[Organochlorine pesticide residues in cow's milk, Nicaragua].

Abstract

This work reports on a preliminary study carried out in Nicaragua to build a profile of the contamination of cow's milk with 10 organochlorine pesticides and make recommendations based on the findings. Between December 1993 and March 1994, milk samples were collected from 48 different sites in the country. The samples were analyzed for residues of hexachlorobenzene (HCB), alpha-BHC, lindane, aldrin, dieldrin, oxychlordane, heptachlor epoxide, and the principal metabolites of DDT (p,p'-TDE, p,p'-DDE, and p,p'-DDT) by means of solid-phase extraction from milk fat, and the quantity of the residues was determined by gas chromatography with electron capture detection. Heptachlor epoxide was found in 1 milk sample, dieldrin in 1, lindane in 3, oxychlordane in 3, alpha-BHC in 3, aldrin in 6, HCB in 9, and metabolites of DDT in 39 (81% of the samples). The six samples most heavily contaminated with by-products of DDT came from the departments of León and Chinandega, in the Pacific region, where there used to be intensive cotton production. The highest concentration was found in the sample from Malpaisillo, with 1105 micrograms of pesticide per kg of milk fat. The authors recommend that studies should be done so that the risk of contamination of other food products can be estimated, and that the public's health should be protected through strict control of the production or importation, storage, sale, and use of organochlorine pesticides.