温州城区大气PM2.5中多环芳烃的污染特征与来源解析

Pollution characteristics and sources apportionment of PAHs bound to PM_(2.5) in Wenzhou

使用中流量采样器采集温州城区2015年4个季节的大气PM_(2.5)样品,利用气相色谱(GC)—质谱(MS)联用仪对PM_(2.5)样品中16种优先控制的多环芳烃(PAHs)进行分析,研究PM_(2.5)中PAHs的污染特征及其可能来源。结果显示,PM_(2.5)中总PAHs质量浓度为5.12~81.59ng/m^3,且表现为冬季>秋季>春季>夏季,季节性变化特征明显。比值法和主成分分析显示,温州城区大气PM_(2.5)中PAHs的主要污染源是燃煤、机动车尾气以及生物质燃烧。总PAHs日均毒性当量浓度为0.44~11.28ng TEFs/m^3,平均值为3.44ng TEFs/m^3。成人和儿童的终生超额致癌风险(ILCR)年均值分别为7.11×10^(-7)、4.98×10^(-7),表明温州城区PM_(2.5)中PAHs对人体健康影响水平较低,在可接受范围内。

PM2.5 samples of 4 seasons were collected in Wenzhou using a sampler of medium-flow capacity in 2015 ,and 16 kinds of polycyclic aromatic hydrocarbons （PAHs） bound to PM2 5 were analyzed by gas chromatography （GC）-mass spectrometer （MS） to investigate their pollution characteristics and sources. The results indicated that annual average of the measure total PAHs in PM2.5 ranged from 5.12 ng/m^3 to 81.59 ng/m^3 , and the order of PAHs concentration was winter〉autumn〉spring〉summer,showing obvious seasonal variations. Ratio method and princi-pal component analysis （PCA） suggested that the PAHs bound to PM2.5 were mainly from coal combustion, vehicle exhaustand biomass burning. The daily mean values of total toxicity equivalent conocentration ranged from 0. 44 ng TEFs/m^3 to 11.28 ng TEFs/m^3 , with the average value 3.44 ng TEFs/m^3. The yearly values of excess lifetime cancer risk （ILCR） for adults and children were 7.11×10^-7 and 4.98×10^-7 ,respectively, meaning that PAHs bound to PM2.5 had small effect on the health of people in Wenzhou, which was within the acceptable limit.