title: Exposure of young infants to environmental tobacco smoke: breast-feeding among smoking mothers.
abstract: OBJECTIVE
  This study examined the degree to which breast-feeding and cigarette smoking by mothers and smoking by other household members contribute to the exposure of infants to the products of tobacco smoke.
  
  
  METHODS
  The subjects were 330 mother-infant pairs derived from a cohort of 1000 pairs enrolled in a longitudinal study of the pulmonary effects of prenatal and postnatal smoking. The main outcome measure was corrected urinary cotinine levels.
  
  
  RESULTS
  Urinary cotinine levels were 10-fold higher in breast-fed infants of smoking mothers than among bottle-fed infants of smoking mothers. Among infants of nonsmoking mothers, urine cotinine levels were significantly increased in infants living in homes with other smokers; in this group there was no significant difference between bottle-fed and breast-fed infants. Infants whose mothers smoked in the same room as the infant had only nonsignificant increases in cotinine levels compared with infants whose mothers restricted their smoking to other rooms.
  
  
  CONCLUSIONS
  Breast-fed infants of smoking mothers have urine cotinine levels 10-fold higher than bottle-fed infants whose mothers smoke, suggesting that breast-feeding, rather than direct inhalation of environmental tobacco smoke, is the primary determinant of cotinine levels in infants whose mothers smoke.
authors.affiliation: Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Mascola
authors.forename: H
authors.initials: H
authors.lastname: Van Vunakis
authors.forename: I B
authors.initials: IB
authors.lastname: Tager
authors.forename: F E
authors.initials: FE
authors.lastname: Speizer
authors.forename: J P
authors.initials: JP
authors.lastname: Hanrahan
mesh_terms: D001903:Bottle Feeding; D001942:Breast Feeding; D015331:Cohort Studies; D003367:Cotinine / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000652:urine*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine