Avaliação da toxicidade da mistura dos agrotóxicos 2,4-D (Ácido Diclorofenoxiacético) e Glifosato em anfíbios

Abstract

In this study assessed the effects of mixing two commercial formulations of herbicides widely used in combination in agriculture, the 2,4-D and glyphosate in an amphibian bioindicator species: Physalaemus cuvieri. The chronic trials were held considering environmentally relevant concentrations and maximum concentrations of these herbicides allowed in waters according to the legislation. The mixture of these two agrotoxics caused changes in oral morphology; in the form and / or size of the intestine; spine format; presence of edemas and changes in swimming activity in tadpoles at the concentrations tested. There was an average of 56.8% mortality in the tested concentrations, and a mean lethal concentration (LC50) of 168 hours from 12.52 μg.L-1 (2,4-D) + 142,60 μg.L-1 (glyphosate) to Physalaemus cuvieri. These figures show that the herbicide mixture may be lethal to the species tested, and proving to be a good bioindicator. We suggest that further toxicological tests be carried out with other species in order to verify the toxicity of the mixture of these agrotoxics that can be found in surface water, verifying the impacts that these herbicides may have on the ecosystem.