Benzo(a)pyrene (BP) and several benzo-ring derivatives of BP were tested for carcinogenic activity in mice by topical application of each compound once every 2 weeks for 60 weeks. Chronic treatment of C57BL/6J mice with (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (0.025 to 0.10 micronmole/application) indicated that the dihydrodiol was slightly more active as a complete carcinogen than ...

Numerous polycyclic aromatic hydrocarbons (PAHs) are carcinogenic, making their presence in foods and the environment a health concern. This study assessed the contamination and or/ formation of PAHs in cocoa butter as affected by their cocoa bean drying methods. Three major drying methods were evaluated, including full sundrying, full artificial drying and the drying combination of sundrying f...

Iron foundry workers, exposed to high levels of polycyclic aromatic hydrocarbons (PAHs), silica, and metal fumes and dusts, are at elevated risk of lung cancer. Benzo(a)pyrene and a number of structurally related PAHs are metabolically activated to diol epoxides (e.g., 7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo(a) pyrene) which are mutagenic, carcinogenic in experi...

Iron foundry workers, exposed to high levels of polycyclic aromatic hydrocarbons (PAHs), silica, and metal fumes and dusts, are at elevated risk of lung cancer. Benzo(a)pyrene and a number of structurally related PAHs are metabolically activated to diol epoxides (e.g., 7/S,8a-dihydroxy9a,10a-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene) which are mutagenic, carcinogenic in experimental animals, and ...

Benzo(a)pyrene 1,6-, 3,6-, and 6,1 2-quinones were found to be noncompetitive inhibitors of mixed-function oxidation of benzo(a)pyrene (BP) and frans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene (BP 7,8-dihydrodiol). BP 6,1 2-quinone was the most potent inhibitor of both BP and BP-7,8-dihydrodiol oxi dation followed by BP 1,6-quinone and BP 3,6-quinone. The K, for inhibition of BP mixed-function oxi...

Distribution ratios and sources of polycyclic aromatic hydrocarbons (PAHs), including Fluoranthene (Flt), Pyrene (Pyr), Benzo(a)pyrene (BaP), Benzo(k)fluoranthene (BkP), Indeno(1,2,3-cd)pyrene (IP), Benzo(ghi)perylene (BgP) in urban surface and subsurface soil collected from Riyadh city, Saudi Arabia was studied. The sum of the six PAHs ranged from 30.5-1016.6 ng g -1 with an average of 286.6 i...

Metabolism of benzo[e]pyrene 9,10-dihydrodiol to the bay-region 9,10-diol-11,12-epoxides by hepatic microsomes from human, rat, mouse, guinea pig, hamster, and rabbit has been examined in the presence and absence of 7,8-benzoflavone. In the absence of 7,8-benzoflavone, the formation of bay-region diol epoxides from benzo[e]pyrene 9,10-dihydrodiol was low in all species except the hamster. With ...

The ability of prostaglandin synthetase (PGS) to cooxidize benzo(a)pyrene, benzo(a)anthracene, chrysene, and several of their dihydrodiol derivatives to mutagenic products was tested with Salmonella typhimurium strains TA98 and TA100. The microsomal fraction of ram seminal vesicles, a known source of PGS, in the presence of the PGS substrate arachidonic acid, metabolized benzo(a)pyrene-7,8-dihy...