Locations and reports
Radon Levels in Pennsylvania
What this means for you
- Your area: EPA rates 49 of Pennsylvania's 67 classified counties 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 Pennsylvania'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 Pennsylvania, EPA's Map of Radon Zones places 49 of its 67 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
67 of 67 counties classified
EPA classifies counties, not states. Of the 67 counties in Pennsylvania with a zone, 49 are in Zone 1, 17 in Zone 2 and 1 in Zone 3.
- Zone 1: Highest predicted potentialgreater than 4 pCi/L49 of 67 counties · 73.1%
- Zone 2: Moderate predicted potential2 to 4 pCi/L17 of 67 counties · 25.4%
- Zone 3: Lower predicted potentialless than 2 pCi/L1 of 67 counties · 1.5%
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 Pennsylvania's radon test figures by county: 67 of its 67 counties have one. Each county's share is in the county list.
Pennsylvania, In figures
Pennsylvania in figures
What the published data says about Pennsylvania, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places 49 of Pennsylvania's 67 counties in Zone 1, 17 in Zone 2 and 1 in Zone 3.
Zone 1 counties, A to Z, begin with Adams County, Allegheny County and Armstrong County; the county section below lists all 49.
Compared
Calculated by Radon41173% of Pennsylvania's counties with a zone on file are in Zone 1, a larger 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 Pennsylvania on file here.
67 of the 67 counties have a published county figure; the most tests in each one's latest year were reported for Montgomery County (6,972 in 2020), Allegheny County (6,123 in 2020) and Philadelphia County (6,089 in 2020).
Local record
Pennsylvania's radon program is the Radon Division, run by Department of Environmental Protection; its contacts are under Local resources.
4 cities have a page setting the figures of the counties it lies in side by side: Allentown, Scranton, Harrisburg and Greensburg.
Pennsylvania, Counties
Pennsylvania counties by EPA zone
PredictedAll 67 counties, by the zone EPA predicts for each. Every county has its own report.
Zone 1: highest predicted potential49
- Adams County39.7% of reported tests at or above 4 pCi/L, 2020
- Allegheny County30.5% of reported tests at or above 4 pCi/L, 2020
- Armstrong County47.6% of reported tests at or above 4 pCi/L, 2020
- Beaver County42.4% of reported tests at or above 4 pCi/L, 2020
- Bedford County47.8% of reported tests at or above 4 pCi/L, 2020
- Berks County39.6% of reported tests at or above 4 pCi/L, 2020
- Blair County42.0% of reported tests at or above 4 pCi/L, 2020
- Bradford County43.4% of reported tests at or above 4 pCi/L, 2020
- Bucks County23.2% of reported tests at or above 4 pCi/L, 2020
- Butler County42.3% of reported tests at or above 4 pCi/L, 2020
- Cameron County75.0% of reported tests at or above 4 pCi/L, 2020
- Carbon County40.6% of reported tests at or above 4 pCi/L, 2020
- Centre County39.3% of reported tests at or above 4 pCi/L, 2020
- Chester County24.0% of reported tests at or above 4 pCi/L, 2020
- Clarion County31.8% of reported tests at or above 4 pCi/L, 2020
- Clearfield County47.5% of reported tests at or above 4 pCi/L, 2020
- Clinton County54.1% of reported tests at or above 4 pCi/L, 2020
- Columbia County34.7% of reported tests at or above 4 pCi/L, 2020
- Cumberland County43.6% of reported tests at or above 4 pCi/L, 2020
- Dauphin County36.9% of reported tests at or above 4 pCi/L, 2020
- Delaware County14.7% of reported tests at or above 4 pCi/L, 2020
- Franklin County42.6% of reported tests at or above 4 pCi/L, 2020
- Fulton County67.9% of reported tests at or above 4 pCi/L, 2020
- Huntingdon County54.0% of reported tests at or above 4 pCi/L, 2020
- Indiana County44.3% of reported tests at or above 4 pCi/L, 2020
- Juniata County52.9% of reported tests at or above 4 pCi/L, 2020
- Lackawanna County27.1% of reported tests at or above 4 pCi/L, 2020
- Lancaster County43.3% of reported tests at or above 4 pCi/L, 2020
- Lebanon County54.2% of reported tests at or above 4 pCi/L, 2020
- Lehigh County39.8% of reported tests at or above 4 pCi/L, 2020
- Luzerne County28.2% of reported tests at or above 4 pCi/L, 2020
- Lycoming County45.2% of reported tests at or above 4 pCi/L, 2020
- Mifflin County41.4% of reported tests at or above 4 pCi/L, 2020
- Monroe County30.7% of reported tests at or above 4 pCi/L, 2020
- Montgomery County21.8% of reported tests at or above 4 pCi/L, 2020
- Montour County41.5% of reported tests at or above 4 pCi/L, 2020
- Northampton County41.3% of reported tests at or above 4 pCi/L, 2020
- Northumberland County49.8% of reported tests at or above 4 pCi/L, 2020
- Perry County57.7% of reported tests at or above 4 pCi/L, 2020
- Schuylkill County53.5% of reported tests at or above 4 pCi/L, 2020
- Snyder County42.4% of reported tests at or above 4 pCi/L, 2020
- Sullivan County29.0% of reported tests at or above 4 pCi/L, 2020
- Susquehanna County37.9% of reported tests at or above 4 pCi/L, 2020
- Tioga County45.0% of reported tests at or above 4 pCi/L, 2020
- Union County44.5% of reported tests at or above 4 pCi/L, 2020
- Venango County34.1% of reported tests at or above 4 pCi/L, 2020
- Westmoreland County34.9% of reported tests at or above 4 pCi/L, 2020
- Wyoming County30.9% of reported tests at or above 4 pCi/L, 2020
- York County46.8% of reported tests at or above 4 pCi/L, 2020
Zone 2: moderate predicted potential17
- Cambria County44.7% of reported tests at or above 4 pCi/L, 2020
- Crawford County29.9% of reported tests at or above 4 pCi/L, 2020
- Elk County47.0% of reported tests at or above 4 pCi/L, 2020
- Erie County22.2% of reported tests at or above 4 pCi/L, 2020
- Fayette County17.4% of reported tests at or above 4 pCi/L, 2020
- Forest County56.3% of reported tests at or above 4 pCi/L, 2020
- Greene County20.0% of reported tests at or above 4 pCi/L, 2020
- Jefferson County38.6% of reported tests at or above 4 pCi/L, 2020
- Lawrence County36.0% of reported tests at or above 4 pCi/L, 2020
- McKean County10.5% of reported tests at or above 4 pCi/L, 2020
- Mercer County31.4% of reported tests at or above 4 pCi/L, 2020
- Pike County30.7% of reported tests at or above 4 pCi/L, 2020
- Potter County17.9% of reported tests at or above 4 pCi/L, 2020
- Somerset County43.7% of reported tests at or above 4 pCi/L, 2020
- Warren County38.7% of reported tests at or above 4 pCi/L, 2020
- Washington County33.6% of reported tests at or above 4 pCi/L, 2020
- Wayne County30.1% of reported tests at or above 4 pCi/L, 2020
Zone 3: lower predicted potential1
Pennsylvania, Cities
Cities in Pennsylvania 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.
Pennsylvania, Local resources
Local resources in Pennsylvania
Who to ask in Pennsylvania: the state's radon program, test kits and professionals.
Radon Division
Department of Environmental Protection
Pennsylvania’s radon program answers questions about testing, mitigation and the rules where you live.
- Phone
- 800-237-2366
- Licensing of radon professionals
The Radon Certification Act requires DEP to establish by regulation, a certification program for persons conducting radon gas and radon progeny testing, laboratory analysis and mitigation...
Test kits
The program says: Through an EPA-funded program, hospitals give parents of newborn children a packet of information which includes a coupon for a free radon test kit from the DEP.
Radon professionals
755 professionals are listed in Pennsylvania.
Professionals in PennsylvaniaPennsylvania, Questions
Questions about radon in Pennsylvania
Common questions9 questions, answered from the figures above
Is radon a problem in Pennsylvania?
EPA's Map of Radon Zones places 49 of the 67 Pennsylvania counties it classifies in Zone 1, the highest predicted potential, 17 in Zone 2 and 1 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.
How do I get a radon test in Pennsylvania?
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 Pennsylvania 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 statePennsylvania radon program
Which Pennsylvania counties are in EPA radon Zone 1?
49 counties are in Zone 1: Adams County, Allegheny County, Armstrong County, Beaver County, Bedford County, Berks County, Blair County, Bradford County, and 41 more in the county table on this page. Zone 1 is EPA's class for highest predicted potential, a predicted average indoor screening level greater than 4 pCi/L. A zone is a prediction for a county, not a measurement of any home.
Radon in Adams CountyRadon in Allegheny CountyRadon in Armstrong County
Who does radon mitigation in Pennsylvania?
Radon411's Pennsylvania directory lists 755 certified radon companies. 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 Pennsylvania
Which Pennsylvania counties have the highest radon?
67 of Pennsylvania's 67 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 Pennsylvania are high?
CDC has published no statewide radon testing statistics for Pennsylvania, 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 Pennsylvania in?
Pennsylvania is in EPA Region 3: Mid-Atlantic.
Do I need to test my home in Pennsylvania?
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 Pennsylvania?
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 Pennsylvania. 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.
Pennsylvania, Products
Testing and mitigation products
Whatever the figures for Pennsylvania 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.
Pennsylvania / 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.