2020年陕西省农村饮用水典型类金属及重金属健康风险评估

Health risk assessment of typical metalloid and heavy metals in rural drinking water in Shaanxi Province in 2020

目的评估陕西省农村饮用水中典型类金属及重金属的健康风险。方法2020年对陕西省农村饮用水进行监测,参照《生活饮用水卫生标准》(GB 5749—2006)对水中砷(As)、镉(Cd)、铬(Cr^(6+))、铅(Pb)、汞(Hg)等5项类金属及重金属浓度进行达标评价,采用美国环保局推荐的健康风险评价方法对农村地区成人经饮水途径暴露于5种类金属及重金属的健康风险进行评价。结果2020年共监测水样6232份,水中Cd、Pb和Hg浓度均达标,As和Cr^(6+)达标率分别为99.98%和98.09%。类金属As的致癌风险水平为3.53×10^(-5),4种重金属的非致癌健康风险水平从大到小依次为Pb>Cr^(6+)>Cd>Hg,总风险水平为0.105;As的浓度水平和健康风险水平分布均为陕北地区>关中地区>陕南地区(P<0.05);As和Cr^(6+)的浓度水平和健康风险水平分布均为地下水>地表水(P<0.05),Cd、Pb、Hg的浓度水平和健康风险水平分布均为地表水>地下水(P<0.05)。结论陕西省农村饮用水中存在潜在As暴露健康风险,通过饮水途径摄入Cd、Hg、Pb、Cr^(6+)4种重金属的非致癌性健康风险尚在可接受水平。

OBJECTIVE Evaluate the health risks of metalloid and heavy metals in rural drinking water in Shaanxi Province,and provide a scientific basis for ensuring the safety of drinking water for rural residents.METHODS In 2020,the rural drinking water in Shaanxi Province were monitored,referring to the“Sanitary Standards for Drinking Water”(GB 5749—2006)for arsenic(As),cadmium(Cd),chromium(Cr^(6+)),lead(Pb),and mercury(Hg)in the water.To evaluate the concentration of five metalloid and heavy metals,the health risk assessment method recommended by United States Environmental Protection Agency was used to evaluate the health risks of adults in rural areas exposed to metalloid and heavy metals through drinking water.RESULTS In 2020,a total of 6232 water samples were monitored.The concentrations of Cd,Pb and Hg in the water all met the standards,and the compliance rates of As and Cr^(6+)were 99.98%and 98.09%,respectively.The carcinogenic risk level of As was 3.53×10^(-5),and the non-carcinogenic health risk levels of the four heavy metals in descending order were Pb>Cr^(6+)>Cd>Hg,and the total risk level was 0.105.The concentration level of As and the distribution of health risk levels were all in northern Shaanxi>Guanzhong region>southern Shaanxi(P<0.05).The concentration level and health risk level distribution of As and Cr^(6+) were all groundwater>surface water(P<0.05),and the concentration level and health risk level distribution of Cd,Pb and Hg were all surface water>groundwater(P<0.05).CONCLUSION There was a potential health risk of As exposure in rural drinking water in Shaanxi Province in 2020.The non-carcinogenic health risks of four heavy metals intake of Cd,Hg,Pb and Cr^(6+) through drinking water were still at an acceptable level.The control of arsenic pollution in drinking water should be further strengthened to ensure drinking water safety.