Placental IGF-1 and IGFBP-3 expression correlate with PAH and PBDE levels from prenatal exposure to electronic waste

Abstract

Background: Electronic waste (E-waste) recycling produces organic pollutants which include polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs). Primitive and uncontrolled recycling in Guiyu, China makes the pollutants ubiquitous. Exposure to PBDEs and PAHs may affect fetal growth and development during pregnancy by altering the insulin-like-growth factor (IGF) system. In this study, the association between chronic PBDE and PAH exposure during pregnancy and the expression of IGF-1 and IGFBP-3 was evaluated. Methods: We recruited 154 pregnant women (101 from Guiyu, 53 from a control city) at the obstetric clinic. Umbilical cord blood (UCB) and placenta were carefully collected upon delivery and questionnaires were administered. PBDEs and a total of sixteen PAHs in UCB were analyzed by GC/MS while placental mRNA levels of IGF-1 and IGFBP-3 were determined by real-time PCR. Results: Infant birth length and Apgar scores were lower in Guiyu with significant differences observed only in females. All PAHs (except Fl, Chr, IP, BbF and BP), total sixteen PAHs (?16-PAHs), total and individual PBDEs concentrations were significantly higher in Guiyu neonates. Higher levels of IGF-1 (median 0.23 vs. 0.19; P<0.05) and IGFBP-3 (median 1.91 vs. 0.68; p<0.001) were observed in Guiyu and compared with Chaoan. Multiple regression analysis adjusted for sex and gestation age showed that BDE 154 and ?5ring-PAHs correlate with IGF-1 expression. Conclusion: The results suggest that prenatal exposure to PAHs and PBDEs in Guiyu influenced placental IGF-1 and IGFBP-3 mRNA expression, which may indirectly affect fetal growth and development.