Selected persistent organic pollutants in human placental tissue from the United States

• We measured 10 PBDEs, 32 PCBs, and DDE in 169 placenta specimens from 43 placentae.
• Significant geographic differences in placental PBDEs in the U.S. were found.
• Worldwide first-order declining trends for PCBs and DDE were identified.
• The concentrations did not vary much for specimens collected <72 h after delivery.

Emerging and legacy environmental pollutants such as polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticide metabolite DDE are found in human placenta, indicating prenatal exposure, but data from the United States are sparse. We sought to determine concentrations of these compounds in human placentae as part of a formative research project conducted by the National Children’s Study Placenta Consortium. A total of 169 tissue specimens were collected at different time points post delivery from 43 human placentae at three U.S. locations, and analyzed by gas chromatography coupled with mass spectrometry following extraction using matrix solid phase dispersion. PBDEs, PCBs, and DDE were detected in all specimens. The concentrations of 10 PBDEs (Σ10PBDEs), 32 PCBs (Σ32PCBs) and p,p′-DDE were 43–1723, 76–856 and 10–1968 pg g−1 wet weight, respectively, in specimens collected shortly after delivery. Significant geographic differences in PBDEs were observed, with higher concentrations in placentae collected in Davis, CA than in those from Rochester, NY or Milwaukee, WI. We combined these with other published data and noted first-order declining trends for placental PCB and DDE concentrations over the past decades, with half-lives of about 5 and 8 years, respectively. The effect of time to tissue collection from refrigerated placentae on measured concentrations of these three classes of persistent organic pollutants was additionally examined, with no significant effect observed up to 120 h. The results of this work indicate that widespread prenatal exposure to persistent organic pollutants in the United States continues.