Updated November 2026 · Data: EPA Map of Radon Zones · Sources
No Alaska boroughs and census areas are in EPA Zone 1, but 5 of 27 are in Zone 2, where the predicted average indoor radon level is between 2 and 4 pCi/L. Find your borough below, then learn how to test your home and what to do if the result is high.
Your county’s zone is not your home’s radon level. Homes with high radon are found in every zone. The EPA recommends testing every home, whatever its zone.
Radon zones by borough in Alaska
The table lists the EPA radon zone for each of the 27 boroughs and census areas in Alaska. The zone shows the predicted average indoor radon screening level for homes in that borough.
| Borough | EPA zone | Predicted average indoor level |
|---|---|---|
| Aleutians East Borough | Zone 3 | Below 2 pCi/L |
| Aleutians West Census Area | Zone 3 | Below 2 pCi/L |
| Anchorage Municipality | Zone 3 | Below 2 pCi/L |
| Bethel Census Area | Zone 3 | Below 2 pCi/L |
| Bristol Bay Borough | Zone 3 | Below 2 pCi/L |
| Denali Borough | Zone 3 | Below 2 pCi/L |
| Dillingham Census Area | Zone 3 | Below 2 pCi/L |
| Fairbanks North Star Borough | Zone 2 | 2 to 4 pCi/L |
| Haines Borough | Zone 3 | Below 2 pCi/L |
| Juneau City and Borough | Zone 3 | Below 2 pCi/L |
| Kenai Peninsula Borough | Zone 2 | 2 to 4 pCi/L |
| Ketchikan Gateway Borough | Zone 2 | 2 to 4 pCi/L |
| Kodiak Island Borough | Zone 3 | Below 2 pCi/L |
| Lake and Peninsula Borough | Zone 3 | Below 2 pCi/L |
| Matanuska-Susitna Borough | Zone 2 | 2 to 4 pCi/L |
| Nome Census Area | Zone 3 | Below 2 pCi/L |
| North Slope Borough | Zone 3 | Below 2 pCi/L |
| Northwest Arctic Borough | Zone 3 | Below 2 pCi/L |
| Prince of Wales-Outer Ketchikan Census Area | Zone 3 | Below 2 pCi/L |
| Sitka City and Borough | Zone 3 | Below 2 pCi/L |
| Skagway Municipality | Zone 3 | Below 2 pCi/L |
| Southeast Fairbanks Census Area | Zone 2 | 2 to 4 pCi/L |
| Valdez-Cordova Census Area | Zone 3 | Below 2 pCi/L |
| Wade Hampton Census Area | Zone 3 | Below 2 pCi/L |
| Wrangell-Petersburg Census Area | Zone 3 | Below 2 pCi/L |
| Yakutat City and Borough | Zone 3 | Below 2 pCi/L |
| Yukon-Koyukuk Census Area | Zone 3 | Below 2 pCi/L |
What the EPA radon zones mean
- Zone 1 (highest potential): predicted average indoor screening level greater than 4 pCi/L. In Alaska: 0 boroughs and census areas (0%).
- Zone 2 (moderate potential): predicted average between 2 and 4 pCi/L. In Alaska: 5 boroughs and census areas (19%).
- Zone 3 (low potential): predicted average below 2 pCi/L. In Alaska: 22 boroughs and census areas (81%).
The EPA built the map from indoor radon measurements, geology, soil permeability and type of house foundation. It was made to help governments and builders target resources, not to decide whether a single home needs testing.
How to test for radon in Alaska
Testing is the only way to know your home’s radon level. Short-term test kits (2 to 90 days) are sold at hardware stores and online, and some state programs offer kits at low cost; check with the Alaska Division of Geological & Geophysical Surveys (radon). Test in the lowest lived-in level of the home, with windows and doors closed, and follow the kit instructions.
- Do-it-yourself kits: a simple, low-cost first step for your own home.
- Long-term tests (more than 90 days): give a better picture of your home’s year-round average.
- Certified professionals: look for certification from the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB), and ask the state program whether Alaska requires a state license.
- Buying or selling a home: ask for a radon test as part of the home inspection.
If your radon level is high
The EPA recommends fixing your home if the radon level is 4 pCi/L or higher, and considering a fix between 2 and 4 pCi/L. The most common fix is a radon mitigation system (sub-slab depressurization), which pulls radon from under the foundation and vents it outside, above the roof line.
- The EPA says most homes can be fixed for about the same cost as other common home repairs; the price depends on the size and design of the home.
- Get estimates from more than one qualified, certified mitigation contractor. See our radon mitigation cost guide for typical prices.
- Test again after the system is installed, and retest every few years.
Alaska radon program
The Alaska Division of Geological & Geophysical Surveys (radon) answers questions from residents about radon testing, results and certified professionals.
- Phone: 907-269-6401
- Website: dggs.alaska.gov/hazards/radon.html
Contact details as listed by the state radon program directory. Please confirm on the program’s website before calling.
Frequently asked questions
Is radon a problem in Alaska?
None of Alaska’s 27 boroughs and census areas are in EPA Zone 1, but high radon levels can be found in any home, in any zone. Testing is the only way to know your level.
Do I need to test if my borough is in Zone 2 or 3?
Yes. The EPA zones show predicted averages for large areas, and they were not designed to decide whether a single home needs testing. The EPA recommends testing every home.
What radon level is safe?
There is no known safe level of radon. The EPA recommends fixing your home at 4 pCi/L or higher and considering a fix between 2 and 4 pCi/L.
Who can I contact about radon in Alaska?
The Alaska Division of Geological & Geophysical Surveys (radon) answers questions about testing, results and certified professionals. Phone: 907-269-6401.
Sources
- U.S. EPA: EPA Map of Radon Zones (county data file, June 2024)
- U.S. EPA: A Citizen’s Guide to Radon (PDF, 2016)
- U.S. EPA: How much can a radon mitigation system cost? (updated September 16, 2026)
- Alaska Division of Geological & Geophysical Surveys (radon) (checked November 2026)
- SOSRadon.org (CRCPD): State radon contacts (checked November 2026)