宝鸡冬季PM_2.5中多环芳烃的来源解析及健康风险评估

Analysis of Source and Health Risk Assessment of PM_2.5-Bound Polycyclic Aromatic Hydrocarbons in Winter of Baoji

通过对宝鸡市高新区冬季大气PM2.5中多环芳烃(PAHs)的研究,获得了采样期间PM2.5的昼夜质量浓度及PAHs的组分特征,PM2.5和ΣPAHs的夜间的平均质量浓度均高于白天,分别为41.7 μg∙m−3、31.8 μg∙m−3、62.9 ng∙m−3和51.9 ng∙m−3,且都以5环和4环为主,6环次之,3环所占的比例最小。通过比值法和主成分分析的来源解析表明,冬季大气PAHs的主要污染源,昼间以机动车尾气排放以及煤燃烧为主,夜间以煤燃烧和生物质燃烧为主。冬季昼夜的致癌等效平均浓度(TEQ)分别为10.3 ng∙m−3和14.3 ng∙m−3;致突变等效平均浓度(MEQ)分别为4.2 ng∙m−3和8.9 ng∙m−3,均超过国际和国家标准;终生致癌风险评价模型(ILCR)的评价结果显示,ILCR值介于10−6~10−4,宝鸡市高新区冬季大气中PAHs可能存在潜在致癌风险。

Through the study of polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 of Baoji High-tech Zone in winter, the day-night mass concentration of PM2.5 and the component characteristics of PAHs during the sampling period were obtained. The average mass concentration of PM2.5 and the total of PAHs at night were higher than that in the daytime. They were 41.7 μg∙m−3, 31.8 μg∙m−3, 62.9 ng∙m−3 and 51.9 ng∙m−3, respectively, and were dominated by 5-ring and 4-ring, followed by 6-ring and 3-ring. According to the ratio method and principal component analysis, the main sources of air PAHs in winter are motor vehicle exhaust emissions and coal combustion during the day, and coal combustion and biomass combustion during the night. The equivalent mean concentration (TEQ) of carcinogenesis in winter was 10.3 ng∙m−3 and 14.3 ng∙m−3, respectively. Mutagenic equivalent mean concentrations (MEQ) were 4.2 ng∙m−3 and 8.9 ng∙m−3, respectively, which exceeded international and national standards. The evaluation results of lifetime carcinogenic risk assessment model (ILCR) showed that the VALUE of ILCR was between 10−6~10−4, indicating that PAHs may have potential carcinogenic risk in winter atmosphere of Baoji High-tech Zone.