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Pennsylvania Radon Map and Levels by County

Pennsylvania's counties span all three EPA radon zones. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    41.7%

    6.0 pts above U.S.

    Pennsylvania
    41.7%
    U.S.
    35.7%

    203,045 tests across 67 counties, 2008 to 2017

  • Rank among states

    14 of 47

    Middle of the states

    Pennsylvania
    41.7%
    North Dakota
    59.3%

    By share, every state pooled the same way, 2008 to 2017

  • Counties in EPA Zone 1

    49 of 67

    Most at highest potential

    Zone 1
    49
    Zone 2
    17

    Most counties sit in Zone 1; Zone 1 is the highest potential

  • Highest county

    69.7%

    Fulton County

    Fulton
    69.7%
    Philadelphia
    12.4%

    Counties with 30+ tests, 2008 to 2017

Read a result for Pennsylvania

Starts at EPA's action level

4.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. 41.7% of Pennsylvania's reported tests reached 4 pCi/L, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Pennsylvania, At a glance

Pennsylvania at a glance

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 predicts a whole county. It is not intended to determine whether any individual home should be tested: homes with elevated levels occur in all three zones, and EPA recommends testing every home regardless of zone.

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

CDC test figures, county by county

CDC publishes Pennsylvania's radon test figures by county: 67 of its 67 counties have one. Each one's share is in the county list.

How to read these figures

Pennsylvania, Compared

Pennsylvania radon figures, compared

Calculated by Radon411
Pennsylvania, 2008 to 2017, laboratory
41.7%
of 203,045 tests at or above 4 pCi/L, pooled
Against the U.S.
+6.0points
35.7% pooled
Rank among the states
14 of 47
1 is the highest share
Counties with 30 or more tests
67
Highest
69.7%
Fulton County
Lowest
12.4%
Philadelphia County

Pennsylvania pools to 41.7%: that share of 203,045 reported tests from 67 counties over the 2008 to 2017 laboratory totals reached EPA's action level. Nationally the pooled share is 35.7%: 6.0 points lower than here.

Among 47 states pooled the same way it ranks 14th, with Utah (41.9%) above it and Idaho (41.5%) below. Fulton County reports the highest share (69.7% of 132 tests) and Philadelphia County the lowest (12.4%); the most tests came from Allegheny County, 19,423 of them at 37.3%.

Across its 4 overlapping ten-year totals, the share went from 45.0% (2005 to 2014) to 41.7% (2008 to 2017), down 3.3 points, with 2005 to 2014 the highest at 45.0%. By band, 30 counties at 50% or more, 31 counties at 30% to 50%, 5 counties at 15% to 30%, 1 county at 5% to 15%.

EPA's 1993 map puts 49 of its 67 classified counties in Zone 1; the tests reported since bear that out at 41.7%.

Pennsylvania ranked among 47 states by pooled share of tests at or above 4 pCi/L, 2008 to 2017, laboratory
StateRankCountiesTestsAt or above 4 pCi/L
Wyoming9 of 47237,63844.3%
Kentucky10 of 4712028,79343.7%
Minnesota11 of 4787130,91243.4%
Illinois12 of 47102108,90943.1%
Utah13 of 472828,34241.9%
Pennsylvania14 of 4767203,04541.7%
Idaho15 of 474412,96141.5%
Indiana16 of 479243,14838.9%
Maine17 of 471611,82537.6%
West Virginia18 of 475510,06137.5%
New Hampshire19 of 471015,60835.0%
Pennsylvania's highest and lowest counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/L
Fulton County1 of 6713269.7%
Juniata County2 of 6725167.3%
Mifflin County3 of 6742967.1%
Centre County4 of 671,69167.0%
Snyder County5 of 6736164.8%
Franklin County6 of 673,73463.6%
Lebanon County7 of 673,51363.6%
Union County8 of 6740762.9%
Perry County9 of 6768362.5%
Montour County10 of 6722961.6%
Philadelphia County67 of 679,57612.4%
Delaware County66 of 679,00521.0%
McKean County65 of 6717426.4%
Montgomery County64 of 6717,05227.2%
Bucks County63 of 6711,34627.5%
Pennsylvania's counties with 30 or more tests, by their own share at or above 4 pCi/L, 2008 to 2017, laboratory
ShareCountiesTheir testsFor example
50% or more3071,107Fulton County, Juniata County, Mifflin County
30% to 50%3171,873Beaver County, Elk County, Lehigh County
15% to 30%550,489Chester County, Bucks County, Montgomery County
5% to 15%19,576Philadelphia County
Under 5%00None
Pennsylvania ten-year laboratory totals, pooled, against the United States
PeriodCountiesTestsAt or above 4 pCi/LUnited StatesChange from the row before
2008 to 201767203,04541.7%35.7%−1.3 points
2007 to 201667191,10343.0%35.8%−1.5 points
2006 to 201567174,35244.6%36.3%−0.4 points
2005 to 201467157,44645.0%36.0%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period. CDC publishes no state or national figure.

Pennsylvania, Counties

Pennsylvania counties by EPA zone

Predicted

Pennsylvania's radon map, then all 67 counties by EPA's zone, the highest reported share of tests at or above 4 pCi/L first; each has its own report.

Pennsylvania radon map by county: EPA radon zones. Map of Pennsylvania's 67 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber, Zone 3 in pale sand. 49 in Zone 1, 17 in Zone 2, 1 in Zone 3.
Pennsylvania radon map by countyEPA radon zones for Pennsylvania's counties: 49 counties in Zone 1, 17 counties in Zone 2, 1 county in Zone 3.A prediction for each county, not a reading of any home; elevated homes occur in all three zones.

The 12 highest in Pennsylvania, 2008 to 2017

Zone 1: highest predicted potential49

Local help

Pennsylvania, Local resources

Local resources in Pennsylvania

Who to ask in Pennsylvania: its radon program, test kits and professionals.

What Pennsylvania's program says
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 of radon contamination in buildings.

What it means

Pennsylvania, Questions

Questions about radon in Pennsylvania

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. Pooled from 67 counties, 41.7% of the 203,045 radon tests reported to CDC over the 2008 to 2017 laboratory totals were at or above 4 pCi/L, 14th of 47 states.

Who does radon mitigation in Pennsylvania?

Radon411's Pennsylvania directory lists 151 radon businesses for testing, mitigation or both, each with the licensing list it was read from.

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.

Which Pennsylvania counties have the highest radon?

By the share of reported tests at or above 4 pCi/L, 2008 to 2017, laboratory: Fulton County 69.7% (132 tests), Juniata County 67.3% (251 tests), Mifflin County 67.1% (429 tests), Centre County 67.0% (1,691 tests), Snyder County 64.8% (361 tests).

Which EPA region is Pennsylvania in?

Pennsylvania is in EPA Region 3: Mid-Atlantic.

Products

Pennsylvania, Products

Testing a home in Pennsylvania

41.7% of the 203,045 tests reported to CDC for Pennsylvania over the 2008 to 2017 laboratory totals reached 4 pCi/L: a short-term kit (2 to 90 days) gives a first answer in days, a long-term test the year-round average. A short-term kit (2 to 90 days) is the quick first check for a home in Pennsylvania; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Pennsylvania homes, compared

Explore

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.