Urban airborne particulate: genotoxicity evaluation of different size fractions by mutagenesis tests on microorganisms and comet assay

The genotoxic effects of different size fractions of airborne particulate ( Total, PM10 and PM2.5), extracted with acetone or toluene, were evaluated b y: the Ames plate test (TA98 and TA100 strains, w/o S9), gene conversion an d reversion (w/o endogenous metabolic activation) in the Saccharomyces cere visiae D7 strain, and the comet assay on human leukocytes. The data on huma n leukocytes confirm the sensitivity of the comet assay and its applicabili ty to assess genotoxicity in environmental samples. The PM2.5 fraction of a irborne particulate generally shows the highest concentration of DNA-damagi ng compounds. Genotoxic response, in all the test systems applied, is highl y dependent on extraction solvent used. Acetone seems to extract compounds with more similar genotoxic responses in the three test systems used than t oluene extracts. Toluene appears to extract air pollutants genotoxic on yea st and leukocytes but is mainly cytotoxic on Salmonella. (C) 2001 Elsevier Science Ltd. All rights reserved.