Long-Term Atmosphere Surveillance (2016-2021) of PM2.5-bound Polycyclic Aromatic Hydrocarbons and Health Risk Assessment in Yangtze River Delta, China.

Long-term atmospheric quality monitoring of fine particulate matter (PM_2.5) and PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) was performed in Wuxi from 2016 to 2021. In total, 504 atmospheric PM_2.5 samples were collected, and PM_2.5-bound 16 PAHs were detected. The PM_2.5 and ∑PAHs level decreased annually from 2016 to 2021, from 64.3 to 34.0 μg/m³ and 5.27 to 4.22 ng/m³, respectively. The benzo[a]pyrene (BaP) levels of 42% of the monitoring days in 2017 exceeded the recommended European Union (EU) health-based standard of 1 ng/m³. Five- and six-ring PAHs were found, including benz[a]anthracene, benzo[k]fluoranthene (Bkf), BaP, and benzo[g,h,i]perylene, which were the dominant components (indicating a prominent petroleum, biomass, and coal combustion contribution) using molecular diagnostic ratios and positive matrix factorization analysis. Moreover, PM_2.5 and PAHs were significantly negatively associated with local precipitation over a period of six years. Statistically significant temporal and spatial distribution differences of PM_2.5, and ∑PAHs were also found. The toxicity equivalent quotient (TEQ) of total PAHs was 0.70, and the TEQ of BaP (0.178) was the highest, followed by that of Bkf (0.090), dibenz[a,h]anthracene (Dah) (0.048), and indeno[1,2,3-cd]pyrene (0.034). The medians of the incremental lifetime cancer risk for long-term exposure to PAHs were 2.74E-8, 1.98E-8, and 1.71E-7 for children, teenagers, and adults, respectively, indicating that the carcinogenic risk of PAHs pollution in air was acceptable to local residents in this area. Sensitivity analysis revealed that BaP, Bkf, and Dah significantly contributed to carcinogenic toxicity. This research provides comprehensive statistics on the local air persistent organic pollutants profile, helps to identify the principal pollution source and compounds, and contributes to the prevention of regional air pollution.

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Supplementary information: The online version contains supplementary material available at 10.1007/s12403-023-00572-x.