Radon risk by county
What's the radon risk where you live?
Radon is an invisible, odorless gas from soil and rock, and the EPA's #2 cause of lung cancer. Find your county's EPA radon zone, real state test results where they exist, and what to do next.
Zones, quickly
| Zone 1 | Highest potential. Predicted average indoor level above 4 pCi/L. |
| Zone 2 | Moderate potential. Predicted average indoor level 2 to 4 pCi/L. |
| Zone 3 | Low potential. Predicted average indoor level below 2 pCi/L. |
Source: U.S. EPA Map of Radon Zones.
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