Lincoln Plaza
Auditorium, First Floor
400 "P" Street
Sacramento, CA

March 26, 1987
1:00 p.m.



87-4-1 Public Meeting to Consider Information 001
Regarding the Effects of Ozone on California
Vegetation and Possible Alternatives for an
Ozone Ambient Air Quality Standard Based on
These Effects.

Other Business

a. Closed Session
1. Personnel (as authorized by State Agency Open Meeting
Act, Govt. Code Sec. 11126(a).).
2. Litigation (Pursuant to the attorney-client privilege,
Evidence Code Sec. 950-962, and Govt. Code Sec.
b. Research Proposals
c. Delegations to Executive Officer

ITEM NO.: 87-4-1

Effect of Ozone on Vegetation and Possible Alternative Ambient
Air Quality Standards.


This report to the Board will describe the effect of ozone on
California vegetation, and will discuss possible alternative
ambient air quality standards specifically based upon ozone
effects on vegetation.

The staff will present information on ozone-caused physiological
injuries to vegetation including effects like reduced
photosynthesis. These physiological changes are seen as obvious
leaf injury, premature aging, early leaf drop, and reduced growth
and vigor. In agricultural crops there have been many
observations of reduced yield and quality. Ornamental plants can
be disfigured or grow in an unsatisfactory manner. Changes in
native plant communities can result in irreversible changes in

The staff will also describe the effects on vegetation damage of
several alternative air quality standards. No specific ambient
air quality standard will be formally proposed at this time.
However, a discussion of the alternatives and the consequences of
attainment of alternative standards will be presented. The
discussion on alternatives will include retention of the current
state standard, statewide three-month seasonal ozone average
standards of varying degrees of stringency, and regional
standards for areas of significant agricultural or natural
biologic resources.

Even though no regulatory action will be taken at this time, the
presentation, the report and its supporting technical document,
testimony and comments may be used in connection with future
Board decisions.


In addition to conducting literature searches and extensive
analyses and contacting experts, staff requested information from
the public on May 30, 1986. This request evoked a number of
comments from the public. These are summarized as follows:

The U.S. Department of the Interior, National Park Service (NPS),
indicated that ozone levels are of great concern to the National
Park Service and the Department of the Interior because of the
deleterious effects ozone has on vegetation in many national
parks, including those in California. They commented that ozone
injury has been documented in several areas where the current
National Ambient Air Quality Standards (NAAQS) of 0.12 ppm has
not been exceeded, indicating that the current NAAQS does not
prevent harmful effects on National Park Service resources.

The U.S. Department of Agriculture, U.S. Forest Service,
submitted comments indicating concern about injury to coniferous
forests in California. They stated that they have found injury
symptoms over a 300-mile long area of the central and southern
Sierra Nevada between elevations of 4,000 and 8,000 feet.
However, they also stated that it remains to be determined if
there are any ozone-induced growth impacts associated with the
injury symptoms.

The Commission of the European Communities sent a copy of a World
Health Organization (WHO) report on the effects of photochemical
oxidants on plants. The report recommended for protection of
sensitive plants the values of .1 ppm for one hour and .03 ppm
for a 100-day growing season.

Dr. Walter E. Westman, of NASA's AMES Research Center, submitted
three articles identifying oxidant damage to California native
vegetation. Oxidants were statistically indicated as the most
likely causal factor in affecting reduced numbers and declining
species variability.

General Motors (GM) submitted comments indicating that it does
not believe there is a justification for a standard lower than
.12 ppm. Those GM comments which address vegetation effects
include conclusions that the NCLAN data are inappropriate for use
in setting a long-term standard in the .04 to .06 ppm range, but
that the data are much clearer in the .06 to .08 ppm range.
Additional comments include the statement that studies using the
antioxidant ethylenediurea (EDU) be given only limited
credibility because of the lack of suitable controls. Other
statements include the suggestion that more resistant cultivars
be developed; and that potential loss in genetic variability has
not been well characterized.

The EPA, Office of Air Quality Planning and Standards (OAQPS),
sent an OAQPS draft staff paper on ozone which includes
recommendations and thorough evaluations of key studies of ozone
relevant to health and welfare.

The EPA staff paper concludes that serious consideration should
be given to setting a long-term standard in the range of 0.04 to
0.06 ppm ozone to protect crops as well as trees and other native

The Western Oil and Gas Association (WOGA) submitted a copy of
the American Petroleum Institute (API) comments on the OAQPS
draft staff paper on ozone dated July 14, 1986 in anticipation
that the comments would also be relevant to the California
review. These comments indicate that API does not believe that
current data supports EPA's suggested long-term standard in the
range of 0.04 to 0.06 ppm to protect vegetation.

The California Dept. of Food and Agriculture submitted a copy of
the Department of Food and Agriculture Air Pollution Manual,
which included information on the methodology used to estimate
crop losses. This manual also indicated that ozone accounts for
80 to 90 percent of the agricultural losses in California due to
air pollutants.