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RankingsArizonaHighest radon potential

Counties with the Highest Radon Potential in Arizona

The top 15 of 15 Arizona counties on GIS Map, ranked by EPA radon zone, where zone 1 carries the highest predicted indoor radon potential and zone 3 the lowest.

#CountyEPA radon zone
1Apache County
2
2Cochise County
2
3Coconino County
2
4Gila County
2
5Graham County
2
6Greenlee County
2
7La Paz County
2
8Maricopa County
2
9Mohave County
2
10Navajo County
2
11Pima County
2
12Pinal County
2
13Santa Cruz County
2
14Yavapai County
2
15Yuma County
2

Source: EPA Map of Radon Zones (September 2025). All counties with data are ranked. Estimates carry margins of error.

Citing this page: GIS Map, “Counties with the Highest Radon Potential in Arizona”, https://gismap.land/rankings/arizona/highest-radon-counties. Figures from EPA Map of Radon Zones (September 2025).

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