Analysis of the confounding factors of PM2.5-bound polycyclic aromatic hydrocarbons in population exposure in Xi’an City, China
摘要
To assess exposure levels and identify the toxicity sources of fine particulate matter (PM2.5)-bound polycyclic aromatic hydrocarbons (PAHs) in Xi’an, this study conducted simultaneous ambient air and personal exposure monitoring. The campaign included seven sampling sites across major urban functional zones and recruited representative residents. PAH concentrations in PM2.5 samples were determined via high-performance liquid chromatography. Correlation analysis and characteristic ratio methods were used to evaluate the relations between ambient and personal exposure levels and to identify PAH sources. Results revealed that the total concentration of PM2.5-bound PAHs in winter was 702.43 ± 568.39 ng m−3, with a toxic equivalent quantity (TEQ) of 40.76 ± 25.50 ng m−3. Carcinogenic PAHs were ubiquitously detected (0.050–274.18 ng m−3). The daily average concentration of benzo[a]pyrene (BaP) reached 14.98 ng m−3, exceeding the Chinese National Ambient Air Quality Standard by up to 4.99 times, with an exceedance rate of 95.83%. The average TEQ (22.07 ng m−3) was 1.85 times that of BaP alone, underscoring the considerable contribution of other carcinogenic PAHs. Pentacyclic PAHs were the dominant toxic contributors, primarily originating from coal and petroleum combustion, and chemical products. This study demonstrates that personal PAH exposure in Xi’an is influenced by ambient air quality and individual lifestyles, providing critical insights for targeted exposure mitigation and public health protection.