Is Mitchell County, IA a radon risk area?

EPA places Mitchell County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Mitchell County lands in the 76th percentile for radon potential.

Mitchell County by the numbers

About 10,632 people live in Mitchell County, Iowa, spread over 469.256 square miles. That works out to roughly 23 people per square mile. Rank 747 by population within its EPA zone puts Mitchell County at the 30th percentile among zone peers. EPA's geology-based Region 7 groups Mitchell County with 411 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Mitchell County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. That doesn't mean every Mitchell County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Testing and mitigation in Mitchell County

Nothing about Mitchell County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Iowa's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Mitchell County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.