STUDY OF THE GENOTOXIC ACTIVITY OF 6 HALOGENATED ACETONITRILES, USINGTHE SOS CHROMOTEST, THE AMES-FLUCTUATION TEST AND THE NEWT MICRONUCLEUS TEST

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 six halogenated acetonitriles identified in chlorinated wa ters (monochloro-, dichloro-, trichloro-, monobromo-, dibromo- and bro mochloroacetonitrile). With the SOS chromotest, three of the chemicals studied (dichloro-, dibromo- and bromochloroacetonitrile) were found to induce primary DNA damage in Escherichia coli PQ37. In the Ames-flu ctuation test, all the compounds except dibromoacetonitrile showed mut agenic activity on Salmonella typhimurium strain TA100. The newt micro nucleus assay detected a clastogenic effect on the peripheral blood er ythrocytes of Pleurodeles waltl larvae for all the six haloacetonitril es studied. Moreover, two structure-activity relationships were noted: (1) the genotoxic activity of haloacetonitriles containing bromine su bstituents appeared higher than the corresponding chlorinated acetonit riles and (2) the clastogenic activity of the chlorinated acetonitrile s increased with the number of chlorine substituents.