title: Passive smoking during the first year of life.
abstract: OBJECTIVE
  A description of passive smoking during the first year of life might assist planning preventive efforts.
  
  
  METHODS
  Changes in the ecology of passive smoking were investigated in a sample of infants in central North Carolina followed from birth to one year of age.
  
  
  RESULTS
  The prevalence of tobacco smoke absorption, indicated by excretion of cotinine, increased from 53 percent to 77 percent (95% CI of difference: 14, 35) during the first year of life. Most infants (92 percent) excreting cotinine at three weeks of age were also excreting it at one year. Moreover, 61 percent of infants not excreting cotinine at age three weeks were excreting it at one year. This increase reflected an increased exposure to household and, particularly, nonhousehold sources of smoke; the proportion of infants exposed to nonhousehold smokers increased from 14 percent to 36 percent.
  
  
  CONCLUSIONS
  These findings suggest that prevention of the onset of passive smoking should begin very early.
authors.affiliation: University of North Carolina, Chapel Hill 27599-7225.
authors.forename: R A
authors.initials: RA
authors.lastname: Greenberg
authors.forename: K E
authors.initials: KE
authors.lastname: Bauman
authors.forename: V J
authors.initials: VJ
authors.lastname: Strecher
authors.forename: L L
authors.initials: LL
authors.lastname: Keyes
authors.forename: L H
authors.initials: LH
authors.lastname: Glover
authors.forename: N J
authors.initials: NJ
authors.lastname: Haley
authors.forename: H C
authors.initials: HC
authors.lastname: Stedman
authors.forename: F A
authors.initials: FA
authors.lastname: Loda
mesh_terms: D000328:Adult; D003367:Cotinine / Q000652:urine; D003404:Creatinine / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009657:North Carolina / Q000453:epidemiology; D010290:Parents / Q000193:education; D015995:Prevalence; D011863:Radioimmunoassay; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000032:analysis / Q000517:prevention & control / Q000706:statistics & numerical data*
chemical_list: D014028:Tobacco Smoke Pollution; D003404:Creatinine; D003367:Cotinine