What is Radon?  Radon is an odorless radioactive gas that is produced from decaying rock and soil.  Radon typically enters the home from small cracks in foundations, concrete and other holes in flooring.   Once inside the home it can become trapped and pose potential risks to occupants.  Radon is the second leading cause of lung cancer in the United States.  The only way to know the radon level, is to get a test.