COMPARATIVE GENOTOXICITY OF HALOGENATED ACETIC-ACIDS FOUND IN DRINKING-WATER

Three short-term assays (SOS chromotest, Ames fluctuation test and new t micronucleus test) were performed to detect the genotoxic activity o f organohalides, compounds likely to be found in chlorinated and/or oz onated drinking water: monochloro-, dichloro-and trichloroacetic acids and mono-bromo-, dibromo-and tribromoacetic acids, With the SOS chrom otest, only three of the chemicals studied (dichloroacetic acid, dibro mo-and tribromoacetic acids) were found to induce primary DNA damage i n Escherichia coil PQ 37, In the Ames fluctuation test, all the compou nds except monochloroacetic acid showed mutagenic activity in Salmonel la typhimurium strain TA100. In these two in vitro tests, a good corre lation between increasing number of substituents and decreasing mutage nicity was observed, Namely, the toxicity of brominated and chlorinate d acetic acids decreased when the number of substituents increased, Th e newt micronucleus test detected a weak clastogenic effect on the per ipheral blood erythrocytes of Pleurodeles waltl larvae for trichloroac etic acid only.