Environmental Tobacco Smoke

Composition

Environmental tobacco smoke contains more than 4,000 chemicals, including at least 250 harmful to health and 50 carcinogens. Carcinogens in tobacco smoke include arsenic (a heavy-metal toxin), benzene (a chemical found in gasoline), beryllium (a toxic metal), cadmium (a metal used in batteries), chromium, ethylene oxide, nickel, and vinyl chloride. The chemical composition of smoke is highly variable and dependent on factors such as the tobacco type, chemical additives, wrapping paper, the way the product is smoked (such as smoking rate), contact with indoor surfaces, and environmental conditions. Research shows that environmental tobacco smoke can have a different composition than mainstream smoke, including more toxic substances, and it is not simply diluted smoke. The presence of tobacco smoke in indoor air is determined by testing for smoke constituents; and [Page 236]exposure of a nonsmoker to smoke can be tested by measuring cotinine (a nicotine by-product in body-fluid levels) in blood, saliva, or urine.

Risks

There is a scientific consensus that environmental tobacco smoke is a risk to human health, although the causal link is not always clear. Exposure to smoke in the environment is associated with the same health problems as direct smoking, particularly, a significant increased risk of cardiovascular diseases, cancers, respiratory problems, and cognitive impairment and dementia.

The Environmental Protection Agency (EPA) classifies environmental tobacco smoke as a known human carcinogen and estimates that each year it is responsible for several thousand lung cancer deaths among nonsmokers. Environmental tobacco smoke can also trigger asthma, allergies, and other respiratory problems; cause breathing and other problems among young children and infants, such as asthma, bronchitis, colds, infant death, ear infections, and pneumonia; and be a risk for pregnant women and babies, such as low birth weight, premature birth, and foetal death.

The health risks of exposure to environmental tobacco smoke are substantially lower than those associated with direct smoking. However, there is no safe exposure level, as studies have shown that even low amounts in the environment can be harmful, although the magnitude of risk remains debated by scientists. The overall risk is higher when non-smokers spend many hours in an environment where environmental tobacco smoke is widespread, such as in the home or workplace. As a consequence of potential health risks, many state and local governments around the world have implemented smoking bans in indoor public facilities such as airports, bus terminals, cafés, hospitals, nightclubs, residential care facilities, restaurants, and schools. At the national level, some countries have adopted legislation to protect citizens from exposure to environmental tobacco smoke; for example, in March 2004, the Republic of Ireland became the first country in the world to impose an outright smoking ban in all indoor workplaces. Since then, many others have followed suit, including Italy, New Zealand, Norway, and Sweden. In countries without bans, an increasing number of private work and other places have taken voluntary measures to be smokefree. Smoking bans tend to be more effective when complemented by additional initiatives such as health awareness campaigns concerning health risks of smoke and programs to help people quit smoking. Alternatives to smoking bans include ventilation and air cleaning systems to reduce tobacco smoke pollutants and separating smokers from nonsmokers, but a ban is the only way to fully protect against smoke exposure.

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