Fact
Acetaldehyde is in tobacco smoke. Acetaldehyde is a hazardous air pollutant.
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: 179.
http://cancercontrol.cancer.gov/brp/tcrb/monographs/13/m13_complete.pdf
Source 2:
"13th Report on Carcinogens (RoC): Acetaldehyde." National Toxicology Program, Department of Health and Human Services. 02 Oct. 2014. Web.
https://ntp.niehs.nih.gov/ntp/roc/content/profiles/acetaldehyde.pdf