Second-hand tobacco smoke and children.

Cigarette smoke contains harmful chemicals with hazardous adverse effects on almost every organ in the body of smokers as well as of nonsmokers exposed to environmental tobacco smoke (ETS). There has been increasing interest in the effects of passive smoking on the health of children. In order to detect the magnitude of passive smoking in children, parental questionnaires, measuring nicotine and cotinine body levels, and evaluating expired carbon monoxide (CO) concentrations, have been used.