A study from 2001, which included 436 non-smokers with lung cancer and a control group of 1649 non-smokers without lung cancer, showed that exposure to radon increased the risk of lung cancer in non-smokers. The group that had been exposed to tobacco smoke in the home appeared to have a much higher risk, while those who were not exposed to passive smoking did not show any increased risk with increasing radon exposure.
A study from 2001 which included 436 non-smokers with lung cancer and a control group of 1649 non-smokers without lung cancer showed that exposure to radon increased the risk of lung cancer in non-smok,ers The group that had been exposed to tobacco smoke in the h:ome appeared to have a much higher risk while those who were not exposed to passive smoking did not show any increased risk with increasing radon exposure