Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Lake County, Ohio
EPA puts Lake County in Zone 2, its middle radon zone, and 27.2% of its 2,349 reported radon tests (2008 to 2017, laboratory totals) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
27.2%
25.1 pts below OH
- Lake
- 27.2%
- Ohio
- 52.3%
2,349 tests, 2008 to 2017
Median result
2.4pCi/L
Below action level
- Lake
- 2.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
2,349
12th of 79 by tests
- Lake
- 2,349
- Franklin
- 16,142
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Ohio
76 of 79
Lowest quarter
- Lake
- 27.2%
- Pickaway
- 81.4%
By share, of 79 with 30+ tests
Read a result for Lake County
Starts at Lake County's median, 2.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.4 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Lake County's median reported result, 2008 to 2017.
The data
Lake County, At a glance
Lake County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Lake County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Lake County, 2008 to 2017, laboratory
Under 2 pCi/L: 41%2 to 4 pCi/L: 32%4 pCi/L and above: 27%
Of 2,349 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 957 | 40.7% |
| 2 to 4 pCi/L | 754 | 32.1% |
| 4 pCi/L and above | 638 | 27.2% |
What these figures count
These are the 2,349 tests reported to CDC for Lake County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Lake County, Compared
Lake County radon figures, compared
Calculated by Radon411Lake County's 2,349 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.4 pCi/L and a maximum of 146.1 pCi/L, and 27.2% reached 4 pCi/L. Ohio as a whole (88 Ohio counties, pooled) comes to 52.3%: 25.1 points higher than here.
Among its state's counties it ranks 76th of 79 Ohio counties with 30 or more tests for the same period. Statewide for the same period, Pickaway County reported the highest share (81.4%) and Cuyahoga County the lowest (21.7%).
Below the action level, 957 tests (40.7%) came in under 2 pCi/L, against 23.1% statewide, and 754 tests (32.1%) fell between 2 and 4, against 24.6% statewide. CDC's ten-year totals for Lake County went from 1,465 tests (2005 to 2014) to 2,349 (2008 to 2017), the share going from 28.9% to 27.2%.
EPA's 1993 zone map puts Lake County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Next door, the shares run from 21.7% in Cuyahoga County to 34.4% in Ashtabula County, with Geauga County and Cuyahoga County below Lake County.
CDC also counts 139 tests taken after mitigation in Lake County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Lake County, Geology
The ground under Lake County
PredictedUSGS's geologic map puts all of Lake County's mapped land in one class: moderate radon potential. The map puts 57.6% of Lake County in the area it calls Lake Plains and 42.0% in Glaciated Plateau. USGS gives the first a radon index of 10 and the second 11, both in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Lake Plains | Glacial lake deposits, Devonian shale and limestone. | Moderate | 10 | 57.6% |
| Glaciated Plateau | Devonian, Mississippian and Permian carbonates and shales. | Moderate | 11 | 42.0% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Lake County beside the ground around it
Across Ohio 62.8% of the land is rated high; none of Lake County's is. Every one of the 3 counties that border it has more moderate-potential ground, Geauga County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Lake County, Local resources
Radon testing and mitigation in Lake County
Listed radon businesses with an address in Lake County:
- Radon Education and Licensing ProgramRadon Education and Licensing Program, run by Ohio Department of Health, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Ohio.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Ohio homeowners.
- Compare kits
- Professionals in Ohio479 professionals are listed in Ohio.
Listed radon professionals by town: Mentor, Eastlake, Willoughby Hills, Kirtland, Madison
What Ohio's program says
- Phone
- 614-728-0272
- indoor.radon@odh.ohio.gov
- Licensing of radon professionals
This program licenses companies and persons directly involved with the radon testing and mitigation industry.
What it means
Lake County, Questions
Questions about radon in Lake County
Are radon levels high in Lake County?
Over the 2008 to 2017 laboratory totals, 27.2% of the radon tests reported to CDC for Lake County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.4 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 75 reported a higher share; pooled, the state comes to 52.3%.
Which counties border Lake County?
Lake County borders 3 counties: Geauga County, Ashtabula County and Cuyahoga County.
Products
Lake County, Products
Testing a home in Lake County
In Lake County, 27.2% of 2,349 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 52.3% pooled across Ohio. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Lake County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorPYZYCKYH
RD17 plug-in radon detector with a rechargeable battery and color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Lake County, Bordering counties
Counties bordering Lake County
Calculated by Radon411- Radon levels in Ashtabula CountyEPA zone 2
34.4%at or above 4 pCi/L
Median 2.5 pCi/L · 314 tests · 7.2 points above Lake County
- Radon levels in Geauga CountyEPA zone 2
23.4%at or above 4 pCi/L
Median 2.4 pCi/L · 1,469 tests · 3.8 points below Lake County
- Radon levels in Cuyahoga CountyEPA zone 2
21.7%at or above 4 pCi/L
Median 2.0 pCi/L · 10,092 tests · 5.5 points below Lake County
Lake County, Cities and towns
Cities and towns in Lake County
Lake County's population has barely moved since 2020: 232,217 residents on July 1, 2025 against 232,517 then, by the Census Bureau's estimates. Packed into its land, that is 1,013 people per square mile. Its largest town, Mentor, has 47,010 residents, 20.2% of the total. Together its 18 incorporated places hold 73.9% of those residents; the other 26.1% live outside any of them. CDC's 2,349 reported tests for 2008 to 2017 work out to 10.1 per 1,000 residents (2025 estimate), close to Ohio's 8.3.
From Mentor to Lakeline, CDC publishes no figure by town: each reads Lake County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Mentor | 47,010 | −0.8% | 20.2% |
| Willoughby | 24,234 | +1.4% | 10.4% |
| Painesville | 20,660 | +1.8% | 8.9% |
| Eastlake | 17,357 | −1.6% | 7.5% |
| Willowick | 14,178 | −0.4% | 6.1% |
| Wickliffe | 12,649 | −0.3% | 5.4% |
| Willoughby Hills | 9,992 | −0.3% | 4.3% |
| Mentor-on-the-Lake | 7,120 | −0.3% | 3.1% |
| Kirtland | 6,925 | −0.1% | 3.0% |
| Madison | 3,427 | −0.3% | 1.5% |
| Fairport Harbor | 3,087 | −0.6% | 1.3% |
| Perry | 1,599 | −0.3% | 0.7% |
- North Perry
- Kirtland Hills
- Timberlake
- Waite Hill
- Grand River
- Lakeline
18 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Lake County, Homes
Homes in Lake County
Of Lake County's 105,877 homes, 72% are detached houses, against 69% across Ohio; 15% are in buildings of five or more homes. Half of its homes were built before 1972, close to Ohio's 1970: 33% date from before 1960 and 14% from 2000 or later. Owners live in 75% of the occupied homes (Ohio: 67%), so for most households a test and a fix are their own to order.
| Homes | Lake County | Ohio |
|---|---|---|
| Housing units | 105,877 | 5,271,573 |
| Detached houses | 72% | 69% |
| In buildings of 5 or more | 15% | 15% |
| Mobile homes | 2% | 4% |
| Built before 1960 | 33% | 38% |
| Built since 2000 | 14% | 16% |
| Middle year built | 1972 | 1970 |
| Owner-occupied | 75% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.