Health Risk Assessment of Drinking Water Supply in Nanchang

Objectives To assess the quality and health risk of drinking water in Nanchang city.Methods Water samples were collected from centralized drinking water facilities. There were 9 conventional water quality parameters including iron, manganese,copper,zinc, arsenic, fluoride, nitrate-nitrogen and trichloromethane were examined in the rainy period(April,2014);while in the dry period(October,2014),a total of 9 unconventional water quality parameters including antimony, carbofuran, barium, nickel, ammonia-nitrogen, boron,molybdenum,dichloromethane and pentachlorophenol were added into the analysis list for 8 finished water and 2 terminal piped water samples. The health risks based on detectable substances in drinking water were assessed according to the assessment model recommended by the U.S. Environmental Protection Agency.Results The qualification rate of drinking water samples was 100%. The risk of genotoxic substance (arsenic)was higher than non-genotoxic substance; the risk caused by arsenic was accounted for 99.99% of total risks. The risk of each substance was lower than the maximal acceptable value recommended by the International Commission on Radiological Protection (ICRP).The health risk of drinking water samples collected in the rainy period was higher than that in dry period, and the health risk of finished water and terminal piped water were stayed in the same level.Conclusions The health risk of drinking water in Nanchang was in acceptable level recommended by the ICRP, but the risk value of carcinogen arsenic in drinking water was higher than the value recommended by USEPA (1.00×10^-6/a), which should be preferentially concerned and controlled.