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State overview

Radon in Missouri

Of Missouri's 115 counties and county equivalents, EPA places 11 in Zone 1, 97 in Zone 2, 7 in Zone 3. Zones are county-wide predictions; testing is the only way to know your home's level.

Radon in the news

Missouri stories

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

All 115 counties

CountyEPA zone
Adair CountyZone 2
Andrew CountyZone 1
Atchison CountyZone 1
Audrain CountyZone 2
Barry CountyZone 2
Barton CountyZone 2
Bates CountyZone 2
Benton CountyZone 2
Bollinger CountyZone 2
Boone CountyZone 2
Buchanan CountyZone 1
Butler CountyZone 3
Caldwell CountyZone 2
Callaway CountyZone 2
Camden CountyZone 2
Cape Girardeau CountyZone 2
Carroll CountyZone 2
Carter CountyZone 2
Cass CountyZone 1
Cedar CountyZone 2
Chariton CountyZone 2
Christian CountyZone 2
Clark CountyZone 2
Clay CountyZone 1
Clinton CountyZone 1
Cole CountyZone 2
Cooper CountyZone 2
Crawford CountyZone 2
Dade CountyZone 2
Dallas CountyZone 2
Daviess CountyZone 2
DeKalb CountyZone 2
Dent CountyZone 2
Douglas CountyZone 2
Dunklin CountyZone 3
Franklin CountyZone 2
Gasconade CountyZone 2
Gentry CountyZone 2
Greene CountyZone 2
Grundy CountyZone 2
Harrison CountyZone 2
Henry CountyZone 2
Hickory CountyZone 2
Holt CountyZone 1
Howard CountyZone 2
Howell CountyZone 2
Iron CountyZone 1
Jackson CountyZone 1
Jasper CountyZone 2
Jefferson CountyZone 2
Johnson CountyZone 2
Knox CountyZone 2
Laclede CountyZone 2
Lafayette CountyZone 2
Lawrence CountyZone 2
Lewis CountyZone 2
Lincoln CountyZone 2
Linn CountyZone 2
Livingston CountyZone 2
Macon CountyZone 2
Madison CountyZone 2
Maries CountyZone 2
Marion CountyZone 2
McDonald CountyZone 2
Mercer CountyZone 2
Miller CountyZone 2
Mississippi CountyZone 3
Moniteau CountyZone 2
Monroe CountyZone 2
Montgomery CountyZone 2
Morgan CountyZone 2
New Madrid CountyZone 3
Newton CountyZone 2
Nodaway CountyZone 1
Oregon CountyZone 2
Osage CountyZone 2
Ozark CountyZone 2
Pemiscot CountyZone 3
Perry CountyZone 2
Pettis CountyZone 2
Phelps CountyZone 2
Pike CountyZone 2
Platte CountyZone 1
Polk CountyZone 2
Pulaski CountyZone 2
Putnam CountyZone 2
Ralls CountyZone 2
Randolph CountyZone 2
Ray CountyZone 2
Reynolds CountyZone 2
Ripley CountyZone 2
Saline CountyZone 2
Schuyler CountyZone 2
Scotland CountyZone 2
Scott CountyZone 3
Shannon CountyZone 2
Shelby CountyZone 2
St. Charles CountyZone 2
St. Clair CountyZone 2
St. Francois CountyZone 2
St. Louis CountyZone 2
St. Louis cityZone 2
Ste. Genevieve CountyZone 2
Stoddard CountyZone 3
Stone CountyZone 2
Sullivan CountyZone 2
Taney CountyZone 2
Texas CountyZone 2
Vernon CountyZone 2
Warren CountyZone 2
Washington CountyZone 2
Wayne CountyZone 2
Webster CountyZone 2
Worth CountyZone 2
Wright CountyZone 2

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