Pollution characteristics and health risk assessment of PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, and halogenated-PAHs in Shanxi, China

Emerging pollutants, nitro-polycyclic aromatic hydrocarbons (NPAHs), and halogenated PAHs (HPAHs), in atmospheric fine particulate matter (PM_2.5) in four cities (Taiyuan, Yangquan, Changzhi, and Jincheng) during the non-heating and heating periods of Shanxi province, China, in 2020, were monitored to investigate their pollution characteristics and potential health risk. The exposure levels of PM_2.5-bound ∑₁₆PAHs, ∑₁₃NPAHs, ∑₆ClPAHs, and ∑₇BrPAHs during the heating period ascended compared to the non-heating period. 2N-Nap, 1N-Nap, 2N-Fle, and 9N-Phe were primary monomers in NPAHs with higher concentrations, while higher levels of 2Br-Fle, 2Cl-Ant, and 9Cl-Phe were in HPAHs. Toxic equivalency quotients (TEQs), incremental lifetime cancer risk (ILCR), and loss of life expectancy (LLE) results suggested that PM_2.5-bound PAHs during the heating periods posed a potential carcinogenic risk. The ILCR and loss of life expectancy (LLE) values of PM_2.5-bound PAHs showed a similar decreasing trend with an order: adults (age 30–70) > toddler >adults (age 18–30) > teenagers > children >baby. The TEQ and ILCR values of ∑₁₃NPAHs and ∑₁₃HPAHs in PM_2.5 were far below the safety threshold, indicating no obvious cancer risks. The pollution of PM_2.5-bound PAHs, NPAHs, and HPAHs and potential health risks in Yangquan and Changzhi was more serious compared to Taiyuan and Jincheng.