台州市大气PM_(2.5)中PAHs的污染特征与毒性评价

使用中流量颗粒物采样器采集台州市2015—2016年大气PM_(2.5)样品,利用气相色谱-质谱仪对样品中16种多环芳烃(PAHs)进行分析,研究PAHs的污染特征及可能来源。结果显示:PAHs总浓度为(20.69±4.84)ng/m3,浓度季节变化大小顺序依次为冬季>春季>秋季>夏季,空间变化为商住区>工业区>背景点。PM_(2.5)中PAHs以高环为主(≥4环),占86%。不同季节商住区和工业区PAHs(4环)含量均略高于背景点,PAHs(5~6环)的含量商住区略高于工业区和背景点。PAHs环数分布和比值法结果表明台州市大气PM_(2.5)中PAHs的主要来源是机动车尾气和燃煤。成年人和儿童的终生超额致癌风险(ILCR)分别为8.02×10-7和5.61×10-7,表明台州市PM_(2.5)中PAHs对人体健康影响在可接受范围内。

POLLUTION CHARACTERISTICS AND TOXICITY ASSESSMENT OF PAHs IN PM2.5 IN TAIZHOU

PM2.5 samples were collected in Taizhou using a sampler of medium-flow capacity in 2015-2016,and 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were analyzed by gas chromatography-mass spectrometer to investigate their pollution characteristics and sources.The results indicated that annual average concentration of the PAHs in PM2.5 was (20.69 ± 4.84) ng/m3.From the aspect of season,the order of concentration was winter ＞ spring ＞ autumn ＞ summer,and from the special distribute,the order of concentration was hybrid area of commerce and residence ＞ industrial area ＞ background site.The proportions of the PAHs with four rings in hybrid area of commerce and residence,industrial area were higher than in background site,the proportions of the PAHs with 5 ～ 6 rings in hybrid area of commerce and residence were higher than in industrial area and background site.The proportions of the PAHs with different rings and ratio method results suggested that the PAHs in PM2.5 were mainly from vehicle exhaust and coal combustion.The yearly value of excess lifetime cancer risk (ILCR) for adults and children was 8.02 × 10-7 and 5.61 × 10 7,respectively,showing that PAHs in PM2.5 had small effect on the health of people in Taizhou,and was within the acceptable limits.