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, with real Census geography
- 3,138
- Counties that have an EPA zone on file (Predicted)
- 3,140
- Counties with a USGS geologic potential class (Predicted)
- 2,862
- Counties with CDC test statistics (Measured)
Every county
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Predicted EPA zone and USGS potentialMeasured the CDC columns
| CDC table | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Abbeville County | SC | Zone 2: Moderate predicted potential | Moderate | 46 | 1.8 pCi/L | 13.6 pCi/L | 22.7% | 2017 | Laboratory |
| Acadia Parish | LA | Zone 3: Lower predicted potential | High | 1 | 3.1 pCi/L | 3.1 pCi/L | 0.0% | 2018 | State-supplied |
| Accomack County | VA | Zone 3: Lower predicted potential | High | 2 | 0.1 pCi/L | 2.2 pCi/L | 0.0% | 2017 | Laboratory |
| Ada County | ID | Zone 2: Moderate predicted potential | Moderate | 2,395 | 2.4 pCi/L | 67.3 pCi/L | 25.2% | 2017 | Laboratory |
| Adair County | IA | Zone 1: Highest predicted potential | Low | 66 | 9.3 pCi/L | 141.6 pCi/L | 72.4% | 2017 | Laboratory |
| Adair County | KY | Zone 1: Highest predicted potential | Low | 42 | 3.8 pCi/L | 33.3 pCi/L | 43.4% | 2017 | Laboratory |
| Adair County | MO | Zone 2: Moderate predicted potential | Moderate | 4 | 2.0 pCi/L | 3.5 pCi/L | No data | 2023 | State-supplied |
| Adair County | OK | Zone 2: Moderate predicted potential | Moderate | 2 | 3.8 pCi/L | 5.4 pCi/L | 50.0% | 2017 | Laboratory |
| Adams County | ND | Zone 1: Highest predicted potential | Low | 9 | 12.7 pCi/L | 22.1 pCi/L | 80.0% | 2017 | Laboratory |
| Adams County | WI | Zone 2: Moderate predicted potential | Moderate | 33 | 1.7 pCi/L | 19.8 pCi/L | 20.8% | 2023 | State-supplied |
| Adams County | WA | Zone 2: Moderate predicted potential | Moderate | 2 | 10.5 pCi/L | 17.9 pCi/L | 50.0% | 2020 | State-supplied |
| Adams County | OH | Zone 1: Highest predicted potential | Low | 19 | 3.8 pCi/L | 45.8 pCi/L | 50.0% | 2017 | Laboratory |
| Adams County | IL | Zone 1: Highest predicted potential | Low | 3,064 | 4.5 pCi/L | 103.6 pCi/L | 55.2% | 2017 | Laboratory |
| Adams County | ID | Zone 3: Lower predicted potential | High | 18 | 4.0 pCi/L | 112.4 pCi/L | 51.6% | 2017 | Laboratory |
| Adams County | IA | Zone 1: Highest predicted potential | Low | 52 | 6.1 pCi/L | 40.7 pCi/L | 65.4% | 2017 | Laboratory |
| Adams County | NE | Zone 1: Highest predicted potential | Low | 136 | 4.8 pCi/L | 23.9 pCi/L | 66.5% | 2023 | State-supplied |
| Adams County | PA | Zone 1: Highest predicted potential | Low | 629 | 2.8 pCi/L | 119.0 pCi/L | 39.7% | 2020 | State-supplied |
| Adams County | IN | Zone 1: Highest predicted potential | Low | 62 | 3.8 pCi/L | 55.8 pCi/L | 48.5% | 2017 | Laboratory |
| Adams County | MS | Zone 3: Lower predicted potential | High | No data | No data | No data | No data | No data | No data |
| Adams County | CO | Zone 1: Highest predicted potential | Low | 940 | 2.3 pCi/L | 96.4 pCi/L | 36.6% | 2023 | State-supplied |
| Addison County | VT | Zone 2: Moderate predicted potential | High | 81 | 1.7 pCi/L | 28.3 pCi/L | 19.3% | 2023 | State-supplied |
| Adjuntas County | PR | Zone not available: No EPA zone on file | No data | No data | No data | No data | No data | No data | No data |
| Aguada County | PR | Zone not available: No EPA zone on file | No data | No data | No data | No data | No data | No data | No data |
| Aguadilla County | PR | Zone not available: No EPA zone on file | No data | No data | No data | No data | No data | No data | No data |
| Aguas Buenas County | PR | Zone not available: No EPA zone on file | No data | No data | No data | No data | No data | No data | No data |
| Aibonito County | PR | Zone not available: No EPA zone on file | No data | No data | No data | No data | No data | No data | No data |
| Aiken County | SC | Zone 3: Lower predicted potential | High | 194 | 1.3 pCi/L | 11.9 pCi/L | 13.3% | 2017 | Laboratory |
| Aitkin County | MN | Zone 2: Moderate predicted potential | Moderate | 22 | 3.1 pCi/L | 8.2 pCi/L | 38.7% | 2023 | State-supplied |
| Alachua County | FL | Zone 2: Moderate predicted potential | High | 624 | 2.4 pCi/L | 27.3 pCi/L | 21.4% | 2023 | State-supplied |
| Alamance County | NC | Zone 3: Lower predicted potential | High | 4 | 0.1 pCi/L | 1.0 pCi/L | 0.0% | 2022 | State-supplied |
| Alameda County | CA | Zone 2: Moderate predicted potential | Moderate | 290 | 0.7 pCi/L | 159.8 pCi/L | 6.7% | 2017 | Laboratory |
| Alamosa County | CO | Zone 2: Moderate predicted potential | Moderate | 5 | 0.6 pCi/L | 8.4 pCi/L | 25.0% | 2023 | State-supplied |
| Albany County | WY | Zone 1: Highest predicted potential | Low | 243 | 2.7 pCi/L | 31.9 pCi/L | 27.9% | 2017 | Laboratory |
| Albany County | NY | Zone 1: Highest predicted potential | Low | 30 | 1.2 pCi/L | 11.8 pCi/L | 16.7% | 2023 | State-supplied |
| Albemarle County | VA | Zone 2: Moderate predicted potential | Moderate | 1,143 | 2.1 pCi/L | 62.4 pCi/L | 24.7% | 2017 | Laboratory |
| Alcona County | MI | Zone 2: Moderate predicted potential | Moderate | 128 | 1.7 pCi/L | 23.8 pCi/L | 20.5% | 2017 | Laboratory |
| Alcorn County | MS | Zone 2: Moderate predicted potential | Moderate | No data | No data | No data | No data | No data | No data |
| Aleutians East | AK | Zone 3: Lower predicted potential | Moderate | 2 | 0.6 pCi/L | 1.0 pCi/L | 0.0% | 2022 | State-supplied |
| Aleutians West | AK | Zone 3: Lower predicted potential | Moderate | No data | No data | No data | No data | No data | No data |
| Alexander County | NC | Zone 2: Moderate predicted potential | Moderate | 1 | 0.1 pCi/L | 0.1 pCi/L | 0.0% | 2022 | State-supplied |
| Alexander County | IL | Zone 3: Lower predicted potential | Moderate | 8 | 2.4 pCi/L | 11.6 pCi/L | 22.2% | 2017 | Laboratory |
| Alexandria city | VA | Zone 3: Lower predicted potential | High | 327 | 1.0 pCi/L | 57.4 pCi/L | 7.3% | 2017 | Laboratory |
| Alfalfa County | OK | Zone 3: Lower predicted potential | High | 1 | 29.3 pCi/L | 29.3 pCi/L | 100.0% | 2017 | Laboratory |
| Alger County | MI | Zone 2: Moderate predicted potential | Moderate | 118 | 1.2 pCi/L | 12.3 pCi/L | 16.4% | 2017 | Laboratory |
| Allamakee County | IA | Zone 1: Highest predicted potential | Low | 321 | 7.0 pCi/L | 84.1 pCi/L | 73.2% | 2017 | Laboratory |
| Allegan County | MI | Zone 3: Lower predicted potential | High | 592 | 1.7 pCi/L | 59.5 pCi/L | 18.4% | 2017 | Laboratory |
| Allegany County | NY | Zone 1: Highest predicted potential | Low | 2 | 10.5 pCi/L | 16.6 pCi/L | 100.0% | 2023 | State-supplied |
| Allegany County | MD | Zone 2: Moderate predicted potential | Low | 202 | 2.7 pCi/L | 79.0 pCi/L | 35.7% | 2017 | Laboratory |
| Alleghany County | NC | Zone 1: Highest predicted potential | Moderate | 3 | 4.0 pCi/L | 5.0 pCi/L | 66.7% | 2022 | State-supplied |
| Alleghany County | VA | Zone 1: Highest predicted potential | Low | 35 | 3.0 pCi/L | 23.8 pCi/L | 40.0% | 2017 | Laboratory |
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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