Project at a Glance

Title: An inventory of carcinogenic substances released into the ambient air of California

Principal Investigator / Author(s): Roberts, R. M.

Contractor: KVB, Inc. and Science Applications, Inc.

Contract Number: 1-068-32-221-12

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution, Toxic Air Contaminants


The development of an inventory of carcinogenic substances released into the ambient air of California involved a four-element program. Science Applications, Inc. (SAI) performed Task I and 111, while KVB, Inc. performed Task 11, the results of which are being described in this volume, and Task IV.
The overall objectives of the program have been to:
1) Identify a limited number of carcinogens posing the greatest potential hazard as ambient atmospheric pollutants in California (Task I - SAI);
2) Locate major sources of and estimate emission factors-for this list of carcinogens (Task 11 - KVB).
3) Determine usage patterns, release rates, and population exposures for the sixteen substances regulated by the Occupational Carcinogens Control Act and investigate substances of concern by incorporating into the Task I evaluation (Task III - SAI); and
4) Develop a field test plan to verify the more significant emission factors estimated on Task 11 (Task IV - KVB).

As discussed in the Task I volume, 114 substances regarded by the EPA as having carcinogenic potential were screened. By rating these under the criteria of: (1) annual U.S. production; (2) fraction lost during production; (3) volatility; and (4) carcinogenicity, the group was reduced to 35 substances (compounds or classes of compounds). Further reduction of the list was done through semi-objective quantitative algorithms based upon adding and multiplying rating factors. These included all of the factors listed above (except applied to the State rather than National level) plus rating factors for: (1) projected growth in usage; (2) stability in ambient air; and (3) potential for dispersion after release.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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