Smoking modify the effects of polycyclic aromatic hydrocarbons exposure on oxidative damage to DNA in coke oven workers

Coke oven emissions containing polycyclic aromatic hydrocarbons (PAHs) are predominant toxic constituents of particulate air pollution that have been linked to increased risk of lung cancer. Numerous epidemiological studies have suggested that oxidative DNA damage may play a pivotal role in the carcinogenic mechanism of lung cancer. Little is known about the effect of interaction between PAHs exposure and lifestyle on DNA oxidative damage. The study population is composed by coke oven workers (365) and water treatment workers (144), and their urinary levels of four PAH metabolites and 8-hydroxydeoxyguanosine (8-OHdG) were determined. Airborne samples of exposed sites (4) and control sites (3) were collected, and eight carcinogenic PAHs were detected by high-performance liquid chromatography. The median values of the sum of eight carcinogenic PAHs and BaP in exposed sites were significantly higher than control sites (P < 0.01). The study found that the urinary PAH metabolites were significantly elevated in coke oven workers (P < 0.01). Multivariate logistic regression analysis revealed that the risk of high levels of urinary 8-OHdG will increase with increasing age, cigarette consumption, and levels of urinary 1-hydroxypyrene, and P for trend were all < 0.05. Smoking can significantly modify the effects of urinary 1-hydroxypyrene on high concentrations urinary 8-OHdG, during co-exposure to both light or heavy smoking and high 1-hydroxypyrene levels (OR 4.28, 95% CI 1.32-13.86 and OR 5.05, 95% CI 1.63-15.67, respectively). Our findings quantitatively demonstrate that workers exposed to coke oven fumes and smoking will cause more serious DNA oxidative damage.