EPA Map of Radon Zones
IMPORTANT: EPA also recommends that this map be supplemented
with any available local data in order to further understand and
predict the radon potential of a specific area. Contact your
state radon coordinator (Click
Here and click on your state) to see if your state has more
detailed information available. If you have questions
about radon in water
Click Here.
PDF version of the National Radon Map (PDF, 1
page, 405KB)
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.
Important points to note:
- All homes should test for radon, regardless of
geographic location or zone designation
- There are many thousands of individual homes with elevated
radon levels in Zone 2 and 3. Elevated levels can be found in
Zone 2 and Zone 3 counties.
- All users of the map should carefully review the map
documentation for information on within-county variations in
radon potential and supplement the map with locally available
information before making any decisions.
- The map is not to be used in lieu of testing during real
estate transactions.
The Map was developed using five factors to determine radon
potential: indoor radon measurements; geology; aerial radioactivity;
soil permeability; and, foundation type. Radon potential assessment
is based on geologic provinces. Radon Index Matrix is the
quantitative assessment of radon potential. Confidence Index Matrix
shows the quantity and quality of the data used to assess radon
potential. Geologic Provinces were adapted to county boundaries for
the Map of Radon Zones.
Sections 307 and 309 of the
Indoor Radon Abatement Act of 1988 (IRAA) directed EPA to list
and identify areas of the U.S. with the potential for elevated
indoor radon levels. EPA's Map of Radon Zones assigns each of the
3,141 counties in the U.S. to one of three zones based on radon
potential:
|
|
Zone 1
counties have a predicted average indoor radon screening
level greater than 4 pCi/L (pico curies 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) |
Low
Potential |
EPA Map of Radon Zones
Radon Map of Georgia
Radon Map of North Carolina
Radon Map of South Carolina
Radon Map of Tennessee
Radon Map of Alabama
