[Residue situation of milk products after the effective carrying out of the "step-by-step program for DDT-replacement" in the GDR].

A step-by-step program had been established to replace the persistent insecticide DDT with other active principles in the GDR by 1975. Monthly thin-layer chromatographic residue determinations in butter samples from all the districts demonstrate that the DDT-residues have decreased gradually since 1973 from an average value of 0.45 mg/kg to an average value of 0.18 mg/kg (in 1976). The DDT intake of adults via the milk products (butter, milk and cheese) was, in 1976, only 2% of the ADI value, which evidences a very positive development. Furthermore, findings concerning the contamination with lindane and HCB are presented.