Mutagenicity of industrial wastewaters collected from two different stations in northern India

Mutagenicity of wastewaters taken from two different cities was compared by means of Ames plate test and Ames fluctuation test. TA100 and TA98 strains of S. typhimurium exhibited the highest sensitivity against the Saharanpur sample (SWW) in terms of the slope (m) of the dose-response curve in the plate incorporation assay. However, the most sensitive strain against the test samples from Aligarh (AWW) was TA98. Interestingly, TA100 and TA98 strains also displayed the highest susceptibility towards the samples from Saharanpur in the fluctuation test. However, TA102 and TA100 responded maximally to AWW in this bioassay. Interestingly, S9 supplementation resulted in the decline in mutagenic potential of SWW contrary to significant increase with AWW by both the tests. Both samples were found to generate different types of ROS as predominant species. While SWW were shown to generate a high concentration of superoxide radicals and hydrogen peroxide, hydroxyl radicals were predominantly occurring in AWW. From our result, we conclude that both the test water samples were highly genotoxic. In view of the complementary nature of these two testing systems, we recommend both bioassays for the genotoxicity assessment of complex water samples.