Health risk assessment of chemical pollutants in drinking water in a Pearl River Delta city

Objective To give an initial evaluation on the potential health risk of chemical pollutants in drinking water in a Pearl River Delta city. Methods The concentration of 5 genetic toxic substances (As, Cr⁶⁺, Cd, CHCl₃, CCl₄) and 12 non-carcinogenic substances (Pb, Hg, Se, CN^-, F^-, NO^-₃, Fe, NH₃-N, Mn, Cu, Zn, volatile phenol) in source water, finished water and tap water in a Pearl River Delta city were tested from January to December, 2015. The health risk of exposure to chemical pollutants through oral route was assessed according to the evaluation models recommended by United States Environmental Protection Agency. Results The carcinogenic risk, non-carcinogenic risk and total health risk caused by chemical pollutants in source water were 3.75×10^-5/a,206.27×10^-11/a and 3.75×10^-5/a respectively. The carcinogenic risk, non-carcinogenic risk and total health risk caused by chemical pollutants in finished water were 3.32×10^-5/a,142.68×10^-11/a and 3.32×10^-5/a respectively. The carcinogenic risk, non-carcinogenic risk and total health risk caused by chemical pollutants in tap water were 3.37×10^-5/a,150.34×10^-11/a and 3.37×10^-5/a respectively. The carcinogenic risk, non-carcinogenic risk and total health risk caused by chemical pollutants ranked from high to low as source water > tap water > finished water. Conclusions The health risk caused by 17 chemical pollutants in source water, finished water and tap water were below the maximal acceptable value recommended by International Commission on Radiological Protection (5.0×10^-5/a) in a Pearl River Delta city.