Exposure to polycyclic aromatic hydrocarbons (PAHs) may lead to adverse health risks. To understand the potential sources and carcinogenic risks of PAHs in Tangshan, 40 PM2.5 samples were collected for analysis of eighteen PM2.5-bound PAHs during non-heating period and heating period. The results display a significant variation. The median concentration of ∑18PAHs during the heating period (282 ng/m3) was higher than during the non-heating period (185 ng/m3). Especially, the median concentration of Benzopyrene (BaP) during the heating period (61.6 ng/m3) was 16.9-fold that during the non-heating period (3.64 ng/m3). It exceeded BaP annual average limit of China (1 ng/m3). Diagnostic ratios (DRs) and principal component analysis (PCA) both indicated that vehicle emissions and coal and biomass combustion were the dominant contributors of PAHs pollution in Tangshan. The incremental lifetime cancer risk (ILCR) of three age groups (children, teenagers, and adults) ranged from 2.56 × 10-6 to 5.26 × 10-5 during the entire sampling periods. The 95% risk values of adults exceeded 10-4 during the heating periods, indicating a potential health risk from PAHs.
Keywords: PM2.5-bound PAHs; heating period; incremental lifetime cancer risk; sources.