Seasonal Variation and Stability of Chlorinated Organic Mutagens in Drinking Water

Abstract

Seasonal variation of several chlorinated compounds, which are mutagenic and/or carcinogenic, in drinking water of Japan was examined by using a gas Chromatograph equipped with an electron-capture detector and a gas Chromatograph connected with a mass spectrometer. Water samples collected from 10 different points were submitted to physico-chemical analysis, and then subjected to the determination of chlorinated compounds. Potassium permanganate consumption values showed high scores in summer and autumn at all sampling points. Trihalomethanes(CHCl3, CHBrCl2, CHBr2Cl, CHBr3) had a tendency to show high values in summer at the urban areas. On the other hand, a new potent mutagen, 3-chloro-4-dichloromethyl-5-hydroxy-2-(5H)-furanone(MX) did not show any characteristic pattern in all seasons. The stability of MX under certain physical and biological conditions was also investigated. The mutagenic activity of MX on Salmonellatyphimurium TA100(-S9mix) decreased with increase of pH and temperature of the incubation solution. When MX was treated with human serum, the mutagenic activity disappeared in a short time. But, there was no change of the activity by treatment with human saliva.