Avalia??o da toxidade cr?nica do fungicida Tebuconazole utilizando o organismo teste Daphnia magna

The increasing agrochemicals use in agricultural activities and the excessive use of these substances can cause more damage to the human health and to the environment, creating the need to study and understand their behavior and their interactions with the ecosystem in which they are dispersed In this way the present study aims to evaluate the effects of chronic toxicity of the fungicide Tebuconazole through the parameters survival, reproduction, growth and morphology of the microcrustacean Daphnia magna. The chronic toxicity tests were performed according to NBR 13.373 (ABNT, 2017), where the organisms were exposed for 21 days at different concentrations of the fungicide Tebuconazole (100 ?g / L - 500 ?g / L and 20 ?g / L - 80 ?g / L). The first generation of the organisms produced in the chronic test was also evaluated in order to identify the possible effects of toxicity among multigenerations. In order to identify the interactions of the fungicide Tebuconazole with D. magna, a test to evaluate the recovery of the reproduction of exposed organisms was carried out. In this test the exposed organisms were arranged in M4 medium for the period of 10 days after finish the chronic test. Through the chronic toxicity tests carried out in this research, effects on the morphology, reproduction and mainly on the longevity of the exposed organisms could be observed. In addition to these effects, it was observed that the first generation of neonates from exposed parental organisms acquired greater resistance to the fungicide Tebuconazole, with Observed Effect Concentration (CEO) for longevity equal to 20?g/L for parental organisms, and equal to 80 ?g/L for the 1st generation organisms. It was also observed that even after 10 days of permanence in culture medium (M4), no positive changes were observed regarding the reproduction parameter, thus indicating the permanence of the effects caused by the fungicide Tebuconazole. It was concluded that the Tebuconazole fungicide has the capacity to cause adverse effects of toxicity on the microcrustacean D. magna, emphasizing the importance of studying the effects of chemical substances in the long term.A crescente utiliza??o de agrot?xicos nas atividades agr?colas e o uso desmedido dessas subst?ncias podem provocar cada vez mais danos ? sa?de humana e ao meio ambiente, gerando assim a necessidade de estudar e entender o comportamento e as intera??es das mesmas com o ecossistema em que s?o dispersas. Desta forma o presente estudo tem por objetivo avaliar os efeitos de toxicidade cr?nica do fungicida Tebuconazole atrav?s dos par?metros sobreviv?ncia, reprodu??o, crescimento e morfologia do microcrust?ceo Daphnia magna. Os testes de toxicidade cr?nica foram realizados de acordo com a NBR 13.373 (ABNT, 2017), onde os organismos foram expostos, pelo per?odo de 21 dias, a diferentes concentra??es do fungicida Tebuconazole (100 ?g/L ? 500 ?g/L e 20 ?g/L ? 80 ?g/L). Ainda foi avaliada a primeira gera??o dos organismos produzidos no teste cr?nico de maneira a identificar os poss?veis efeitos de toxicidade entre multigera??es. Para avaliar de forma mais completa as intera??es do fungicida Tebuconazole com a D. magna um teste de avalia??o da recupera??o da reprodu??o dos organismos expostos foi realizado. Neste teste os organismos expostos foram dispostos em meio M4 pelo per?odo de 10 dias. Atrav?s dos testes de toxicidade cr?nica realizados nesta pesquisa p?de-se observar efeitos sobre a morfologia, reprodu??o e principalmente sobre a longevidade dos organismos expostos. Al?m destes efeitos p?de-se observar que a 1? gera??o de neonatos provenientes de organismos parentais expostos adquiriram maior resist?ncia ao fungicida Tebuconazole, sendo Concentra??o de Efeito Observado (CEO) para a longevidade igual ? 20 ?g/L para os organismos parentais, e igual a 80 ?g/L para os organismos da 1? gera??o. Observou-se ainda, que mesmo ap?s 10 dias de perman?ncia em meio de cultivo (M4), n?o foram observadas mudan?as positivas referentes ao par?metro reprodu??o, indicando assim a perman?ncia dos efeitos causados pelo fungicida Tebuconazole. P?de-se concluir, atrav?s dos resultados encontrados neste estudo, que o fungicida Tebuconazole tem a capacidade de provocar efeitos adversos de toxicidade sobre o microcrust?ceo D. magna, destacando a import?ncia de estudar os efeitos de subst?ncias qu?micas a longo prazo