杭州市主城区大气PM2.5中多环芳烃污染特征分析

Pollution characteristics of polycyclic aromatic hydrocarbons in atmospheric PM2.5 in main urban areas of Hangzhou City

目的 监测大气PM2.5中多环芳烃组分及含量,以了解杭州市主城区大气中多环芳烃的污染特征。方法 2014年9月—2021年12月每月定期连续采样7 d~8 d,每日采样23 h。样品经称重后检测多环芳烃组分及含量。结果 2014年—2021年大气PM2.5浓度呈逐年下降趋势;冬春季浓度高于夏秋季。其多环芳烃含量也呈逐年下降趋势,冬春季浓度高于夏秋季。所检测的多环芳烃,除Any、Flu、Acl以外均显示冬春季平均浓度大于夏秋季平均浓度。多环芳烃总质量也呈下降趋势,冬春浓度高于夏秋。在640个监测日中,有20个监测日BaP浓度超过标准限值,占3.125%;以BaP作为参照,有228个监测日,毒性等效浓度超过标准限值,占35.625%。结论 大气PM2.5浓度、多环芳烃总含量、大多数多环芳烃含量、多环芳烃总质量占比呈逐年下降趋势,并具有季节性差异,冬春季浓度(或占比)高于夏秋季。

Objective This paper aims to investigate the pollution characteristics of polycyclic aromatic hydrocarbons(PAHs) in the main urban area of Hangzhou City by monitoring the composition and contents of PM2.5 in the atmosphere. Methods From September 2014 to December 2021, samples were collected regularly and continuously for 7-8 days, 23 hours a day. The weight of samples was measured, and the composition and contents of PAHs were detected. Results From 2014 to 2021, the concentration of atmospheric PM2.5 decreased year by year, the concentration was higher in winter and spring than in summer and autumn. The content of polycyclic aromatic hydrocarbons also decreased year by year, and the concentration was higher in winter and spring than in summer and autumn. The average concentration of PAHs in winter and spring was higher than that in summer and autumn except for Any, Flu and Acl. The total mass of PAHs also decreased, and the concentration was higher in winter and spring than in summer and autumn. In 640 monitoring days, BaP concentration exceeded the standard limit in 20 monitoring days, accounting for 3.125%. Using BaP as reference, the toxicity equivalent concentration exceeded the standard limit in 228 monitoring days, accounting for 35.625%. Conclusion Atmospheric PM2.5 concentration, total mass of PAHs contents, most PAHs contents, and total PAHs mass ratio showed a downward trend year by year, with seasonal differences, and the concentration(or proportion) in winter and spring was higher than that in summer and autumn.