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Published November 1994 | public
Journal Article Open

Bacterial Mutagenicity of Urban Organic Aerosol Sources in Comparison to Atmospheric Samples


The bacterial mutagenicity of a comprehensive set of urban particulate air pollution source samples is examined using the Salmonella typhimurium forward mutation assay. Each of the combustion source samples examined, including the exhaust from catalyst-equipped autos, noncatalyst autos, heavy-duty diesel trucks, plus natural gas, distillate oil, and wood combustion sources, is mutagenic in this assay, with a response per microgram of organic carbon in these samples generally greater than that of cigarette smoke aerosol. The noncombustion source samples tested generally are not mutagenic at the levels examined. The specific mutagenicity (mutant fraction per microgram of organic carbon) of ambient aerosol samples collected in southern California is compared to a weighted average of the specific mutagenicity of the primary source samples assembled in proportion to their emission rates in the Los Angeles area. In most cases where a comparison can be made, the specific mutagenicity of the source composites and the ambient samples are of similar magnitude, with the exception that the -PMS mutagenicity of the aerosol at Long Beach, CA, during the first half of the calendar year 1982 and at Azusa, CA, during the April-June 1982 period is much higher than can be explained by direct emissions from the sources studied here.

Additional Information

© 1994 American Chemical Society. Received for review November 23, 1993. Revised manuscript received July 26, 1994. Accepted August 1, 1994. We thank Henny Smith, Woody Bishop, and Deb Allison for performing the S. typhimurium assays; Ed Kruzel for assistance during sample extraction; and Bill Busby for valuable discussions during data analysis. Source and ambient samples were obtained from the archives created during the experiments reported by Hildemann et al. (24) and Gray et al. (251, and we again thank all those who participated in those sampling programs. This work was supported in part by the NIEHS Program Grant 'Health Effects of Combustion Emissions' and an NIEHS Center Grant to MIT, in part by the Caltech Center for Air Quality Analysis, and in part by the US. Environmental Protection Agency (Grant R-819714). This paper has not been subject to the EPA's peer and policy review and, hence, does not necessarily reflect the views of the EPA.

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August 20, 2023
August 20, 2023