鄱阳湖平原浅层地下水有机污染物含量特征与健康风险评价

为掌握鄱阳湖平原地下水的有机物污染状况,采样并分析了该区地下水中14种挥发性有机物(VOCs)与10种半挥发性有机物(SVOCs)的含量,利用美国环境保护署(USEPA)的健康风险评价模型对其进行健康风险评价。结果表明:鄱阳湖平原地下水的这些有机物的检出率为3. 03%～27. 27%,其中14种VOCs的检出率为6. 06%～15. 15%,10种SVOCs的检出率为3. 03%～27. 27%,部分区域地下水受有机物污染,主要污染物为1,1,2-三氯乙烷、苯并(a)芘和萘;使用内梅罗多项指标的综合污染指数评价污染程度,区域有机物污染特征分为无污染、轻度污染、中度污染以及严重污染四个等级,污染源主要来自杀虫剂、石油化工企业和垃圾填埋场;有机的致癌物质通过饮用途径产生的健康风险远大于非致癌物质的健康风险,其中三氯乙烯、1,1-二氯乙烷、1,2-二氯乙烷、1,1,2,2-四氯乙烷、1,2-二氯丙烷、1,1,2-三氯乙烷、苯并a]芘等通过饮水产生的致癌风险水平分别为最小可接受水平10-6的7. 06、1. 06、18. 7、54、1. 64、14. 4、2. 87倍,a-六六六通过饮水途径引起的致癌风险水平甚至高达1. 03×10~(-4),是区域地下水中主要致癌风险物质。研究成果可为鄱阳湖平原地下水水质污染状况研究及治理监管工作提供理论依据,为其他区域地下水有机物的监测和质量控制提供参考和借鉴。

Characteristics and Health Risk Assessment of Organic Pollutants in Groundwater of the Poyang Lake Plain

In order to understand the status of organic pollution in groundwater of the Poyang lake plain, 14 kinds of volatile organic compounds (VOCs) and 10 kinds of semi-volatile organic compounds (SVOCs) in groundwater samples were analyzed and their health risks were assessed by the health risk assessment model from USEPA. The results showed that organic pollution in groundwater of the Poyang lake plain had become nonnegligible, the main organic pollutants were found to be 1,1,2-trichloroethane, benzo-a]-pyrene and naphthalene, and detection rates of VOCs and SVOCs were in the ranges of 6.06%-15.15% and 3.03%-27.27%, respectively. The organic pollution status in groundwater of the Poyang lake plain could be classified into 4 levels, non-pollution, light pollution, moderate pollution and serious pollution, according to the Nemerow''s comprehensive pollution index method. Three major sources of organic pollutants were pesticides, petrochemical companies, and garbage landfills in the study area. The risks of carcinogenic chemicals in drinking water were significantly higher than those of non-carcinogenic chemicals, and carcinogenic risks of trichloroethylene, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane and benzo-a]-pyrene were 7.06, 1.06, 18.7, 54, 1.64, 14.4, 2.87 times, respectively, of their acceptable levels. The carcinogenic risk index of a-hexachlorocyclohexane, the main substance of carcinogenic risk in groundwater of the study area, in drinking water was as high as 1.03×10^-4. This paper provided a theoretical basis in the groundwater pollution study to control and supervise groundwater quality in the Poyang lake plain, and provided references for monitoring and controlling of groundwater organic pollutants in other regions.