Human risk assessment of As, Cd, Cu and Zn in the abandoned metal mine site

The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters of the abandoned Songcheon Au-Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils were 230, 2.5, 120, 160, and 164 mg kg(-1), respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 microg L(-1), 161 microg L(-1) and 3899 microg L(-1), respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals. (2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable risk of 1 in 10,000 set for regulatory purposes.