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State overview
Radon in Illinois
Of Illinois's 102 counties and county equivalents, EPA places 56 in Zone 1, 43 in Zone 2, 3 in Zone 3. Zones are county-wide predictions; testing is the only way to know your home's level.
Radon in the news
Illinois stories
- Illinois Students Raise Awareness of Deadly Radon Gas Through Award-Winning CreationsAmerican Lung Association · 2026-07-14
- Naperville couple pushing for mandated radon testing in Illinois schoolsNCTV17 · 2026-05-06
- Test Your Home for Radon: High Levels of Cancer-Causing Gas Found in 33% of Illinois HomesAmerican Lung Association · 2026-01-23
- State says Radon gas linked to 1,200 Illinois deaths annually, homeowners should testShaw Local · 2026-01-21
- Health officials warn of elevated radon levels in Illinois homes | ChicagoLIVEFOX 32 Chicago · 2026-01-12
Headlines link to the original publishers via Google News. Updated 2026-10-27.
All 102 counties
Source: EPA radon zones spreadsheet (EPA 402/A-16/001).