Investigação da ocorrência de agrotóxicos em águas superficiais nas bacias hidrográficas dos rios Piratinim e Comandaí.

Abstract

Contamination of surface water bodies has been growing as population increases and agricultural production intensifies, which leads to an increase in the use of pesticides for food production. Thus, the objective of this work is to carry out a punctual diagnosis in relation to contamination by multi-residues of pesticides in surface waters in stretches of the Comandaí River Basin (in Cândido Godói/RS, Campina das Missões/RS and Ubiretama/RS) and in the basin of the Piratinim River (São Luiz Gonzaga/RS and São Nicolau/RS). To this end, 12 sample collections were carried out in the spring season of 2021, and 12 collections were carried out in the same season of 2022, the collections were carried out in the Fundão stream, in the Pessegueiro stream, in the Ximbocu stream and in the Ivaí stream, in each stream, 3 collections were carried out, at the source, at the intermediate and at the mouth. Subsequently, some laboratory procedures were performed, where solid phase extraction was performed to prepare the samples. For the determination of pesticide residues in the collected samples, the technique of high performance liquid chromatography was used. Regarding pesticides in surface water, atrazine, clomazone, simazine, penoxsulam, 2,4D, metsulfuron, imidacloprid, imazapik, profenofos, pyrazosulfuron and trifloxystrobin were detected below the Method Quantification Limit (LQm), and with values above the LQm , atrazine, simazine and profenofos were detected, among those quantified, only atrazine and simazine have maximum permitted values (VMP), according to CONAMA resolution nº 357/2005 for class III, these compounds, which are within the VMP . Thus, it is extremely important that the compounds detected and quantified, and even the compounds that meet the VMP of CONAMA resolution nº 357/2005, be constantly monitored, to determine the water quality of the Fundão stream, in the Pessegueiro stream, in the Ximbocu and the Ivaí stream.