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1D - Soil and Sediment Contamination (TUP/25) Pesticides in Sediments of the Main Rivers of Pantanal Mato–grossense Brazil. Cunha, Marcelo1, De-Lamonica-Freire, Ermelinda2, Dores, Eliana1, Carbo, Leandro1, 1 Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil2 Universidade de Cuiabá, Cuiabá, Mato Grosso, Brazil ABSTRACT- The Pantanal, located in the Centerwest of Brazil, is one of the world′s largest sweet water wetlands with an extension of about 140.000 km2. It has great ecological significance, due to its rich biodiversity, as well as economic importance in relation to tourism and fishery. However, intensive agriculture, cultivated pastures, agroindustry, gold mining and urban centers are the main potential factors that may be causing environmental alterations in the Pantanal. The use of potentially toxic agrochemicals in the highlands, which surround the Pantanal basin, especially pesticide intensive cultures like soybean and cotton is a great concern. The objective of this study was to assess the level of pesticides contamination in river bottom sediment, collected in the main rivers in the borders of the Pantanal. A multi-residue method validated for 9 herbicides and 23 insecticides was used. In the laboratory, each sediment sample was dried at ambient temperature, sieved and homogeneized. The analysis consisted on mechanical shaking extraction with solvent, followed by concentration in rotatory evaporator, further clean-up by liquid/liquid extraction, concentration and re–dissolution of the extract with toluene, with addition of internal standard. The extracts were analyzed in gas chromatograph/mass detector (GC/MS). In the analyzed samples, chlordane, acetochlor, mevinphos, carbaryl, Key words: sediment, pesticides, wetland, GC/MS |
–endosulfan, diazinon, trifluralin, aldrin, metolachlor, chlorpyrifos, p,p′DDE, p,p′DDT, ditalimphos, ametryn, monocrotophos, terbutilazine, parathion methyl, cypermethrin, lambda-cyalothrin were detected. In 84% of the samples at least one pesticide was found. The most frequently detected molecules were p,p′DDT (71%), and its metabolite p,p′DDE (40%),