Dataset · CC-BY-4.0 Radon Mitigation
Radon Action Levels and Lung-Cancer Risk Reference (U.S.)
Reference table of regulatory radon action levels and the EPA’s modeled lifetime lung-cancer risk per 1,000 people at each concentration, in picocuries per liter (pCi/L). Use it to interpret a radon test result.
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| Measure | Value |
|---|---|
| EPA action level (mitigate at or above) | 4.0 pCi/L |
| EPA "consider mitigation" range | 2.0–4.0 pCi/L |
| WHO reference level | 2.7 pCi/L (100 Bq/m³) |
| Average U.S. indoor radon level | 1.3 pCi/L |
| Average U.S. outdoor radon level | 0.4 pCi/L |
| Est. lifetime lung-cancer deaths per 1,000 at 4 pCi/L (never-smokers) | ~7 per 1,000 |
| Est. lifetime lung-cancer deaths per 1,000 at 20 pCi/L (never-smokers) | ~36 per 1,000 |
| Annual U.S. radon-attributable lung-cancer deaths | ~21,000 |
| Typical reduction from an active soil depressurization system | 80–99% |
Source: U.S. EPA, "A Citizen’s Guide to Radon" and "Assessment of Risks from Radon in Homes" (EPA 402-R-03-003); World Health Organization Handbook on Indoor Radon.
License: Free to reuse under CC-BY-4.0. Please cite HomeAllClear (https://homeallclear.com/data/radon-action-levels-and-risk/).
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