Mutagenic 1‐nitropyrene in wastewater from oil‐water separating tanks of gasoline stations and in used crankcase oil

Wastewater collected from oil-water separating tanks of ten gasoline stations for a year was fractionated into diethyl ether-soluble neutral, acidic, and basic fractions. Mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98 and TA100 in the presence or