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)
- Zone 2 counties have a predicted average indoor radon
screening level between 2 and 4 pCi/L (orange zones)
- Zone 3 counties have a predicted average indoor radon
screening level less than 2 pCi/L (yellow zones)
An Adobe Acrobat pdf version of the map is available (suitable
for printing): color - zonemapcolor.pdf (327KB file) | black & white
- b&wmap.pdf (98KB file)
You can view your State's radon potential map by clicking on your
State below.
Alabama || Alaska || Arizona || Arkansas || California || Colorado || Connecticut || Delaware || Florida || Georgia || Hawaii || Idaho || Illinois || Indiana || Iowa || Kansas || Kentucky || Louisiana || Maine || Maryland || Massachusetts || Michigan || Minnesota || Mississippi || Missouri || Montana || Nebraska || Nevada || New Hampshire || New Jersey || New Mexico || New York || North Carolina || North Dakota || Ohio || Oklahoma || Oregon || Pennsylvania || Rhode Island || South Carolina || South Dakota || Tennessee || Texas || Utah || Vermont || Virginia || Washington || West Virginia || Wisconsin || Wyoming

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: Consult the EPA Map of Radon Zones document
(EPA-402-R-93-071) before using this map [call your State
Radon Contact for a copy of the Map and the Zones document].
This document contains information on radon potential variations
within counties. 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. If you have
questions about radon in water, you should contact your State
Radon
Coordinator. |