Ohio · county radon data
Radon in Mahoning County, Ohio
23.4% of the 556 home radon tests on record here reached the EPA action level — toward the lower end of the state's tested counties, ranked #85 of 88 tested Ohio counties.
What the numbers say
Mahoning County sits 30.4 points below the Ohio median (53.8% of tests over the limit across the state's counties). The median reading among its 556 reported tests was 2.5 pCi/L — and the single highest test on record reached 44.1 pCi/L, more than 11× the action level. EPA maps place the county in Radon Zone 2 — moderate predicted potential (2–4 pCi/L average screening levels), which still produces plenty of homes over the limit.
Why: the ground under Mahoning County
Underlain by Devonian–Mississippian shales beneath glacial deposits — a combination that sustains elevated soil-gas radon across much of northeast Ohio. (Regional attribution here is well supported; unit-level detail is coarser — see methodology.)
Geology sources: USGS WRI 98-4169 · EPA OH zone documentation.
The housing stock factor
The median Mahoning County home dates to 1963 — decades before radon-resistant new construction entered building codes. With 226,491 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Mahoning County
Ohio doesn't publish ZIP-level test results, so these ZIPs share the county figures above — the roster is here so you can confirm your address is covered by this data.
| ZIP | Place |
|---|---|
| 44401 | Berlin Center |
| 44405 | Campbell |
| 44406 | Canfield |
| 44429 | Lake Milton |
| 44436 | Lowellville |
| 44442 | New Middletown |
| 44443 | New Springfield |
| 44449 | North Benton |
| 44451 | North Jackson |
| 44452 | North Lima |
| 44454 | Petersburg |
| 44471 | Struthers |
| 44502 | Youngstown |
| 44503 | Youngstown |
| 44504 | Youngstown |
| 44505 | Youngstown |
| 44506 | Youngstown |
| 44507 | Youngstown |
| 44509 | Youngstown |
| 44510 | Youngstown |
| 44511 | Youngstown |
| 44512 | Youngstown |
| 44514 | Youngstown |
| 44515 | Youngstown |
| 44555 | Youngstown |
| 44609 | Beloit |
| 44619 | Damascus |
| 44672 | Sebring |
Mahoning County in the Ohio picture
| Mahoning County | 23.4% over the limit | 556 tests |
| Ohio's highest: Pickaway County | 81.4% | 154 tests |
| Ohio county median | 53.8% | 88 counties ranked |
| Share of all Ohio tests from this county | 0.7% | |
Ranked nearby in Ohio
- Lake County — #82, 27.2% of 2,194 tests over the limit
- Vinton County — #83, 25% of 4 tests over the limit
- Geauga County — #84, 23.4% of 1,382 tests over the limit
- Paulding County — #86, 23.1% of 12 tests over the limit
- Cuyahoga County — #87, 21.7% of 8,861 tests over the limit
- Meigs County — #88, 20% of 16 tests over the limit
(Ranking neighbors — counties adjacent in the Ohio test ranking, not necessarily on the map.)
High test? Fixes and real pricing: the Ohio mitigation cost guide. Every statistic here traces to the methodology (CDC EPHT (labs), 2008–2017; zones: EPA; year built & population: ACS 5-year).
Mahoning County radon FAQ
- Is radon high in Mahoning County?
- 23.4% of 556 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 30.4 points below the Ohio county median of 53.8%, ranking #85 of 88 tested counties. EPA classifies the county as Zone 2.
- Does an older home in Mahoning County mean more radon risk?
- The county's median home was built in 1963 — 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 Mahoning County numbers come from?
- 556 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 2.5 pCi/L; the highest recorded test hit 44.1 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Mahoning County?
- 44.1 pCi/L — 11× the EPA action level — against a county median of 2.5 pCi/L across 556 tests. That spread is the point: neighboring homes routinely test wildly differently.