Ohio · county radon data
Radon in Stark County, Ohio
60.1% of the 3,174 home radon tests on record here reached the EPA action level — mid-pack for the state, ranked #25 of 88 tested Ohio counties.
What the numbers say
Stark County sits 6.3 points above the Ohio median (53.8% of tests over the limit across the state's counties). The median reading among its 3,174 reported tests was 4.9 pCi/L — and the single highest test on record reached 277 pCi/L, more than 69× 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 Stark 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 Stark County home dates to 1966 — decades before radon-resistant new construction entered building codes. With 373,713 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Stark 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 |
|---|---|
| 44601 | Alliance |
| 44608 | Beach City |
| 44613 | Brewster |
| 44614 | Canal Fulton |
| 44626 | East Sparta |
| 44630 | Greentown |
| 44632 | Hartville |
| 44640 | Limaville |
| 44641 | Louisville |
| 44646 | Massillon |
| 44647 | Massillon |
| 44652 | Middlebranch |
| 44662 | Navarre |
| 44666 | North Lawrence |
| 44669 | Paris |
| 44670 | Robertsville |
| 44688 | Waynesburg |
| 44702 | Canton |
| 44703 | Canton |
| 44704 | Canton |
| 44705 | Canton |
| 44706 | Canton |
| 44707 | Canton |
| 44708 | Canton |
| 44709 | Canton |
| 44710 | Canton |
| 44714 | Canton |
| 44718 | Canton |
| 44720 | North Canton |
| 44721 | Canton |
| 44730 | East Canton |
Stark County in the Ohio picture
| Stark County | 60.1% over the limit | 3,174 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 | 3.8% | |
Ranked nearby in Ohio
- Wayne County — #22, 61.8% of 950 tests over the limit
- Union County — #23, 60.2% of 968 tests over the limit
- Shelby County — #24, 60.1% of 206 tests over the limit
- Putnam County — #26, 59.6% of 74 tests over the limit
- Crawford County — #27, 59.5% of 175 tests over the limit
- Huron County — #28, 59.4% of 692 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).
Stark County radon FAQ
- Is radon high in Stark County?
- 60.1% of 3,174 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 6.3 points above the Ohio county median of 53.8%, ranking #25 of 88 tested counties. EPA classifies the county as Zone 1.
- Does an older home in Stark County mean more radon risk?
- The county's median home was built in 1966 — 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 Stark County numbers come from?
- 3,174 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 4.9 pCi/L; the highest recorded test hit 277 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Stark County?
- 277 pCi/L — 69× the EPA action level — against a county median of 4.9 pCi/L across 3,174 tests. That spread is the point: neighboring homes routinely test wildly differently.