Columbia, IL Radon Levels
Check local Columbia radon levels and find certified testing and mitigation professionals to keep your home safe
Columbia, IL Radon Facts
Located in Monroe County on the Illinois side of the St. Louis metropolitan area, Columbia sits on Mississippi River bluff deposits and underlying limestone that contribute to elevated radon levels. Testing data shows an average reading of 8.0 pCi/L, well above the EPA action threshold and reflecting the area's geological complexity. The 62236 zip code features many homes with full basements typical of Midwest construction, creating enclosed spaces where radon accumulates most readily.
Based on 4 user-submitted radon tests for homes in Columbia, IL. The EPA recommends taking action at or above 4.0 pCi/L.
Columbia, IL Radon Mitigation
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Columbia, IL Radon Levels
User-submitted radon test readings from homes in the Columbia area.
| Radon Level | City | Home Age | Foundation |
|---|---|---|---|
| 4 pCi/L | Columbia, IL | 21-50 Years | Partial Basement |
| 10 pCi/L | Columbia, IL | 0-20 Years | Full Basement |
| 9 pCi/L | Columbia, IL | — | — |
Have a radon test result for Columbia? Submit your reading to help other homeowners.
Radon Readings Near Columbia, IL
Compare radon levels in Columbia with the closest nearby cities that have user-submitted test data.
| City | Distance | Avg User Level | Readings |
|---|---|---|---|
| Waterloo | 8.2 mi | 9.20 pCi/L | 5 |
| Belleville | 13.2 mi | 7.33 pCi/L | 3 |
| Fairview Heights | 15.5 mi | 9.00 pCi/L | 1 |
| Caseyville | 17.3 mi | 7.50 pCi/L | 2 |
| O Fallon | 19.2 mi | 6.00 pCi/L | 1 |
| Granite City | 20.9 mi | 8.00 pCi/L | 1 |
| Collinsville | 20.9 mi | 5.00 pCi/L | 1 |
| Mascoutah | 22.6 mi | 6.50 pCi/L | 2 |
Monroe County Radon Profile
EPA mapping assigns Monroe County to Radon Zone 2, indicating moderate predicted indoor screening levels in the 2 to 4 pCi/L range based on regional geology. Homeowner-submitted tests from 2 cities in Monroe County average 8.67 pCi/L across 9 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. As the second leading cause of lung cancer in the U.S., radon warrants testing in every Monroe County home regardless of zone or a neighbor's results.