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

Abstract

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.