Destino ambiental dos agrotóxicos e avaliação de risco ambiental e humano nos municípios de Manaus, Iranduba e Careiro da Várzea, no Estado do Amazonas

Abstract

pesticides. This indiscriminate and incorrect use of pesticides in the Amazon State is threatening the environment and the health of farmers and consumers. Thus, the objective of this study was to evaluate the environmental and health risk associated with pesticide use in agricultural areas of the district of Manaus, Careiro the Varzea and Iranduba. Residues of pesticides (deltamethrin, lambda-cyhalothrin, malathion and parathion methyl) were determined in samples of fruits, vegetables, water and soil. From May 2007 to December 2008 16 samples of soil and 25 samples of water, and 190 samples of fruit and vegetables were collected at the production areas, markets and supermarkets. Pesticides residues were determined by gas chromatograph with selective electron capture detector (GC-ECD) after micro-solid phase extraction headspace method (HS-SPME). Environmental risk assessment was calculates using the Exposure/Toxicity ratio (ETR) and human risk by diet as the reason between pesticide daily intake and acute reference dose (ARfD) or Acceptable Daily Intake (IDA). Parathion methyl was present in a greater number of samples in concentrations above the maximum residue levels (MRLs) in both, pre-harvest and post-harvest phase, for all crops, followed by lambda cyhalothrin, deltamethrin and malathion in descending order of samples and cultures that had residues above the maximum allowed. The average concentration of pesticide residues in post-harvest samples were from 2 to 5 times higher than the concentration on pre-harvest samples, except for deltamethrin, suggesting that farmers apply pesticides until the moment just before harvest and transportation to market. Chronic and acute health risk was established for lambda-cyhalothrin and parathion methyl. To malathion was observed only chronic risk. The deltamethrin posed only acute and chronic risk for pre-harvest phase in Iranduba. Concentrations of pesticides found in soil represented only risk to the case of parathion methyl and malathion in Iranduba. In the case of water, the risk was to chronic parathion methyl, malathion and deltamethrin in Iranduba, and for parathion methyl and malathion in Manaus and Careiro of Várzea. In the acute risk, was only set for deltamethrin in Iranduba. For groundwater the risk situation was established for methyl-parathion in Manaus. The use of pesticide in the Amazon s state clearly represents an environmental and health problem since the population and environment are subject to acute and chronic risks. The study also highlights the need for monitoring the use of pesticide in the Amazon State, assessing the environmental and food levels with a higher frequency, considering the seasonality of agriculture and the use of pesticides on different crops.