Sidestream smoke is responsible for 85 percent of the smoke passive smokers inhale. Sidestream smoke is not filtered by the tobacco, the filter or a smoker's lungs, so it contains more nicotine, carbon dioxide and carbon monoxide than mainstream smoke. Sidestream smoke also has 20 to 100 times the quantity of cancer-causing substances that mainstream smoke has. Recent studies report that passive smoking may be responsible for between 10,000 and 20,000 premature deaths per year for nonsmokers in the United States. In addition, ETS is associated with lung cancer, heart disease, low birth weight babies, asthma, eye irritations, ear infections, headaches and coughs in nonsmokers.
Passive smoking poses serious threats to nonsmokers within residential settings.
Nonsmoking spouses of smokers are three times more likely to experience heart attacks and also have a 30 percent greater risk of lung cancer than nonsmoking spouses of nonsmokers. The children of parents who smoke are twice as likely as children of nonsmoking parents to experience bronchitis or pneumonia the first year of life. In addition, throughout their childhood, these children will experience more wheezing, coughing and colds than children whose parents do not smoke. The effect on children is greatest when both parents smoke. Because of the small size of the particles produced by burning tobacco, even the most modern ventilation system cannot completely remove ETS from an indoor site.