Marion, IL Radon Levels
Check local Marion radon levels and find certified testing and mitigation professionals to keep your home safe
Marion, IL Radon Facts
Located in Williamson County in southern Illinois, Marion has recorded an average radon level of 5.0 pCi/L, above the EPA's recommended action threshold. The area sits within Illinois's coal belt region, where Pennsylvanian-era coal measures and shale deposits create generally moderate radon conditions that can occasionally spike higher. Homeowners in this zip code 62959 community should consider professional radon mitigation given the documented elevated readings.
Based on 1 user-submitted radon test for homes in Marion, IL. The EPA recommends taking action at or above 4.0 pCi/L.
Marion, IL Radon Mitigation
Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.
Need Radon Mitigation or Testing in Marion?
- 100% Free, No-Obligation Quotes
- Matches You with State-Licensed Williamson County Pros
Marion, IL Radon Levels
User-submitted radon test readings from homes in the Marion area.
| Radon Level | City | Home Age | Foundation |
|---|---|---|---|
| 5 pCi/L | Marion, IL | 51-99 Years | Full Basement |
Have a radon test result for Marion? Submit your reading to help other homeowners.
Radon Readings Near Marion, IL
Compare radon levels in Marion with the closest nearby cities that have user-submitted test data.
| City | Distance | Avg User Level | Readings |
|---|---|---|---|
| Murphysboro | 22.2 mi | 10.00 pCi/L | 1 |
| Campbell Hill | 38.0 mi | 1.00 pCi/L | 1 |
| Mount Vernon | 40.9 mi | 4.00 pCi/L | 1 |
Williamson County Radon Profile
EPA mapping assigns Williamson 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 1 city in Williamson County average 5.00 pCi/L across 1 test — 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 Williamson County home regardless of zone or a neighbor's results.