Over 83 million people around the U.S. live in residences with radon levels over the EPA's action level, new data reveals.

COLUMBUS, Ohio – Over 50% of buildings in Ohio that have undergone radon testing have elevated levels of the colorless and odorless gas, which is a leading cause of lung cancer in the United States.

The researchers' map reveals the geographical ... northern Kansas, central Ohio and central Pennsylvania. This is concerning as radon is the second-leading cause of lung cancer after smoking ...