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State overview

Radon in Iowa

Of Iowa's 99 counties and county equivalents, EPA places 99 in Zone 1. Zones are county-wide predictions; testing is the only way to know your home's level.

Radon in the news

Iowa stories

Headlines link to the original publishers via Google News. Updated 2026-10-27.

All 99 counties

CountyEPA zone
Adair CountyZone 1
Adams CountyZone 1
Allamakee CountyZone 1
Appanoose CountyZone 1
Audubon CountyZone 1
Benton CountyZone 1
Black Hawk CountyZone 1
Boone CountyZone 1
Bremer CountyZone 1
Buchanan CountyZone 1
Buena Vista CountyZone 1
Butler CountyZone 1
Calhoun CountyZone 1
Carroll CountyZone 1
Cass CountyZone 1
Cedar CountyZone 1
Cerro Gordo CountyZone 1
Cherokee CountyZone 1
Chickasaw CountyZone 1
Clarke CountyZone 1
Clay CountyZone 1
Clayton CountyZone 1
Clinton CountyZone 1
Crawford CountyZone 1
Dallas CountyZone 1
Davis CountyZone 1
Decatur CountyZone 1
Delaware CountyZone 1
Des Moines CountyZone 1
Dickinson CountyZone 1
Dubuque CountyZone 1
Emmet CountyZone 1
Fayette CountyZone 1
Floyd CountyZone 1
Franklin CountyZone 1
Fremont CountyZone 1
Greene CountyZone 1
Grundy CountyZone 1
Guthrie CountyZone 1
Hamilton CountyZone 1
Hancock CountyZone 1
Hardin CountyZone 1
Harrison CountyZone 1
Henry CountyZone 1
Howard CountyZone 1
Humboldt CountyZone 1
Ida CountyZone 1
Iowa CountyZone 1
Jackson CountyZone 1
Jasper CountyZone 1
Jefferson CountyZone 1
Johnson CountyZone 1
Jones CountyZone 1
Keokuk CountyZone 1
Kossuth CountyZone 1
Lee CountyZone 1
Linn CountyZone 1
Louisa CountyZone 1
Lucas CountyZone 1
Lyon CountyZone 1
Madison CountyZone 1
Mahaska CountyZone 1
Marion CountyZone 1
Marshall CountyZone 1
Mills CountyZone 1
Mitchell CountyZone 1
Monona CountyZone 1
Monroe CountyZone 1
Montgomery CountyZone 1
Muscatine CountyZone 1
O'Brien CountyZone 1
Osceola CountyZone 1
Page CountyZone 1
Palo Alto CountyZone 1
Plymouth CountyZone 1
Pocahontas CountyZone 1
Polk CountyZone 1
Pottawattamie CountyZone 1
Poweshiek CountyZone 1
Ringgold CountyZone 1
Sac CountyZone 1
Scott CountyZone 1
Shelby CountyZone 1
Sioux CountyZone 1
Story CountyZone 1
Tama CountyZone 1
Taylor CountyZone 1
Union CountyZone 1
Van Buren CountyZone 1
Wapello CountyZone 1
Warren CountyZone 1
Washington CountyZone 1
Wayne CountyZone 1
Webster CountyZone 1
Winnebago CountyZone 1
Winneshiek CountyZone 1
Woodbury CountyZone 1
Worth CountyZone 1
Wright CountyZone 1

Source: EPA radon zones spreadsheet (EPA 402/A-16/001).