The role of passive smoking in the development of bronchial obstruction during the first 2 years of life

Epidemiology. 1997 May;8(3):293-7. doi: 10.1097/00001648-199705000-00011.


We assessed the effect of exposure to environmental tobacco smoke on the risk of developing bronchial obstruction in a 2-year cohort study of 3,754 children born in Oslo, Norway, during a period of 15 months in 1992-1993. We collected questionnaire information on the child's health and environmental exposures at birth and when the child was age 6 months (follow up rate = 95%), 12 months (92%), 18 months (92%), and 24 months (81%). The outcome of interest was defined as two or more episodes of bronchial obstruction or one obstruction lasting more than 1 month, and it was verified by a specialist group evaluating data from questionnaires, clinical examinations, and health records. The risk of bronchial obstruction was increased in children exposed to environmental tobacco smoke (cumulative incidence = 0.109) compared with unexposed children (0.071), with an adjusted odds ratio of 1.6 [95% confidence interval (CI) = 1.3-2.1]. The effect was seen for maternal smoking alone (odds ratio = 1.6; 95% CI = 1.0-2.6), paternal smoking alone (odds ratio = 1.5; 95% CI = 1.1-2.2), and both parents smoking (odds ratio = 1.5; 95% CI = 1.0-2.2). There was no clear exposure-response pattern. The findings indicate that exposure to environmental tobacco smoke such as is experienced in Norwegian housing increases the risk of developing bronchial obstruction during the first 2 years of life.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asthma / epidemiology
  • Asthma / etiology*
  • Child, Preschool
  • Cohort Studies
  • Female
  • Humans
  • Incidence
  • Infant
  • Male
  • Norway / epidemiology
  • Odds Ratio
  • Risk Factors
  • Socioeconomic Factors
  • Surveys and Questionnaires
  • Tobacco Smoke Pollution / adverse effects*


  • Tobacco Smoke Pollution