Concentrations of Ames Mutagenic Chlorohydroxyfuranones and Related Compounds in Drinking Waters

Abstract

The extremely potent Ames mutagen MX [3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone] has been found to account for a substantial part of the mutagenicity of drinking waters. Some compounds showing structural relationship with MX have been identified in drinking waters, but it has not been investigated whether they are commonly occurring. Therefore, the main purpose of this study was to make a comprehensive survey of the occurrence of such compounds in drinking waters and of their importance as mutagenicity contributors. Drinking water was collected from 35 localities in Finland and from St. Petersburg, Russia. The acidified water samples were processed through XAD-8 resin and eluted with ethyl acetate. The mutagenic activity was measured in the extracts using the Ames Salmonella typhimurium strain TA100 without metabolic activation. In addition, the concentrations of a total of 13 compounds were determined in the extracts using GC/MS in the selected ion monitoring mode. The study confirms that MX is the most important Ames mutagen in chlorine-disinfected drinking waters, accounting for up to 67% of the overall mutagenicity. Furthermore, the study shows that compounds with structural similarities to MX are commonly present in drinking waters, but their total contribution to the overall mutagenicity is on average only 4%.