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

Abstract

Emerging and legacy environmental pollutants such as polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (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 42 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 (∑10PBDEs), 32 PCBs (∑32PCBs) and p,p’-DDE were 43–1,723, 76–856 and 10–1,968 pg/g 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 hours. The results of this work indicate that widespread prenatal exposure to persistent organic pollutants in the United States continues.

Concentrations of polybrominated diphenyl ethers (PBDEs) and 2,4,6-tribromophenol in human placental tissues

“…However, we observed no significant correlations between BFR concentrations on a wet weight basis (ng/g ww) with percent lipid. But despite the inconsistencies in subsampling, the median values of PBDE concentrations from this study agree with PBDE measurements from previous studies 9,34,44 .…”

“…To date, only two other studies have measured PBDEs in placenta tissue samples from US populations 9,36 . Additionally, placenta tissues from China, Japan, and European countries including Spain, Denmark, and Finland have been evaluated for PBDEs 31,37–40 .…”

“…As a result, human exposure to PBDEs will continue for years to come, especially with the use of recycled foams and plastics in consumer products that may contain these phased-out chemicals. As such, PBDEs continue to be measured in human tissues such as serum, breast milk, umbilical cord blood, and placental tissues, suggesting that prenatal exposures to PBDEs occurs during pregnancy, and continues during infancy via breast feeding 6–9 .…”

Brominated flame retardants in placental tissues: associations with infant sex and thyroid hormone endpoints

“…While BFRs have been detected in human placenta samples previously (e.g. [23–25]), the clinical significance of these measures, and their potential importance in thyroid hormone regulation have not, to our knowledge, been evaluated.…”

Success rates for consent and collection of prenatal biological specimens in an epidemiologic survey of child health

“…Analyte stability in short-and long-term storage was evaluated prospectively. Biospecimen quality was assessed further through pilot testing for environmental chemicals by the Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention (Caldwell et al, 2013;Mortensen et al, 2014), NCS supported formative research projects (Smith et al, 2014;Nanes et al, 2014), and independent supplemental methodologic studies (Ghantous et al, 2014;Bakulski et al, 2015).…”