The "biohazard" stuff is crap.
Well, third-hand smoke is considered by at least some docs to be a direct cancer risk.
Among the substances in third-hand smoke are hydrogen cyanide, used in chemical weapons; butane, which is used in lighter fluid; toluene, found in paint thinners; arsenic; lead; carbon monoxide; and even polonium-210, the highly radioactive carcinogen that was used to murder former Russian spy Alexander V. Litvinenko in 2006. Eleven of the compounds are highly carcinogenic.
"Never ascribe to malice that which is caused by greed and ignorance." -- Cal Keegan