title: Gestational exposure to endocrine-disrupting chemicals and reciprocal social, repetitive, and stereotypic behaviors in 4- and 5-year-old children: the HOME study.
abstract: BACKGROUND
  Endocrine-disrupting chemicals (EDCs) may be involved in the etiology of autism spectrum disorders, but identifying relevant chemicals within mixtures of EDCs is difficult.
  
  
  OBJECTIVE
  Our goal was to identify gestational EDC exposures associated with autistic behaviors.
  
  
  METHODS
  We measured the concentrations of 8 phthalate metabolites, bisphenol A, 25 polychlorinated biphenyls (PCBs), 6 organochlorine pesticides, 8 brominated flame retardants, and 4 perfluoroalkyl substances in blood or urine samples from 175 pregnant women in the HOME (Health Outcomes and Measures of the Environment) Study (Cincinnati, OH). When children were 4 and 5 years old, mothers completed the Social Responsiveness Scale (SRS), a measure of autistic behaviors. We examined confounder-adjusted associations between 52 EDCs and SRS scores using a two-stage hierarchical analysis to account for repeated measures and confounding by correlated EDCs.
  
  
  RESULTS
  Most of the EDCs were associated with negligible absolute differences in SRS scores (≤ 1.5). Each 2-SD increase in serum concentrations of polybrominated diphenyl ether-28 (PBDE-28) (β = 2.5; 95% CI: -0.6, 5.6) or trans-nonachlor (β = 4.1; 95% CI: 0.8-7.3) was associated with more autistic behaviors. In contrast, fewer autistic behaviors were observed among children born to women with detectable versus nondetectable concentrations of PCB-178 (β = -3.0; 95% CI: -6.3, 0.2), β-hexachlorocyclohexane (β = -3.3; 95% CI: -6.1, -0.5), or PBDE-85 (β = -3.2; 95% CI: -5.9, -0.5). Increasing perfluorooctanoate (PFOA) concentrations were also associated with fewer autistic behaviors (β = -2.0; 95% CI: -4.4, 0.4).
  
  
  CONCLUSIONS
  Some EDCs were associated with autistic behaviors in this cohort, but our modest sample size precludes us from dismissing chemicals with null associations. PFOA, β-hexachlorocyclohexane, PCB-178, PBDE-28, PBDE-85, and trans-nonachlor deserve additional scrutiny as factors that may be associated with childhood autistic behaviors.
authors.affiliation: Department of Epidemiology, Brown University, Providence, Rhode Island, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Braun
authors.forename: Amy E
authors.initials: AE
authors.lastname: Kalkbrenner
authors.forename: Allan C
authors.initials: AC
authors.lastname: Just
authors.forename: Kimberly
authors.initials: K
authors.lastname: Yolton
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.forename: Andreas
authors.initials: A
authors.lastname: Sjödin
authors.forename: Russ
authors.initials: R
authors.lastname: Hauser
authors.forename: Glenys M
authors.initials: GM
authors.lastname: Webster
authors.forename: Aimin
authors.initials: A
authors.lastname: Chen
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Lanphear
mesh_terms: D002652:Child Behavior / Q000187:drug effects; D002675:Child, Preschool; D052244:Endocrine Disruptors / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity; D005260:Female; D005411:Flame Retardants / Q000633:toxicity; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity; D001556:Hexachlorocyclohexane / Q000633:toxicity; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects
chemical_list: D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D001556:Hexachlorocyclohexane; C086401:pentabromodiphenyl ether; D011078:Polychlorinated Biphenyls; C023888:beta-hexachlorocyclohexane