Inhalation bioaccessibility, health risk assessment, and source appointment of ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Caofeidian, China.

The inhalation bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) is significant for accurately assessing the health risks posed by PM2.5-bound PAHs. In this study, 96 PM2.5 samples from Caofeidian, China, were investigated for PM2.5-bound PAH source appointment and bioaccessibility assessment during four seasons. PAH18 potential sources were identified by positive matrix factorization. The inhalation bioaccessibility of PAH18 was investigated by simulated epithelial lung fluid extraction. The incremental lifetime cancer risk (ILCR) model was subsequently used to evaluate the carcinogenic risk posed by PM2.5-bound PAHs in children, teenagers, and adults. Four potential sources of PM2.5-bound PAH18 were identified: industry emissions (44%), petroleum volatilization (30%), vehicle emissions (15%), and coal combustion (11%). The average inhalation bioaccessibility of PAHs ranged from 17.8% (dibenzo [a,h] anthracene) to 67.9% (fluorene). The ILCR values for children and teenagers were lower than the acceptable levels (10-6) in the four seasons considering inhalation bioaccessibility. However, the ILCR value of adults was higher than the threshold in winter (1.26 × 10-6). Source identification suggested that reducing industrial pollution was the primary measure for controlling PM2.5-bound PAHs in Caofeidian. Additionally, the inhalation bioaccessibility of PM2.5-bound PAHs was evaluated to precisely estimate the health risks caused by PAHs.

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. © 2019 SETAC.