Secondhand smoke is a combination both of the smoke exhaled by the smoker, and the smoke that comes from the burning end of the cigarette.¹

Secondhand smoke is a proven health hazard that kills thousands of people every year.

Reports by the all of the following organizations have all determined that secondhand smoke is harmful:

	Office of the U.S. Surgeon General
	Centers for Disease Control and Prevention
	Environmental Protection Agency
	National Academy of Sciences
	American College of Occupational and Environmental Medicine
	U.S. Public Health Service's National Toxicology Program
	National Institute of Occupational Safety and Health
	World Health Organization
	American Medical Association
	American Lung Association
	Occupational Safety and Health Administration

Like asbestos and benzene, secondhand smoke has been classified as a Group A (known human) carcinogen.^1,3,4

Nonsmokers exposed to secondhand smoke are exposed to about 4,000 chemical compounds, including formaldehyde, cyanide, ammonia, nicotine, carbon monoxide, and cancer-causing agents such as benzene, asbestos, and N-nitrosamines.^1,4

According to a 1992 EPA report, secondhand smoke is a human lung carcinogen, responsible for 3,000 deaths in nonsmokers every year.⁵

According to a 1992 EPA report, more people die each year from secondhand smoke than all other regulated occupational substances combined.⁵

According to the 1986 Surgeon General's report, exposure to secondhand smoke can cause lung cancer - as evidence, nonsmoking spouses of heavy smokers have nearly twice the risk of developing lung cancer.¹

According to a 1997 report by the National Cancer Institute (NCI), not only is secondhand smoke responsible for 3,000 lung cancer deaths every year, but also for between 35,000 to 62,000 deaths associated with ischemic heart disease.³

That NCI report also determined that lifelong nonsmokers living with smokers have, on average, a 24% higher chance of contracting lung cancer than those living with nonsmokers, and those exposed to the heaviest smokers for the longest time have the highest risks.³

Scientific studies published in peer-reviewed journals on both animals and humans indicate that nonsmokers exposed to secondhand smoke have higher death rates from heart disease.  More specifically, a 1997 British Medical Journal meta-analysis of 19 published studies found that exposure to secondhand smoke increases an individual's risk of ischemic heart disease by 25%.³

Nonsmokers exposed to secondhand smoke only at work have been found to have significantly higher levels of a nicotine metabolite in their blood than nonsmokers who aren't exposed to secondhand smoke at work.¹

The Surgeon General has determined that simple separation of smokers and nonsmokers within the same airspace may reduce but does not eliminate exposure of nonsmokers to secondhand smoke.¹

The National Institute of Occupational Safety and Health (NIOSH) has stated that secondhand smoke poses an increased risk of lung cancer and heart disease to people exposed at work, and has recommended that exposure be reduced to the lowest feasible level, and that employers should use all available preventive measures to minimize occupational exposure.¹

A 2001 study in the Journal of the American Medical Association concluded that exposure to secondhand smoke "substantially reduced" coronary circulation in healthy nonsmokers, providing "direct evidence" that exposure to secondhand smoke causes coronary circulatory dysfunction in nonsmokers.³

A 2001 study in The Lancet found that exposure to secondhand smoke was significantly associated with nighttime chest tightness and breathlessness after physical activity, and that workplace exposure to secondhand smoke was significantly associated with all types of respiratory symptoms and current asthma.³