Marissa, IL Radon Levels
Check local Marissa radon levels and find certified testing and mitigation professionals to keep your home safe
Marissa, IL Radon Facts
This St. Clair County community on the Illinois side of the St. Louis metropolitan area recorded an average radon level of 4.0 pCi/L, exactly at the EPA action threshold. Located within Mississippi River floodplain deposits over limestone bedrock, the area's geology creates moderate radon potential that warrants continued monitoring. Homeowners in zip code 62257 should consider radon testing and potential mitigation given the borderline reading.
Based on 1 user-submitted radon test for homes in Marissa, IL. The EPA recommends taking action at or above 4.0 pCi/L.
Marissa, 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 Marissa?
- 100% Free, No-Obligation Quotes
- Matches You with State-Licensed St Clair County Pros
Marissa, IL Radon Levels
User-submitted radon test readings from homes in the Marissa area.
| Radon Level | City | Home Age | Foundation |
|---|---|---|---|
| 4 pCi/L | Marissa, IL | 21-50 Years | Full Basement |
Have a radon test result for Marissa? Submit your reading to help other homeowners.
Radon Readings Near Marissa, IL
Compare radon levels in Marissa with the closest nearby cities that have user-submitted test data.
| City | Distance | Avg User Level | Readings |
|---|---|---|---|
| Mascoutah | 16.0 mi | 6.50 pCi/L | 2 |
| Waterloo | 22.2 mi | 9.20 pCi/L | 5 |
| O Fallon | 23.9 mi | 6.00 pCi/L | 1 |
| Belleville | 23.9 mi | 7.33 pCi/L | 3 |
| Campbell Hill | 24.1 mi | 1.00 pCi/L | 1 |
| Lebanon | 25.0 mi | 10.50 pCi/L | 2 |
| Columbia | 27.7 mi | 8.00 pCi/L | 4 |
| Fairview Heights | 27.9 mi | 9.00 pCi/L | 1 |
St Clair County Radon Profile
EPA mapping assigns St Clair 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 7 cities in St Clair County average 7.50 pCi/L across 12 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 St Clair County home regardless of zone or a neighbor's results.