Tobacco smoke contains over 4,000 chemicals and occurs in two phases, gas and particulate. Since tobacco smoke is a complex mixture of particles and gases, filtering out all the toxic components is extremely difficult and costly. Scientists and physicians have long recognized smoking as the leading preventable cause of death and disability in the world. The toxins in tobacco smoke kill over 434,000 people per year in the United States alone. Nonsmokers exposed to secondhand cigarette smoke inhale these same toxins which produce damage similar to that observed in smokers.
Secondhand smoke causes many lung cancer deaths annually.
The gas phase of secondhand smoke contains such poisons and irritants as carbon monoxide, formaldehyde, acrolein, ammonia, nitrogen oxides, benzene, pyridine, and hydrogen cyanide. It also contains at least fifteen known or probable carcinogens. In 1986, the United States Surgeon General issued his first report devoted entirely to the effects of involuntary smoking. The children of parents who smoke, as compared with the children of nonsmoking parents, have an increased frequency of respiratory infections, increased respiratory symptoms and lower rates of increase in lung functions as the lung matures. The simple separation of smokers and nonsmokers within the same air space may reduce, but does not eliminate, the exposure of nonsmokers to environmental tobacco smoke.