Locations and reports
Radon Levels in Arizona
What this means for you
- Your area: None of Arizona's 15 classified counties is in EPA Zone 1, the highest of its three radon zones. Zones are predictions for whole counties, and homes with elevated levels occur in all three zones.
- Local tests: CDC publishes Arizona's radon test results by county. Open your county below to see its figures.
- Your home: The only way to know your home’s level is to test it.
pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.
For Arizona, EPA's Map of Radon Zones places 0 of its 15 classified counties in Zone 1, highest predicted potential, a prediction for each county as a whole. Radon levels vary from home to home, so only a test measures the level in yours.
Predicted: EPA radon zone
15 of 15 counties classified
EPA classifies counties, not states. Of the 15 counties in Arizona with a zone, 15 are in Zone 2.
- Zone 2: Moderate predicted potential2 to 4 pCi/L15 of 15 counties · 100.0%
An EPA radon zone describes predicted potential across a whole county. It is not intended to determine whether any individual home should be tested, and homes with elevated levels occur in all three zones. EPA recommends testing every home regardless of zone, and testing is the only way to know the radon level in a specific building.
This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
CDC publishes Arizona's radon test figures by county: 13 of its 15 counties have one. Each county's share is in the county list.
Arizona, In figures
Arizona in figures
What the published data says about Arizona, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places 15 of Arizona's 15 counties in Zone 2.
No Arizona county is in Zone 1.
Compared
Calculated by Radon4110% of Arizona's counties with a zone on file are in Zone 1, a smaller share than across all U.S. counties (34%). It is a share of counties, not of land, people or homes.
Reported tests
MeasuredCDC has no statewide testing figure for Arizona on file here.
13 of the 15 counties have a published county figure; the most tests in each one's latest year were reported for Maricopa County (1,512 in 2017), Pima County (219 in 2017) and Yavapai County (187 in 2017).
Local record
Arizona's radon program and its page are under Local resources.
2 cities have a page setting the figures of the counties it lies in side by side: Tucson and Phoenix.
Arizona, Counties
Arizona counties by EPA zone
PredictedAll 15 counties, by the zone EPA predicts for each. Every county has its own report.
Zone 2: moderate predicted potential15
- Apache County0.0% of reported tests at or above 4 pCi/L, 2017
- Cochise County26.9% of reported tests at or above 4 pCi/L, 2017
- Coconino County30.0% of reported tests at or above 4 pCi/L, 2017
- Gila County64.7% of reported tests at or above 4 pCi/L, 2017
- Graham County36.4% of reported tests at or above 4 pCi/L, 2017
- Greenlee CountyReported testing not yet available
- La Paz CountyReported testing not yet available
- Maricopa County17.4% of reported tests at or above 4 pCi/L, 2017
- Mohave County4.1% of reported tests at or above 4 pCi/L, 2017
- Navajo County0.0% of reported tests at or above 4 pCi/L, 2017
- Pima County6.8% of reported tests at or above 4 pCi/L, 2017
- Pinal County8.9% of reported tests at or above 4 pCi/L, 2017
- Santa Cruz County0.0% of reported tests at or above 4 pCi/L, 2017
- Yavapai County16.2% of reported tests at or above 4 pCi/L, 2017
- Yuma County0.0% of reported tests at or above 4 pCi/L, 2017
Arizona, Cities
Cities in Arizona with their own page
Radon data is published by county, not by city. Each city page sets the figures of the counties the city lies in side by side.
Arizona, Local resources
Local resources in Arizona
Who to ask in Arizona: the state's radon program, test kits and professionals.
Arizona's radon program
Arizona Department of Health Services
Arizona’s radon program answers questions about testing, mitigation and the rules where you live.
Visit the program's page(opens in a new tab)Test kits
Ask the program whether it has free or discounted kits, or compare kits you can buy.
Radon professionals
No professionals are listed in Arizona yet. The state program can point you to registered testers and mitigators.
See the Arizona directoryArizona, Questions
Questions about radon in Arizona
Common questions8 questions, answered from the figures above
Is radon a problem in Arizona?
EPA's Map of Radon Zones places 0 of the 15 Arizona counties it classifies in Zone 1, the highest predicted potential, 15 in Zone 2 and 0 in Zone 3. An EPA radon zone describes predicted potential across a whole county. It is not intended to determine whether any individual home should be tested, and homes with elevated levels occur in all three zones. EPA recommends testing every home regardless of zone, and testing is the only way to know the radon level in a specific building.
Who does radon mitigation in Arizona?
Radon411 has no certified mitigators listed for Arizona yet. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional.
How radon mitigation worksWhat mitigation costsRadon professionals in Arizona
How do I get a radon test in Arizona?
EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. The Arizona radon program is the place to ask about certified testers and any test kit offer it runs.
How to test a homeFree and low-cost kits by stateArizona radon program
Which Arizona counties have the highest radon?
15 of Arizona's 15 counties have an EPA radon zone published here. Radon411 will not rank counties on data it does not hold, and a zone is a prediction for an area rather than a measurement of any building.
What share of radon tests in Arizona are high?
CDC has published no statewide radon testing statistics for Arizona, so we cannot give a figure. Where CDC does publish one, the percentage describes radon tests reported to CDC, not homes.
Which EPA region is Arizona in?
Arizona is in EPA Region 9: Pacific Southwest.
Do I need to test my home in Arizona?
Yes, wherever you live in the state. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L.
Why does this page show coverage rather than one radon level for Arizona?
A statewide figure averages counties with very different geology and very different numbers of reported tests, so it hides more than it shows. The county report is the level at which the EPA zone, the geologic potential and the reported testing statistics are actually published, which is why the county table above links to every one of them.
What these figures mean if you own, buy, sell or rent
The zone counts on this page describe counties across Arizona. They are predictions for areas, and none of them measures your building.
- How to test a home
If you own your home
Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.
- Buying a house: radon guide
If you are buying
Ask for past results and any system's post-mitigation test, and test during the sale.
- Selling a house: radon guide
If you are selling
Testing before you list puts the timing in your hands; disclosure rules differ by state.
- Radon in rental homes
If you rent, or rent out a home
A tenant can test; a fix is the owner's to make, and duties differ by state.
How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.
Arizona, Products
Testing and mitigation products
Whatever the figures for Arizona show, only a test tells you about one home.
Testing
- Short-term test kitsPassive detectors exposed for a few days under closed-building conditions, then analyzed by a lab.
- Long-term test kitsDetectors exposed for more than 90 days, for a closer picture of the annual average.
- Continuous monitorsPowered devices that log radon on a repeating cycle, often used for transaction tests.
- Digital detectorsConsumer devices that display a running radon reading without a lab.
- Water radon testsKits for radon dissolved in well water, analyzed by a lab.
Mitigation
- Mitigation fansThe inline fan that keeps a soil depressurization system running, sized by the installer.
- System indicatorsU-tube manometers and fan alarms that show whether a mitigation system is still working.
- Sealing materialsCrack, joint and sump sealing used alongside a mitigation system, not instead of one.
Arizona / Next steps
What to do next
Learn
Know what radon is
What radon is, how it gets indoors, and why a county zone is not a reading for your home.
Learn about radonTest
Test the building you live in
Short-term or long-term, where the device goes, and closed-house conditions.
How to testFix
Bring a high level down
How a mitigation system works, and the retest that confirms it.
How mitigation worksFind a pro
Hire a certified professional
Measurement and mitigation professionals by state, with their certifications.
Find a professional
Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.