Determination of mutagenic activities in different fractions of automobile exhaust condensate by the Salmonella/oxygenase mutagenicity test system.

Automobile exhaust condensate of a passenger car (gasoline engine) was separated into fractions of 2-3 rings containing -, 4-7 rings containing polycyclic aromatic hydrocarbons (PAHs) and PAH-free fractions. All fractions were tested for mutagenicity by the Ames system. The highest dose-dependent increase in revertant colonies was found for the 4-7 ring PAH-fraction when tested with Salmonella typhimurium TA 98 and TA 100. These results are compatible with data obtained in in-vivo tests by previous investigations. The mutagenicity of these fractions in the absence of the oxygenase was negligible.