Tobacco smoke as a source of acetaldehyde exposure

During smoking, acetaldehyde is released into saliva, which transports it all the way to the mucous membranes of the oesophagus, throat and stomach. Therefore, smoking significantly increases the risk of cancer in these areas.

The more people smoke, the greater their acetaldehyde exposure and  risk of cancer. Two million people are diagnosed with cancer of the upper gastrointestinal tract every year worldwide.

How is acetaldehyde formed in tobacco?

Acetaldehyde is formed in tobacco when the tobacco leaves and the sugars added to tobacco (i.e. sorbitol and glycerol) burn. Acetaldehyde is irritating to the respiratory system, and the International Agency for Research on Cancer (IARC) has classified it as a Group 1 human carcinogen, like radon and asbestos.

Normally, acetaldehyde is not found in saliva in significant concentrations. During smoking, the acetaldehyde content of saliva is 10 mg/l on average. The amount exceeds the safety limit by 2 to 4 times. In some people, the limit is exceeded by up to 5 times during smoking. The way a person smokes affects the amount of acetaldehyde exposure.

Acetaldehyde is also indirectly harmful to smokers as it is known to increase nicotine addiction. Therefore, in the worst-case scenario smokers become even more exposed to the toxic substances of tobacco smoke (Valvira and the Netherlands National Institute for Public Health and the Environment (RIVM)).