ENVIRONMENTAL AIR-POLLUTION AND DNA-ADDUCTS IN COPENHAGEN BUS DRIVERS- EFFECT OF GSTM1 AND NAT2 GENOTYPES ON ADDUCT LEVELS

The lymphocyte bulky PAH-DNA adduct levels have been studied in person s occupationally exposed to ambient air pollution, The exposure group consisted of 90 healthy, non-smoking bus drivers from the Copenhagen a rea, divided into three exposure groups according to driving area, and 60 rural controls (smokers and non-smokers), PAH-DNA adducts were det ermined by P-32-postlabelling with the butanol enrichment procedure, T he bus drivers answered a comprehensive questionnaire on passive smoki ng, residential area, diet and other potential confounding variables, A significantly higher adduct level was observed in bus drivers workin g in central Copenhagen (1.214 fmol/mu g DNA, n = 49) compared with bo th those driving in the dormitory (median: 0.507 fmol/mu g DNA, P = 0. 046, n = 16) and suburban (median: 0.585 fmol/mu g DNA, P = 0.041, n = 25) areas, All three groups had higher adduct levels than rural contr ols (0.074 fmol/mu g DNA, n = 60, P < 0.001), No significant influence on adduct levels was demonstrated from potential confounders, includi ng smoking and diet, The effect of the metabolizing enzymes, GSTM1 and NAT2, on adduct levels was investigated, No statistically significant effects were observed on adduct levels from GSTM1 or NAT2, either ind ividually or combined, but a non-significant trend was seen for indivi duals with GSTM10/0 (null), since they had higher adduct levels in al l exposure groups, This study demonstrated that lymphocyte PAH-DNA add uct levels were related to levels of exposure to urban air pollution a nd indicated that these adducts might be helpful as a means of classif ying better different exposure groups for epidemiological studies, Fur thermore, it demonstrated the ability of P-32-postlabelling to discern small differences in low exposure to ambient air pollution and sugges ted a possible effect of GSTM10/0 on DNA adduct levels.