Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Buchanan County, Missouri
EPA puts Buchanan County in Zone 1, its highest radon zone, and only 7 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
52.9%
22.3 pts above MO
- Buchanan
- 52.9%
- Missouri
- 30.6%
575 tests, 2008 to 2017
Median result
4.2pCi/L
Action level reached
- Buchanan
- 4.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
575
14th of 72 by tests
- Buchanan
- 575
- St. Louis
- 17,747
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 Missouri
3 of 72
Top quarter
- Buchanan
- 52.9%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for Buchanan County
Starts at Buchanan County's median, 4.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.2 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Buchanan County's median reported result, 2008 to 2017.
The data
Buchanan County, At a glance
Buchanan County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Buchanan County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Buchanan County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 61.1% |
| 2015 | 60.0% |
| 2016 | 57.1% |
| 2017 | 46.2% |
| 2018 | 60.0% |
| 2019 | 42.9% |
| 2020 | 66.7% |
| 2021 | 57.1% |
| 2022 | 60.9% |
| 2023 | 28.6% |
2023: 28.6%. Across these years the share ran from 28.6% to 66.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 7 tests were reported to CDC for Buchanan 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).
Buchanan County, Compared
Buchanan County radon figures, compared
Calculated by Radon411More than half: 52.9% of the 575 radon tests reported to CDC for Buchanan County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 3rd of 72 Missouri counties with 30 or more tests for the same period. That is 22.3 points above the 30.6% pooled from 115 Missouri counties.
The newest figure, in 2023, counts only 7 tests (28.6% at or above 4 pCi/L), too few to compare, so this reading uses the 575-test figure.
The median result, 4.2 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 39.4 pCi/L. The rest split 20.5% under 2 pCi/L and 26.6% from 2 to 4 (Missouri: 41.2% and 28.1%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 52.9% share point the same way here.
1 of its 4 bordering counties with figures ran higher, led by Andrew County at 60.8%; DeKalb County reported 24.2%. Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%).
The busiest year on file was 2014, with 167 tests reported; the quietest, 2020, had 6.
Nationally, every county with a figure for the same period pools to 35.7%; Buchanan County sits 17.2 points above it. CDC also counts 13 tests taken after mitigation in Buchanan 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.
Buchanan County, Geology
The ground under Buchanan County
PredictedUSGS's geologic map puts all of Buchanan County's mapped land in one class: high radon potential. All of it lies in the area the map calls Northwestern Dissected Till Plains, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Northwestern Dissected Till Plains | Pennsylvanian shales covered by thick loess. | High | 13 | 99.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Buchanan County beside the ground around it
Buchanan County has more high-potential ground than Missouri as a whole: 100% of its land against 8.2%. Of the 6 counties that border it, none has as large a share of high-potential ground; Doniphan County, KS comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Buchanan County, Local resources
Radon testing and mitigation in Buchanan 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
Buchanan County, Questions
Questions about radon in Buchanan County
Are radon levels high in Buchanan County?
In 2023, 28.6% of the radon tests reported to CDC for Buchanan County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 2 reported a higher share; pooled, the state comes to 30.6%.
Which counties border Buchanan County?
Buchanan County borders 6 counties: Doniphan County, KS, Clinton County, MO, Andrew County, MO, Platte County, MO, DeKalb County, MO and Atchison County, KS.
Products
Buchanan County, Products
Testing a home in Buchanan County
In Buchanan County, 52.9% of 575 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.6% pooled across Missouri. In Zone 1 the year-round level in Buchanan 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
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Buchanan County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Buchanan County
Explore
Buchanan County, Bordering counties
Counties bordering Buchanan County
Calculated by Radon411- Radon levels in Andrew County, MOEPA zone 1
60.8%at or above 4 pCi/L
Median 4.9 pCi/L · 158 tests · 7.9 points above Buchanan County
- Radon levels in Clinton County, MOEPA zone 1
38.1%at or above 4 pCi/L
Median 2.8 pCi/L · 105 tests · 14.8 points below Buchanan County
- Radon levels in Platte County, MOEPA zone 1
37.8%at or above 4 pCi/L
Median 3.0 pCi/L · 1,789 tests · 15.1 points below Buchanan County
- Radon levels in DeKalb County, MOEPA zone 2
24.2%at or above 4 pCi/L
Median 2.3 pCi/L · 33 tests · 28.7 points below Buchanan County
- Radon levels in Doniphan County, KSEPA zone 2
No CDC figure for 2008 to 2017; its page reads it against its own neighbours.
- Radon levels in Atchison County, KSEPA zone 1
No CDC figure for 2008 to 2017; its page reads it against its own neighbours.
Buchanan County, Cities and towns
Cities and towns in Buchanan County
About 83,540 people live in Buchanan County by the Census Bureau's estimate for July 1, 2025, 931 fewer than in 2020 (−1.1%). That works out to 205 people per square mile of land. St. Joseph alone is home to 71,001 of them, 85.0% of the total. CDC's 575 reported tests for 2008 to 2017 work out to 6.9 per 1,000 residents (2025 estimate), close to Missouri's 9.3.
From St. Joseph to Lewis and Clark Village, CDC publishes no figure by town: each reads Buchanan County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| St. Joseph | 71,001 | −1.6% | 85.0% |
| Gowerextends beyond Buchanan County | 1,514 | −1.1% | Counted whole |
| Agency | 651 | −2.1% | 0.8% |
| Dearbornextends beyond Buchanan County | 518 | +6.8% | Counted whole |
| De Kalb | 243 | +4.7% | 0.3% |
| Easton | 226 | +0.4% | 0.3% |
| Rushville | 221 | −2.2% | 0.3% |
| Lewis and Clark Village | 92 | −2.1% | 0.1% |
8 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 Buchanan County is counted whole, so it has no share.
Buchanan County, Homes
Homes in Buchanan County
Of Buchanan County's 38,415 homes, 74% are detached houses, against 70% across Missouri; 13% are in buildings of five or more homes. The homes are older than Missouri's as a whole: half were built before 1964 (1978 for Missouri), and 45% date from before 1960. 65% 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 | Buchanan County | Missouri |
|---|---|---|
| Housing units | 38,415 | 2,809,501 |
| Detached houses | 74% | 70% |
| In buildings of 5 or more | 13% | 13% |
| Mobile homes | 4% | 5% |
| Built before 1960 | 45% | 28% |
| Built since 2000 | 12% | 21% |
| Middle year built | 1964 | 1978 |
| Owner-occupied | 65% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.