Radon Is the Nation's Second Leading Cause of Lung Cancer Deaths Radon is the second leading cause of lung cancer after smoking. Each year in the United States exposure to indoor radon gas causes thousands of preventable lung cancer deaths. You cannot see, taste, or smell radon, but at elevated levels indoors, it can pose a significant health risk. Radon is a naturally occurring radioactive gas that can be emitted from surrounding soil into the home. Any soil anywhere can contain radon.
Radon is the second leading cause of lung cancer deaths in the United States after smoking.