Influence of region and lactation period on DDT and lindan content in mares' milk from Poland.

Milk samples were collected from 2000 to 2001, between 7 th to 180 th d of lactation from mares differing in age and the number of lactations. The content of DDT and HCH was determined by gas chromatography with electron capture detection. It was confirmed that mare’s milk was contaminated with various amounts of hazardous residues of DDT and its metabolites, probably depending on stud localisation.