RESUMO
A cross sectional study was designed to measure DDT residues and its metabolites in breast milk samples collected randomly from Saudi lactating mothers living in Al-Ehssa region; which was under leishmania control until 1995, and compare them to samples from mothers living in Riyadh region where no spraying activities was involved. p,p'-DDE, p,p'-DDD and p,p'-DDT residues were measured in 878 breast milk samples by Gas Chromatography/Electron Capture Detector (GC/ECD) and confirmed by Gas Chromatography/Mass Spectrometer Detector (GC/MSD). Variation in the DDT and its metabolites levels were investigated with respect to regional distribution. Wilcoxon rank sum tests showed that the average ranks of p,p'-DDE, p,p'-DDD, p,p'-DDT and sigma p,p'-DDT in lactating mothers from Al-Ehssa region were significantly higher than those living in Riyadh region. These differences supported our hypothesis that the implications of the spraying activities to control vector borne diseases in Al-Ehssa region are obvious. We estimated that 99.2% of infants of lactating mothers living in Al-Ehssa region had sigma p,p'-DDT daily intakes that exceeded 20 micrograms/Kg-day of body weight, the WHO/UNEP Acceptable Daily Intakes for a 5-Kg infant. Exposure of infants to these chemicals through breast-feeding is clearly a public health concern. Because the bulk of literature highlights the adverse health effects of DDT and its metabolites on children and infants, public health polices should enforce the ban of DDT use and advise pregnant and lactating women to avoid DDT containing food or any other type of exposure.