郑州市环境空气中挥发性卤代烃污染特征与健康风险评价

Pollution characters and health risk assessment of VHCs in ambient air in Zhengzhou

用苏玛罐采样、气相色谱/质谱法分析,研究郑州市环境空气中挥发性卤代烃(VHCs)的污染特征并对其健康风险进行评价。结果显示,郑州市环境空气中共定性检出43种VHCs,其中卤代烷烃28种,卤代烯烃9种,卤代芳香烃6种,卤代烷烃、卤代烯烃、卤代芳香烃的年均质量浓度分别为67.40、34.70、20.30μg/m^3,郑州市各功能区环境空气中VHCs化合物种类稍有差异,背景点VHCs浓度与其他功能区并无显著差异,说明VHCs污染呈现区域性特征;垂直方向上,卤代烷烃浓度随高度呈先降后升趋势,卤代烯烃和卤代芳香烃浓度随高度呈先升后降趋势。健康风险评价结果显示,VHCs单体化合物对人体的非致癌风险均在安全范围内,而总风险超出了安全范围,氯乙烯、三氯乙烯、四氯化碳、氯仿、1,2-二溴乙烷、1,2-二氯乙烷和1,1,2-三氯乙烷的致癌风险超出美国环境保护署规定的可接受值;致癌风险合计为5.32×10^(-4),说明长期暴露于环境空气中对人群健康具有一定危害。

Volatile halocarbons in Zhengzhou ambient air were sampled by summa canister and determined by GC/MS. Pollution characters of VHCs were studied and their health risk were assessed. Results showed that 43 kinds of VHCs which consisting 28 kinds of halogenated hydrocarbons, 9 kinds of alkenyl halides and 6 kinds of halogenated aromatic were identified qualitatively. The annual mean concentrations of halogenated hydrocarbons （67.40 μg/m^3）, alkenyl halides （34.70 μg/m^3） and halogenated aromatic （20.30μg/m^3） were calculated. VHCs species in different functional regions of Zhengzhou were different slightly, while the difference of VHCs concentration between back- ground region and other functional region was insignificant,illustrated that the VHCs pollution had regional character. In vertical direction, the concentration of halogenated hydrocarbons decreased first and then increased, but the distribu- tions of alkenyl halides and halogenated aromatic were opposite. The results of health risk assessment （HRA） indica- ted that non-carcinogenic risk indexes of single VHCs compounds were safe, but the pooled risk of VHCs exceeded the acceptable range. The cancer risk indexes exposed to vinyl chloride, trichloroethylene, carbon tetrachloride, chloroform, 1,2-dibromoethane, 1,2-dichloroethane, 1,1,2-trichloroethane were higher than the acceptable values of EPA. The total cancer risk of these VHCs was 5.32×10^-4. These results indicated that exposed in ambient air of Zheng-zhou might cause potential harm to human health.