Health risk assessment for traffic policemen exposed to polycyclic aromatic hydrocarbons (PAHs) in Tianjin, China

In China, traffic policemen have to stand for several hours a day at the road intersections with high vehicle flows. To assess their exposure to airborne carcinogenic polycyclic aromatic hydrocarbons (PAHs) during their working time, a preliminary study was conducted to measure the personal exposure level to PAHs. And a probabilistic incremental lifetime cancer risk (ILCR) model together with the benzo[a]pyrene (BaP) toxic equivalents (BaPeq) method was used to conduct health risk assessment. Personal exposure monitors (PEM) were carried by traffic policemen to collect PM10 samples during their daily work in Tianjin, China. Meanwhile, PM100 samples were collected at the roadsides and on campus of Nankai University as comparison. PAHs species were quantitatively analyzed by GC/MS. Experimental results showed that the concentrations of total PAHs, BaP and BaPeq were much higher at the road intersections (867.5, 26.2, 82.4 ng m−3), where the traffic policemen stand during their work time, than those at the roadsides (46.6, 1.5, 5.7 ng m−3), and on campus (19.5, 0.7, 2.4 ng m−3). According to the risk assessment results, the occupational risk falls within the range from 10−6 to 10−3. On the basis of sensitivity analysis results, further research should be directed to give better characterization of the yearly concentration distribution of PAHs and the cancer slope factor (CSF) of BaP in order to improve the accuracy of the health risk assessment.