title: Neuropsychological measures of attention and impulse control among 8-year-old children exposed prenatally to organochlorines.
abstract: BACKGROUND
  We previously reported associations between organochlorines and behaviors related to attention deficit hyperactivity disorder among boys and girls at 8 years of age using a teacher's rating scale for a birth cohort in New Bedford, Massachusetts (USA).
  
  
  OBJECTIVE
  Our goal was to corroborate these findings using neuropsychological measures of inattentive and impulsive behaviors.
  
  
  METHODS
  We investigated the association between cord serum polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) and attention and impulse control using a Continuous Performance Test (CPT) and components of the Wechsler Intelligence Scale for Children, 3rd edition (WISC-III). Participants came from a prospective cohort of children born during 1993-1998 to mothers residing near a PCB-contaminated harbor in New Bedford. Median (range) cord serum levels for the sum of four prevalent PCBs [congeners 118, 138, 153, and 180 (ΣPCB4)] and p,p'-DDE were 0.19 (0.01-2.59) and 0.31 (0-14.93) ng/g serum, respectively.
  
  
  RESULTS
  We detected associations between PCBs and neuropsychological deficits for 578 and 584 children with CPT and WISC-III measures, respectively, but only among boys. For example, boys with higher exposure to ΣPCB4 had a higher rate of CPT errors of omission [rate ratio for the exposure interquartile range (IQR) = 1.12; 95% confidence interval (CI): 0.98, 1.27] and slower WISC-III Processing Speed (change in score for the IQR = -2.0; 95% CI: -3.5, -0.4). Weaker associations were found for p,p'-DDE. For girls, associations were in the opposite direction for the CPT and null for the WISC-III.
  
  
  CONCLUSIONS
  These results support an association between organochlorines (mainly PCBs) and neuropsychological measures of attention among boys only. Sex-specific effects should be considered in studies of organochlorines and neurodevelopment.
authors.affiliation: Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts 02118, USA. sagiv@bu.edu
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Sagiv
authors.forename: Sally W
authors.initials: SW
authors.lastname: Thurston
authors.forename: David C
authors.initials: DC
authors.lastname: Bellinger
authors.forename: Larisa M
authors.initials: LM
authors.lastname: Altshul
authors.forename: Susan A
authors.initials: SA
authors.lastname: Korrick
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000139:chemically induced / Q000453:epidemiology*; D002648:Child; D002849:Chromatography, Gas; D015331:Cohort Studies; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood / Q000633:toxicity; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000139:chemically induced / Q000453:epidemiology*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000633:toxicity*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D009483:Neuropsychological Tests; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000633:toxicity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors; D014888:Wechsler Scales
chemical_list: D006843:Hydrocarbons, Chlorinated; D003633:Dichlorodiphenyl Dichloroethylene; D011078:Polychlorinated Biphenyls