Characterization of PM2.5-bound parent and oxygenated PAHs in three cities under the implementation of Clean Air Action in Northern China

Ambient polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (oPAHs) could act as carcinogenic substances and cause severe health outcome on human beings through inhalation exposure. To protect human health, China government implemented strict control actions (Air Pollution Prevention and Control Action Plan, APPC) to reduce air pollutants emission. Notable achievement of PM2.5 pollution reduction was reported in several studies, while the pollution characteristics of non-routine monitoring PAHs and oPAHs under the impact of APCC were poorly understood. In this study, daily PM2.5 samples in three Chinese cites (Xingtai, Liaocheng, and Heze) were collected for one month in four seasons form 2018-2019 and determined for the PM2.5-bound PAHs and oPAHs. The results showed that the annual PAHs and oPAHs were 58.3 & PLUSMN; 86.1 and 62.7 & PLUSMN; 75.2 ng/m(3) in Xingtai, 36.2 & PLUSMN; 55.6 and 35.9 & PLUSMN; 28.3 ng/m(3) in Liaocheng, and 24.5 & PLUSMN; 37.7 and 35.1 & PLUSMN; 24.7 ng/m(3)& nbsp;in Heze, respectively, suggesting that the PAHs pollution in the measured cities was still considerable and more solid control measures are needed. Significant variations in seasonal concentrations were observed in all the cities with the highest occurring in winter, which is mainly due to solid fuel burning for house heating. Meanwhile, composition profiles of PAHs and oPAHs also showed significant seasonal variations due to the source differences in different seasons. The results of PMF model showed both vehicle exhausts emission and solid fuels burning dominated the PAHs pollution. In summer, vehicles were the major contributor to the total PAHs pollution, while in winter, the contribution of coal combustion emission increased sharply. The correlations analysis between PAHs (oPAHs) and K+ and hopanes also showed a stronger impact of coal combustion in winter time. The result of this study confirmed the goal of clean air in China was calling for continuous actions