Increase of urinary concentrations of 8-hydroxy-20-deoxyguanosine in diesel exhaust emission inspector exposed to polycyclic aromatic hydrocarbons

Purpose The objectives of this study were to explore the factors influencing urinary 8-hydroxy-20-deoxyguanosine (8-OHdG) levels in diesel engine exhaust emission inspectors (inspectors), the association between polycyclic aromatic hydrocarbons (PAHs) exposure and fine particulate matter (PM2.5) levels in diesel exhaust particles (DEPs), and the PAHs exposure levels in diesel vehicle emission inspection stations (inspection stations). Methods Twenty-eight inspectors and a control group of thirty-eight individuals matched by age and gender were recruited for this study. Fifteen ambient air samples and eighty-four personal air samples were monitored during 3-day work periods using a repeated-measures study design in each inspection station. Airborne samples were analyzed with a fluorescence detector and by high-performance liquid chromatography. Urinary 8-OHdG was measured in 168 pre- and post-work urine samples from inspectors, and in 38 urine samples from controls. Results The concentrations of PAHs in DEP2.5 (PM2.5 in DEPs) were significantly and positively related to urinary log10 8-OHdG levels after adjusting for smoking status and BMI. Statistically, there was a significant correlation between air log10 PAHs and air log10 PM2.5 concentrations in inspectors. Fifteen PAHs compounds within DEP2.5 revealed the concentrations ranged from 5.18 to 22.93 ng/ m3 in ambient air monitoring and 1.03 to 12.60 ng/m3 in personal air monitoring. Conclusions This study is the first to indicate an association between occupational PAHs exposure from DEP2.5 at an inspection station and an increased excretion of urinary 8-OHdG in inspectors. In addition, this study also found smoking is not a confounder in inspectors exposed to PAHs in DEP2.5.