Herbicidas no alto Rio Poxim, Sergipe e os riscos de contaminação dos recursos hídricos

Abstract

Increased agricultural activity in watershed areas has been causing concern over contamination by herbicides inagricultural areas. The problem becomes more important when contamination can affect water for human consumption, ashappens with water from the Poxim river, which supplies the city of Aracaju, capital of the State of Sergipe. The aim of thisstudy was to evaluate the risk of contamination by herbicides to both surface and groundwater in the upper sub-basin of thePoxim River, and to detect the presence of the active ingredients Diuron and Ametrine up-river from the sugar-cane plantations.Risk analysis was carried out using criteria from the Environmental Protection Agency (EPA), the GUS index, and the GOSSmethod. It was observed that several active ingredients are at risk of leaching, demonstrating the importance of monitoring theriver to control both the quality of water and the frequency and volume of herbicides used in the region. Based on the results,monitoring was carried out bi-monthly from July 2009 to July 2010 at two sampling points. Water samples were analyzed inthe laboratory, where the presence of Diuron and Ametrine was noted. Water quality in the Sub-basin of the Rio Poxim is beinginfluenced by the use of herbicides in the region. There was an increase in herbicide concentration in the surface water duringthe rainy season, possibly caused by soil runoff.