Source Identification and Health Risk Assessment of Polycyclic Aromatic Hydrocarbon-Enriched PM2.5 in Tangshan, China.

Tangshan city in Hebei Province is one of the most heavily polluted cities in China, with substantial industrial emissions. The development of effective air pollution emission reduction policies requires knowledge of the sources and health risks of polycyclic aromatic hydrocarbon (PAH)-enriched fine particulate matter (PM2.5 ). We investigated the seasonal variation and source apportionment of 16 priority PAH-enriched PM2.5 samples in Tangshan during 2014 and 2015, and we assessed the health risks associated with inhalation exposure to PAHs. The PM2.5 samples were collected from April 2014 to February 2015. We analyzed the concentrations of PM2.5 and PAH-enriched PM2.5 , and used principal component analysis and molecular diagnostic ratios to identify potential sources. We explored the relationship between distribution and meteorological conditions, and used an incremental lifetime cancer risk (ILCR) model to quantitatively evaluate exposure from the inhalation risk of PAHs. The average mass concentration of PM2.5 was 196 µg/m3 , with a range 34.0 to 586 µg/m3 . The median ∑16 PAH values in PM2.5 were 190 ng/m3 , with a range of 60.2 to 862 ng/m3 over the sampling period. The order of ∑16 PAHs concentration was winter > autumn > summer > spring. The results show that the primary sources of PAH-enriched PM2.5 are coal combustion, vehicle exhaust, and biomass burning. The annual mean of benzo[a]pyrene (BaP) was 8.37 ng/m3 , more than 8-fold greater than the BaP annual standard (1 ng/m3 ) set by the Chinese State Environmental Protection Agency. The ILCR values for 3 groups (children, teenagers, and adults) over the 4 seasons were between 10-6 and 10-4 , indicating a potential health risk from PAHs in Tangshan. Environ Toxicol Chem 2020;39:458-467.