郑州市大气PM2.5中多环芳烃的污染特征及健康风险评价

Pollution Characterization and Health Risk Assessment of PM2.5-bound PAHs in Ambient Air in Zhengzhou

为探究郑州市大气细颗粒物PM2.5中多环芳烃(PAHs)的污染特征,在2017年10月—2018年7月期间,选取典型月份采集四季PM2.5样品进行分析。郑州市PM2.5和PAHs的年均质量浓度分别为(93.0±54.6)μg/m^3和(26.3±21.0)ng/m^3,呈现冬季高、夏季低的季节变化趋势;冬季4环PAHs的占比高达41%,春、夏、秋3个季节的环数分布以5和6环比例最大;苯并[a]芘(BaP)和BaP毒性当量的年均质量浓度分别为2.3 ng/m^3和4.0 ng/m^3,四季的质量浓度均在较高水平。增量终生致癌风险评估结果表明,PAHs致癌风险值在0.13×10^-6~1.45×10^-6范围内,部分时间高于美国环境保护署规定的可接受风险水平,存在一定的健康风险。

In order to explore the pollution characteristics of polycyclic aromatic hydrocarbons(PAHs)in fine particulate matter(PM2.5)in Zhengzhou,typical months were selected to collect PM2.5 samples from October 2017 to July 2018.The averagely total mass concentrations of PM2.5 and PAHs in Zhengzhou were(93.0±54.6)μg/m^3 and(26.3±21.0)ng/m^3,presenting the significant seasonal dynamics with remarkably higher concentration in winter and lower concentration in summer.The proportion of PAHs with 4 rings in winter was as high as 41%,while the percentages of PAHs with 5 and 6 rings in other seasons were the largest.The averagely total mass concentrations of Benzo[a]pyrene(BaP)and BaP toxicity equivalent quantity were 2.3 ng/m^3 and 4.0 ng/m^3,and the concentrations of them in four seasons were all at a high level.The results of incremental lifetime cancer risk assessment showed that the carcinogenic risk values of PAHs were in the range of 0.13×10^-6~1.45×10^-6,part of which were higher than the acceptable level of carcinogenic risk set by the US Environmental Protection Agency,indicating that there was certain health risk.