title: Methyl mercury exposure and neurodevelopmental outcomes in the Seychelles Child Development Study Main cohort at age 22 and 24years.
abstract: All fish contain methyl mercury (MeHg), a known neurotoxicant at adequate dosage. There is still substantial scientific uncertainty about the consequences, if any, of mothers consuming fish with naturally-acquired levels of MeHg contamination. In 1989-1990, we recruited the Main Cohort of the Seychelles Child Development Study to assess the potential developmental effects of prenatal MeHg exposure. We report here on associations with neurodevelopmental outcomes obtained at 22 and 24years of age.
  
  
  
  Neurodevelopmental tests at 22years included the Boston Naming Test, Cambridge Neuropsychological Test Automated Battery (CANTAB), and the Profile of Mood States. At 24years, we administered the Stroop Word-Color Test, the Barkley Adult ADHD Rating Scale, the Test of Variables of Attention, and the Finger Tapping test. We also administered a healthy behaviors survey at both ages. Primary analyses examined covariate-adjusted associations in multiple linear regression models with prenatal MeHg exposure. In secondary analyses we also examined associations with recent postnatal MeHg exposure.
  
  
  
  We did not observe adverse associations between prenatal MeHg exposure and any of the measured endpoints. Some measures of attention, executive function, and delayed recall showed improved performance with increasing exposure. Secondary analysis did not show consistent patterns of association with postnatal exposure.
  
  
  
  Our cohort has been examined at ten different ages over 24years of follow-up. Findings suggest that prenatal and recent postnatal MeHg exposure from ocean fish consumption is not adversely associated with neurobehavioral development at levels that are about ten times higher than typical U.S. exposures.
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States. Electronic address: edwin_van_wijngaarden@urmc.rochester.edu.
authors.forename: Edwin
authors.initials: E
authors.lastname: van Wijngaarden
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Sally W
authors.initials: SW
authors.lastname: Thurston
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Myers
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Donald
authors.initials: D
authors.lastname: Harrington
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Cory-Slechta
authors.affiliation: Ulster University, Coleraine, Northern Ireland, United Kingdom.
authors.forename: J J
authors.initials: JJ
authors.lastname: Strain
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Gene E
authors.initials: GE
authors.lastname: Watson
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Zareba
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Tanzy
authors.initials: T
authors.lastname: Love
authors.affiliation: Ministry of Health, Republic of Seychelles, Seychelles.
authors.forename: Juliette
authors.initials: J
authors.lastname: Henderson
authors.affiliation: Ministry of Health, Republic of Seychelles, Seychelles.
authors.forename: Conrad F
authors.initials: CF
authors.lastname: Shamlaye
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
authors.forename: Philip W
authors.initials: PW
authors.lastname: Davidson
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D005506:Food Contamination; D006304:Health Status; D006801:Humans; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000523:psychology*; D017747:Seafood / Q000009:adverse effects; D055815:Young Adult
chemical_list: D008767:Methylmercury Compounds; C073972:dimethyl mercury
keywords: Child development; Methyl mercury; Postnatal exposure; Prenatal exposure