TOXIC POTENTIAL OF RIVER SURFACE WATER LOCATED IN AN AREA OF INTENSE AGRICULTURAL ACTIVITY

POTENCIAL TÓXICO DAS ÁGUAS SUPERFICIAIS DE RIO LOCALIZADO EM ÁREA DE INTENSA ATIVIDADE AGRÍCOLA

Abstract

The use of water in irrigated agriculture generates wealth, create jobs, and support production chains. However, high water consumption impacts aquatic ecosystems. In addition, agricultural activity generates toxic waste which is leached into river. Here, the toxic potential of the waters of the Rio dos Patos, a river with intense agricultural activity, was evaluated using physicochemical parameters and the toxicity test using Allium cepa. The samples of surface water were collected at nine points, in two seasons of the year. The values ​​found for the physicochemical parameters are in accordance with those recommended by CONAMA Resolution (357/2005). The electrical conductivity in all samples showed high values, which may be indicative of an impacted environment. In bioassays, seed germination rate, root growth and response to vital dye were evaluated. The results obtained show that the surface waters of the Rio dos Patos did not present toxicity for any parameter evaluated. Thus, it was not possible to identify impacts of degradation on the water quality in this river. Other studies that assess the genotoxic potential of the surface waters of the Rio dos Patos should be carried out to better assess the safety of consumption and recreational use of water from this river.