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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