What EPA's radon map says about Christian County

Christian County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Rank it against the rest of the country and Christian County lands in the 51st percentile for radon potential.

Where Christian County sits nationally

About 33,247 people live in Christian County, Illinois, spread over 709.483 square miles. That works out to roughly 47 people per square mile. Among counties sharing Christian County's EPA zone, it outranks 56% of them by population. Christian County falls in EPA Radon Region 5, one of 524 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Christian County's Zone 2 prediction lands in the gap between the two. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Christian County — testing is the only way to know an individual home's actual level.

If Christian County tests above the action level

Mitigation cost doesn't depend on Christian County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Illinois's state radon program

Christian County's test kit answers today; a Airthings radon monitor keeps answering for Christian County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

Christian County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.