The influence of 18 environmentally relevant polycyclic aromatic hydrocarbons and Clophen A50, as liver monooxygenase inducers, on the mutagenic activity of benz[a]anthracene in the Ames test.

In the presence of various liver S9 preparations induced by different polycyclic aromatic hydrocarbons, the weak carcinogen, benz[a]anthracene, exhibited mutagenic activities comparable to those of benzo[a]pyrene in the Ames test. A series of positive correlations were found between mutagenic activity and the hydroxylation products of benz[a]anthracene at the 3,4-, 5,6- and 8,9-positions, of which 5,6-position was the most pronounced one (p less than 0.01). Our results suggest that the observed mutagenic activity is due mainly to the generation of K-region epoxides.