Exposure assessment of PM2.5 and urinary 8-OHdG for diesel exhaust emission inspector

Animal studies have shown exposure to diesel exhaust particles (DEPs) to induce production of reactive oxygen species (ROSs) and increase levels of 8-hydroxydeoxyquanosine (8-OHdG). Controversial results have been obtained regarding the effects of workplace exposure on urinary 8-OHdG level. This study assessed concentrations of environmental PM2.5 in DEP (DEP2.5), personal DEP2.5 and urinary 8-OHdG of diesel engine exhaust emission inspector (inspector) at a diesel vehicle emission inspection station (inspection station). The analysis specifically focuses on the factors that influence inspector urinary 8-OHdG. Repeated-measures study design was used to sample for five consecutive days. A total of 25 environmental PM2.5 measurements were analyzed at 5 different locations by using a dichotomous sampler, and a total of 55 personal PM2.5 measurements were analyzed from inspectors by using PM2.5 personal sampler. During the sampling period, a total of 110 pre- and post-work urine samples from inspectors, and 32 samples from the control group were collected. Following age and sex matching between the inspectors and the control group, levels of urinary 8-OHdG were analyzed.Environmental and personal concentrations of DEP2.5 were 107.25 ± 39.76 (mean ± SD) and 155.96 ± 75.70 μg/m3, respectively. Also, the concentration of urinary 8-OHdG differed significantly between inspector and control non-smokers, averaging 14.05 ± 12.71 and 6.58 ± 4.39 μg/g creatinine, respectively. Additionally, urinary 8-OHdG concentrations were associated with diesel exposure after controlling for smoking and cooking at home. Compared with the control group, the inspector displayed significantly increased levels of urinary 8-OHdG. Diesel exhaust is the single pollutant involved in the exposure of DEP2.5 at the inspection station, as confirmed by the final results.