title: Seven-year neurodevelopmental scores and prenatal exposure to chlorpyrifos, a common agricultural pesticide.
abstract: BACKGROUND
  In a longitudinal birth cohort study of inner-city mothers and children (Columbia Center for Children's Environmental Health), we have previously reported that prenatal exposure to chlorpyrifos (CPF) was associated with neurodevelopmental problems at 3 years of age.
  
  
  OBJECTIVE
  The goal of the study was to estimate the relationship between prenatal CPF exposure and neurodevelopment among cohort children at 7 years of age.
  
  
  METHODS
  In a sample of 265 children, participants in a prospective study of air pollution, we measured prenatal CPF exposure using umbilical cord blood plasma (picograms/gram plasma) and 7-year neurodevelopment using the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV). Linear regression models were used to estimate associations, with covariate selection based on two alternate approaches.
  
  
  RESULTS
  On average, for each standard deviation increase in CPF exposure (4.61 pg/g), Full-Scale intelligence quotient (IQ) declined by 1.4% and Working Memory declined by 2.8%. Final covariates included maternal educational level, maternal IQ, and quality of the home environment. We found no significant interactions between CPF and any covariates, including the other chemical exposures measured during the prenatal period (environmental tobacco smoke and polycyclic aromatic hydrocarbons).
  
  
  CONCLUSIONS
  We report evidence of deficits in Working Memory Index and Full-Scale IQ as a function of prenatal CPF exposure at 7 years of age. These findings are important in light of continued widespread use of CPF in agricultural settings and possible longer-term educational implications of early cognitive deficits.
authors.affiliation: Heilbrunn Center for Population and Family Health, Mailman School of Public Health, New York, NY 10032 USA. var1@columbia.edu
authors.forename: Virginia
authors.initials: V
authors.lastname: Rauh
authors.forename: Srikesh
authors.initials: S
authors.lastname: Arunajadai
authors.forename: Megan
authors.initials: M
authors.lastname: Horton
authors.forename: Frederica
authors.initials: F
authors.lastname: Perera
authors.forename: Lori
authors.initials: L
authors.lastname: Hoepner
authors.forename: Dana B
authors.initials: DB
authors.lastname: Barr
authors.forename: Robin
authors.initials: R
authors.lastname: Whyatt
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004390:Chlorpyrifos / Q000633:toxicity*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000187:drug effects; D008297:Male; D008568:Memory / Q000187:drug effects; D010575:Pesticides / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D055815:Young Adult
chemical_list: D010575:Pesticides; D004390:Chlorpyrifos