Pennsylvania · county radon data
Radon in Allegheny County, Pennsylvania
37.3% of the 17,929 home radon tests on record here reached the EPA action level — toward the lower end of the state's tested counties, ranked #54 of 67 tested Pennsylvania counties.
What the numbers say
Allegheny County sits 11.7 points below the Pennsylvania median (49% of tests over the limit across the state's counties). The median reading among its 17,929 reported tests was 2.9 pCi/L — and the single highest test on record reached 432 pCi/L, more than 108× the action level. EPA maps place the county in Radon Zone 1 — its highest-potential category, where average indoor screening levels are predicted above 4 pCi/L.
Why: the ground under Allegheny County
Underlain by uranium-bearing Devonian black shales (the Marcellus and relatives). Shale ranks among the highest-radon rock types measured in Pennsylvania basements, and roughly 3 in 10 tested homes in these counties exceed the action level.
Geology sources: USGS OFR 93-292-C · AARST 2024 rock-type correlation study.
The housing stock factor
The median Allegheny County home dates to 1957 — decades before radon-resistant new construction entered building codes. With 1,238,177 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
Radon by ZIP in Allegheny County
Pennsylvania is one of the few states publishing actual test results at ZIP level (PA DEP residential data, 1986–2026) — county averages hide a lot; this doesn't.
| ZIP | Place | Tests | % ≥ 4 pCi/L | Max |
|---|---|---|---|---|
| 15007 | Bakerstown | 54 | 57.4% | 26.8 |
| 15015 | Bradfordwoods | 651 | 48.2% | 205.7 |
| 15051 | Indianola | 72 | 45.8% | 568.4 |
| 15046 | Crescent | 423 | 45.6% | 49.9 |
| 15116 | Glenshaw | 3,839 | 44.9% | 309 |
| 15090 | Wexford | 11,912 | 44.7% | 240.9 |
| 15101 | Allison Park | 7,258 | 44.4% | 133 |
| 15237 | Pittsburgh | 16,104 | 42.7% | 237.9 |
| 15044 | Gibsonia | 230 | 42.6% | 108 |
| 15076 | Russellton | 73 | 42.5% | 20.4 |
| 15229 | Pittsburgh | 3,585 | 41.8% | 121 |
| 15238 | Pittsburgh | 5,867 | 41.8% | 171.9 |
| 15024 | Cheswick | 1,405 | 40.1% | 131 |
| 15084 | Tarentum | 809 | 39.7% | 239.5 |
| 15209 | Pittsburgh | 2,229 | 38.8% | 608 |
| 15143 | Sewickley | 9,161 | 38.7% | 208.2 |
| 15086 | Warrendale | 161 | 37.9% | 125 |
| 15146 | Monroeville | 5,929 | 37.6% | 267 |
| 15108 | Coraopolis | 9,483 | 37.3% | 605 |
| 15025 | Clairton | 1,963 | 37% | 57.4 |
| 15223 | Pittsburgh | 1,141 | 36.8% | 143.7 |
| 15064 | Morgan | 56 | 35.7% | 14.8 |
| 15235 | Pittsburgh | 6,837 | 35.1% | 101.7 |
| 15214 | Pittsburgh | 1,973 | 35% | 100 |
| 15030 | Creighton | 58 | 34.5% | 25.8 |
| 15104 | Braddock | 316 | 34.5% | 35.9 |
| 15037 | Elizabeth | 1,229 | 34.3% | 89.5 |
| 15065 | Natrona Heights | 1,195 | 33.8% | 134.8 |
| 15135 | Mckeesport | 559 | 33.8% | 35.7 |
| 15132 | Mckeesport | 1,018 | 33% | 772 |
| 15239 | Pittsburgh | 3,620 | 32.6% | 611.6 |
| 15120 | Homestead | 2,222 | 31.9% | 103.5 |
| 15082 | Sturgeon | 41 | 31.7% | 10.3 |
| 15147 | Verona | 2,289 | 31.7% | 190 |
| 15031 | Cuddy | 38 | 31.6% | 50 |
| 15131 | Mckeesport | 67 | 31.3% | 16 |
| 15137 | North Versailles | 1,176 | 31.3% | 97.7 |
| 15035 | East Mc Keesport | 151 | 31.1% | 27.6 |
| 15215 | Pittsburgh | 3,550 | 30.6% | 84.9 |
| 15204 | Pittsburgh | 834 | 30.5% | 164 |
| 15006 | Bairdford | 33 | 30.3% | 19.3 |
| 15241 | Pittsburgh | 33 | 30.3% | 15 |
| 15145 | Turtle Creek | 612 | 30.2% | 66.1 |
| 15122 | West Mifflin | 2,964 | 30% | 102 |
| 15221 | Pittsburgh | 4,873 | 29.8% | 126 |
| 15133 | Mckeesport | 657 | 29.5% | 52.6 |
| 15140 | Pitcairn | 201 | 29.4% | 22.8 |
| 15106 | Carnegie | 3,020 | 29.2% | 5401 |
| 15126 | Imperial | 1,599 | 29.2% | 151 |
| 15047 | Greenock | 31 | 29% | 33 |
| 15220 | Pittsburgh | 3,139 | 29% | 71.1 |
| 15136 | Mc Kees Rocks | 3,021 | 28.7% | 86.5 |
| 15071 | Oakdale | 1,729 | 28.6% | 116.8 |
| 15102 | Bethel Park | 7,956 | 28.1% | 408 |
| 15034 | Dravosburg | 97 | 27.8% | 22.5 |
| 15129 | South Park | 2,113 | 27.4% | 106.7 |
| 15210 | Pittsburgh | 2,038 | 27.1% | 97.4 |
| 15217 | Pittsburgh | 7,714 | 27.1% | 103.1 |
| 15014 | Brackenridge | 216 | 26.9% | 29.3 |
| 15243 | Pittsburgh | 4,930 | 26.7% | 33.9 |
+34 more — look yours up in the ZIP tool.
Allegheny County in the Pennsylvania picture
| Allegheny County | 37.3% over the limit | 17,929 tests |
| Pennsylvania's highest: Fulton County | 69.7% | 90 tests |
| Pennsylvania county median | 49% | 67 counties ranked |
| Share of all Pennsylvania tests from this county | 10.3% | |
Ranked nearby in Pennsylvania
- Greene County — #51, 39% of 142 tests over the limit
- Sullivan County — #52, 38.8% of 43 tests over the limit
- Washington County — #53, 37.9% of 2,504 tests over the limit
- Mercer County — #55, 36.7% of 1,230 tests over the limit
- Lackawanna County — #56, 36.3% of 1,103 tests over the limit
- Fayette County — #57, 35.8% of 526 tests over the limit
(Ranking neighbors — counties adjacent in the Pennsylvania test ranking, not necessarily on the map.)
High test? Fixes and real pricing: the Pennsylvania mitigation cost guide. Every statistic here traces to the methodology (CDC EPHT (labs), 2008–2017; zones: EPA; year built & population: ACS 5-year; ZIP results: PA DEP).
Allegheny County radon FAQ
- Is radon high in Allegheny County?
- 37.3% of 17,929 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 11.7 points below the Pennsylvania county median of 49%, ranking #54 of 67 tested counties. EPA classifies the county as Zone 1.
- Does an older home in Allegheny County mean more radon risk?
- The county's median home was built in 1957 — before radon-resistant construction practices entered building codes in the 1990s, so most of the housing stock has no built-in radon protection. Construction age changes the odds, not the answer: only a test tells you about your house.
- Where do these Allegheny County numbers come from?
- 17,929 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 2.9 pCi/L; the highest recorded test hit 432 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- Which ZIP codes in Allegheny County test highest?
- In PA DEP's residential results (1986–2026): 15007 (Bakerstown) — 57.4% of 54 tests over the limit; 15015 (Bradfordwoods) — 48.2% of 651 tests over the limit; 15051 (Indianola) — 45.8% of 72 tests over the limit. Full ZIP table below.