title: Early thimerosal exposure and neuropsychological outcomes at 7 to 10 years.
abstract: BACKGROUND
  It has been hypothesized that early exposure to thimerosal, a mercury-containing preservative used in vaccines and immune globulin preparations, is associated with neuropsychological deficits in children.
  
  
  METHODS
  We enrolled 1047 children between the ages of 7 and 10 years and administered standardized tests assessing 42 neuropsychological outcomes. (We did not assess autism-spectrum disorders.) Exposure to mercury from thimerosal was determined from computerized immunization records, medical records, personal immunization records, and parent interviews. Information on potential confounding factors was obtained from the interviews and medical charts. We assessed the association between current neuropsychological performance and exposure to mercury during the prenatal period, the neonatal period (birth to 28 days), and the first 7 months of life.
  
  
  RESULTS
  Among the 42 neuropsychological outcomes, we detected only a few significant associations with exposure to mercury from thimerosal. The detected associations were small and almost equally divided between positive and negative effects. Higher prenatal mercury exposure was associated with better performance on one measure of language and poorer performance on one measure of attention and executive functioning. Increasing levels of mercury exposure from birth to 7 months were associated with better performance on one measure of fine motor coordination and on one measure of attention and executive functioning. Increasing mercury exposure from birth to 28 days was associated with poorer performance on one measure of speech articulation and better performance on one measure of fine motor coordination.
  
  
  CONCLUSIONS
  Our study does not support a causal association between early exposure to mercury from thimerosal-containing vaccines and immune globulins and deficits in neuropsychological functioning at the age of 7 to 10 years.
authors: National Center for Immunizations and Respiratory Diseases, Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. wct2@cdc.gov
authors: William W
authors: WW
authors: Thompson
authors: Cristofer
authors: C
authors: Price
authors: Barbara
authors: B
authors: Goodson
authors: David K
authors: DK
authors: Shay
authors: Patti
authors: P
authors: Benson
authors: Virginia L
authors: VL
authors: Hinrichsen
authors: Edwin
authors: E
authors: Lewis
authors: Eileen
authors: E
authors: Eriksen
authors: Paula
authors: P
authors: Ray
authors: S Michael
authors: SM
authors: Marcy
authors: John
authors: J
authors: Dunn
authors: Lisa A
authors: LA
authors: Jackson
authors: Tracy A
authors: TA
authors: Lieu
authors: Steve
authors: S
authors: Black
authors: Gerrie
authors: G
authors: Stewart
authors: Eric S
authors: ES
authors: Weintraub
authors: Robert L
authors: RL
authors: Davis
authors: Frank
authors: F
authors: DeStefano
mesh_terms: D002648:Child; D002657:Child Development / Q000187:drug effects*; D002658:Developmental Disabilities / Q000139:chemically induced / Q000453:epidemiology / Q000517:prevention & control; D004781:Environmental Exposure / Q000032:analysis; D005035:Ethylmercury Compounds / Q000009:adverse effects / Q000032:analysis / Q000494:pharmacology; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000008:administration & dosage / Q000737:chemistry; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence / Q000187:drug effects*; D008297:Male; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects / Q000494:pharmacology*; D012044:Regression Analysis; D013849:Thimerosal / Q000009:adverse effects / Q000494:pharmacology*; D014612:Vaccines / Q000009:adverse effects / Q000737:chemistry
chemical_list: D005035:Ethylmercury Compounds; D007136:Immunoglobulins; D011310:Preservatives, Pharmaceutical; D014612:Vaccines; D013849:Thimerosal