Commercial tobacco smoke is a mixture of more than 5,000 chemicals. A 2011 report in the International Journal of Environmental Research and Public Health (IJERPH) lists 65 carcinogens or possible carcinogens: "Our list of hazardous smoke components includes all nine components reported in mainstream cigarette smoke that are known human carcinogens (IARC Group I carcinogens), as well as all nine components that are probably carcinogenic to humans (IARC Group 2A carcinogens). In addition, it contains 34 of the 48 components that are possibly carcinogenic to humans (IARC Group 2B carcinogens)."
IJERPH table "1Cancer inhalation risk values provide an excess lifetime exposure risk, in this case the human lung cancer risk at a 1 in 100,000 (E-5) level."
See also Kent, a cigarette that contained a filter made of asbestos. Composition of electronic cigarette aerosol Health effects of tobacco smoking List of additives in cigarettes
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