Predictors of urinary flame retardant concentration among pregnant women

Abstract

Background Organophosphate compounds are commonly used in residential furniture, electronics, and baby products as flame retardants and are also used in other consumer products as plasticizers. Although the levels of exposure biomarkers are generally higher among children and decrease with age, relatively little is known about the individual characteristics associated with higher levels of exposure. Here, we investigate urinary metabolites of several organophosphate flame retardants (PFRs) in a cohort of pregnant women to evaluate patterns of exposure. Methods Pregnant North Carolina women (n=349) provided information on their individual characteristics (e.g. age and body mass index (BMI)) as a part of the Pregnancy Infection and Nutrition Study (2002–2005). Women also provided second trimester urine samples in which six PFR metabolites were measured using mass spectrometry methods. Results PFR metabolites were detected in every urine sample, with BDCIPP, DHPH, ip-PPP and BCIPHIPP detected in >80% of samples. Geometric mean concentrations were higher than what has been reported previously for similarly-timed cohorts. Women with higher pre-pregnancy BMI tended to have higher levels of urinary metabolites. For example, those classified as obese at the start of pregnancy had ip-PPP levels that were 1.52 times as high as normal weight range women (95% confidence interval: 1.23, 1.89). Women without previous children also tended to have higher urinary levels of DPHP, but lower levels of ip-PPP. In addition, we saw strong evidence of seasonal trends in metabolite concentrations (e.g. higher DPHP, BDCIPP, and BCIPHIPP in summer, and evidence of increasing ip-PPP between 2002 and 2005). Conclusions Our results indicate ubiquitous exposure to PFRs among NC women in the early 2000s. Additionally, our work suggests that individual characteristics are related to exposure and that temporal variation, both seasonal and annual, may exist.

Variability and predictors of urinary concentrations of organophosphate flame retardant metabolites among pregnant women in Rhode Island

“…Our findings generally suggest that women with higher weight or greater BMI tend to have higher concentrations of BCEP, BDCPP, and DPhP in their urine than lighter women. This is consistent with one prior study of pregnant women in which women who were overweight or obese before pregnancy tended to have higher urinary concentrations of BDCPP and DPhP than women with normal pre-pregnancy body mass index [25]. One possible explanation is that TPhP, the parent PFR of DPhP, has been used as a plasticizer (potentially as a substitute for dibutyl phthalates) in nail polish [38], and may be used as a plasticizer or phthalate substitute in other personal care products.…”

“…Both BDCPP and DPhP have been frequently detected in the urine of mothers [13, 14, 24, 25], young children [12, 13, 24], and the general population [10–12, 15–18]. Urinary concentrations of BDCPP and DPhP observed in our study were generally consistent with those previously observed among pregnant women [14, 25] (Additional file 1: Table S10).…”

“…Additional research would be useful to confirm this hypothesis. In contrast, Hoffman et al observed similar urinary BDCPP concentrations among parous and primiparous women, but urinary DPhP concentrations were elevated among parous women in their study population [25]. Collectively, our findings suggest that future etiologic studies assessing health outcomes potentially associated with exposure to TCEP, TDCPP, and TPhP would benefit from considering anthropometrics (i.e., weight), sociodemographic, and perinatal factors that may be associated with exposure.…”

Flame retardants and their metabolites in the homes and urine of pregnant women residing in California (the CHAMACOS cohort)

“…Metabolites of TDCIPP (BDCIPP) and TPHP (DPHP) were detected in 77% and 79% of urine samples. Compared to PFR exposure assessed in 349 pregnant women from North Carolina in the early 2000s (Hoffman et al 2017), the median (max) PFR metabolite levels in the CHAMACOS cohort were lower (BDCIPP: 0.4 (53.1) ng/ml, DPHP: 0.9 (54.1) ng/ml) than the North Carolina study (BDCIPP: 1.9 (140) ng/ml, DPHP: 1.3 (112) ng/ml). The relatively high urinary PFR levels reported by Hoffman et al 2017 were not expected as sample collection for the study occurred before the phase out of the penta-BDE flame retardant mixture (Stapleton et al 2012).…”

Final Report: Applying a tested procedure for the identification of potential emerging chemical risks in the food chain to the substances registered under REACH ‐ REACH 2

“…Literature (Butt et al, 2014;Hoffman et al, 2015;Butt et al, 2016;Hoffman et al, 2017) Additional biomonitoring studies from the USA summarised in a recent review Review ASSESSMENT The lack of data on occurrence is most likely the result of the complex and variable composition of the substance and its commercial products. Limited analyses of commercial products indicate that substances containing only one isopropyl group are major constituents.…”