三峡库区万州段城乡居民饮用水化学污染物健康风险评价

Health risk assessment research of chemical pollutants in drinking water for urban and rural residents in Wanzhou Section of Three Gorges Reservoir area

目的了解三峡库区万州段城乡居民饮用水化学污染物状况,并进行健康风险评价,分析其危害因素,为人群饮水安全提供科学依据。方法选择三峡库区万州段城乡74家水厂为研究对象,于2020—2021年枯水期(1—5月)和丰水期(6—8月)对其出厂水与末梢水进行监测,按照美国环保署健康风险评价模型对17项化学污染物经饮水途径所致的健康风险进行评价。结果三峡库区万州段城市与农村居民饮用水年均健康总风险与年均致癌风险均分别为1.21×10^(-6)(a^(-1))、1.09×10^(-6)(a^(-1)),非致癌风险分别为4.06×10^(-9)(a^(-1))、3.66×10^(-9)(a^(-1));致癌风险主要来自水中铬(六价)、三氯甲烷、砷、铅、四氯化碳,在城市和农村居民饮用水中化学致癌物的健康风险值占比分别为64.20%和71.41%、22.52%和15.18%、11.59%和11.51%、1.65%和1.84%、0.04%和0.06%。城市与农村的健康风险水平均在国际辐射防护委员会推荐的最大可接受风险水平5×10^(-5)(a^(-1))之下,但均超过瑞典环境保护局推荐的最大可接受风险水平1×10^(-6)(a^(-1))。结论三峡库区万州段城乡居民饮用水健康总风险均超过瑞典环保局推荐的可接受风险水平,须进一步对其相关化学污染物开展监测,特别是要控制好铬(六价)、三氯甲烷、砷、铅、四氯化碳等致癌危害因素。

ObjectiveTo understand the status of chemical pollutants in drinking water of urban and rural residents in Wanzhou section of the Three Gorges reservoir area,and to carry out health risk assessment,analyze the hazard factors,and provide scientific basis for drinking water safety of the population.MethodsSeventy-four water factories in the Wanzhou section of the Three Gorges Reservoir area were selected as the research objects.The factory water and the peripheral water were monitored during the dry season(January to May)and the wet season(June to August)in 2020-2021,and the health risks caused by 17 chemical pollutants through drinking water were evaluated according to the US Environmental Protection Agency health risk assessment model.ResultsIn Wanzhou section of the Three Gorges Reservoir area,the annual total health risk and annual cancer risk of urban and rural residents were 1.21×10^(-6)(a^(-1)),1.09×10^(-6)(a^(-1)),and the annual non-cancer risk were 4.06×10^(-9)(a^(-1)),3.66×10^(-9)(a^(-1)),respectively.All carcinogenic risks were caused by Chromium(hexavalent),Chloroform,Arsenic,Plumbum and Carbon tetrachloride in drinking water.The health risk values of chemical carcinogens in drinking water of urban and rural residents were 64.20%and 71.41%,22.52%and 15.18%,11.59%and 11.51%,1.65%and 1.84%,0.04%and 0.06%,respectively.Both urban and rural health risk levels are below the maximum acceptable risk level of 5×10^(-5)(a^(-1))recommended by the International Commission on Radiological Protection,but exceeded the maximum acceptable risk level of 1×10^(-6)(a^(-1))recommended by the Swedish Environmental Protection Agency.ConclusionsThe total health risk of drinking water for urban and rural residents in Wanzhou section of the Three Gorges Reservoir area exceeds the acceptable risk level recommended by the Swedish Environmental Protection Agency.It is necessary to further monitor the related chemical pollutants,especially to control carcinogenic factors such as Chromium(hexavalent),Chloroform,Arsenic,Plumbum and Carbon tetrachloride.