According to the Environmental Protection Agency (EPA), the eastern one-third of Nebraska, as well as the south central region of the state, are Level 1 areas for radon. These counties have predicted average indoor radon screening levels greater than 4 pCi/L − the level high enough to require mitigation.
The Panhandle and several other counties are Level 2 areas. Their predicted average indoor radon screen levels are expected to range from 2 to 4 pCi/L.