Prenatal exposure to organic pollutants in northwestern Spain using non-invasive matrices (placenta and meconium)

Abstract

Human exposure to environmental organic pollutants (OPs) begins in the uterine life period by trans-placental transfer. Epidemiological studies have consistently demonstrated the vulnerability of human fetuses and infants to the effects of OPs because of their rapid growth and organ development, cell differentiation, and immaturity of metabolism. The aim of the present study was to evaluate the prenatal exposure to OPs characterized by different physicochemical properties using non-invasive biological samples (meconium and placenta). A total of 88 placenta and 53 meconium samples were collected in Ourense, a city located in northwestern Spain, at the delivery and after birth from mothers and their infants from the University Hospital of Ourense, respectively. Selective pressurized liquid extraction (SPLE) methodologies were used to determine the targeted OPs in the selected biological samples. Cleanup of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges and detection by gas chromatography (GC) coupled to tandem mass spectrometry (QqQ-MS/MS). The targeted OPs were detected with the following mean level total concentration order polycyclic aromatic hydrocarbons (PAHs) > organophosphorus pesticides (OPPs) > non-dioxin like polychlorinated biphenyls (NDLPCBs) > pyrethroids (PYRs) > polybrominated diphenyl ethers (PBDEs) > dioxin like polychlorinated biphenyls (DLPCBs) > organochlorine pesticides (OCPs) for placenta and ΣNDLPCBs > ΣPAHs > ΣOCPs > ΣPYRs > ΣOPPs > ΣDLPCBs > ΣPBDEs for meconium, respectively. Significant correlations (p < .050) between the socio-demographic characteristics of the selected population (mother's parity, age, weight increase during pregnancy, place of living and smoking habits) and log transformed concentration of some of the targeted OPs (OCPs, PBDEs, PYRs, OPPs and PAHs) were detected. The results obtained shown the complementary information given by both biological samples selected. Nevertheless, additional research will be needed to gain an understanding of the trans-placental transfer of OPs, to choose the best biological matrix to evaluate the prenatal exposure to OPs in a correct way and to know their health implications.

Keywords: Meconium; Non-invasive samples; Organic pollutants; Placenta; Prenatal exposure.