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State overview
Radon in Arizona
Of Arizona's 15 counties and county equivalents, EPA places 15 in Zone 2. Zones are county-wide predictions; testing is the only way to know your home's level.
Radon in the news
Arizona stories
- Here's why Arizona residents should test homes for radon gasKTAR News 92.3 FM · 2024-01-16
Headlines link to the original publishers via Google News. Updated 2026-10-27.
All 15 counties
| County | EPA zone |
|---|---|
| Apache County | Zone 2 |
| Cochise County | Zone 2 |
| Coconino County | Zone 2 |
| Gila County | Zone 2 |
| Graham County | Zone 2 |
| Greenlee County | Zone 2 |
| La Paz County | Zone 2 |
| Maricopa County | Zone 2 |
| Mohave County | Zone 2 |
| Navajo County | Zone 2 |
| Pima County | Zone 2 |
| Pinal County | Zone 2 |
| Santa Cruz County | Zone 2 |
| Yavapai County | Zone 2 |
| Yuma County | Zone 2 |
Source: EPA radon zones spreadsheet (EPA 402/A-16/001).