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(38-59) Dispersion of DDT in a heavily contaminated soil in Cuiaba, Mato Grosso, Brazil. Dalla Villa, Ricardo1, Dores, Eliana*,1, 1 Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil ABSTRACT- In Mato Grosso State, Centerwest of Brazil, organochlorine pesticides were intensively used in health campaings for the erradication of insect vectores of human diseases, including malaria. Among the organochlorine insecticides, DDT was used in Mato Grosso until 1997 according to the National Health Foundation (FUNASA), when its use was prohibited by judicial decision. At this time, the unused DDT was kept on the naked soil of an area belonging to the FUNASA until late 1998, when it was sent for incineration. The local soil was heavily polluted due to leaking of broken packages. Considering the risks presented by this pollution, this study was developed aiming to determine the dissipation of this insecticide in this soil. For this purpose the soil of the contaminated area was divided in six fractions of equal size, starting at the more contaminated site downward the slope of the terrain. Composed surface soil samples were collected in each fraction at three different times during one year. Soil samples were also collected at different depths (30-40 cm; 60-70 cm and 90-100 cm). The soil samples were extracted and analyzed by GC/ECD. Surface soil physico-chemical properties were organic matter 46 g/dm3, pH 5.7 and texture: 410 g/kg of sand; 470 g/kg silt and 120 g/kg clay. Surface soil concentrations ranged from 3.85 to 7,290 Key words: DDT, soil, dispersion |
g/g. Subsurface soil samples at the most contaminated point showed concentrations of 467.1