title: Variability and predictors of urinary concentrations of organophosphate flame retardant metabolites among pregnant women in Rhode Island.
abstract: Organophospate flame retardants (PFRs) are chemicals of emerging concern due to restrictions on polybrominated diphenyl ether flame retardant formulations. We describe the occurrence, variability, and predictors of urinary metabolites of PFRs among pregnant women.
  
  
  
  In 2014-2015, 59 women from Providence, RI provided up to 3 spot urine samples during pregnancy (~12, 28, and 35 weeks' gestation). We created a pooled urine sample per woman and measured nine relevant metabolites in individual and pooled samples. We used linear mixed models to calculate intraclass correlation coefficients (ICCs) across the 3 measurements and to assess sociodemographic and dietary predictors of PFRs.
  
  
  
  The median (IQR) of bis-2-chloroethyl phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), and diphenyl phosphate (DPhP), the metabolites most frequently detected, from pooled samples were: 0.31 μg/L (0.17-0.54), 1.18 μg/L (0.64-2.19), 0.93 μg/L (0.72-1.97), respectively. We observed fair to good reproducibility for BCEP (ICC = 0.50), BDCPP (ICC = 0.60), and DPhP (ICC = 0.43), and excellent agreement between the urinary flame retardant metabolite concentrations averaged across pregnancy versus pooled urine sample concentrations for BCEP (ICC = 0.95), BDCPP (ICC = 0.89), and DPhP (ICC = 0.93). Adjusting for pertinent sociodemographic factors and gestational week of urine collection, each 1 kg increase in pre-pregnancy weight was associated with greater BCEP (1.1%; 95% CI: 0.1, 2.1), BDCPP (1.5%; 95% CI: 0.3, 2.7), and DPhP (0.5%; 95% CI: 0.0, 1.1). Dietary factors were generally not associated with urinary flame retardant metabolites.
  
  
  
  Urinary concentrations of BCEP, BDCPP, and DPhP were frequently detected among women in this pilot study and had fair reproducibility across pregnancy. Body size may be an important predictor of urinary flame retardant metabolite concentrations.
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA. megan.e.romano@dartmouth.edu.|Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA. megan.e.romano@dartmouth.edu.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Romano
authors.affiliation: Department of Epidemiology (Chronic Diseases), Yale University School of Public Health, New Haven, CT, USA.
authors.forename: Nicola L
authors.initials: NL
authors.lastname: Hawley
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Eliot
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Nayana K
authors.initials: NK
authors.lastname: Jayatilaka
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.|Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Kelsey
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.|Department of Anthropology, Brown University, Providence, RI, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: McGarvey
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.|Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, and Women & Infants Hospital of Rhode Island, Providence, RI, USA.
authors.forename: Maureen G
authors.initials: MG
authors.lastname: Phipps
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.|Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, and Women & Infants Hospital of Rhode Island, Providence, RI, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Savitz
authors.affiliation: Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, and Women & Infants Hospital of Rhode Island, Providence, RI, USA.
authors.forename: Erika F
authors.initials: EF
authors.lastname: Werner
authors.affiliation: Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Braun
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D004032:Diet; D004522:Educational Status; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000652:urine*; D005260:Female; D005411:Flame Retardants / Q000032:analysis*; D006801:Humans; D007182:Income; D010755:Organophosphates / Q000652:urine*; D010298:Parity; D010865:Pilot Projects; D011247:Pregnancy / Q000652:urine*; D044469:Racial Groups; D015203:Reproducibility of Results; D012237:Rhode Island
chemical_list: D004785:Environmental Pollutants; D005411:Flame Retardants; D010755:Organophosphates
keywords: Flame retardants; Pregnancy; Urine metabolites