Ohio · county radon data
Radon in Summit County, Ohio
38.7% of the 6,002 home radon tests on record here reached the EPA action level — toward the lower end of the state's tested counties, ranked #71 of 88 tested Ohio counties.
What the numbers say
Summit County sits 15.1 points below the Ohio median (53.8% of tests over the limit across the state's counties). The median reading among its 6,002 reported tests was 3.1 pCi/L — and the single highest test on record reached 194.7 pCi/L, more than 48× 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 Summit 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 Summit County home dates to 1966 — decades before radon-resistant new construction entered building codes. With 537,864 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Summit 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 |
|---|---|
| 44056 | Macedonia |
| 44067 | Northfield |
| 44087 | Twinsburg |
| 44203 | Barberton |
| 44216 | Clinton |
| 44221 | Cuyahoga Falls |
| 44223 | Cuyahoga Falls |
| 44224 | Stow |
| 44232 | Green |
| 44236 | Hudson |
| 44250 | Lakemore |
| 44262 | Munroe Falls |
| 44264 | Peninsula |
| 44278 | Tallmadge |
| 44286 | Richfield |
| 44301 | Akron |
| 44302 | Akron |
| 44303 | Akron |
| 44304 | Akron |
| 44305 | Akron |
| 44306 | Akron |
| 44307 | Akron |
| 44308 | Akron |
| 44310 | Akron |
| 44311 | Akron |
| 44312 | Akron |
| 44313 | Akron |
| 44314 | Akron |
| 44319 | Akron |
| 44320 | Akron |
| 44321 | Akron |
| 44325 | Akron |
| 44333 | Akron |
| 44685 | Uniontown |
Summit County in the Ohio picture
| Summit County | 38.7% over the limit | 6,002 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 | 7.1% | |
Ranked nearby in Ohio
- Ottawa County — #68, 40.3% of 479 tests over the limit
- Lucas County — #69, 40.2% of 1,752 tests over the limit
- Portage County — #70, 39.3% of 1,561 tests over the limit
- Athens County — #72, 38.1% of 181 tests over the limit
- Washington County — #73, 38.1% of 290 tests over the limit
- Scioto County — #74, 37% of 48 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).
Summit County radon FAQ
- Is radon high in Summit County?
- 38.7% of 6,002 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 15.1 points below the Ohio county median of 53.8%, ranking #71 of 88 tested counties. EPA classifies the county as Zone 1.
- Does an older home in Summit 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 Summit County numbers come from?
- 6,002 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 3.1 pCi/L; the highest recorded test hit 194.7 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Summit County?
- 194.7 pCi/L — 48× the EPA action level — against a county median of 3.1 pCi/L across 6,002 tests. That spread is the point: neighboring homes routinely test wildly differently.