Current-use flame retardants: Maternal exposure and neurodevelopment in children of the CHAMACOS cohort

Chemosphere. 2017 Dec:189:574-580. doi: 10.1016/j.chemosphere.2017.09.037. Epub 2017 Sep 12.

Abstract

Flame retardants are commonly used in consumer products found in U.S. households. Restrictions on the use of polybrominated diphenyl ether flame retardants have resulted in increased use of replacement chemicals, including Firemaster 550® (FM 550®) and organophosphate flame retardants (PFRs): tris(1,3- dichloro-2-propyl) phosphate (TDCIPP); tris(chloropropyl) phosphate (TCIPP); tris(2-chloroethyl) phosphate (TCEP); and triphenyl phosphate (TPHP). Animal research suggests that PFRs may affect neurodevelopment through noncholinergic mechanisms similar to some organophosphate (OP) pesticides. Despite the widespread presence of these compounds in home environments, and their structural similarity to neurotoxic OP pesticides, understanding of human exposure and health effects of PFRs is limited. We measured four urinary PFR metabolites from pregnant women in the CHAMACOS birth cohort study (n = 310) and assessed neurodevelopment of their children at age 7. Metabolites of TDCIPP (BDCIPP: bis(1,3-dichloro-2-propyl) phosphate) and TPHP (DPHP: diphenyl phosphate) were detected in >75% of urine samples, and isopropylphenyl phenyl phosphate (ip-PPP), a metabolite of one component of FM 550®, was detected in 72% of urine samples. We observed decreases of 2.9 points (95% Confidence Interval (CI): -6.3, 0.5) and 3.9 points (95% CI: -7.3,-0.5) in Full-Scale intelligence quotient and Working Memory, respectively, for each ten-fold increase in DPHP in adjusted regression models (n = 248). Decreases in Full-Scale IQ and Working Memory were greater in models of the molar sum of the PFR metabolites compared to the DPHP models. This is the first study to examine PFR and FM 550® exposures and potential neurodevelopmental outcomes in pregnant women and children. Additional research is warranted.

Keywords: Children; Exposure; FM 550(®); Flame retardants; Neurodevelopment; PFRs.

MeSH terms

  • Adult
  • Animals
  • Biphenyl Compounds
  • Child
  • Cohort Studies
  • Data Collection
  • Environmental Pollutants / analysis
  • Environmental Pollutants / metabolism*
  • Environmental Pollutants / toxicity
  • Female
  • Flame Retardants / analysis
  • Flame Retardants / metabolism*
  • Flame Retardants / toxicity
  • Halogenated Diphenyl Ethers / metabolism
  • Humans
  • Insecticides / metabolism
  • Intelligence Tests
  • Male
  • Maternal Exposure / statistics & numerical data*
  • Memory, Short-Term
  • Nervous System / drug effects*
  • Organophosphates / metabolism
  • Organophosphorus Compounds / metabolism
  • Phosphates
  • Phosphoric Acids
  • Polybrominated Biphenyls / metabolism
  • Pregnancy

Substances

  • Biphenyl Compounds
  • Environmental Pollutants
  • Firemaster 550
  • Flame Retardants
  • Halogenated Diphenyl Ethers
  • Insecticides
  • Organophosphates
  • Organophosphorus Compounds
  • Phosphates
  • Phosphoric Acids
  • Polybrominated Biphenyls
  • diphenyl
  • phosphoric acid
  • triphenyl phosphate