A STUDY ON SAFETY EVALUATION FOR DRINKING-WATER AND CONTROL OF ORGANIC-COMPOUNDS ON WATER-SUPPLY .1. SAFETY EVALUATION FOR ORGANIC-COMPOUNDS IN MUNICIPAL DRINKING-WATER

As sources of water supply are polluted by a number of organic compounds, the pollutants cannot be necessarily eliminated by the usual management such as prechlorination, coagulation and filtration. Moreover, newly halogenated organic compounds such as trihalomethane (THM) are produced during the chlorination process. Consequently, the safety evaluation for drinking water has been required. For this purpose, we have conducted acute toxicity, mutagenicity and carcinogenicity of drinking water. The organic compounds in municipal drinking water were concentrated according to the carbon-adsorption method, and the components adsorbed to charcoal were eluted by chloroform (CCE), ethanol (CAE) and benzene (CBE), in order. The acute toxicity tests of CCE and CAE for mice were carried out by oral dose. CCE and CAE were showed to be toxic mainly in the liver. In the mutagenicity test for CCE, CAE and CBE with the Ames methods showed that only CCE was mutagenic. The concentration of organic halogen in CCE was higher than another two components. From these results, we suppose that the mutagenicity of CCE was due to the halogenated organic compounds. In the carcinogenic test of CCE for A/J-mouse, the occurrence of lung tumor was recognized. However, no strong carcinogenic compound was found in CCE.