Is Iowa County, IA a radon risk area?

EPA's own radon map rates Iowa County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Iowa County lands in the 80th percentile for radon potential.

Iowa County by the numbers

About 16,423 people live in Iowa County, Iowa, spread over 586.455 square miles. Averaged across its land area, Iowa County runs about 28 people per square mile. Rank 632 by population within its EPA zone puts Iowa County at the 41st percentile among zone peers. EPA's geology-based Region 7 groups Iowa County with 411 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Iowa County

Where the national indoor average runs about 1.3 pCi/L, Iowa County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Iowa County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Iowa County

Nothing about Iowa 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

Iowa County's test kit answers today; a Airthings radon monitor keeps answering for Iowa 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 Iowa County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.