USE OF THE SOS CHROMOTEST, THE AMES-FLUCTUATION TEST AND THE NEWT MICRONUCLEUS TEST TO STUDY THE GENOTOXICITY OF 4 TRIHALOMETHANES

Three short-term assays (the SOS chromotest, the Ames-fluctuation test and the newt micronucleus test) were carried out to evaluate the geno toxicity of four trihalomethanes (chloroform, bromodichloromethane, ch lorodibromomethane and bromoform), With the SOS chromotest, all the ch emicals studied except chloroform were found to induce primary DNA dam age in Escherichia coil PQ37, In the Ames-fluctuation test, only bromo form showed mutagenic activity on Salmonella typhimurium strain TA100. The newt micronucleus assay detected a clastogenic effect on the peri pheral blood erythrocytes of Pleurodeles walt1 larvae for bromodichlor omethane and bromoform. It appeared that the presence of bromine subst ituent(s) generally led to significant genotoxic activity. Moreover, t he use of the metabolic system significantly increased the genotoxicit y of the brominated trihalomethanes in the SOS chromotest. Unlike prev ious investigations in which the SOS chromotest was always the least i nteresting assay, this study exhibited the good efficiency of this in vitro test on E. coli for the detection of trihalomethanes with bromin e substituents.