Resumo

UZCATEGUI, Jorge; ARAUJO, Yelinda  e  MENDOZA, Luz. Organochlorine pesticides residues and their relation to soil parameters in Pueblo Llano, Mérida State, Venezuela. Bioagro [online]. 2011, vol.23, n.2, pp.115-120. ISSN 1316-3361.

The horticultural farms in Pueblo Llano, Mérida State, have been using uncontrolled quantities of different kinds of pesticides, so the aim of this work was to determine the residual levels of organochlorine pesticides (OCPs) in those soils. Samples were taken in 20 farms, and Soxhlet extraction procedure (EPA 3540C) and sulfur elimination (EPA 3660B) were performed. According to the EPA 8081A method, the OCPs were determinined by gas chromatography with electronic capture detector. Nine OCPs were quantified in most samples in the following concentration ranges (mg·kg^-1): DDT (0,04-0,99); DDE (0,01-0,56); DDD (0,04-0,83); α-endosulfan (0,01-0,47); β-endosulfan (0,02-0,45); endosulfan sulfato (0,04-0,62); aldrin (0,005-0,009); dieldrin (0,01-0,03), and endrin (0,01-0,04). The soils presented high levels of organic matter, which may favor OCPs retention. It was found that the total OCPs concentration, DDT and isomers (DDE and DDD) decrease as the soil pH increases, and enlarge as the clay percentage increases. The soils were classified as potentially contaminated, according to their levels of DDT, dieldrin and endrin.

Palavras-chave : DDT; Dieldrin; Endrin; potato; carrot.