Avaliação do potencial de contaminação de águas superficiais e subterrâneas por agrotóxico na Bacia Hidrográfica do Rio Tibagi

Abstract

The increasing and uncontrolled use of pesticides is associated with several negative impacts on human health and the environment, among them are the increased risk of human poisoning, increased incidence of cancer cases, malformation of fetuses, contamination of soil and water resources, and may also cause impacts on aquatic organisms. The presence of pesticides in water bodies makes water monitoring an important tool for identifying places with the greatest risk of contamination. From the survey of information on the most used pesticides in the state of Paraná in the last year, the present study sought to carry out a preliminary assessment of the risk of contamination of water resources using the EPA criteria and the GUS index to determine the contaminating potential of pesticides in groundwater and the Goss method for determining the potential contaminant in surface water. The study also estimated the concentration of glyphosate in these waters in different municipalities that make up the Tibagi River Hydrographic Basin, as it is the most widely used pesticide in the world. From the total of 16 principles that were evaluated, considering both the EPA and GUS criteria, atrazine, tebuconazole and cyproconazole showed high groundwater contaminating potential. The contaminating potential of surface waters determined by the Goss criteria, indicated that paraquat and pyraclostrobin have a high potential for contamination through transport associated with sediment, while atrazine, pyraclostrobin and diuron have a high potential for contamination through transport dissolved in water. The estimated concentrations indicated that the presence of glyphosate in groundwater bodies is zero or very close to zero. Contrary to the estimates obtained in relation to surface waters, which ranged from 9.7 μg / L to 45.9 μg / L. The highest concentrations of glyphosate estimated in surface waters occurred in the municipalities of Sertanópolis, Sertaneja, Castro, Palmeira, Carambeí and Piraí do Sul. The results obtained through these tools serve as a warning about the risk related to the indiscriminate use of some pesticides, to the potential mobility and the possibility of water contamination by the active ingredients of pesticides most used in Paraná.