Health Risk Assessment and Source Apportionment for Heavy Metals in a Southern Chinese Reservoir Impacted by Stone Mining Activities.

Metal contaminants in drinking water pose a potential threat to human health. Metal elements (Fe, Mn, Cu, Cr, Cd, As, and Pb) in Shanzi Reservoir, China, a drinking water source for nearby cities, were measured in 2013 and 2014. The distribution characteristics of metal elements in water were identified and a health risk assessment model was used to evaluate potential harm. Principal component analysis and cluster analysis were used to determine the main sources of metal pollutants. The results showed that Pb and As exceeded the standard at some sampling sites, whereas other metal elements met the drinking water standards. The spatial distribution of metal elements was extremely uneven and might be affected by either the geochemical environment or human activities in the study region. The total risk value of metals (5 × 10-5  a-1 ) was below the recommended value of the United States Environmental Protection Agency (USEPA), the total cancer risk was higher than the total noncancer risk, and both risks were higher for children than for adults. Arsenic was the priority control pollutant, and the priority control site was located upstream of the reservoir. Source analysis showed that Fe, Mn, and Cu were mainly from soil formation and stone mining and processing industries; Pb and As were mainly from agricultural activities, free dumping and burning of domestic garbage, and atmospheric deposition from transportation emissions; Cd was mainly from agricultural application of fertilizers and pesticides; and Cr was from the stone mining and processing industry and from the electroplating and metal manufacturing industries. Integr Environ Assess Manag 2020;16:342-352.