This report summarizes the results obtained from testing 201 extracts of engine exhaust particulates in the Salmonella/mammalian-microsome mutagenicity assay (Ames test) from June 1980 to December 1982. Exhaust particulates collected on filters were subjected to a 24 hr soxhlet extraction with methylene chloride. Each blown down sample was shipped to Microbiological Associates where it was assayed at least twice in the Ames test in two separate experiments conducted over a period of several weeks. Each Ames test was conducted in triplicate at five dose levels using up to five Salmonella typhimurium tester strains, TA98, TA100, TA1535, TA1537 and TA1538, both with and without metabolic activation by Aroclor induced Fischer rat liver microsomes. Very often, when the amount of available test article was limited, only one or two tester strains (TA98, TA100) were used. The resulting mutagenicity data was sent to the Data Management Branch of the EPA's Biometry Division in RTP in North Carolina where it was entered into a computerized data base and was statistically analyzed using the method of Stead, et al (1,2).
"April 1984." "EPA 460/3-84-003." "Contract No. 68-03-2923"--T.p. "EPA Project Officer: Craig Harvey"--T.p. Includes bibliographical references (p. 38-44).