Biological monitoring the exposure to polycyclic aromatic hydrocarbons of coke oven workers in relation to smoking and genetic polymorphisms for GSTM1 and GSTT1

Abstract

Occupational exposure to polycyclic aromatic hydrocarbons (PAH) increases the risk of developing lung cancer. Human exposure is often demonstrated by increased internal levels of PAH metabolites and of markers for early biological effects, like DNA adducts and cytogenetic aberrations.Objective: This study aimed to assess whether the current exposure to PAH of coke oven workers in a Dutch plant induced biological effects, and to determine if these effects are influenced by tobacco smoking and by genetic polymorphisms for the glutathione S-transferase genes GSTM1 and GSTT1.Methods: Urinary 1-hydroxypyrene (1-OHpyr) levels were used to monitor the internal dose, while the internal effective dose was assessed by monitoring PAH–DNA adducts, DNA strand breaks (Comet assay), sister-chromatid exchanges (SCE) and cells with a high frequency of SCE (HFC) in lymphocytes together with micronuclei (MN) in exfoliated urothelial cells.Results: Occupational exposure to PAH resulted in statistically significant increased 1-OHpyr levels (P<0.001), but it did not cause a significant induction of SCE, HFC, MN, DNA strand breaks or DNA adducts. Smoking caused a significant increase of 1-OHpyr (P<0.05), SCE (P<0.001), HFC (P<0.001) and DNA adducts (P<0.05), but not of MN or DNA strand breaks. Following correction for the smoking-related effects, no occupational induction of the effect biomarkers could be discerned. Multi-variate analysis did not show a significant influence of GSTM1 and GSTT1 polymorphisms on any biomarker. Also no significant interactions were observed between the various biomarkers.Conclusion: This study shows that in the examined plant, the occupational exposure to PAH does not result in measurable early biological effects