Ames testing and use of other toxicity tests on drinking water has been proposed before. In general it is not possible to distinguish which compounds in drinking water are responsible for the toxicity. We’ve certainly known for many years that the majority of toxicity potential in drinking water can be attributed to a single compound that goes by the name of MX. General toxicity testing such as this has been debated in the past.
Ceretti E, Moretti M, Zerbini I, Villarini M, Zani C, Monarca S, Feretti D. Occurrence and Control of Genotoxins in Drinking Water: A Monitoring Proposal. Journal of public health research. 2016 Dec 21;5(3):769. doi: 10.4081/jphr.2016.769.
Many studies have shown the presence of numerous organic genotoxins and carcinogens in drinking water. These toxic substances derive not only from pollution, but also from the disinfection treatments, particularly when water is obtained from surface sources and then chlorinated. Most of the chlorinated compounds in drinking water are nonvolatile and are difficult to characterize. Thus, it has been proposed to study such complex mixtures using short-term genotoxicity tests predictive of carcinogenic activity. Mutagenicity of water before and after disinfection has mainly been studied by the Salmonella/microsome (Ames test); in vitro genotoxicity tests have also been performed in yeasts and mammalian cells; in situ monitoring of genotoxins has also been performed using complete organisms such as aquatic animals or plants (in vivo). The combination of bioassay data together with results of chemical analyses would give us a more firm basis for the assessment of human health risks related to the consumption of drinking water. Tests with different genetic end-points complement each other with regard to sensitivity toward environmental genotoxins and are useful in detecting low genotoxicity levels which are expected in drinking water samples.