Arizona Radon Levels
0Zone 1 (High)
15Zone 2 (Moderate)
0Zone 3 (Low)
No counties in Arizona are classified as Zone 1 (highest risk), but 15 counties are Zone 2 (moderate potential). The EPA recommends testing all homes regardless of zone classification, as elevated radon can occur in any zone.
| County | EPA Zone | Risk Level |
|---|---|---|
| Apache County | Zone 2 | Moderate Potential |
| Cochise County | Zone 2 | Moderate Potential |
| Coconino County | Zone 2 | Moderate Potential |
| Gila County | Zone 2 | Moderate Potential |
| Graham County | Zone 2 | Moderate Potential |
| Greenlee County | Zone 2 | Moderate Potential |
| La Paz County | Zone 2 | Moderate Potential |
| Maricopa County | Zone 2 | Moderate Potential |
| Mohave County | Zone 2 | Moderate Potential |
| Navajo County | Zone 2 | Moderate Potential |
| Pima County | Zone 2 | Moderate Potential |
| Pinal County | Zone 2 | Moderate Potential |
| Santa Cruz County | Zone 2 | Moderate Potential |
| Yavapai County | Zone 2 | Moderate Potential |
| Yuma County | Zone 2 | Moderate Potential |