Assessment of environmental pollution by PCBs, DDT and its metabolites using human milk of mothers in Zimbabwe.

The milk samples were collected from mothers who had lived in the area for at least 5 years, healthy and breast feeding their first, second or third child. Of the 175 mothers' milk samples analysed, the organochlorine pesticide residues were detected in the following order of frequency: pp-DDE, 100%, pp-DDT 98%; and sum PCB, 53%. Of all the seven areas analysed the Kariba area and the highest mean level of sum DDT--25,259 ng/g milk fat and the lowest mean level of sum DDT of 1607 ng/G milk fat was found in Esigodini which is a rural area. The major DDT metabolite was pp-DDE. The ratio of pp-DDT/pp-DDE was highest in Kariba (0.6) suggesting recent pollution by DDT in that area. The results show that the vector control programmes (extensive pesticide spraying of disease-carrying pests, such as mosquitoes and tsetse flies), agricultural activities and dietary habits were the main contributing factors towards the high levels of pesticides in most of the areas. Kadoma area had the highest mean level of sum-PCB (60 ng/g milk fat).