Iowa Radon Guide: Levels, Testing, Mitigation Rules (2026)

Updated October 18, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Iowa average	About 8.5 pCi/L, vs. about 1.3 nationally	Iowa Cancer Consortium (via KCRG)
Homes above action level	More than 70% of Iowa homes at or above 4 pCi/L	Iowa Cancer Consortium (via KCRG)
Risk zone	EPA considers all of Iowa high risk	Iowa HHS
Action level	4 pCi/L; don't decide on a single test	Iowa HHS
Health	Leading cause of lung cancer in never-smokers; about 400 Iowa deaths a year	EPA via Iowa HHS; Iowa HHS via KCRG
Mitigation credential	Required to mitigate radon for pay in Iowa	Iowa Admin. Code 641-44.3
Test kits	Iowa Radon Hotline 1-800-383-5992; Linn County Public Health sells kits	Iowa HHS; Linn County
Schools	Iowa law (HF 2412, 2022) requires school radon testing and mitigation plans	Iowa Legislature

How bad is radon in Iowa?

Very common. According to the Iowa Cancer Consortium, the average Iowa home measures about 8.5 picocuries per liter, compared with a national average of about 1.3, and more than 70 percent of Iowa homes are at or above the EPA's 4 pCi/L action level. Iowa HHS notes that the EPA considers the entire state high risk.

Why does radon matter?

Radon breaks down into radioactive particles that can lodge in the lungs. Iowa HHS cites the EPA's ranking of radon as the leading cause of lung cancer in people who have never smoked and the second leading cause in smokers, and estimates about 400 radon-related lung cancer deaths a year in Iowa. Smokers exposed to radon face a much higher combined risk.

How should I test?

Test the lowest lived-in level of the home with the house closed up. Short-term tests take days; long-term tests run more than 90 days and better reflect your yearly average. Iowa HHS recommends against basing a mitigation decision on a single test, so confirm a high result with a second test. Iowa's Radon Hotline, 1-800-383-5992, sells low-cost kits, Iowa HHS has offered free kits through partners while supplies last, and Linn County Public Health has sold short-term and long-term kits at its Cedar Rapids office.

When should I fix it?

At or above 4 pCi/L, confirmed by testing, Iowa HHS recommends mitigation. The EPA also suggests considering mitigation between 2 and 4 pCi/L, since any reduction lowers risk. Sub-slab depressurization, a pipe and fan that pull radon from under the foundation and vent it above the roof, is the standard fix for basements and slabs; crawl spaces use a sealed membrane with the same approach.

Who can install a radon system in Iowa?

Iowa's radon rules, Iowa Administrative Code 641-44.3, say no person may mitigate for radon in Iowa for a fee unless credentialed by Iowa HHS. Iowa HHS tells homeowners that mitigation should be done by credentialed radon mitigation contractors. Ask for the contractor's credential, get a written proposal, and ask how the follow-up test will be handled; Iowa's rules address testing before and after mitigation, including keeping the tester independent of the mitigation company.

What about schools?

In 2022, Iowa passed House File 2412, which requires school districts to adopt radon testing plans, test classrooms and attendance centers, retest periodically, post results, and develop mitigation plans when levels stay at or above 4 pCi/L. New school buildings must use radon-resistant construction.

Common questions

Do radon mitigation companies need a license in Iowa?

Yes. Iowa's rules require a credential from Iowa HHS to mitigate radon for pay.

What radon level should I fix in Iowa?

Iowa HHS recommends mitigation at or above 4 pCi/L, confirmed by more than one test. The EPA also suggests considering a fix between 2 and 4 pCi/L.

Where can I get a radon test kit in Cedar Rapids?

Call Iowa's Radon Hotline at 1-800-383-5992, or check with Linn County Public Health, which has sold kits at its Cedar Rapids office.

Iowa radon guide for Cedar Rapids and Iowa City homeowners (2026)