Monitoring of urban air pollution by mutagenicity assays.

Urban air particulate extracts were assayed for mutagenicity in Salmonella typhimurium strain TA98 and in the nitroreductase deficient derivatives TA98NR and TA98/1,8DNP6. The results obtained indicate a low contribution of nitropyrenes from diesel exhausts to air particulate mutagenicity in the city of Rome. Fractionation of extracts into acidic, basic and neutral components showed that neutral compounds account for about two-thirds of the total mutagenic activity. No significant mutagenic activity was detected in body fluids of rodents treated with airborne particulate extracts nor in the micronucleus test in mice. Basic and neutral fractions of air particulate extracts proved to inhibit liver aminopyrine-N-demethylase in the mouse.