Crankcase oils: are they a major mutagenic burden in the aquatic environment?

Fractions from used crankcase oil enriched in polyaromatic hydrocarbons induced revertant colonies in Salmonella typhimurium strain TA 98 when activated by rat or trout liver extracts. The mutagenic activity was not due to benzopyrene or benzanthracene. Fractions from various crude and refined petroleums were nonmutagenic. Among various petroleum hydrocarbons entering inland and coastal waters, used crankcase oils may represent a major mutagenic burden.