| 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 (330KB file) | black & white -
b&wmap.pdf (101KB file)
You can view your State's radon potential map by
clicking on your State below. |
