2023-2024年西安市雁塔区PM2.5中多环芳烃的污染状况及健康风险评价OA

[Background]Polycyclic aromatic hydrocarbons(PAHs)readily adsorb onto the surface of fine particulate matter(PM2.5)and are representative components of organic pollutants in the atmo-sphere.PAHs are known for their significant carcinogenic,teratogenic,and mutagenic toxicity,and long-term exposure to PAHs has adverse effects on human health. [Objective]To investigate the concentration,composition,and pollution sources of 16 priority PAHs in PM2.5 of Yanta District,Xi'an,and to evaluate the associated health risks. [Methods]PM2.5 samples were collected from March 2023 to February 2024.The concentrations of 16 PAHs(ΣPAHs)were determined by high performance liquid chromatography(HPLC).Diag-nostic ratios(DR)and positive matrix factorization(PMF)were used to identify the sources of PAHs.Pearson correlation analysis was applied to examine the relationship between PAHs con-centrations and meteorological factors.Furthermore,the toxicity of individual PAHs was conver-ted into benzo[a]-pyrene(BaP)toxicity equivalents to calculate the toxicity of total PAHs.An in-cremental lifetime carcinogenic risk(ILCR)model was established to evaluate the health risks of PAHs inhalation across different demographic groups. [Results]The average concentration of ΣPAHs in PM2.5 of Yanta District,Xi'an followed a seasonal descending order:winter(15.71 ng·m-3)>spring(5.55 ng·m-3)>autumn(4.34 ng·m-3)>summer(1.47 ng·m-3).The relative abundances of PAHs in PM2.5 varied sig-nificantly by ring number,4-ring PAHs accounted for the largest proportion,followed by 5-ring,3-ring and 6-ring PAHs,while 2-ring PAHs were the least abundant.This ring distribution pattern remained consistent across seasons.The contribution rates of different emission sources to ΣPAHs concentration exhibited seasonal variations.Source apportionment revealed that industrial and traffic emissions were major contributors in spring;traffic emissions dominated in summer and autumn;and coal,natural gas,and biomass combustion were the predominant sources in winter.Correlation analysis showed that ΣPAHs concentration was highly positively correlated with atmospheric pressure and negatively correlated with temperature,but not significantly correlated with precipitation,wind speed,solar radiation,and relative humidity.The ILCR model indicated significant seasonal differences(winter>spring>autumn>summer)in inhalation health risks between adults and children,primarily due to variations in inhalation rates and body weight.Adults faced higher health risks than children across all seasons. [Conclusion]PAHs pollution in PM2.5 of Yanta District,Xi'an is primarily driven by traffic emissions and the combustion of coal,natural gas,and biomass.PAHs concentrations are significantly influenced by meteorological factors,particularly air pressure,and temperature.Inhalation exposure poses distinct health risks to adults in winter.To effectively reduce ΣPAHs concentrations and mitigate air pollution,emission controls on winter coal combustion should be prioritized.