Genotoxicity of Selected Pesticides in the Hen’s Egg Test for Micronucleus Induction

The presence of toxic substances in natural environments can potentially cause several alterations in organisms. Therefore, it becomes important the use of tests in order to evaluate the potential genotoxicity of these substances. In this work it was used the frequency of micronuclei in hen’s embryos as toxic end point for evaluation of the genotoxic effect of the substances tested. Fertilized eggs of Gallus gallus domesticus were collected and incubated during eleven days. In the eighth day of incubation, the agrochemicals quinclorac, fipronil and pyrazosulfuron-ethyl, used in the irrigated rice culture, were injected and in the eleventh day, a sample of blood was taken. The analysis included the calculation of the frequency of micronuclei for 1000 polychromatic erythrocytes (PCE), to measure genotoxic damages. To evaluate the cytotoxic damages, the ratio between polychromatic erythrocytes and normochromatic erythrocytes was calculated (PCE/NCE). Results demonstrated that the technique is simple, sensible and of easy application. For the dose of 2.7 mg/kg the insecticide fipronil showed significant effect for the presence of micronucleus as well as in the dose of 104.2 mg/kg for the pyrazosulfuron-ethyl herbicide. The herbicide quinclorac did not show significant effects in none of the tested doses. We therefore conclude that these agrochemicals should be better studied with regard to its damaging potential to the environment and to human beings.