Secondhand Smoke
What Is It?
Secondhand smoke, also known as environmental tobacco smoke (ETS) or passive smoke, is a mixture of two forms of smoke from burning tobacco products:
Sidestream smoke: smoke that comes from a lighted cigarette, pipe, or cigar
Mainstream smoke: smoke that is exhaled by a smoker
When nonsmokers are exposed to secondhand smoke it is called involuntary smoking or passive smoking. Nonsmokers exposed to secondhand smoke absorb nicotine and other compounds just as smokers do. The greater the exposure to secondhand smoke, the greater the level of these harmful compounds in your body.
Why Is It a Problem?
The US Environmental Protection Agency (EPA) has classified secondhand smoke as a Group A carcinogen, which means that there is sufficient evidence that it causes cancer in humans. Environmental tobacco smoke has also been classified as a "known human carcinogen" by the US National Toxicology Program.
Secondhand tobacco smoke contains over 4,000 chemical compounds. More than 60 of these are known or suspected to cause cancer.
Secondhand smoke can be harmful in many ways. In the United States alone, each year it is responsible for:
An estimated 35,000 to 40,000 deaths from heart disease in people who are not current smokers
About 3,000 lung cancer deaths in nonsmoking adults
Other respiratory problems in nonsmokers, including coughing, phlegm, chest discomfort, and reduced lung function
150,000 to 300,000 lower respiratory tract infections (such as pneumonia and bronchitis) in children younger than 18 months of age, which result in 7,500 to 15,000 hospitalizations
Increases in the number and severity of asthma attacks in about 200,000 to 1 million asthmatic children
The 1986 US Surgeon General's report on the health consequences of involuntary smoking reached 3 important conclusions about secondhand smoke:
Involuntary smoking causes disease, including lung cancer, in healthy nonsmokers.
When compared with the children of nonsmoking parents, children of parents who smoke have more frequent respiratory infections, more respiratory symptoms, and slower development of lung function as the lung matures.
Separating smokers and nonsmokers within the same air space may reduce, but does not eliminate, the exposure of nonsmokers to secondhand smoke.
Where Is It a Problem?
There are 3 locations where you should be especially concerned about exposure to secondhand smoke:
Your workplace: Secondhand smoke meets the criteria to be classified as a potential cancer-causing agent by the Occupational Safety and Health Administration (OSHA), the federal agency responsible for health and safety regulations in the workplace. The National Institute for Occupational Safety and Health (NIOSH), another federal agency, also recommends that secondhand smoke be considered a potential occupational carcinogen. Because there are no known safe levels, they recommend that exposures to secondhand smoke be reduced to the lowest possible levels.
Aside from protecting nonsmokers, workplace smoking restrictions may also encourage smokers who wish to quit or reduce their consumption of tobacco products.
Public places: Everyone is vulnerable to secondhand smoke exposure in public places, such as restaurants, shopping centers, public transportation, schools and daycare centers. Although some businesses are reluctant to ban smoking, there is no credible evidence that going smoke-free is bad for business. Public places where children go are a special area of concern.
Your home: Making your home smoke-free is perhaps one of the most important things you can do. Any family member can develop health problems related to secondhand smoke. Think about it: we spend more time at home than anywhere else. A smoke-free home protects your family, your guests, and even your pets.
Smoking Odors
There is no research in the medical literature about the cancer-causing effects of cigarette odors, but the literature shows that secondhand tobacco smoke can permeate the hair, clothing, and other surfaces. The unknown cancer causing effects would be minimal in comparison to direct secondhand smoke exposure, such as living in a household that has a smoker.
What Can Be Done About It?
Local, state, and federal authorities can enact public policies to protect people from secondhand smoke and to protect children from tobacco-caused diseases and addiction. Because there are no safe levels of secondhand smoke, it is important that any such policies be as strong as possible, and that they do not prevent action at other levels of government.
To learn how you can become involved in reducing exposure to secondhand smoke, contact your American Cancer Society at 1-800-ACS-2345.
). 
Who knows, but my guess would be that they're pretty close (they could in fact, be higher). But you can check with any number of reputable organizations including the American Heart Association, the Centers for Disease Control, the Environmental Protection Agency, etc and you will see the same information which comes from decades of data. The bottom line is that the link between cigarette smoke and disease has been clearly established. We are lucky to know about it, our elders were not.
