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Charleston, IL Radon Levels

Check local Charleston radon levels and find certified testing and mitigation professionals to keep your home safe


Charleston, IL Radon Facts

EPA Radon Zone Zone 1 — High Risk > 4.0 pCi/L (Zone 1)
County Coles County, IL
Zip Code 61920
Avg. User Level 8.00 pCi/L
User Tests 1

Home to Eastern Illinois University in Coles County, Charleston has recorded a notable radon reading of 8.0 pCi/L, doubling the EPA action level. The community sits atop central Illinois's characteristic glacial moraine deposits over limestone bedrock, geological conditions known for supporting radon gas production and migration. Given this documented elevated reading in zip code 61920, both university housing and private residences should prioritize radon testing and mitigation where necessary.

8.00
pCi/L average
Above EPA Action Level

Based on 1 user-submitted radon test for homes in Charleston, IL. The EPA recommends taking action at or above 4.0 pCi/L.

0
4.0 EPA
10+

Charleston, IL Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Charleston, IL Radon Levels

User-submitted radon test readings from homes in the Charleston area.

Radon LevelCityHome AgeFoundation
8 pCi/L Charleston, IL 21-50 Years Full Basement

Have a radon test result for Charleston? Submit your reading to help other homeowners.

Radon Readings Near Charleston, IL

Compare radon levels in Charleston with the closest nearby cities that have user-submitted test data.

CityDistanceAvg User LevelReadings
Mattoon 10.7 mi 9.33 pCi/L 3
Tuscola 22.3 mi 17.00 pCi/L 1
Paris 26.9 mi 9.67 pCi/L 3
Effingham 32.6 mi 4.33 pCi/L 3
Shelbyville 33.6 mi 17.00 pCi/L 1
Homer 39.5 mi 20.00 pCi/L 1
Urbana 41.8 mi 15.00 pCi/L 1
Monticello 42.7 mi 4.50 pCi/L 2

Coles County Radon Profile

Because of its underlying geology, Coles County is mapped as EPA Radon Zone 1 — the most elevated classification — where predicted indoor screening averages exceed 4 pCi/L. Homeowner-submitted tests from 2 cities in Coles County average 9.00 pCi/L across 4 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 Coles County home regardless of zone or a neighbor's results.

Radon FAQ for Charleston, IL

What is the average radon level in Charleston, IL?
Based on 1 user-submitted test, the average radon level in Charleston is 8.00 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.
What EPA Radon Zone is Charleston in?
Charleston and the 61920 zip code are in Coles County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.
How much does radon mitigation cost in Charleston?
Radon mitigation in Charleston typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.
Should I test for radon if I'm buying a home in Charleston?
Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.