河北省某市农村地区集中式供水水质及健康风险分析
Drinking Water Quality of Centralized Water Supply and Health Risk Assessment in Rural Areas of a City of Hebei Province
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摘要:
目的 了解河北省石家庄市农村地区集中式供水的水质卫生状况及其健康风险水平。 方法 于2012年枯水期(4 月)和丰水期(7 月)分别采集该农村地区10 个县的245 个行政村的地下水出厂水水样,检测其砷、镉、铬、铅、汞、氟化物、硝酸盐等16 项指标,采用美国环保局推荐的健康风险评价模型对饮用水中的8 个指标经饮水途径所引起的健康风险作出初步评价。 结果 石家庄市农村饮用水的总合格率为71.84%,不合格的指标有氟化物、硫酸盐、硝酸盐、总硬度、菌落总数和总大肠菌群,其中微生物为主要不合格指标;砷、镉、铬3 种污染物所引起的个人年致癌风险水平由高至低依次为铬(7.38& #215;10-5/a) > 镉(0.68& #215;10-5/a) > 砷(0.67& #215;10-5/a),总风险值为8.73& #215;10-5/a,超过国际辐射防护委员会(ICRP)推荐的最大可接受值(5.0& #215;10-5/a)。非致癌风险中8 种污染物的个人年健康危害风险由高到低依次为砷 > 氟化物 > 硝酸盐 > 铬 > 镉 > 铅 > 锰 > 汞,总风险值为1.30& #215;10-8/a,低于ICRP 推荐的最大可接受值。 结论 石家庄市农村部分县饮用水中铬可能存在一定的健康风险。 Abstract:Objective To evaluate the drinking water quality of centralized water supply in rural areas of Shijiazhuang City, Hebei Province, and assess its health risks. Methods Finished water samples from water treatment plants using underground water as sources were collected from totally 245 villages of 10 counties in the city during dry (April) and wet (July) seasons of 2012, and tested for 16 indicators including As, Cd, Cr, Pb, Hg, fluoride, and nitrate. The health risk assessment model recommended by US. Environmental Protection Agency (US EPA) was used to preliminarily assess the health risks caused by eight indicators through drinking water. Results The total qualified rate was 71.84% for drinking water in the investigated rural areas. Unqualified indicators included fluoride, sulfate, nitrate, total hardness, total bacterial count, and total coliform, and microform was the leading unqualified indicator. The individual levels of cancer risk were 7.38& #215;10-5/a for Cr, 0.68& #215;10-5/a for Cd, and 0.67& #215;10-5/a for As. The total level of cancer risk was 8.73& #215;10-5/a, higher than the maximum tolerable value of 5.0& #215;10-5/a recommended by International Committee of Radiological Protection (ICRP). The individual levels of non-cancer risk caused by the eight pollutants ranked from high to low as follows: As > fluoride > nitrate > Cr > Cd > Pb > Mn > Hg, and the total level of non-cancer risk was 1.30& #215;10-8/a, lower than the maximum tolerable value recommended by ICRP (5.0& #215;10-5/a). Conclusion Cr in drinking water may pose potential health risks in some rural counties of Shijiazhuang City.
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