Radon zones in Iowa
Last updated
EPA’s Map of Radon Zones places 99 Iowa counties in its three radon potential zones: 99 in Zone 1 (highest), 0 in Zone 2 (moderate), and 0 in Zone 3 (low).
What this means for Iowa homes
Most Iowa counties fall in Zone 1. EPA predicts average indoor screening levels above 4 pCi/L across much of Iowa, so elevated radon is common. Testing is especially worthwhile here, and radon-resistant construction features make sense for new homes.
EPA’s guidance is the same everywhere: test your home, fix it if the level is 4 pCi/L or higher, and consider fixing between 2 and 4 pCi/L. The zone map is from 1993 and should not be used to decide whether a single home needs testing.
Iowa radon program
EPA lists the following state contact for Iowa: Iowa Department of Health and Human Services, phone 515-281-4928. Website: idph.iowa.gov/radon. State programs can tell you about local testing data, free or discounted test kits, disclosure rules for home sales, and credentialed radon professionals.
Iowa counties and their EPA radon zones
County names follow the 2020 Census. Zones from the EPA Map of Radon Zones (text version). Rows marked “zone of” use the zone EPA gave the predecessor or surrounding county.
Next steps: read how to test your home, check a result with the level calculator, or look up a single address by ZIP code.