What are the dangers of environmental tobacco smoke (ETS), or passive smoking, or second-hand smoke?
Passive smoking occurs when nonsmokers inhale the tobacco smoke created by smokers (environmental tobacco smoke). ETS, also known as second-hand smoke, includes mainstream smoke, which is smoke drawn through the mouthpiece of a cigarette, pipe, or cigar that is then exhaled into the air by smokers, and side stream smoke, the smoke that comes directly from the burning tobacco before it reaches the smoker. ETS contains the same harmful chemicals as the smoke that smokers inhale. In fact, because side stream smoke is formed at lower temperatures, it gives off even larger amounts of cancer-causing substances. At least 43 of the chemicals taken in by those breathing ETS are known cancer-causing substances, and ETS is now classified by the US Environmental Protection Agency (EPA) as a Group A carcinogen (known to cause cancer in humans). ETS causes lung cancer in healthy nonsmokers. A nonsmoker who is married to a smoker has a 30% greater risk of developing lung cancer than a nonsmoker livin
