Ohio - EPA Radon Map

 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. All homes should be tested regardless of geographic location. 

Radon Zones by County


Zone 1: Counties with predicted average indoor radon screening levels greater than 4 pCi/L


Zone 2: Counties with predicted average indoor radon screening levels from 2 to 4 pCi/L


Zone 3: Counties with predicted average indoor radon screening levels less than 2 pCi/L