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Particulate Matter Speciation File and Field Descriptions

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PMSPEC: This file contains the actual weight fractions (WTFRACOFPMT, WTFRACOFPM10, and WTFRACOFPM2PT5) that each compound is of the total particulate matter (PMT), particulate matter less than 10 microns (PM10), and particulate matter less than 2.5 microns (PM25), respectively.  Unlike the TOG-based speciation, these fractions have to be multiplied by size fraction data (contained in the PMPROF) file, before they can be multiplied by the PMT-based emissions estimates found in the ARB's CEIDARS database. The PMPRFCD and ARBCHEM codes are the two key (index fields) that define unique records.  The CHEMNAME, CAS, and SPECIE fields are not necessary in this file, and are repeated in the CHEMXREF file (see the information for that file for their field definitions).

  1. PMPRFCD: Field containing the particulate matter profile code assigned to the speciation profile. This code is an arbitrary code assigned by the CARB. It is uniquely listed in the PMPROF file.
  2. ARBCHEM: Field containing the CARB's entirely arbitrary 5 digit chemical code. This is not the same as any code used by any other organization. It used to be referred to as the SAROAD code, but that allowed for confusion, since other organizations also used the "SAROAD" designation. This code allows linkage to the CHEMXREF file, which contains further definitions for this compound. The linkage to the CAS code is very important, since the CAS code is the standard code used by many organizations. Unfortunately, not all of the compound groupings included in the CARB speciation profiles have CAS codes, and in some cases there may be multiple CAS codes for a given CARB speciation profile. The ARBCHEM code reduces the possibility of confusion.
  3. WTFRACOFPMT: This is the actual weight fraction that each compound from the PMT (total particulate matter) fraction is of the PMT emitted by a source. This is the number that will be multiplied by the total PMT emissions contained in the CEIDARS database for a given source to produce the speciated PMT emissions.
  4. WTFRACOFPM10: This is the actual weight fraction that each speciated compound from the PM10 (particulate matter less than 10 microns) fraction is of the PM10 emitted by a source. This is the number that will be multiplied by the size fraction-splitting  WTFRACPM10 field contained in the PMPROF file, and then the resultant product subsequently multiplied by the nonspeciated PMT emissions contained in the CEIDARS database to produce the speciated emissions for the compound that are less than 10 microns.
  5. WTFRACOFPM2PT5: This is the actual weight fraction that each speciated compound from the PM25 (particulate matter less than 2.5 microns) fraction is of the PM25 emitted by a source. This is the number that will be multiplied by the size fraction-splitting WTFRACPM2PT5 field contained in the PMPROF file, and then the resultant product subsequently multiplied by the nonspeciated PMT emissions contained in the CEIDARS database to produce the speciated emissions for the compound that are less than 10 microns.

Master-detail link diagram

Using the data

The data in this file are used in order to speciate the PMT emissions from a source into PMT, PM10, or PM25 size fraction-specific compounds.  For the PM10 and PM25 emissions, you would first have to multiply the WTFRACOFPM10 and WTFRACOFPM2PT5 fields in the PMSPEC file by the WTFRACPM10 and WTFRACPM2PT5 fields, respectively, in the PMPROF file, by linking on the PMPRFCD field. You would then take the PM10 and PM25 products, and also the original, unmodified WTFRACOFPMT fields, and multiply each of them, independently by the CEIDARS PMT emissions values by linking via the PMPRFCD field to the source categories (SCC/EIC codes) indicated in the SCCPM file via the PMPRFCD field, and then to the CEIDARS emission data files via the SCC field (actually SCC or EIC codes). Note that this profile may link to many SCC/EIC designated source codes.

Note that the calculation process for PMT is similar to the TOG calculation process, but for PM10 and PM25 there is the additional step of multiplying by the size fraction.