Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Cape Girardeau County, Missouri
EPA puts Cape Girardeau County in Zone 2, its middle radon zone, and only 11 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
35.2%
4.6 pts above MO
- Cape Girardeau
- 35.2%
- Missouri
- 30.6%
253 tests, 2008 to 2017
Median result
2.8pCi/L
Below action level
- Cape Girardeau
- 2.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
253
20th of 72 by tests
- Cape Girardeau
- 253
- St. Louis
- 17,747
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 Missouri
27 of 72
Middle half
- Cape Girardeau
- 35.2%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for Cape Girardeau County
Starts at Cape Girardeau County's median, 2.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.8 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. Cape Girardeau County's median reported result, 2008 to 2017.
The data
Cape Girardeau County, At a glance
Cape Girardeau County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Cape Girardeau County is a
USGS geologic potential: Moderate across 83% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Cape Girardeau County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 30.8% |
| 2015 | 23.1% |
| 2016 | 25.0% |
| 2017 | 41.2% |
| 2018 | 57.1% |
| 2019 | 25.0% |
| 2020 | 0.0% |
| 2021 | 20.0% |
| 2022 | 43.5% |
| 2023 | 54.5% |
2023: 54.5%. Across these years the share ran from 0.0% to 57.1%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 11 tests were reported to CDC for Cape Girardeau County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Cape Girardeau County, Compared
Cape Girardeau County radon figures, compared
Calculated by Radon411In Cape Girardeau County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (89 of 253) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.5 points lower. Across 115 Missouri counties pooled together, 30.6% of tests reached that level, so Cape Girardeau County runs 4.6 points above its state.
The newest figure, in 2023, counts only 11 tests (54.5% at or above 4 pCi/L), too few to compare, so this reading uses the 253-test figure.
Of 3 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 25.3% (Union County, IL) to 37.8% (Perry County). By share, Cape Girardeau County is 27th of 72 Missouri counties with 30 or more tests for the same period.
Half the tests came in under 2.8 pCi/L and half over it; the single highest reached 45.1 pCi/L. Below the action level, 100 tests (39.5%) came in under 2 pCi/L, against 41.2% statewide, and 64 tests (25.3%) fell between 2 and 4, against 28.1% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 35.2% share point the same way here. USGS geology rates 83% of the county's land moderate radon potential. CDC also counts 14 tests taken after mitigation in Cape Girardeau County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2022, with 23 tests reported; the quietest, 2019, had 4.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cape Girardeau County, Geology
The ground under Cape Girardeau County
PredictedMost of the ground under Cape Girardeau County is one class on USGS's geologic map: 82.9% of its land is moderate radon potential, with 17.1% low. The map puts 82.6% of Cape Girardeau County in the area it calls Salem Plateau and 17.1% in Coastal Plains Province. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 5, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Salem Plateau | Ordovician dolomite, sandstone, limestone, and shale. | Moderate | 11 | 82.6% |
| Coastal Plains Province | Tertiary-Quaternary sandstone, shale, and alluvium. | Low | 5 | 17.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cape Girardeau County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Cape Girardeau County's is. Of the 6 counties that border it, 3 have more moderate-potential ground, Perry County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Cape Girardeau County, Local resources
Radon testing and mitigation in Cape Girardeau County
- Missouri Radon ProgramMissouri Radon Program, run by Missouri Department of Health and Senior Services, offers free or discounted test kits, and answers questions about testing and mitigation in Missouri.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Missouri residents (limit one per household).
- Compare kits
- Professionals in Missouri27 professionals are listed in Missouri.
What Missouri's program says
- Phone
- 573-751-6102
- radon@health.mo.gov
What it means
Cape Girardeau County, Questions
Questions about radon in Cape Girardeau County
Are radon levels high in Cape Girardeau County?
In 2023, 54.5% of the radon tests reported to CDC for Cape Girardeau County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.0 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 26 reported a higher share; pooled, the state comes to 30.6%.
Which counties border Cape Girardeau County?
Cape Girardeau County borders 6 counties: Bollinger County, MO, Scott County, MO, Alexander County, IL, Union County, IL, Perry County, MO and Stoddard County, MO.
Products
Cape Girardeau County, Products
Testing a home in Cape Girardeau County
In Cape Girardeau County, 35.2% of 253 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.6% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Cape Girardeau 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
MonitorX-Sense
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Best radon monitors for Cape Girardeau County homes, compared
Explore
Cape Girardeau County, Bordering counties
Counties bordering Cape Girardeau County
Calculated by Radon411- Radon levels in Perry County, MOEPA zone 2
37.8%at or above 4 pCi/L
Median 3.2 pCi/L · 82 tests · 2.6 points above Cape Girardeau County
- Radon levels in Scott County, MOEPA zone 3
29.4%at or above 4 pCi/L
Median 2.2 pCi/L · 51 tests · 5.8 points below Cape Girardeau County
- Radon levels in Union County, ILEPA zone 2
25.3%at or above 4 pCi/L
Median 1.9 pCi/L · 87 tests · 9.9 points below Cape Girardeau County
- Radon levels in Alexander County, ILEPA zone 3
22.2%at or above 4 pCi/L
Median 2.4 pCi/L · 9 tests · 13.0 points below Cape Girardeau County
- Radon levels in Stoddard County, MOEPA zone 3
12.0%at or above 4 pCi/L
Median 1.1 pCi/L · 25 tests · 23.2 points below Cape Girardeau County
- Radon levels in Bollinger County, MOEPA zone 2
0.0%at or above 4 pCi/L
Median 1.4 pCi/L · 6 tests · 35.2 points below Cape Girardeau County
Cape Girardeau County, Cities and towns
Cities and towns in Cape Girardeau County
The Census Bureau estimates 83,999 residents in Cape Girardeau County for July 1, 2025, 2,188 more than in 2020 (+2.7%). That works out to 145 people per square mile of land. Cape Girardeau, the largest place on its list (40,977 residents in all), extends beyond Cape Girardeau County, so no share of the total is worked out for it. Reported testing is thin here: 253 tests over 2008 to 2017, or 3.0 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Cape Girardeau to Old Appleton, CDC publishes no figure by town: each reads Cape Girardeau County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Cape Girardeauextends beyond Cape Girardeau County | 40,977 | +3.0% | Counted whole |
| Jackson | 16,033 | +3.8% | 19.1% |
| Scott Cityextends beyond Cape Girardeau County | 4,593 | +6.0% | Counted whole |
| Gordonville | 626 | +1.0% | 0.7% |
| Delta | 382 | +1.9% | 0.5% |
| Oak Ridge | 239 | +1.3% | 0.3% |
| Pocahontas | 97 | +4.3% | 0.1% |
| Allenville | 94 | +1.1% | 0.1% |
| Whitewater | 86 | +1.2% | 0.1% |
| Old Appleton | 75 | +1.4% | Under 0.1% |
10 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 Cape Girardeau County is counted whole, so it has no share.
Cape Girardeau County, Homes
Homes in Cape Girardeau County
Of Cape Girardeau County's 35,892 homes, 71% are detached houses, against 70% across Missouri; 13% are in buildings of five or more homes. Half of its homes were built before 1982, close to Missouri's 1978: 20% date from before 1960 and 23% from 2000 or later. 66% of occupied homes are lived in by their owner (Missouri: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Cape Girardeau County | Missouri |
|---|---|---|
| Housing units | 35,892 | 2,809,501 |
| Detached houses | 71% | 70% |
| In buildings of 5 or more | 13% | 13% |
| Mobile homes | 5% | 5% |
| Built before 1960 | 20% | 28% |
| Built since 2000 | 23% | 21% |
| Middle year built | 1982 | 1978 |
| Owner-occupied | 66% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.