遵义市秋冬季PM_(2.5)中多环芳烃的污染特征、来源及健康风险评价

Characteristics,sources and health risk assessment of PAHs in PM_(2.5) during autumn and winter in Zunyi

为探究遵义市秋、冬季PM_(2.5)中多环芳烃(PAHs)的污染特征及来源,于2020年10月~2021年1月采集了遵义市大连路、忠庄和新蒲3个采样点位PM_(2.5)样品,利用GC-MS对样品中16种优控PAHs进行分析,利用特征比值法和多元统计法(PCA-MLR)解析其来源,并采用BaP毒性当量浓度和终生致癌风险模型(ILCR)探讨了PAHs对人体的健康风险。结果表明,研究期间遵义市PM_(2.5)中16种PAHs浓度范围为9.68~108.80 ng/m^(3),平均值为(30.53±22.63)ng/m^(3),呈冬季高、秋季低的季节变化趋势。秋、冬季PM_(2.5)中PAHs环数分布特征一致,高环(5~6环)>中环(4环)>低环(2~3环),以中环、高环PAHs为主。PCA-MLR分析表明PAHs主要来自燃煤和生物质燃烧混合源、机动车尾气,其中,燃煤和生物质燃烧对颗粒物中PAHs的来源贡献最大,秋季为50.6%,冬季为54.8%。遵义市冬季PAHs总毒性当量浓度(TEQ)高于秋季,ILCR结果表明,成年人的ILCR值高于10^(-6),表明有潜在的致癌风险。

To investigate the pollution characteristics and sources of PAHs in PM_(2.5)in Zunyi during autumn and winter,PM_(2.5)samples were collected at Dalian Road,Zhongzhuang and Xinpu from October 2020 to January 2021.Then the concentrations of the 16 PAHs(US EPA priority)were analyzed by using gas chromatography mass spectrometer(GC-MS).Diagnostic ratios and principal component analysis-multiple linear regression(PCA-MLR)were performed for the 16 PAHs sources apportionment,and equivalent carcinogenic concentration of BaP and incremental lifetime cancer risks(ILCR)were applied to assess the health risk.The results showed that the concentrations of the 16 PAHs ranged from 9.68 to 108.80 ng/m^(3),with an average of 30.53±22.63 ng/m^(3)during the study period.The PAHs concentrations exhibited an obvious seasonal variation,with a higher level in winter than in autumn.The percentages of PAHs with different rings were in the following order,5~6 ring PAHs>4 ring PAHs>2~3 ring PAHs,5~6 ring and 4 ring PAHs mainly occurred during autumn and winter.PCA-MLR indicated that PAHs were mainly derived from the emissions of coal combustion,biomass burning and motor vehicle.Coal combustion and biomass burning were the main pollution sources of PAHs in particulate matter,with 50.6%in autumn and 54.8%in winter.The TEQ in Zunyi was higher in winter than in autumn.The results from the risk model showed that the ILCR of adults exceeded 10^(−6),indicating the potential cancer risk of PAHs.