Exposures to environmental toxicants and attention deficit hyperactivity disorder in U.S. children

Environ Health Perspect. 2006 Dec;114(12):1904-9. doi: 10.1289/ehp.9478.


Objective: The purpose of this study was to examine the association of exposures to tobacco smoke and environmental lead with attention deficit hyperactivity disorder (ADHD).

Methods: Data were obtained from the National Health and Nutrition Examination Survey 1999-2002. Prenatal and postnatal tobacco exposure was based on parent report; lead exposure was measured using blood lead concentration. ADHD was defined as having current stimulant medication use and parent report of ADHD diagnosed by a doctor or health professional.

Results: Of 4,704 children 4-15 years of age, 4.2% were reported to have ADHD and stimulant medication use, equivalent to 1.8 million children in the United States. In multivariable analysis, prenatal tobacco exposure [odds ratio (OR) = 2.5; 95% confidence interval (CI), 1.2-5.2] and higher blood lead concentration (first vs. fifth quintile, OR = 4.1; 95% CI, 1.2-14.0) were significantly associated with ADHD. Postnatal tobacco smoke exposure was not associated with ADHD (OR = 0.6; 95% CI, 0.3-1.3; p = 0.22). If causally linked, these data suggest that prenatal tobacco exposure accounts for 270,000 excess cases of ADHD, and lead exposure accounts for 290,000 excess cases of ADHD in U.S. children.

Conclusions: We conclude that exposure to prenatal tobacco and environmental lead are risk factors for ADHD in U.S. children.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Attention Deficit Disorder with Hyperactivity / chemically induced
  • Attention Deficit Disorder with Hyperactivity / epidemiology*
  • Attention Deficit Disorder with Hyperactivity / etiology
  • Child
  • Child, Preschool
  • Female
  • Hazardous Substances / poisoning*
  • Humans
  • Lead / blood
  • Male
  • Multivariate Analysis
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Tobacco / adverse effects
  • Tobacco Smoke Pollution / adverse effects*
  • United States / epidemiology


  • Hazardous Substances
  • Tobacco Smoke Pollution
  • Lead