在江苏某癌症高发县5个乡镇10个村进行布点取样,采集深层地下水与浅层地下水共计20个水样.采用吹扫捕集与气相色谱-质谱联用方法测定水样中14种挥发性有机物(VOCs),检出二氯甲烷、1,3-二氯丙烷、三氯甲烷、苯和四氯化碳5种VOCs,其质量浓度分别为0.14 ～1.71、ND ～ 50.98、0.29～90.02、0.09 ～2.35、0.18～3.45 μg/L.2个水样中的三氯甲烷和6个水样中四氯化碳超过《生活饮用水卫生标准》(GB 5749-2006)规定的限值.采用优化的美国环保局风险评价模型进行人体健康风险评价,其非致癌风险指数为0.000 7 ～0.072,致癌风险水平1.70 ×10-7 ～2.03×10-5,70％水样的致癌风险水平超过10-6水质监控值,2个浅层地下水的致癌风险水平较高.四氯化碳和三氯甲烷对非致癌风险指数和致癌风险水平贡献较大.%Twenty water samples from 10 villages of 5 towns in high cancer incidence area in Jiangsu Province were collected.The water samples from deep underground water and shallow groundwater were analyzed for 14 kinds of volatile organic compounds (VOCs) by GC-MS coupled with a purge and trap thermal desorption system as the extraction technique.The results showed that 5 substances were detected including dichloromethane,1,3-dichloropropane,chloroform,benzene,carbon tetrachloride and their concentrations were respectively 0.14-1.71,ND-50.98,0.29-90.02,0.09-2.35,0.18-3.45 μg/L.Concentrations of chloroform in two samples exceeded the standard level,and concentrations of carbon tetrachloride in 6 samples exceeded the standard level.The health-based risk of VOCs was assessed using the improved USEPA model.The noncarcinogenic risk index was 0.0007-0.072 and the carcinogenic level was 1.70 × 10-7-2.03 × 10-5.The carcinogenic risk level of 70％ water samples exceeded the recommended risk level (10-6).The carcinogenic risk level of two shallow groundwater samples was obviously higher than others.Carbon tetrachloride and chloroform were the most important substances to the noncarcinogenic risk index and carcinogenic risk level of VOCs.
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