINES: Well, I just -- the
21 other thing is I would hate to see the ARB sued because an
22 inadequate justification for a selection of a value was
23 made.
24 DR. BLANC: No, I think you're right. You don't
25 have to justify yourself to us.
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1 ACTING CHAIRMAN FROINES: You have to tell people
2 why you do things.
3 DR. BLANC: While they're out of the room,
4 Dr. Kennedy, I think you had supported the view, and Stan
5 before he left and Hanspeter had both seemed to be saying
6 that they could live with point 19 coming out. Is that --
7 did anybody object to point 19 coming out?
8 ACTING CHAIRMAN FROINES: I think given the
9 changes in diesel exhaust that are occurring, that makes
10 perfect sense.
11 DR. BLANC: So I think we should move forward and
12 just hear from Dr. Kennedy if there are other issues he
13 wants to bring up.
14 DR. KENNEDY: I have very few. They've
15 essentially all been discussed.
16 I am on this board representing probably a
17 position closer to every man than any of the rest of you.
18 I'm a clinician.
19 I don't deal with the sorts of calculations and
20 perspectives that you do, and I frankly found a lot of the
21 mental gymnastics that were involved in model development
22 and manipulation to be somewhat baffling.
23 And whether it be a function of perspective or
24 simply knowledge based, I am more comfortable in this
25 simpler method of arriving at this information.
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1 Because of it, I think also that section 19 is
2 window dressing. It is not really essential to the
3 information that you're trying to convey and I think it just
4 has no value.
5 With a bit of background in biology, I had some
6 concerns about the mixing of animal and human epidemiologic
7 data, and that's been taken care of, I think, with good
8 compulsive concern for detail.
9 On all other fronts, my only other question
10 relates specifically to section 15 in the middle of the
11 second sentence, sister chromatid exchange in rodents and
12 human cells in vitro. Are the rodent data in vitro as well?
13 ACTING CHAIRMAN FROINES: George?
14 DR. BUDROE: John Budroe, OEHHA.
15 Yes. Both.
16 DR. KENNEDY: Both, yes. Okay. Then I'm happy.
17 DR. BLANC: If you're happy, I'm happy.
18 DR. FUCALORO: Well, go ahead.
19 DR. BLANC: Are you sitting in for John?
20 DR. FUCALORO: Yes.
21 DR. BLANC: Why don't you suggest we take a
22 ten-minute break.
23 DR. FUCALORO: I'm suggesting we take a ten-minute
24 break.
25 (Thereupon a short recess was taken.)
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1 ACTING CHAIRMAN FROINES: Do we have everybody in
2 the room? I want Peter to finish.
3 Peter, I appreciate your comments.
4 All right. I want to wait for Friedman if he's
5 here.
6 DR. KENNEDY: For the record, can I add one
7 additional small statement and that was I am grateful that
8 we have the addition of two additional two studies to expand
9 the database. I think that -- again, as someone who is
10 sitting on the periphery of all this, I'm much more
11 comfortable in our deliberations with the ability to see
12 different perspectives coming up with the same answer.
13 And I think great credit goes to the folk at OEHHA
14 for laboring so long and hard with the work, the information
15 they had.
16 ACTING CHAIRMAN FROINES: Actually I labored to
17 get those two, but that's okay.
18 DR. GLANTZ: Here's what he wrote.
19 And this sort of actually gets --
20 ACTING CHAIRMAN FROINES: Just read it.
21 DR. GLANTZ: The point that Peter just made that
22 you get -- the fact that you get to the same place by such
23 different pathways is, I think, important.
24 Okay. Here is what we wrote.
25 After considering the results of the meta-analysis
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1 of all -- I should say all human studies probably -- as well
2 as the detailed analysis of the studies of railroad workers,
3 the SRP believes that 3 times 10 to the minus 4 is a
4 reasonable estimate of the unit risk expressed in terms of
5 micrograms per cubic meter of diesel exhaust particulates or
6 their surrogates.
7 DR. FUCALORO: To the minus 1?
8 DR. GLANTZ: 3 times 10 --
9 DR. FUCALORO: Micrograms to cubic meter, quantity
10 to the minus 1.
11 DR. GLANTZ: Right.
12 DR. WITSCHI: We can even say instead of believe,
13 came to the conclusion.
14 DR. GLANTZ: Concludes. All right.
15 ACTING CHAIRMAN FROINES: Now, what was the basis
16 for that conclusion?
17 DR. GLANTZ: The basis for the conclusion was what
18 Peter Kennedy said, that when you come at this through two
19 totally disparate approaches you end up with almost
20 identically the same number.
21 ACTING CHAIRMAN FROINES: Write that down, because
22 you can come to a conclusion, but then you tell the audience
23 how you came to the conclusion.
24 DR. GLANTZ: We did. We considered the results of
25 the meta-analysis of all the studies, which is one approach,
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1 and the other approach was the detailed analysis of the
2 railroad workers, which is the second approach.
3 ACTING CHAIRMAN FROINES: And then add Peter's
4 sentence then.
5 DR. BLANC: How about this as that sentence.
6 Thus, this unit risk value reflects two separate approaches
7 yielding similar values.
8 DR. GLANTZ: That's fine.
9 DR. FRIEDMAN: I thought that you said before that
10 it was five. How did you get three?
11 DR. ALEXEEFF: It's actually Dr. Fucaloro
12 explained why it's three and not five. Five would be the
13 risk for the background level of 1.5 micrograms per cubic
14 meter.
15 DR. FUCALORO: No, no, no, no. Five is the five
16 additional cancer cases per -- four and a half -- per
17 10,000.
18 DR. ALEXEEFF: Five is the cancer burden. That is
19 to say when you take into account the background level, but
20 the unit risk value he calculates is three.
21 DR. FUCALORO: Three micrograms per cubic meter to
22 the minus one power.
23 ACTING CHAIRMAN FROINES: Thank you, George.
24 Let me say that we now have a -- how are we
25 describing it? As a reasonable unit risk value, which is
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1 justified on the basis of the evaluation of the data,
2 understanding that there are different data sources and yet
3 when looking at all those data sources this summation
4 represents the best value.
5 Is that --
6 DR. GLANTZ: We're happy with that.
7 ACTING CHAIRMAN FROINES: I'm trying to make sure
8 the record indicates that this is a best value which we have
9 scientific -- what's the word -- scientific confidence in.
10 DR. GLANTZ: Yes.
11 ACTING CHAIRMAN FROINES: And it's meaningful in
12 that regard.
13 DR. GLANTZ: Yes.
14 ACTING CHAIRMAN FROINES: Everybody agrees with
15 that?
16 So around the room, there's no dissent on that
17 point of view?
18 And George or Genevieve are going to take all
19 that's been said today and produce a new draft findings,
20 which will be circulated to the panel for final final
21 agreement; correct?
22 MS. SHIROMA: Yes, that's correct. Before you
23 sign the final.
24 ACTING CHAIRMAN FROINES: Right. I'm trying to be
25 very clear, because simply because we make offhand comments
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1 about risk assessment values, I want to make sure that we
2 all believe in what has been done here.
3 And I think the record that our lawyer friends
4 will now feel confident that we haven't created uncertainty
5 in the findings of the panel.
6 DR. GLANTZ: Paul, why don't you read me the
7 sentence, just to be sure, why don't you read me your
8 sentence, let me write it down and let me reread the whole
9 thing one more time.
10 DR. BLANC: Thus, this unit risk value reflects
11 two separate approaches.
12 DR. GLANTZ: Just a second. This unit risk
13 value --
14 DR. BLANC: Reflects two separate approaches
15 yielding similar values.
16 DR. GLANTZ: Let me just for the record read this
17 one last time, make sure everyone agrees with it.
18 After controlling -- or after considering the
19 results of the meta-analysis of all human studies, as well
20 as the detailed analysis of the railroad workers, the SRP
21 concludes that 3 times 10 to the minus 4 per microgram per
22 cubic meter is -- should I say the best estimate? Because
23 that's what people are now saying.
24 DR. BLANC: No. Reasonable.
25 DR. GLANTZ: Is a reasonable estimate of the unit
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1 risk expressed in terms of diesel particulates or their
2 surrogates. Thus, this unit risk -- or this unit risk --
3 thus, this unit risk value reflects two separate approaches,
4 which yields similar values.
5 ACTING CHAIRMAN FROINES: Great. That's great.
6 DR. GLANTZ: Who should I give that to?
7 ACTING CHAIRMAN FROINES: Give that to Genevieve.
8 That's really good work, gang. That's really good
9 work.
10 And we sent the two people who I would never have
11 predicted would have come back that fast to do it.
12 Friedman and Blanc be back in ten seconds, but you
13 guys.
14 Now, George keeps trying to get in here.
15 DR. ALEXEEFF: Yes. If I could make one proposed
16 modification or clarification.
17 The meta-analysis did not include all of the human
18 studies. There were exclusion criteria for selecting those
19 studies which --
20 ACTING CHAIRMAN FROINES: Can't we put that as a
21 footnote?
22 DR. ALEXEEFF: We can just take out the word all,
23 because it's the meta-analysis of all humans studies, but
24 it's a meta-analysis of human studies.
25 DR. FUCALORO: What you're referring to is a
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1 specific meta-analysis that was done in the report so it's
2 not a vague term.
3 ACTING CHAIRMAN FROINES: Okay. Now, gentlemen --
4 DR. GLANTZ: What about No. 19?
5 DR. BLANC: We got rid of that.
6 DR. GLANTZ: Okay.
7 ACTING CHAIRMAN FROINES: Now, the following is a
8 proposed addition to our findings, and I'm not sure the
9 exact number, but it will be towards the end, maybe 22.
10 It reads as follows.
11 The panel has reviewed the report, "Proposed
12 Identification of Diesel Exhaust as a Toxic Air Contaminant
13 Report," as well as the scientific procedures and methods
14 used to support the data, the data itself and the
15 conclusions and assessments on which the report is based.
16 The panel finds that the report is based on sound scientific
17 knowledge, methods and practices.
18 That's simply is a requirement that says that the
19 panel is acknowledging the State has met the obligation
20 under the law.
21 DR. GLANTZ: So moved.
22 ACTING CHAIRMAN FROINES: So moved.
23 DR. WITSCHI: Second.
24 ACTING CHAIRMAN FROINES: Okay. Secondly, No. 20,
25 we have based on the available scientific information a
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1 level of diesel exhaust exposure below which no carcinogenic
2 effects are anticipated cannot be identified.
3 DR. WITSCHI: I know we have used the sentence
4 before, but strictly speaking the scientific method never
5 can show the evidence that something is not going to happen.
6 DR. FUCALORO: Had not been identified, is that
7 better?
8 ACTING CHAIRMAN FROINES: Shall we say has not
9 been identified?
10 DR. FUCALORO: I don't know if it's plural. It
11 has not been identified.
12 ACTING CHAIRMAN FROINES: Has not. And we reserve
13 the right to --
14 DR. FUCALORO: To find it.
15 ACTING CHAIRMAN FROINES: To find it.
16 Based on available scientific evidence as well as
17 the results of the risk assessment, we conclude that diesel
18 exhaust be identified as a toxic air contaminant.
19 Any no votes at this point we throw that person
20 out.
21 DR. GLANTZ: Actually --
22 DR. BLANC: Oh, please.
23 ACTING CHAIRMAN FROINES: And that's it.
24 DR. GLANTZ: I move we accept the findings.
25 DR. FUCALORO: Before we do that, I really need to
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1 mention something that Jim Seiber wrote, and just be a
2 consideration. I actually think we've covered much of this,
3 so let's see. I haven't read it since we've had this
4 discussion.
5 He writes although the accumulated evidence
6 indicates that diesel exhaust is carcinogenic, there is much
7 uncertainty over the unit risk or potency factor for cancer
8 in humans due to exposure to diesel exhaust.
9 In part this is due to species differences and
10 effects in experimental animals, and in part due to the lack
11 of measured exposure data in diesel locomotive work in
12 epidemiological study.
13 SRP does not support selection of either a single
14 unit -- he does not support a selection of either single
15 unit risk factor or definitive range based upon available
16 data. SRP rather supports a continuing search for
17 scientific basis for developing a single factor with
18 definitive range. A search should focus on diesel exhaust
19 as emitted from diesel engines in current use using diesel
20 fuels in current use.
21 I think the last thing we are going to do, but
22 we've grappled with those other issues.
23 ACTING CHAIRMAN FROINES: I don't think we should
24 take up most of that, because we've already dealt with it.
25 But I would agree that we could put a sentence in
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1 that says that given the difficult issues associated with
2 diesel exhaust that we support and --
3 DR. FUCALORO: Encourage.
4 ACTING CHAIRMAN FROINES: Encourage additional
5 research.
6 DR. GLANTZ: We've already said that. It's in
7 there already.
8 ACTING CHAIRMAN FROINES: Where?
9 DR. FUCALORO: We did it.
10 DR. GLANTZ: It's in there somewhere.
11 It's in No. 7.
12 ACTING CHAIRMAN FROINES: Not in my No. 7.
13 DR. FUCALORO: No. 8.
14 ACTING CHAIRMAN FROINES: It's now become No. 8.
15 But I still don't think that's enough. I think we
16 should have a concluding statement that says further
17 research on diesel exhaust exposure issues and health
18 effects and risk assessment would be -- should be
19 encouraged.
20 DR. BLANC: I would just -- I would not do that,
21 actually.
22 DR. GLANTZ: I agree.
23 DR. BLANC: I would not do that because I think
24 that placing that statement at the end unnecessarily weakens
25 the conclusion, which could come back to be negatively
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1 exploited in ways that you would not intend from such a
2 statement. So I would simply leave well enough alone.
3 I don't think you have any reason to doubt that
4 there's going to be a lot of interest in further research.
5 ACTING CHAIRMAN FROINES: I think -- I disagree on
6 this one with you guys. I think that further research is
7 required and it's important.
8 DR. BLANC: I don't disagree with that. I'm just
9 purely arguing on a tactical, strategic basis, not because I
10 disagree with that.
11 DR. GLANTZ: Our job is not to outline the
12 research agenda. Further research is always required on
13 everything.
14 And I agree. I think that for -- I think that of
15 all the reports that we have looked at on this committee,
16 this is the strongest, except, of course, maybe the one on
17 secondhand smoke, and I think the evidence -- I had to get
18 that in.
19 And I think the statement that he's proposed, that
20 Seiber proposed, really makes it sound like it's weaker than
21 it is. And I mean there's lot of issues that have been
22 brought up in the discussion today that need further
23 research and I think that that speaks for itself.
24 But I don't think that -- I think to put that in
25 as a formal finding at the end like that will make it sound
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1 like there's a lot more uncertainty here than there is.
2 DR. FUCALORO: In fact we have put it in, and you
3 put in No. 7, but look at the last sentence in the old No.
4 10, what is that, No. 11 now. And it says further research
5 would be helpful to quantify the amounts of specific
6 compounds emitted from a variety of engine technologies,
7 operating cycles and fuel to better characterize any
8 differences between old and new fuels and technologies. And
9 I assume old and new refers to both fuels.
10 DR. BLANC: We also said in the non-cancer health
11 that we added a statement that said as new data emerge that
12 this should be --
13 ACTING CHAIRMAN FROINES: I don't have that,
14 because I don't have --
15 DR. BLANC: It's now item 15, the old item 14,
16 that we added the sentence that should be recognized that
17 this REL may need to be lowered further as quantitative --
18 ACTING CHAIRMAN FROINES: I think that there
19 are -- I believe that there are significant research around
20 the mechanism of carcinogenicity, how one addresses
21 interactive effects and complex mixtures. We have never
22 said a word about dermal absorption in this particular
23 document. We do not know the role of nitro-PAHs.
24 And I can give you a list of hundred things that
25 are important.
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1 I think that research is important --
2 DR. BLANC: I'll compromise this far. I don't
3 object to putting in such a sentence. I don't think it
4 should be the last sentence of the document, so if you can
5 figure out a place --
6 ACTING CHAIRMAN FROINES: George and Genevieve,
7 George and Melanie, as you guys are working to finalize this
8 to come back to us, find a place to put a sentence in about
9 the need for additional health effects related to research.
10 And we won't try and do it right this minute.
11 And we'll circulate it.
12 But I frankly think that this -- that there are so
13 many very deep scientific issues, some of which have to do
14 with the fact, for example, I think Mauderly is not entirely
15 correct in the way he's interpreting his animal data, and
16 there are a number of issues that are -- that may show
17 diesel's less of a carcinogen and some may show it more, but
18 I think those issues need to be resolved, because there are
19 immense industrial significance to this use of diesel in the
20 country, and I think we have to take that seriously.
21 So I really believe that a call to recognize that
22 research has to go on is an important and I think this panel
23 should be able to say that without feeling as though we were
24 undercutting ourselves, or causing more insecurity about our
25 findings, because I think this is quite -- this is one of
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1 the best discussions of the science I've ever had in the 15
2 years I've been on this committee.
3 So I think it's a great effort, but I think we do
4 need to recommend that further actions go forward.
5 DR. BLANC: One other small question.
6 The very end of the finding, are you still acting
7 chair? When do you just become chair?
8 ACTING CHAIRMAN FROINES: I don't have anything to
9 do with that.
10 DR. BLANC: That has to come from the ARB?
11 ACTING CHAIRMAN FROINES: Yeah. Maybe I've been
12 here long enough and I can retire.
13 DR. GLANTZ: I'd like to move that we accept the
14 findings as amended.
15 DR. BLANC: I second that.
16 ACTING CHAIRMAN FROINES: I want to congratulate
17 the staff of the two agencies.
18 DR. BLANC: I think, can the record just reflect
19 that we've reached consensus?
20 DR. GLANTZ: Let's vote.
21 ACTING CHAIRMAN FROINES: We'll take a vote.
22 Sorry, I thought I took that as being a given almost.
23 So that the accepting of the findings vote, all
24 those in favor raise their hand for aye.
25 (Showing of hands.)
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1 DR. GLANTZ: It's unanimous.
2 Could I also move that we accept the reports as
3 amended.
4 DR. BLANC: Second.
5 ACTING CHAIRMAN FROINES: All those in favor, say
6 aye.
7 (Ayes.)
8 ACTING CHAIRMAN FROINES: Now can I say thank you?
9 DR. BYUS: Say nice things.
10 ACTING CHAIRMAN FROINES: I think this has been
11 the most extraordinary effort that I've ever viewed in
12 federal or state or local government. I think that the
13 intellectual effort, the perseverance, the tenaciousness is
14 unparalleled. And I think we owe a debt of gratitude, and I
15 think the public of this state owes a debt of gratitude to
16 the people in this room, because I think this has been a
17 real difficult effort, and I think we've come through it and
18 I think we've come through it very very well.
19 And I'm really pleased at the consensus of this
20 committee. I think this committee worked very hard and very
21 well today and at the last meetings, and I think we owe a
22 pat on the back for ourselves, as well as the pat on the
23 back to the staff who have been working with us.
24 So thank you very much. We've made a big step
25 today, I think. And we should all take credit for it.
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1 Good luck at the next stage.
2 MR. OLIVER: Thank you, Chairman Froines.
3 Please let the record reflect that the second
4 motion to adopt the report was carried by unanimous vote of
5 the panel.
6 DR. BLANC: So does you saying Chairman Froines,
7 instead of Acting Chairman Froines, reflect any kind of
8 change in status?
9 MR. OLIVER: Don't worry, it's not correct. It's
10 only a statement from a lawyer.
11 DR. GLANTZ: Are we done?
12 ACTING CHAIRMAN FROINES: We're done. We did it.
13 (Thereupon the meeting was adjourned
14 at 4:25 p.m.)
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1 CERTIFICATE OF SHORTHAND REPORTER
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3 I, JANET H. NICOL, a Certified Shorthand Reporter
4 of the State of California, do hereby certify that I am a
5 disinterested person herein; that I reported the foregoing
6 meeting in shorthand writing; that I thereafter caused my
7 shorthand writing to be transcribed into typewriting.
8 I further certify that I am not of counsel or
9 attorney for any of the parties to said meeting, or in any
10 way interested in the outcome of said meeting.
11 IN WITNESS WHEREOF, I have hereunto set my hand
12 this 29th day of April 1998.
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Janet H. Nicol
17 Certified Shorthand Reporter
License Number 9764
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