Fact
Hydrogen cyanide is in tobacco smoke. Hydrogen cyanide exposure causes cardiovascular and respiratory illness.
Source 1:
"Smoking and Tobacco Control." U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Cancer Institute. Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine. 19 Nov. 2001.
http://cancercontrol.cancer.gov/brp/tcrb/monographs/13/m13_complete.pdf
Source 2:
"Medical Management Guidelines for Hydrogen Cyanide." Agency for Toxic Substances & Disease Registry. 21 Oct. 2014. Web.