What's in secondhand smoke?

Secondhand smoke — also known as environmental tobacco smoke — includes the smoke that a smoker exhales (mainstream smoke) and the smoke that comes directly from the burning tobacco product (sidestream smoke).

Secondhand smoke contains thousands of toxic chemicals, including: Ammonia, used in cleaning products Butane, used in lighter fluid Carbon monoxide, found in car exhaust Chromium, used to make steel Cyanide, used in chemical weapons Formaldehyde, an industrial chemical Lead, a toxic metal Polonium, a radioactive substance The dangerous particles in secondhand smoke can linger in the air for hours or even longer. It isn't just the smoke that's a concern, though.

 The residue that clings to a smoker's hair and clothing, as well as cushions, carpeting and other goods — sometimes referred to as thirdhand smoke — also can pose risks, especially for children.