Secondhand smoke is a combination of the smoke from a burning cigarette and the smoke exhaled by the smoker. Also known as environmental tobacco smoke (ETS), it can be recognized easily by its distinctive odor.
ETS contaminates the air and is retained in clothing, curtains and furniture. Many people find ETS unpleasant, annoying, and irritating to the eyes and nose. More importantly, it represents a dangerous health hazard. Over 4,000 different chemicals have been identified in ETS, and at least 43 of these chemicals cause cancer.