Carcinogens and Mutagens in Ambient Air Particulate Matter: Sources and Trends in Contra Costa County

摘要

The report describes a more sensitive method for measuring aerosol mutagens, the identification of sources of mutagens and the analysis of trends in mutagen and polycyclic aromatic hydrocarbon (PAH) levels in particulate organic matter (POM). A highly sensitive version of the Ames Salmonella test, called the microsuspension test, was applied to measure the mutagenic activity in organic extracts of community aerosols. Application of the test made possible high resolution diurnal studies of mutagenicity in air samples of only 2 hours duration. The origins of mutagens in POM were investigated during seasonal pollution episodes. Samples were analyzed for mutagenic activity, PAH, NO3(-1), pollutant gases and elemental source tracers. Industrial contributions to mutagenic aerosols were suggested by significant positive correlations between mutagens and S at stations near oil refineries and chemical plants. Mutagens and PAH were also positively correlated with tracers for motor vehicles, (Br, CO) and secondary aerosols (NO3(-1)). Routine collection and analysis of 4 month seasonal composite filter samples was carried out between 1979-1984. Levels of most pollutants, including mutagens and PAH, were highest in the winter (Nov. - Feb.). Monitoring also revealed a positive trend in the concentration of mutagenic aerosols, despite decreasing or constant levels of other pollutants including PAH.