林芝市饮用水水源地健康风险评价

为掌握林芝市饮用水源地水质安全现状,对其境内7个县级以上饮用水源地水样进行检测和分析,通过综合水质标识指数法评价了各水源地水质现状,运用健康风险评价模型评价了各水源水的健康风险。结果表明:林芝市水源地水质总体良好,能满足地表水源地保护区水质功能区II类标准(镉除外),各水源地水体中重金属和氮盐指标经饮水途径对人体造成健康危害的总风险8. 88×10-5～1. 12×10-4a-1之间,均超过了国际放射防护委员会推荐值5. 0×10-5a-1,主要风险因子为致癌物Cd。各水源地致癌物质风险值远高于非致癌物质,该地区人们所面临的致癌风险以镉为主,这需引起水源地管理部门的重视,其余非致癌物风险低于最大可接受限制,对人体健康几乎不构成危害,适合作为饮水水源.。

Health risk assessment of drinking water sources in Linzhi City

In order to grasp the water quality safety status of drinking water sources in Linzhi City, we tested and analyzed the drinking water from seven water sources of county level and above. The respective water quality of the seven sources was assessed using comprehensive water quality labeling index method and their individual health risk assessments were carried out using a health risk assessment model. The results show that the water quality of the city is generally good, and meets the Class II standard of water quality (excluding Cd content). The total health risk of heavy metals and nitrogen salts in the water bodies of these sources is 8.88×10^-5a^-1~1.12×^-4a^-1. Because of the over-high mass concentration of Cd, most of the individual annual health risks exceed the value (5.0×10^-5a^-1) recommended by International Commission on Radiological Protection (ICRP). It is found that the health risk of carcinogens in each water source is much higher than that of non-carcinogens, and the cancer risk faced by the people in this area is mainly caused by Cd, which needs to be addressed by the local department of water source administration. Whereas the remaining non-carcinogen risk is below the maximum acceptable limit, which has little effect on the water quality and poses hardly any threat to human health.