[Effects of smoking on concentration of urinary 8-hydroxydeoxyguanosine in coke oven workers]

Objective: To explore the influence of smoking and polycyclic aromatic hydrocarbons (PAHs) on urinary 8-hydroxydeoxyguanosine (8-OHdG) in coke oven workers and investigate their dose-dependent relationships. Methods: A total of 436 workers exposed to coke oven emissions (COEs) and 132 controls were recruited in this study. Questionnaires were completed in a personal interview. Then their urine samples were also collected and the concentrations of urinary four OH-PAHs and 8-OHdG were determined by high performance liquid chromatography (HPLC) which was used to evaluate the levels of occupational PAHs internal exposure among workers and the DNA damage. Results: The differences of concentrations of urinary 2-NAP (2-hydroxynathalene) , 2-FLU (2-hydroxyfluorene) , 9-PHE (9-hydroxyphenanthrene) , 1-OHP (1-hydroxypyrene) between exposure group and control group were statistically significant (P<0.05) . In exposure group and control group, the level of 8-OHdG in heavy smoking workers were significantly higher than that in other groups (P<0.05) . Multivariate logistic regression analysis revealed high levels of urinary 8-OHdG were associated with a significantly increased risk of having higher urinary1-hydroxypyrene levels[OR=1.43 (95%CI: 1.06-1.94) , P<0.01] and heavy smoking [OR=1.44 (95%CI: 1.08-1.91) , P<0.01], respectively. Trend test showed that linear dose response relationship between smoking, 1-OHP in urine and higher concentrations of 8-OHdG (P<0.05) . Smoking could significant modify the effects of urinary 1-hydroxypyrene, while co-exposure to both heavy smoking and high urinary 1-hydroxypyrene levels[OR=5.64 (95%CI: 2.15-14.80) , P<0.05]. Conclusion: Urinary 1-hydroxypyrene is a useful biomarker for evaluating total PAHs exposure, coke oven workers with heavy smoking present more serious DNA oxditive damage.