title: A strategy for comparing the contributions of environmental chemicals and other risk factors to neurodevelopment of children.
abstract: BACKGROUND
  The impact of environmental chemicals on children's neurodevelopment is sometimes dismissed as unimportant because the magnitude of the impairments are considered to be clinically insignificant. Such a judgment reflects a failure to distinguish between individual and population risk. The population impact of a risk factor depends on both its effect size and its distribution (or incidence/prevalence).
  
  
  OBJECTIVE
  The objective was to develop a strategy for taking into account the distribution (or incidence/prevalence) of a risk factor, as well as its effect size, in order to estimate its population impact on neurodevelopment of children.
  
  
  METHODS
  The total numbers of Full-Scale IQ points lost among U.S. children 0-5 years of age were estimated for chemicals (methylmercury, organophosphate pesticides, lead) and a variety of medical conditions and events (e.g., preterm birth, traumatic brain injury, brain tumors, congenital heart disease).
  
  
  CONCLUSIONS
  Although the data required for the analysis were available for only three environmental chemicals (methylmercury, organophosphate pesticides, lead), the results suggest that their contributions to neurodevelopmental morbidity are substantial, exceeding those of many nonchemical risk factors.
  
  
  CONCLUSIONS
  A method for comparing the relative contributions of different risk factors provides a rational basis for establishing priorities for reducing neurodevelopmental morbidity in children.
authors.affiliation: Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115 , USA. david.bellinger@childrens.harvard.edu
authors.forename: David C
authors.initials: DC
authors.lastname: Bellinger
mesh_terms: D001822:Body Burden; D002657:Child Development; D002675:Child, Preschool; D004194:Disease; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity; D004812:Epidemiologic Methods; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence; D018570:Risk Assessment; D012307:Risk Factors; D012959:Socioeconomic Factors
chemical_list: D004785:Environmental Pollutants