"Atmospheric" Epoxidation of Benzo[a]pyrene by Ozone: Formation of the Metabolite Benzo[a]pyrene-4,5-Oxide

Benzoa]pyrene deposited on a glass fiber filter reacts rapidly in the dark or light with ambient levels of ozone to yield a mixture of products that display strong direct mutagenicity in the Ames assay. The major stable contributor to this activity has been identified as benzoa]pyrene-4,5-oxide, a DNA-binding metabolite in biological systems, known to be a strong direct mutagen with Salmonella typhimurium strain TA98.