EVALUATION OF PRENATAL EXPOSURE TO PERSISTENT TOXIC SUBSTANCES (PTS) IN SELECTED REGIONS OF SOUTH AFRICA

摘要

Background: There is a paucity of investigations into exposure to environmental contaminants (PTS) in general population but especially in the pregnant women in the Southern Hemisphere. Exposure to environmental toxicants places pregnant women and the developing foetus at the highest risk. Over last 6 years, under auspices of Arctic Monitoring and Assessment Programme (AMAP), a number of studies investigating exposure and birth outcomes were performed in South Africa. Aims: The purpose of the studies was to investigate prenatal exposure to selected toxic elements and pesticides in different regions of South Africa. Methods: In total 650 pregnant women presenting for delivery at the local hospitals situated in different regions of the country participated in these studies. Paired blood samples were collected from mother prior to delivery and cord blood after delivery. Selected elements and organic compounds were analysed using ICP/MS and GS/MS respectively. Data from socioeconomic questionnaires and birth records were also collected. Results: Most of the toxic elements measured were detected in both maternal and paired umbilical cord blood, some in elevated concentrations. High concentrations of DDT and its metabolites in maternal plasma were measured in malaria endemic sites. The high levels of banned y-HCH and endosulfan (1 and 2) were found in maternal plasma samples in predominantly agricultural sites. For most of the compounds measured, significant differences between regions were found. Predictors of elevated levels for compounds measured were identified. Conclusion: Study found prenatal exposure to high levels of banned substances in some regions of South Africa which is of concern, particularly in view of future climate change and food security. Results of these studies inform policy and regulatory agencies.