Climate Change Based Pm2.5-Bound Pahs Air Pollution In  Chongqing, China from 2015 to 2022: Concentration, Source Tracking, and Health Risks

Abstract

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) are a major environmental challenge worldwide. In this study, the characteristics, sources, and health risks of PM2.5-bounded PAHs and their long-term trends were investigated during the period of 2015-2022 at an urban site in Chongqing, southwest China. The PM2.5 and total PAHs level markedly decreased during the observation period from 100.60 μg/m3 and 25.99 ng/m3 to 48.75 μg/m3 and 7.18 ng/m3, respectively. high-molecular-weight (HMW) were the dominating species among all PAHs subtypes at 55%. Traffic emissions/coal combustion, biomass burning and petroleum were the main sources of PAHs in urban Chongqing, with a relative contribution rate of 56%, 33% and 11%, respectively. The cancer risk showed a downward trend through the observation period, and varied within different age groups. Mont-Carlo simulation showed that the 95th percentile of CR for all groups ranged from 10-6-10-4, indicating a potential carcinogenic risk by inhalation exposure to PM2.5-bound PAHs and necessiating the development of corresponding control measures in urban Chongqing. This research elucidates the principal sources and compositions of PAHs and the associated health risks, facilitating the development of effective prevention measures to control urban air pollution.

Keywords: PM2.5, PAHs, Health risk assessment, Monte Carlo