Published by admin on June 26, 2025 Secondhand smoke (sometimes called passive smoke, environmental tobacco smoke, or involuntary smoke) is a mixture of sidestream smoke (the smoke from the burning tip of a cigarette or other smoked tobacco product) and mainstream smoke (smoke exhaled by a smoker that is diluted by the surrounding air) (1–3). Major settings of exposure to secondhand smoke include workplaces, public places such as bars, restaurants and recreational settings, and homes (4). Workplaces and homes are especially important sources of exposure because of the length of time people spend in these settings. The home is a particularly important source of exposure for infants and young children. Children and nonsmoking adults can also be exposed to secondhand smoke in vehicles, where levels of exposure can be high. Exposure levels can also be high in enclosed public places where smoking is allowed, such as restaurants, bars, and casinos, resulting in substantial exposures for both workers and patrons