The Jaylet test (newt micronucleus test) and the micronucleus test in xenopus: two in vivo tests on amphibia evaluation of the genotoxicity of five environmental pollutants and of five effluents

The sensitivity and the reliability of two in vivo genotoxicity tests were compared: the Jaylet test (or the newt micronucleus test) and the micronucleus test in xenopus. The Jaylet test is now a French standard method for testing genotoxicity in water, whereas the micronucleus test in xenopus was set up much more recently. Xenopus does, however, have certain practical advantages over the pleurodele. The study involved two phases, in the first we assessed the ability to detect the genotoxicity of five pure substances (selected for their environmental interest) added to the rearing water, and in the second we used the tests to evaluate genotoxicity of five effluents of urban and industrial origin. Three of the five tested substances (carbendazim, potassium chromate and cadmium chloride) were positive in the micronucleus test in xenopus but negative in the Jaylet test. One of these substances was positive with the Jaylet test but not with the micronucleus test in xenopus (pyrene). One substance (bis(tributyltin)oxide) gave negative results in both micronucleus tests. Only two of the five wastewaters were genotoxic with the Jaylet test: wastewater from a built-up area and effluent from a cokery. The effluent from a chemical plant was positive prior to the treatment stage. These two effluents give a positive response with the micronucleus test in xenopus. Wastewaters from the steel factory and the chemical plant were negative with the Jaylet test, but genotoxic to xenopus tadpoles.