Definition of Secondhand Smoke
First, what is secondhand smoke? Secondhand smoke (or environmental tobacco smoke (ETS) refers to the exposure to smoke from cigarettes another person is smoking. It is also called passive smoking or involuntary smoking. Secondhand smoke is made up of two components. “Sidestream smoke” is the smoke that is present in air from the end of a burning cigarette. “Mainstream smoke” is smoke that is exhaled by someone who is smoking after it has traveled through the lungs. Research on animals suggests that sidestream smoke may be even more dangerous than mainstream smoke, but regardless of the debate, secondhand smoke is a known human carcinogen (cancer causing substance).
Secondhand smoke alone is responsible for roughly 3,000 lung cancer deaths each year in the United States, and over 21,000 lung cancer deaths worldwide. Living with a smoker increases an individual’s chance of developing lung cancer by 20 to 30%.
According to U.S. Surgeon General’s report in 2006, even brief secondhand smoke exposure can cause the damage that can lead to lung cancer. Despite this risk, the report also found that nearly half of non-smoking individuals are regularly exposed to secondhand smoke. The best ventilation systems are unable to filter out secondhand smoke completely, and only smoke-free establishments are risk free.