Cytologic changes in the respiratory tract in children smokers.

Cytologic investigation was carried out on sputum of 45 children who were cigarette smokers and in a control group of nonsmoking children matched for age and environment. All but one of the children smokers were able to produce sputa whereas none of the controls could do so. Abnormal columnar cells were frequent, and squamous metaplasia was noted in 15.5% of the 45 patients. Atypical metaplasia was not found. The rate of metaplasia was much lower in children than in adult smokers. It is possible that the respiratory epithelium of children is resistant to the noxious effects of cigarette smoke.