Investigação de agrotóxicos carbamatos em águas superficiais bruta e tratada no Rio Branco em Roraima

Abstract

Pesticides have been widely used to combat numerous groups of insects, plants, fungi and other living beings that reduce crop yield in various crops, can also be manipulated against disease vectors to humans and other animals. In many cases, their indiscriminate use, causes environmental problems seemingly imperceptible, but of great magnitude in biota impacted. As some groups of pesticides used in small doses, can cause death and accumulate in animal and plant tissues, their decay can be very slow allowing reach distant regions from which they were used. Are transported by groundwater and surface water, and on some occasions, dispersed by atmospheric winds. Its detection and quantification is done by standard techniques and equipment with high sensitivity since its distribution in the environment, in most cases, is in small concentrations. In this work we collected surface water of the Branco river and Treatment Station of the city of Boa Vista and then subjected to extraction technique Liquid - Solid -off -line SPE for pre-concentration of pesticides and then the High Performance Liquid Chromatography efficiency - HPLC for their separation and quantification. Pesticides were detected carbamates aldicarb sulfone, carbofuran, carbaryl, hydroxicarbofuran, methomyl and naphytol always with their concentrations above recommended by Ordinance 2.914/11 MS and CONAMA Resolution 357 / 05. The treated water distributed population showed traces of three types of carbamates above those permitted by Brazilian law, Aldicarb sulfone 9.10 mg L-1, Carbaryl 1.0 mg L-1 and methomyl 32 mg L-1. Tests were made to recover the analytes carbaryl and methomyl, which showed results of 85 and 105 %, respectively, for the method used, demonstrated that the procedure is reliable. The results presented raise concern about the impact that pesticides can cause to the environment and health of people who use the waters of the Branco river daily.