Spatial distribution and health risk assessment of heavy metals in drinking water of rural schools in Henan Province / 中国学校卫生

ABSTRACT

Objective@#To evaluate health risks of five heavy metals in drinking water of rural schools in Henan Province, so as to provide scientific basis for drinking water safety in rural schools.@*Methods@#Totally 1 269 drinking water samples were collected and analyzed for five heavy metals (As, Cd, Cr 6+ , Pb, Hg) concentration in 106 cities and counties of Henan Province, and its spatial distribution characteristics were explored by geographic information system (GIS). Risk assessment method recommended by the United States Environmental Protection Agency (U.S. EPA) was applied to evaluate health risks from five heavy metals through oral ingestion.@*Results@#The qualified rate of As concentration was 100%, and the qualified rates of Cd, Cr 6+ , Pb and Hg were 99.9% , 99.9%, 99.5%, 99.6%. The highest carcinogenic risk was As (3.05×10 -5 ), followed by Cr 6+ (2.73×10 -5 ), and the highest non carcinogenic risk was As (0.158 3), followed by Pb(0.041 7). The carcinogenic risk and non carcinogenic risk were all higher in girls than boys. The carcinogenic and non carcinogenic risks were differences in different regions( P <0.05).@*Conclusion@#Health risks of five heavy metals in drinking water for rural schools in Henan Province were within the acceptable risk level recommended by EPA. As, Cr 6+ and Pb were the main health risk factors in drinking water, and that might impact negatively the healthy growth of primary and middle school students. These should be future efforts of drinking water safety management.