What are TSNAs?

What TSNAs are:

Tobacco-specific N-nitrosamines (TSNAs) are known to be some of the most potent carcinogens present in smokeless tobacco, snuff and tobacco smoke.

TSNAs consist of four chemical compounds:

• N-nitrosonornicotine (NNN)
• 4-methyl-N-nitrosamino-1-(3-pyridyl)-1-butanone (NNK)
• N-nitrosoanatabine (NAT)
• N-nitrosoanabasine (NAB)

Two of these chemical compounds, NNN and NNK, have been classifed as Group 2B carcinogens.

Where TSNAs come from:

While TSNAs exist in low concentrations in green tobacco, it is the process of fermenting and curing tobacco that produces high levels of TSNAs in smokeless tobacco as well as tobacco smoke.

Cancers associated with TSNAs:

TSNAs are highly toxic and linked to several cancers:

• Lung cancer

• Oral cancer

• Esophageal cancer

• Liver cancer

• Pancreatic cancer

There is a growing concern that TSNAs may be associated with cervical cancer, because these carcinogens have been found in large quantities in the cervical mucus of women who smoke.

More on the chemicals in tobacco:

Cigarette smoke is a toxic cocktail of over 4,000 chemicals including 200 poisonous and 40 carcinogenic compounds.

• The List of Additives in Cigarettes

• The Chemicals Found in Cigarette Smoke

Sources:

Hoffman, D et al, "The biological significance of tobacco-specific N-nitrosamines: smoking and adenocarcinoma of the lung." Critical Reviews in Toxicology, 1996; 26(2): 199-211.

"Reducing the Health Consequences of Smoking: 25 Years of Progress. A report of the Surgeon General 1989." U.S. Department of Health and Human Services.

Prokopczyk, B et al. "Identification of Tobacco-specific carcinogen in the cervical mucus of smokers and non-smokers." Journal of the National Cancer Institute, 1997 Jun 18;89(12):868-73.