Organochlorine pesticides in Argentinian butter.

Organochlorine pesticide residues were analysed in 150 samples of butter collected from several places in the cities of Santa Fe and Rosario (Argentine Republic) over a period of 18 months. Pesticides analysed in butter were: HCH (alpha and gamma isomers), heptachlor and its epoxide, aldrin, dieldrin, and DDT (p,p' DDE, o,p' DDT and p,p' DDT). Most samples contained residues of gamma-HCH (Lindane) and heptachlor (92% and 78%, respectively); alpha-HCH and aldrin were detected in 58% and 55% of samples; dieldrin, heptachlor epoxide, DDT isomers were found in few cases (30%). Mean values of pesticides residues in butter fat were: sigma HCH 0.029 ppm; sigma heptachlor 0.064 ppm; sigma aldrin 0.11 ppm and sigma DDT 0.024 ppm. Residue levels exceeded the limits prescribed by the Food and Agricultural Organization/World Health Organization in only very few cases.