Second-hand Smoke in Homes and Cars
Second-hand smoke (SHS) refers to the mixture of smoke emanating from the lit end of a cigarette and the smoke exhaled by a smoker. The toxic mixture contains more than 4,000 substances in gaseous and particle form, and is a major source of indoor air pollution. Two-thirds of the smoke emanating from a burning cigarette is not inhaled by the smoker, but is released into the ambient air,
contaminating the air supply of others.