Environmental Tobacco Smoke

Introduction
Why Is It a Problem?
Where Is It a Problem?
Smoking Odors
What Can Be Done About It?

Environmental tobacco smoke (ETS), also known as Secondhand smoke or passive smoke, is a mixture of 2 forms of smoke from burning tobacco products.

• Sidestream smoke: smoke that comes from the end of 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 toxic chemicals just as smokers do. The greater the exposure to secondhand smoke, the greater the level of these harmful chemicals in your body.

Secondhand smoke is classified as a "known human carcinogen" (cancer-causing agent) by the US Environmental Protection Agency (EPA), the US National Toxicology Program, and the International Agency for Research on Cancer (IARC), a branch of the World Health Organization.

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 deaths from heart disease in people who live with smokers but are not current smokers
• about 3,400 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
• increased incidence of middle ear infections in young children

Pregnant women exposed to ETS are also at increased risk of having low birth weight babies.

An issue that continues to be an active focus of scientific research is whether secondhand smoke may increase the risk of breast cancer. Both mainstream and secondhand smoke contain about 20 chemicals that, in high concentrations, cause breast cancer in rodents. Chemicals in tobacco smoke reach breast tissue and are found in breast milk.

The evidence regarding secondhand smoke and breast cancer risk in human studies is controversial, at least in part because the risk has not been shown to be increased in active smokers. One possible explanation for this is that tobacco smoke may have different effects on breast cancer risk in smokers and in those who are just exposed to smoke.

The 2006 US Surgeon General's report reached several important conclusions:

• Secondhand smoke causes premature death and disease in children and in adults who do not smoke.
• Children exposed to secondhand smoke are at an increased risk of sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, and more severe asthma. Smoking by parents causes respiratory symptoms and slows lung growth in their children.
• Exposure of adults to secondhand smoke has immediate adverse effects on the cardiovascular system and causes coronary heart disease and lung cancer.
• The scientific evidence indicates that there is no risk-free level of exposure to secondhand smoke.
• Many millions of Americans, both children and adults, are still exposed to secondhand smoke in their homes and workplaces despite substantial progress in tobacco control.
• Eliminating smoking in indoor spaces fully protects nonsmokers from exposure to secondhand smoke. Separating smokers from nonsmokers, cleaning the air, and ventilating buildings cannot eliminate exposures of nonsmokers to secondhand smoke.

There are 3 locations where you should be especially concerned about exposure to secondhand smoke:

Your workplace: The workplace is a major source of secondhand smoke exposure for adults. 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.

Secondhand smoke exposure in the workplace has been linked to an increased risk for heart disease and lung cancer among adult nonsmokers. The Surgeon General has concluded that smoke-free workplace policies are the only effective way to eliminate secondhand smoke exposure in the workplace. Separating smokers from nonsmokers, cleaning the air, and ventilating buildings cannot eliminate exposure. 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 for the health of your family. Any family member can develop health problems related to secondhand smoke. Children are especially sensitive. In the United States, 21 million, or 35% of children live in homes where residents or visitors smoke in the home on a regular basis. Approximately 50% to 75% of children in the United States have detectable levels of cotinine, the breakdown product of nicotine, in their blood.

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 likely be minimal in comparison to direct secondhand smoke exposure, such as living in a household that has a smoker.

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.

Government administrators in many US localities and states (and even federal governments in some other countries) have decided that protecting the health of employees and others in public places is of the utmost importance, and many have passed clean indoor air laws in recent years. While the regulations vary from place to place, they are growing in popularity