Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Macon County, Missouri
EPA puts Macon County in Zone 2, its middle radon zone, and only 3 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
19.4%
11.2 pts below MO
- Macon
- 19.4%
- Missouri
- 30.6%
36 tests, 2008 to 2017
Median result
1.7pCi/L
Below action level
- Macon
- 1.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
36
65th of 72 by tests
- Macon
- 36
- 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
60 of 72
Lowest quarter
- Macon
- 19.4%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for Macon County
Starts at Macon County's median, 1.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.7 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Macon County's median reported result, 2008 to 2017.
The data
Macon County, At a glance
Macon County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Macon 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 Macon County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 66.7% |
| 2015 | 22.2% |
| 2016 | 0.0% |
| 2018 | 50.0% |
| 2019 | 0.0% |
| 2022 | 14.3% |
| 2023 | 33.3% |
2023: 33.3%. Across these years the share ran from 0.0% to 66.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Macon 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).
Macon County, Compared
Macon County radon figures, compared
Calculated by Radon411Macon County's 36 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.7 pCi/L and a maximum of 15.7 pCi/L, and 19.4% reached 4 pCi/L. Missouri as a whole (115 Missouri counties, pooled) comes to 30.6%: 11.2 points higher than here.
The newest figure, in 2023, counts only 3 tests (33.3% at or above 4 pCi/L), too few to compare, so this reading uses the 36-test figure.
Among its state's counties it ranks 60th of 72 Missouri counties with 30 or more tests for the same period. Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%).
Below the action level, 20 tests (55.6%) came in under 2 pCi/L, against 41.2% statewide, and 9 tests (25.0%) fell between 2 and 4, against 28.1% statewide. The busiest year on file was 2015, with 9 tests reported; the quietest, 2019, had 1.
EPA's 1993 zone map puts Macon 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 17.2% in Randolph County to 27.2% in Adair County, with Linn County and Randolph County below Macon County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Macon County, Geology
The ground under Macon County
PredictedUSGS's geologic map puts all of Macon County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Dissected Till Plains, to which USGS gives a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Dissected Till Plains | Till-covered Pennsylvanian sandstone, shale, and limestone. | Moderate | 11 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Macon County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Macon County's is. Of the 7 counties that border it, none has as large a share of moderate-potential ground; Adair County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Macon County, Local resources
Radon testing and mitigation in Macon 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
Macon County, Questions
Questions about radon in Macon County
Are radon levels high in Macon County?
In 2023, 33.3% of the radon tests reported to CDC for Macon County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.4 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 59 reported a higher share; pooled, the state comes to 30.6%.
Which counties border Macon County?
Macon County borders 7 counties: Adair County, Randolph County, Shelby County, Linn County, Knox County, Chariton County and Monroe County.
Products
Macon County, Products
Testing a home in Macon County
In Macon County, 19.4% of 36 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 Macon County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
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
MonitorAEGTEST
HOUND-1085 palm-sized rechargeable radon detector
- 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
Macon County, Bordering counties
Counties bordering Macon County
Calculated by Radon411- Radon levels in Adair CountyEPA zone 2
27.2%at or above 4 pCi/L
Median 1.8 pCi/L · 92 tests · 7.8 points above Macon County
- Radon levels in Shelby CountyEPA zone 2
24.1%at or above 4 pCi/L
Median 1.7 pCi/L · 29 tests · 4.7 points above Macon County
- Radon levels in Monroe CountyEPA zone 2
23.3%at or above 4 pCi/L
Median 1.5 pCi/L · 30 tests · 3.9 points above Macon County
- Radon levels in Linn CountyEPA zone 2
18.9%at or above 4 pCi/L
Median 1.8 pCi/L · 37 tests · 0.5 points below Macon County
- Radon levels in Randolph CountyEPA zone 2
17.2%at or above 4 pCi/L
Median 1.8 pCi/L · 58 tests · 2.2 points below Macon County
- Radon levels in Chariton CountyEPA zone 2
13.3%at or above 4 pCi/L
Median 1.7 pCi/L · 15 tests · 6.1 points below Macon County
- Radon levels in Knox CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 1.9 pCi/L · 10 tests · 19.4 points below Macon County
Macon County, Cities and towns
Cities and towns in Macon County
Macon County's population has barely moved since 2020: 15,190 residents on July 1, 2025 against 15,199 then, by the Census Bureau's estimates. That works out to 19 people per square mile of land. Its largest town, Macon, has 5,532 residents, 36.4% of the total. Together its 9 incorporated places hold 54.6% of those residents; the other 45.4% live outside any of them. Reported testing is thin here: 36 tests over 2008 to 2017, or 2.4 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Macon to South Gifford, CDC publishes no figure by town: each reads Macon County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Macon | 5,532 | +1.6% | 36.4% |
| La Plata | 1,251 | +0.1% | 8.2% |
| Bevier | 625 | −1.3% | 4.1% |
| Atlanta | 370 | −1.6% | 2.4% |
| Callao | 245 | −2.0% | 1.6% |
| New Cambria | 150 | −2.0% | 1.0% |
| Elmer | 51 | −1.9% | 0.3% |
| Ethel | 47 | Level | 0.3% |
| South Gifford | 23 | Level | 0.2% |
9 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).
Macon County, Homes
Homes in Macon County
Macon County is a place of houses on their own lots: 78% of its 7,425 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1972, close to Missouri's 1978: 35% date from before 1960 and 19% from 2000 or later. Owners live in 76% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.
| Homes | Macon County | Missouri |
|---|---|---|
| Housing units | 7,425 | 2,809,501 |
| Detached houses | 78% | 70% |
| In buildings of 5 or more | 2% | 13% |
| Mobile homes | 10% | 5% |
| Built before 1960 | 35% | 28% |
| Built since 2000 | 19% | 21% |
| Middle year built | 1972 | 1978 |
| Owner-occupied | 76% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.