Boone County, IA: EPA's radon zone, explained

Boone County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Boone County sits at the 84th percentile nationally for radon potential — above 84 of every 100 rated counties.

Boone County by the numbers

Boone County, Iowa is home to about 26,729 people across 570.461 square miles. Averaged across its land area, Boone County runs about 47 people per square mile. By population, Boone County is the 497th largest of every county sharing its EPA zone — the 53rd percentile by population within that zone. Boone County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

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 Boone County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Some Boone County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

If Boone County tests above the action level

For a Boone County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Iowa's state radon program

For Boone County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Boone County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where Boone County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.