Radon is a colorless, tasteless, and odorless gas that comes from the decay of uranium found in nearly all soils. Levels of radon vary throughout the country. Radon usually moves from the ground up and migrates into homes and other buildings through cracks and other holes in their foundations. The buildings trap radon inside, where it accumulates and may become a health hazard if the building is not properly ventilated. When you breathe air containing a large amount of radon, the radiation can damage your lungs and eventually cause lung cancer.
Scientists believe that radon is the second leading cause of lung cancer in the United States.
It is estimated that 7,000 to 30,000 Americans die each year from radon-induced lung cancer. Only smoking causes more lung cancer deaths and smokers exposed to radon are at higher risk than nonsmokers. Controlling the Risks from Radon Exposure Radon is found all over the United States. Scientists estimate that nearly one out of every 15 homes in this country has radon levels higher than four picocuries per liter, the level above which EPA recommends that homeowners take corrective action. Picocuries per liter is how radon in the air is measured.