Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Bartholomew County, Indiana
EPA puts Bartholomew County in Zone 1, its highest radon zone, and high results are common there: 48.7% of the 1,707 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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
48.7%
9.8 pts above IN
- Bartholomew
- 48.7%
- Indiana
- 38.9%
1,707 tests, 2008 to 2017
Median result
3.9pCi/L
Below action level
- Bartholomew
- 3.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,707
7th of 69 by tests
- Bartholomew
- 1,707
- St. Joseph
- 7,346
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Indiana
21 of 69
Middle half
- Bartholomew
- 48.7%
- Miami
- 63.3%
By share, of 69 with 30+ tests
Read a result for Bartholomew County
Starts at Bartholomew County's median, 3.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.9 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. Bartholomew County's median reported result, 2008 to 2017.
The data
Bartholomew County, At a glance
Bartholomew County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Bartholomew County in
USGS geologic potential: High across 71% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Bartholomew County, 2008 to 2017, laboratory
Under 2 pCi/L: 27%2 to 4 pCi/L: 24%4 pCi/L and above: 49%
Of 1,707 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 465 | 27.2% |
| 2 to 4 pCi/L | 410 | 24.0% |
| 4 pCi/L and above | 832 | 48.7% |
What these figures count
These are the 1,707 tests reported to CDC for Bartholomew 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).
Bartholomew County, Compared
Bartholomew County radon figures, compared
Calculated by Radon411In Bartholomew County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (832 of 1,707) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 13.0 points higher. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Bartholomew County runs 9.8 points above its state.
Of 6 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 5 a smaller one; the spread is 25.9% (Brown County) to 50.0% (Shelby County). By share, Bartholomew County is 21st of 69 Indiana counties with 30 or more tests for the same period.
Half the tests came in under 3.9 pCi/L and half over it; the single highest reached 86.7 pCi/L. Below the action level, 465 tests (27.2%) came in under 2 pCi/L, against 32.8% statewide, and 410 tests (24.0%) fell between 2 and 4, against 28.3% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 48.7% share point the same way here. USGS geology rates 71% of the county's land high radon potential. CDC also counts 111 tests taken after mitigation in Bartholomew County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Bartholomew County went from 1,453 tests (2005 to 2014) to 1,707 (2008 to 2017), the share going from 51.0% to 48.7%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Bartholomew County, Geology
The ground under Bartholomew County
PredictedUSGS's geologic map splits Bartholomew County: 70.7% of its land is high radon potential and 29.3% moderate. The map puts 55.9% of Bartholomew County in the area it calls Huron-Erie Lobe and 29.3% in Crawford Upland/Mitchell Plain/Norman Upland, with one smaller area beside them. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Huron-Erie Lobe | Calcareous clayey and loamy glacial deposits derived from marine carbonate and clastic sedimentary rocks. | High | 13 | 55.9% |
| Crawford Upland/Mitchell Plain/Norman Upland | Unglaciated, underlain by karsted Mississippian carbonate rocks. | Moderate | 11 | 29.3% |
| New Albany Shale | New Albany black shale. | High | 12 | 14.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Bartholomew County beside the ground around it
Bartholomew County has more high-potential ground than Indiana as a whole: 70.7% of its land against 56.6%. Of the 6 counties that border it, 2 have more high-potential ground, Shelby County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Bartholomew County, Local resources
Radon testing and mitigation in Bartholomew County
- Indiana's radon programIndiana Department of HealthIndiana's radon program licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Indiana.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
To purchase a low-cost radon short term or long term test kit, please visit the American Lung Association
- Compare kits
- Professionals in Indiana17 professionals are listed in Indiana.
What Indiana's program says
- Phone
- 1-800-272-9723
- Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.
What it means
Bartholomew County, Questions
Questions about radon in Bartholomew County
Are radon levels high in Bartholomew County?
Over the 2008 to 2017 laboratory totals, 48.7% of the radon tests reported to CDC for Bartholomew County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.9 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 20 reported a higher share; pooled, the state comes to 38.9%.
Which counties border Bartholomew County?
Bartholomew County borders 6 counties: Brown County, Decatur County, Shelby County, Johnson County, Jennings County and Jackson County.
Products
Bartholomew County, Products
Testing a home in Bartholomew County
In Bartholomew County, 48.7% of 1,707 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 38.9% pooled across Indiana. In Zone 1 the year-round level in Bartholomew County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
RadonPro Wi-Fi radon monitor with a built-in Geiger counter
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Bartholomew County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Bartholomew County
Explore
Bartholomew County, Bordering counties
Counties bordering Bartholomew County
Calculated by Radon411- Radon levels in Shelby CountyEPA zone 1
50.0%at or above 4 pCi/L
Median 4.0 pCi/L · 84 tests · 1.3 points above Bartholomew County
- Radon levels in Johnson CountyEPA zone 1
39.4%at or above 4 pCi/L
Median 2.9 pCi/L · 556 tests · 9.3 points below Bartholomew County
- Radon levels in Jennings CountyEPA zone 1
35.1%at or above 4 pCi/L
Median 2.8 pCi/L · 57 tests · 13.6 points below Bartholomew County
- Radon levels in Decatur CountyEPA zone 1
33.3%at or above 4 pCi/L
Median 2.8 pCi/L · 63 tests · 15.4 points below Bartholomew County
- Radon levels in Jackson CountyEPA zone 2
27.3%at or above 4 pCi/L
Median 2.8 pCi/L · 88 tests · 21.4 points below Bartholomew County
- Radon levels in Brown CountyEPA zone 2
25.9%at or above 4 pCi/L
Median 2.8 pCi/L · 112 tests · 22.8 points below Bartholomew County
Bartholomew County, Cities and towns
Cities and towns in Bartholomew County
The Census Bureau estimates 85,729 residents in Bartholomew County for July 1, 2025, 3,516 more than in 2020 (+4.3%). That works out to 211 people per square mile of land. Columbus alone is home to 52,655 of them, 61.4% of the total. Testing is reported here more often than across the state: CDC's 1,707 reported tests for 2008 to 2017 come to 19.9 for every 1,000 residents (2025 estimate), against 6.2 for Indiana.
From Columbus to Jonesville, CDC publishes no figure by town: each reads Bartholomew County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Columbus | 52,655 | +4.2% | 61.4% |
| Edinburghextends beyond Bartholomew County | 4,575 | +3.1% | Counted whole |
| Hope | 2,181 | +4.0% | 2.5% |
| Elizabethtown | 419 | +3.2% | 0.5% |
| Hartsville | 326 | +3.8% | 0.4% |
| Clifford | 212 | +3.9% | 0.2% |
| Jonesville | 182 | +2.8% | 0.2% |
7 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). A place that extends beyond Bartholomew County is counted whole, so it has no share.
Bartholomew County, Homes
Homes in Bartholomew County
Of Bartholomew County's 35,517 homes, 75% are detached houses, against 73% across Indiana; 15% are in buildings of five or more homes. Half of its homes were built before 1978, close to Indiana's 1976: 25% date from before 1960 and 24% from 2000 or later. 70% of occupied homes are lived in by their owner (Indiana: 70%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Bartholomew County | Indiana |
|---|---|---|
| Housing units | 35,517 | 2,953,344 |
| Detached houses | 75% | 73% |
| In buildings of 5 or more | 15% | 13% |
| Mobile homes | 5% | 4% |
| Built before 1960 | 25% | 32% |
| Built since 2000 | 24% | 21% |
| Middle year built | 1978 | 1976 |
| Owner-occupied | 70% | 70% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.