Is Wayne County, IA a radon risk area?

EPA places Wayne 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 Wayne County lands in the 73rd percentile for radon potential.

Where Wayne County sits nationally

About 6,622 people live in Wayne County, Iowa, spread over 525.469 square miles. That works out to roughly 13 people per square mile. Rank 859 by population within its EPA zone puts Wayne County at the 19th percentile among zone peers. EPA's geology-based Region 7 groups Wayne County with 411 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Wayne County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Being in Zone 1 raises the odds Wayne County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Next steps for a home in Wayne County

Nothing about Wayne 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

Wayne County's test kit answers today; a Airthings radon monitor keeps answering for Wayne 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 Wayne County's numbers. Whatever zone Wayne County carries, the zone explainer covers what it does and doesn't tell you about any one house.