南宁市环境空气中挥发性有机物污染特征与健康风险评价

摘要

In order to analyze the pollution characteristics and health risk assessment of atmospheric VOCs in Nanning city, eight air sites in different parts of Nanning city were chosen to get the air samples by tenax-TA adsorption pipe, the measurements of 22 kinds of VOCs in the ambient air of Nanning city were carried out by hot stripping gas chromatography-mass spectrometry, the ambient level, pollution characteristics and the sources identification were studied, on this basis, the health risk of VOCs in the ambient air in Nanning city was assessed with the international recognized health risk assessment method.Results showed that a total of 10 kinds of substances which belonged to benzene series and halogenated hydrocarbon had been detected in the ambient air, the benzene series was the main source of VOCs in the ambient air.The mean and the range of the mass concentrations of VOCs were 14.2 μg/m3 and 2.8~31.2 μg/m3 , respectively.The concentration ratio of benzene and toluene was between 0.21~0.60.In addition to the motor vehicle exhaust emission, volatilization of paints and solvent were another important sources of VOCs.The order of mean concentration of VOCs in different area was the urban area >industrial area>suburb, the concentration of VOCs in 2014 was higher than that of in 2009.Health risk assessment showed that the hazard index ( HI) was 9.51×10-2 , the cancer RISK value ( RISK) were from 1.14 ×10-7 to 1.22 ×10-5 .VOCs in ambient air had no appreciable risk of adverse non-cancer health effect on the exposed population, the cancer risk for tetrachloroethylene could be accepted, but the chloroform, 1, 2-dichloroethane and benzene in ambient air existed cancer risk, close attention should be paid to this condition.%为分析南宁市环境空气中挥发性有机物（ VOCs）的污染特征、来源与健康风险，选取8个空气采样点，使用Tenax－TA吸附管采样，热脱附气相色谱－质谱法测定了22种VOCs，分析了VOCs的浓度水平、污染特征及其主要来源，并在此基础上采用国际公认的健康风险评价方法，对南宁市环境空气中VOCs的健康风险进行评价。结果表明，南宁市环境空气中VOCs检出了苯系物和卤代烃共10种物质，苯系物是环境空气中VOCs污染的主要来源。南宁市环境空气中VOCs浓度为2．8～31．2μgm／3，均值为14．2μg／m3。苯和甲苯的比值B／T为0．21～0．60。除机动车尾气排放外，涂料和溶剂的挥发是VOCs的另一个重要来源。空气中VOCs平均质量浓度：城市区域＞工业区域＞郊区，2014年高于2009年。健康风险评价，非致癌风险危害指数为9．51×10－2，各污染物致癌风险熵值在11．4×10－7～1．22×10－5之间。环境空气中VOCs对人体不存在非致癌风险，四氯乙烯的致癌风险在可接受范围内，但三氯甲烷、1，2－二氯乙烷和苯存在致癌风险，需引起注意。