某市农村地区饮用地下水健康危险度特征分析

[目的]评价某市农村居民饮用地下水中化学污染物对人群带来的健康风险大小,为政府环保部门的治理决策提供科学依据。[方法]对该市A、B、C、D、E 5个边远郊区所辖的1 945个行政村进行饮用地下水抽样调查,计算各区饮用地下水中砷、氟化物、硝酸盐、铁、锰的平均浓度,采用美国环保局推荐的健康风险评价模型对地下水中的化学污染物通过饮水途径所引起的健康风险作初步评价。[结果]该市农村地区地下水中砷的个人终生患癌风险为6.05×10-5;非致癌风险中,砷、硝酸盐、氟化物、锰、铁的终生健康危害指数分别为1.34×10-1、1.75×10-1、1.29×10-1、2.78×10-1、1.68×10-1。A、B、C、D、E区地下水中砷的个人终生患癌风险分别为2.08×10-5、0、1.25×10-5、8.99×10-5、1.03×10-4。均超过了USEPA推荐的可接受的致癌超额危险度1.0×10-6。各地区个人终生患癌风险排列顺序为E区﹥D区﹥A区﹥C区﹥B区。[结论调查地区饮用地下水的健康风险主要来自化学致癌物,需对农村地区饮用地下水中致癌物污染优先治理。

RISK CHARACTERIZATION OF THE RURAL GROUNDWATER FOR DRINKING IN A CERTAIN CITY

[Objective]To assess the risk of chemical pollutants in ground water for drinking on human health and provide the scientific basis for decision-making for government.[Methods]1 945 administrative villages in 5 remote suburbs of A,B,C,D,E were respondents,each administrative village selected a well as the groundwater quality respondent at random;investigated concentrations of As,F-,NO3-,Fe,Mn in groundwater,then used USEPA health risk assessment model to assess health risk associated average concentrations of chemical pollutants in groundwater.[Results]The risk of drinking water mainly came from chemical carcinogens.The carcinogenic risk of As in groundwater of A,B,C,D and E was 2.08 10-5,0,1.25 10-5,8.99 10-5,1.03×10-4,respectively,all of which exceeded 1.0 10-6,the value was recommended by USEPA.[Conclusion]The interrelated government branch should deal with the contaminations of carcinogens preferentially.