Organophosphorus Flame Retardants in Pregnant Women and Their Transfer to Chorionic Villi

Abstract

The potential for prenatal exposure has recently raised concerns over the health risks of endocrine disruptors; however, knowledge about human prenatal exposure to organophosphorus flame retardants (OPFRs) is lacking. In this study, 2-ethylhexyl diphenyl phosphate (EHDPP), tributyl phosphate (TBP), triphenyl phosphate (TPHP), and tris(2-chloroethyl) phosphate (TCEP) were detected in the majority of chorionic villus samples, with median concentrations of 13.6, 18.8, 11.1, and 0.51 ng/g of dry weight (dw), respectively, significantly higher than those in the matching maternal decidua samples (5.96, 10.8, 1.44, and 0.26 ng/g of dw, respectively). The ratios of concentrations in chorionic villi (containing embryos) to those in maternal deciduae (CMRs) were 4.17, 3.82, 2.81, and 2.00 for EHDPP, TPHP, TBP, and TCEP, respectively, which correlated with their log K values (p = 0.003). The results of transthyretin (TTR) binding assays indicated that the stronger the binding ability to TTR, the higher the CMRs. The median concentrations of the metabolites diphenyl phosphate (DPHP), dibutyl phosphate (DBP), and bis(2-chloroethyl) phosphate (BCEP) were 4.11, 429, and 157 ng/g of dw in chorionic villi, higher than those in deciduae (1.64, 181, and 25.4 ng/g of dw, respectively). The ratios of DPHP/TPHP and DPHP/EHDPP were 0.20 and 0.43 in chorionic villi and 1.24 and 2.03 in deciduae, respectively, much lower than those of DBP/TBP and BCEP/TCEP (20.9 and 165.6 in chorionic villi and 13.1 and 35.3 in deciduae, respectively), suggesting that the difference in metabolism between the deciduae and chorionic villi would affect their maternal transfer.

Prenatal exposure to organophosphates and associations with birthweight and gestational length

“…65 Other research demonstrates that exposure to phthalates is associated with molecular changes in placental tissue in sexually dimorphic ways. 66 Though OPEs have been reported in placental tissues 16–18 , it remains unclear whether sex specific impacts extend to OPEs or preterm birth.…”

“…12 Data suggest OPEs can be transferred from the mother to her child in utero. 16–18 TPHP was detected in placenta samples of dose rats and both TDCIPP and TPHP have been detected in human placenta samples. 17,18 OPEs also have been detected in human chronic villi and deciduae, suggesting transfer early in gestation (i.e.…”

Recent biomonitoring reports on phosphate ester flame retardants: a short review

“…A number of studies have reported the presence of PEFRs in other human tissues and body fluids. PEFRs were frequently detected in placenta (Ding et al, 2016;Zhao et al, 2017) and breast milk (Sunddkvist et al, 2010;Kim et al, 2014;He et al, 2018a). The median concentration of total PEFRs was around 10-100 ng/g of lipids in breast milk from Sweden and several Asian countries, indicating that substantial exposure occurs at a young age via breastfeeding (Sunddkvist et al, 2010;Kim et al, 2014).…”

Metabolomic and Transcriptomic Analysis of MCF-7 Cells Exposed to 23 Chemicals at Human-Relevant Levels: Estimation of Individual Chemical Contribution to Effects

“…Mixtures consisting of 23 xenobiotic chemicals at several humanrelevant levels from already available biomonitoring data were prepared to mimic actual human exposure in the United States (CDC 2018;Frederiksen et al 2010;Högberg et al 2008;Kim et al 2015;Li et al 2015Li et al , 2017Li et al , 2018aNagayama et al 2000;Thomsen et al 2002;Wang et al 2015a;Xiao et al 2011;Zhao et al 2017). The MCF-7 cell was chosen as the experimental model because it is a sensitive hormone-responsive cell line (Levenson and Jordan 1997), and many selected chemicals have been previously reported to be xenoestrogens and EDCs.…”