Description of the differences in risk of lung cancer between smokers and non-smokers exposed to radon

Health Canada estimates a non-smoker exposed to elevated levels of radon over a lifetime has a 1 in 20 chance of developing lung cancer. The combined effects of radon exposure and smoking tobacco significantly increase the risk of lung cancer. If a smoker is exposed to the same level of radon over a lifetime, the risk increases to a 1 in 3 chance.