title: Prenatal exposure to the organophosphate pesticide chlorpyrifos and childhood tremor.
abstract: BACKGROUND
  The organophosphate insecticide chlorpyrifos (CPF), widely used for agricultural purposes, has been linked to neurodevelopmental deficits. Possible motor effects at low to moderate levels of exposure have not been evaluated.
  
  
  METHODS
  Prenatal exposure to CPF was measured in umbilical cord blood in a sample of 263 inner-city minority children, who were followed prospectively. At approximately 11 years of age (mean age 10.9 ± 0.85 years, range=9.0-13.9), during a neuropsychological assessment, children were asked to draw Archimedes spirals. These were rated by a senior neurologist specializing in movement disorders who was blind to CPF exposure level.
  
  
  RESULTS
  Compared to all other children, those with prenatal CPF exposure in the upper quartile range (n=43) were more likely to exhibit mild or mild to moderate tremor (≥ 1) in either arm (p=0.03), both arms (p=0.02), the dominant arm (p=0.01), and the non-dominant arm (p=0.055). Logistic regression analyses showed significant CPF effects on tremor in both arms, either arm, the dominant arm (p-values <0.05), and the non-dominant arm (p=0.06), after adjustment for sex, age at testing, ethnicity, and medication.
  
  
  CONCLUSIONS
  Prenatal CPF exposure is associated with tremor in middle childhood, which may be a sign of the insecticide's effects on nervous system function.
authors.affiliation: Heilbrunn Department of Population and Family Health, Mailman School of Public Health, Columbia University, New York, NY, USA; Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, USA. Electronic address: var1@columbia.edu.
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Rauh
authors.affiliation: Heilbrunn Department of Population and Family Health, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Wanda E
authors.initials: WE
authors.lastname: Garcia
authors.affiliation: Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Whyatt
authors.affiliation: Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Horton
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Dana B
authors.initials: DB
authors.lastname: Barr
authors.affiliation: Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA; Department of Epidemiology, Yale School of Public Health, Yale University, New Haven, CT, USA; Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
mesh_terms: D000293:Adolescent; D002648:Child; D004390:Chlorpyrifos / Q000097:blood / Q000633:toxicity*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007306:Insecticides / Q000097:blood / Q000633:toxicity*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008431:Maternal-Fetal Exchange; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000097:blood / Q000503:physiopathology*; D014202:Tremor / Q000139:chemically induced*
chemical_list: D007306:Insecticides; D004390:Chlorpyrifos
keywords: Brain; Children; Chlorpyrifos; Neurodevelopment; Tremor