Assessment of Prenatal and Early Postnatal Exposure to Organochlorine Compounds

Abstract

P-481 Introduction: First exposure of children to environmental chemicals takes place in utero via transplacental transport. For the developing foetus, the mother represents both a source of genetic information and environmental exposure. Organochlorine compounds are persistent lipophilic compounds that cross the placental barrier easily and are also excreted into breast milk. The purpose of this study was to assess prenatal and early postnatal exposure to selected organochlorine compounds and to compare level of exposure among 3 different European regions. Methods: Within the 5th FP EU project PLUTOCRACY, a birth cohort was established in 5 localities in 3 European countries – Belgium, Slovakia and Romania. Samples of maternal blood sera and placentas were collected at full-term deliveries and breast milk samples were collected within the 6th week postpartum (N=464). Concentrations of selected organochlorine pesticides (HCB, β-HCH, p,p′ -DDE and p,p′ -DDT) and the 3 most abundant congeners of polychlorinated biphenyls (PCB #153, #138 and #180) were determined using GC/MS. Results were expressed per amount of lipid. Results: The most predominant compound was p,p′ -DDE in each of the biological matrices (median values/g lipid: serum: 312 ng, placenta: 213 ng, milk: 693 ng). Concentrations of organochlorine compounds were highest in breast milk samples, followed by maternal blood serum and placenta, except for HCB which reached highest levels in the blood serum (median 70 ng/g lipid). Significant correlations were found for organochlorine pesticides among maternal blood, placenta and breast milk, with the strongest associations for β-HCH (p< 0.001). PCB levels correlated between maternal blood and placenta and placenta and breast milk (p< 0.001), Higher maternal age was correlated with increased PCBs concentrations in each of the biological matrices (p< 0.001); however, this correlation was not observed for pesticides. Level of maternal education and parity were negatively associated with the concentrations of β-HCH, p,p′ -DDE and p,p′ -DDT (p< 0.001) in all sample types. Results suggest a wide variation in exposure to organochlorines across the regions, mainly with respect to pesticides. Concentrations of β-HCH, DDE and DDT were significantly higher in all biological samples from Romania, compared to Belgium and Slovakia (p< 0.001) but no clear trend was found for PCB exposure. Discussion and Conclusions: Organochlorine residues stored in the maternal body are continuously released into blood during pregnancy and into breast milk during lactation and are a major source of pre- and perinatal exposure.