The U.S. Public Health Service documents on the health consequences of smoking have conclusively established cigarette smoking as the largest single preventable cause of premature death and disability in the United States.
Involuntary smoking is a cause of disease, including lung cancer, in healthy nonsmokers.
The children of parents who smoke, compared with the children of nonsmoking parents, have an increased frequency of respiratory infections, increased respiratory symptoms, and slightly smaller rates of increase in lung function as the lung matures. Simple separation of smokers and nonsmokers within the same air space may reduce, but does not eliminate, exposure of nonsmokers to environmental tobacco smoke. Cigarette smoke is a complex mixture of over 1200 identified substances which affect indoor air quality. Among them are carbon monoxide, nicotine, hydrogen cyanide, metals, aldehydes, phenol, ammonia, and sulfur dioxide. Exposure to these and other potentially harmful substances through environmental tobacco smoke in the workplace can be substantial both in duration and intensity.