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The spectroscopic characterization of purine deoxyribonucleoside adducts derived from the fjord-region syn-benzo[g]chrysene 11,12-dihydrodiol 13,14-epoxide and the mutagenic specificity of the latter compound for the supF gene in the pSP189 shuttle vector are described. This dihydrodiol epoxide preferentially forms adducts with deoxyadenosine residues in DNA and is preferentially opened trans in reactions with DNA or with deoxyribonucleotides. In common with other fjord-region syn-dihydrodiol epoxides, the most frequently observed mutational changes were A-->T and G-->T changes. This hydrocarbon dihydrodiol epoxide is structurally similar to syn-benzo[c]phenanthrene 3,4-dihydrodiol 1,2-epoxide but has an additional benzene ring annelated distant from the reaction center. As anticipated, there were some common features in the chemistry and mutagenicities of these two compounds, but there were also substantive differences which indicate factors of importance in controlling reactions of these kinds of compounds with DNA.

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DNA adducts were measured by 32P-postlabelling in lymphocytes and granulocytes of 75 healthy men exposed occupationally and environmentally to high concentrations of aromatic compounds in the ambient air. Volunteers enrolled in the study were men working at the coke batteries and nonoccupationally exposed inhabitants of Silesia, a highly industrialized region in southern Poland. Blood samples were drawn twice: in February and September 1992. Seasonal variations in the levels of DNA adducts were found only in lymphocytes: 3.6- and 8.7-fold in the occupationally and environmentally exposed groups respectively. In smokers the seasonal variation was as large as 12.8-fold in the environmentally exposed group. No seasonal variations were observed in granulocytes. The observed seasonal variation in the level of aromatic DNA adducts coincided with winter/summer differences in the concentrations of benzo[a]pyrene in the ambient air of Silesia. The study recommends the application of lymphocytes for adduct studies in chronic exposures and provides evidence on the repair of aromatic adducts in lymphocytes.