Health Canada
Symbol of the Government of Canada

Common menu bar links

Environmental and Workplace Health

What are the Health Effects of Radon?

Did you know?

16% of lung cancers deaths in Canada are attributable to radon exposure.

The only known health effect of radon is an increased chance of developing lung cancer. Radon is the second leading cause of lung cancer after smoking. Because it is radioactive, radon decays. As it decays, radon produces decay products, sometimes called "radon daughters" or "radon progeny". Radon gas and radon progeny in the air can be breathed into the lungs where they breakdown further and emit "alpha particles". Alpha particles release small bursts of energy which are absorbed by nearby lung tissue. This results in lung cell death or damage. When lung cells are damaged, they have the potential to result in cancer when they reproduce.

Lung cancer risk. Smoker + high radon = 1 in 3; high radon only = 1 in 20

Not everyone exposed to radon will develop cancer. The time between exposure and the onset of the disease is usually many years. Unlike smoking, occasional exposure to radon does not produce any symptoms, such as coughing or headaches.

Your risk of developing lung cancer from radon depends on the concentration of radon in the air you breathe and the length of time you are exposed. If you are a smoker also exposed to elevated levels of radon your risk of lung cancer is significantly increased.

Related Resources