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RADON411

Data

Data explorer

Every U.S. county, one row each, with its EPA zone, USGS geologic potential and CDC-reported testing statistics.

On file today

What the table holds

An empty cell below means there is no figure on file, not zero.

3,231
Counties and county-equivalent areas, from Census files
3,138
Counties that have an EPA zone on file (Predicted)
3,141
Counties with a USGS geologic potential class (Predicted)
2,863
Counties with CDC test statistics (Measured), covering 2005 to 2023

Every county

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Sort by:County ▲StateEPA zoneUSGS potentialBuildings testedMedianMaximum% at or above 4 pCi/LData year

Predicted EPA zone and USGS potentialMeasured the CDC columns

County-level EPA zone, USGS potential and CDC testing data
CDC table
Abbeville CountySCZone 2: Moderate predicted potentialModerate461.8 pCi/L13.6 pCi/L22.7%2008 to 2017Laboratory
Acadia ParishLAZone 3: Lower predicted potentialLow13.1 pCi/L3.1 pCi/L0.0%2018State-supplied
Accomack CountyVAZone 3: Lower predicted potentialLow20.1 pCi/L2.2 pCi/L0.0%2008 to 2017Laboratory
Ada CountyIDZone 2: Moderate predicted potentialModerate2,3952.4 pCi/L67.3 pCi/L25.2%2008 to 2017Laboratory
Adair CountyMOZone 2: Moderate predicted potentialModerate42.0 pCi/L3.5 pCi/L0.0%2023State-supplied
Adair CountyKYZone 1: Highest predicted potentialHigh423.8 pCi/L33.3 pCi/L43.4%2008 to 2017Laboratory
Adair CountyOKZone 2: Moderate predicted potentialModerate23.8 pCi/L5.4 pCi/L50.0%2008 to 2017Laboratory
Adair CountyIAZone 1: Highest predicted potentialHigh669.3 pCi/L141.6 pCi/L72.4%2008 to 2017Laboratory
Adams CountyWAZone 2: Moderate predicted potentialModerate210.5 pCi/L17.9 pCi/L50.0%2020State-supplied
Adams CountyCOZone 1: Highest predicted potentialHigh9402.3 pCi/L96.4 pCi/L36.6%2023State-supplied
Adams CountyOHZone 1: Highest predicted potentialHigh193.8 pCi/L45.8 pCi/L50.0%2008 to 2017Laboratory
Adams CountyNEZone 1: Highest predicted potentialHigh1364.8 pCi/L23.9 pCi/L66.5%2023State-supplied
Adams CountyMSZone 3: Lower predicted potentialLowNo dataNo dataNo dataNo dataNo dataNo data
Adams CountyIDZone 3: Lower predicted potentialLow184.0 pCi/L112.4 pCi/L51.6%2008 to 2017Laboratory
Adams CountyILZone 1: Highest predicted potentialHigh2953.6 pCi/L103.6 pCi/L46.1%2017State-supplied
Adams CountyIAZone 1: Highest predicted potentialHigh526.1 pCi/L40.7 pCi/L65.4%2008 to 2017Laboratory
Adams CountyPAZone 1: Highest predicted potentialHigh6292.8 pCi/L119.0 pCi/L39.7%2020State-supplied
Adams CountyINZone 1: Highest predicted potentialHigh623.8 pCi/L55.8 pCi/L48.5%2008 to 2017Laboratory
Adams CountyWIZone 2: Moderate predicted potentialModerate331.7 pCi/L19.8 pCi/L20.8%2023State-supplied
Adams CountyNDZone 1: Highest predicted potentialHigh912.7 pCi/L22.1 pCi/L80.0%2008 to 2017Laboratory
Addison CountyVTZone 2: Moderate predicted potentialLow811.7 pCi/L28.3 pCi/L19.3%2023State-supplied
Adjuntas MunicipioPRZone not available: No EPA zone on fileNo dataNo dataNo dataNo dataNo dataNo dataNo data
Aguada MunicipioPRZone not available: No EPA zone on fileNo dataNo dataNo dataNo dataNo dataNo dataNo data
Aguadilla MunicipioPRZone not available: No EPA zone on fileNo dataNo dataNo dataNo dataNo dataNo dataNo data
Aguas Buenas MunicipioPRZone not available: No EPA zone on fileNo dataNo dataNo dataNo dataNo dataNo dataNo data
Aibonito MunicipioPRZone not available: No EPA zone on fileNo dataNo dataNo dataNo dataNo dataNo dataNo data
Aiken CountySCZone 3: Lower predicted potentialLow1941.3 pCi/L11.9 pCi/L13.3%2008 to 2017Laboratory
Aitkin CountyMNZone 2: Moderate predicted potentialModerate223.1 pCi/L8.2 pCi/L38.7%2023State-supplied
Alachua CountyFLZone 2: Moderate predicted potentialLow6242.4 pCi/L27.3 pCi/L21.4%2023State-supplied
Alamance CountyNCZone 3: Lower predicted potentialLow40.1 pCi/L1.0 pCi/L0.0%2022State-supplied
Alameda CountyCAZone 2: Moderate predicted potentialModerate2900.7 pCi/L159.8 pCi/L6.7%2008 to 2017Laboratory
Alamosa CountyCOZone 2: Moderate predicted potentialModerate50.6 pCi/L8.4 pCi/L25.0%2023State-supplied
Albany CountyWYZone 1: Highest predicted potentialHigh2432.7 pCi/L31.9 pCi/L27.9%2008 to 2017Laboratory
Albany CountyNYZone 1: Highest predicted potentialHigh301.2 pCi/L11.8 pCi/L16.7%2023State-supplied
Albemarle CountyVAZone 2: Moderate predicted potentialModerate1,1432.1 pCi/L62.4 pCi/L24.7%2008 to 2017Laboratory
Alcona CountyMIZone 2: Moderate predicted potentialModerate1281.7 pCi/L23.8 pCi/L20.5%2008 to 2017Laboratory
Alcorn CountyMSZone 2: Moderate predicted potentialModerateNo dataNo dataNo dataNo dataNo dataNo data
Aleutians East BoroughAKZone 3: Lower predicted potentialModerate20.6 pCi/L1.0 pCi/L0.0%2022State-supplied
Aleutians West Census AreaAKZone 3: Lower predicted potentialModerateNo dataNo dataNo dataNo dataNo dataNo data
Alexander CountyILZone 3: Lower predicted potentialModerate12.0 pCi/L2.0 pCi/L0.0%2017State-supplied
Alexander CountyNCZone 2: Moderate predicted potentialModerate10.1 pCi/L0.1 pCi/L0.0%2022State-supplied
Alexandria cityVAZone 3: Lower predicted potentialLow3271.0 pCi/L57.4 pCi/L7.3%2008 to 2017Laboratory
Alfalfa CountyOKZone 3: Lower predicted potentialLow129.3 pCi/L29.3 pCi/L100.0%2008 to 2017Laboratory
Alger CountyMIZone 2: Moderate predicted potentialModerate1181.2 pCi/L12.3 pCi/L16.4%2008 to 2017Laboratory
Allamakee CountyIAZone 1: Highest predicted potentialHigh3217.0 pCi/L84.1 pCi/L73.2%2008 to 2017Laboratory
Allegan CountyMIZone 3: Lower predicted potentialLow5921.7 pCi/L59.5 pCi/L18.4%2008 to 2017Laboratory
Allegany CountyNYZone 1: Highest predicted potentialHigh210.5 pCi/L16.6 pCi/L100.0%2023State-supplied
Allegany CountyMDZone 2: Moderate predicted potentialHigh2022.7 pCi/L79.0 pCi/L35.7%2008 to 2017Laboratory
Alleghany CountyNCZone 1: Highest predicted potentialModerate34.0 pCi/L5.0 pCi/L66.7%2022State-supplied
Alleghany CountyVAZone 1: Highest predicted potentialHigh353.0 pCi/L23.8 pCi/L40.0%2008 to 2017Laboratory

Reading it

What the columns do not mean

An EPA zone is a prediction

An EPA radon zone describes predicted potential across a whole county. It is not intended to determine whether any individual home should be tested, and homes with elevated levels occur in all three zones. EPA recommends testing every home regardless of zone, and testing is the only way to know the radon level in a specific building.

CDC counts tests, not homes

The CDC columns count radon tests that were reported to CDC, not homes, and not a representative sample of them.

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