Risk Assessment of Drinking Water Pollutants

Abstract

P-238 Abstract: As expanding municipal and industrial areas since the economic development plan started in earnest from 1970's, the water resource, mainly river surface water has been seriously polluted. Even though the treatment technologies for the drinking water have been upgraded, the safety has been issued one of crucially social problems in Korea. The water authorities has tried to improve the quality such as amending the drinking water quality standard to be monitored; kinds of the standard have been increased to 57 items from 47 items since 2002 by adding more hazardous chemicals and microorganisms. The Water Authorities of Seoul, the capital city of Korea, planned to assess the safety of drinking water quality after amended the standard. This study was conducted to asses the risk due to polluted chemicals including 47 species of heavy metals, VOCs, pesticides, PAHs, DBPs and organic chemicals among the regulated items. The risk assessment was undertaken the hazard identification, the exposure assessment, the dose-response assessment and the risk characterization. For the exposure assessment, the tap water, the bottled water, and the purified water were sampled and analyzed in February 2004. Risk characterization of detected chemicals was categorized into carcinogenicity and non-carcinogenicity. The chemicals of carcinogenicity ware estimated the excess death of carcinogens and the others compared with reference dose (RFD) of non-carcinogens. The excess risk of carcinogens from samples was considered comparatively in the acceptable levels; 10–6 for cancer risk and hazard quotient (HQ) 1.0 for non-cancer risk. The detected levels were estimated in 10–5∼10–6 of cancer risk and below 1.0 of HQ of non-cancer risk. While three kinds of water were determined within the acceptable levels, DBPs were detected in the tap water and the purified water, and some undesirable chemicals in the bottled water such as more fluoride were detected rather than the quality standard. For the drinking water safety, it should be continuously monitored, assessed and managed. As well, there should be the risk communication between the authorities and the public lively.