We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean SDDT levels in breast
milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest SDDT level ever reported for breast milk from South Africa (140 mg/kg mf). Understanding
the causes for these differences would be informative for exposure reduction intervention. The Provisional Tolerable Daily Intake (PTDI) for DDT by infants, and the Maximum Residue Limit (MRL) were
significantly exceeded. DDT had no effect on duration of lactation. There were indications (not significant) from DDT-sprayed villages that first-born female infants drink milk with more SDDT than firstborn
male infants, and vice versa for multipara male and female infants, suggesting gender involvement on levels of DDT in breast milk e requiring further investigation.