These Philip Morris Tobacco Company documents reveal that dioxins are present in secondhand tobacco smoke.
Dioxins are a product of combustion.
The following description of dioxin is taken from the Dioxin Home Page , a page which also has links to studies and other information about dioxins. Dioxin is one of the most toxic chemicals known. A report released for public comment in September 1994 by the US Environmental Protection Agency clearly describes dioxin as a serious public health threat. The public health impact of dioxin may rival the impact that DDT had on public health in the 1960's. In order to simplify the process, the amount of dioxins in sidestream smoke is used as a measure for the amount originating from the cigarette.