Objective and design: To study the effects of passive smoking on health in adolescent schoolchildren by questionnaire, spirometry and laboratory investigations.
Setting: Two schools in the Vanderbijlpark area.
Participants: Seven hundred and twenty-six high-school children of average age 16 years.
Outcome measures: Lung function, serological abnormality or historical (i.e. questionnaire) evidence of ill health.
Results: The prevalence of respiratory illness before and after 2 years, respiratory symptoms, earache over the past year, low birth weight and learning difficulties were found to be significantly increased in the children exposed to parenteral smoke in the home, especially those exposed to maternal smoking. Spirometric and laboratory parameters, however, were not affected by passive smoking.