成都市饮用水水质监测状况及健康风险初评

[目的]了解近两年成都市饮用水的水质卫生状况及其可致的健康风险水平。[方法]根据供水方式的不同对2008~2009年成都市饮用水及源水进行分层随机抽样,检测砷、耗氧量、总大肠菌群等11项指标,并采用美国EPA推荐的模型对饮用水中主要有害化学物质进行健康风险初步评价。[结果]共检测水样190份(源水25份,饮用水165份),合格率为72.6%,其中饮用水合格率为69.1%,源水合格率为96.0%;饮用水的主要污染物为大肠菌群和锰,其合格率分别为72.7%和92.7%;饮用水合格率农村分散式供水(19.2%)﹤乡镇集中式供水(72.5%)﹤城市集中式供水(98.4%),差异均有统计学意义(P﹤0.01),不合格的饮用水多位于山区且多采用地下水为源水;饮用水中砷、六价铬等8种有害物质累计致癌风险的P50和P95分别为128.3×10-6和299.1×10-6,均低于国际辐射防护委员会(ICRP)推荐的通过饮水途径最大可接受风险水平(5×10-5/年,以70年计为3.5×10-3),主要致癌风险因子为砷、六价铬和铅;累计非致癌风险的P50和P95分别为0.3904和1.0016,主要非致癌风险因子为砷、镉和铅。[结论]本研究初步阐明了成都地区饮用水的卫生状况、水质健康风险水平和污染物的主次,对该地区饮用水水质改善和健康风险管理提供了帮助。

DRINKING WATER QUALITY AND ITS PRELIMINARY HEALTH RISK ASSESSMENT IN CHENGDU

[Objective]To understand the hygienic status and health-based risk level of drinking water in Chengdu for the past two years.[Methods]Levels of As,chemical oxygen demand,total coliforms,etc. in drinking water and source water from all types of water supplies in 2008-2009 were determined based on stratified random samples,and health-based risk caused by the chemical pollutants in drinking water was assessed using US EPA health-based risk assessment model.[Results]A total of 190 water samples consisted of 165...