Up to a quarter of all Americans live in areas where radon levels are above the "action level" set by the United States Environmental Protection Agency (EPA). According to a new paper in the ...

[Perhaps} it may have a type of rock that isn’t high on uranium.” In almost 14% of homes in New York, radon levels are at or above 4 picocuries per liter. This is known as the action level.

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