Abstract
Polycyclic aromatic hydroxycarbons (PAH) are common air pollutants generated from incomplete combustion such as automobile exhaust and cigarette smoke. This study was to investigate the influence of individual polymorphisms on PAH exposure and DNA damage from traffic exhaust and/or smoking. The level of urinary 1-hydroxypyrene (1-OHP) and 8-hydroxydeoxyguanosine (8-OHdG) were respectively as biomarkers of PAH exposure and DNA damage for taxi drivers exposed to vehicle exhaust and office employees as the reference. The results showed taxi drivers significantly had higher urinary 1-OHP than office employees (0.17 vs. 0.10 �mol/mol creatinine and 12.2 vs. 10.1 mg/g creatinine). After adjusting for relevant variables, there was a significant correlation between the levels of urinary 8-OHdG and 1-OHP. The subjects with the m1/m2 or m2/m2 genotype of CYP1A1 MspI or GSTM1 deficiency had significantly higher urinary 1-OHP levels than in those with other CYP1A1 MspI and GSTM1 genotypes. 8-OHdG level was correlated with GSTM1 genotypes. In the multiple linear regression, after adjusting for smoking, genotype and other variables, the level of 8-OHdG was correlated to the level of 1-OHP. This study supports that taxi drivers had higher levels of 1-OHP resulted in oxidative DNA damage due to traffic exhaust exposure