I said tobacco, not cigarette.
As for source:
http://firescope.caloes.ca.gov/spec...combustion_products_effect_on_life_safety.pdf
"Organic Irritants Pyrolysis and/or incomplete combustion of organic materials can lead to a wide variety of organic irritant species. Those considered to be the most important toxicologically are formaldehyde, unsaturated aldehydes (especially acrolein), and isocyanates (from nitrogen-containing polymers15). The first two result from partial oxidation of the carbon in the material. (Further oxidation leads to the formation of CO and then CO2.) Acrolein, in particular, has been demonstrated to be present in many fire atmospheres.16 It is also formed from the smoldering of all cellulosic materials and from the oxidative pyrolysis of polyethylenes."
Just the formaldehyde is enough to cause cancer. Of course this is OBVIOUSLY if the person survive after smoking, that should be obvious enough.