The purpose of this map is to assist National, State, and local organizations to target their resources and to implement radon-resistant building codes. This map is not intended to be used to determine if a home in a given zone should be tested for radon. Homes with elevated levels of radon have been found in all three zones. EPA recommends that all homes should be tested regardless of geographic location.
What do the colors mean?
Zone 1 counties have a predicted average indoor radon screening level greater than 4 pCi/L (picocuries per liter) (red zones)
Highest Potential
Zone 2 counties have a predicted average indoor radon screening level between 2 and 4 pCi/L(orange zones)
Moderate Potential
Zone 3 counties have a predicted average indoor radon screening level less than 2 pCi/L (yellow zones)
