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Radon Levels in Columbia County, Florida

EPA puts Columbia 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

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  • Share at 4+ pCi/L

    6.7%

    16.0 pts below FL

    Columbia
    6.7%
    Florida
    22.7%

    30 tests, 2008 to 2017

  • Median result

    1.0pCi/L

    Below action level

    Columbia
    1.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    30

    40th of 40 by tests

    Columbia
    30
    Collier
    20,308

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Florida

    20 of 40

    Middle half

    Columbia
    6.7%
    Marion
    42.9%

    By share, of 40 with 30+ tests

Read a result for Columbia County

Starts at Columbia County's median, 1.0 pCi/L

1.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 1.0 pCi/L

Below 2 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Columbia County's median reported result, 2008 to 2017.

Interpret this reading

The data

Columbia County, At a glance

Columbia County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Columbia County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Low across 77% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Columbia County, 2023

Share of reported tests at or above 4 pCi/L, by year, Columbia County
Share of reported tests at or above 4 pCi/L, by year, Columbia County
YearShare of reported tests at or above 4 pCi/L
20150.0%
20160.0%
201733.3%
20180.0%
20190.0%
20200.0%
20210.0%
20220.0%
20230.0%

2023: 0.0%. Across these years the share ran from 0.0% to 33.3%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 3 tests were reported to CDC for Columbia 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).

How to read these figures

Columbia County, Compared

Columbia County radon figures, compared

Calculated by Radon411

Columbia County reports fewer high tests than Florida overall. 6.7% of its 30 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 16.0 points below the 22.7% pooled from 62 Florida counties.

The newest figure, in 2023, counts only 3 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 30-test figure.

Ordered from highest share down, it comes 20th of 40 Florida counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Columbia County sits 29.0 points below it.

Alachua County, the one bordering county with a figure for the same period, reported 35.2%. The reported tests do not follow EPA's Zone 2 label for Columbia County (predicted average between 2 and 4 pCi/L): 6.7% of them reached 4 pCi/L, fewer than that label suggests.

Half the tests came in under 1.0 pCi/L and half over it; the single highest reached 7.2 pCi/L. The rest split 76.7% under 2 pCi/L and 16.7% from 2 to 4 (Florida: 45.5% and 31.8%).

The busiest year on file was 2015, with 18 tests reported; the quietest, 2020, had 1.

Columbia County against Florida, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Columbia County
Columbia County306.7%1.0 pCi/LThis county
Florida, pooled62 counties, pooled53,79422.7%Not pooled+16.0 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+29.0 points
Marion Countyhighest in the state90342.9%3.3 pCi/L+36.2 points
St. Lucie Countylowest in the state460.0%0.1 pCi/L−6.7 points
Union County, FLborders it366.7%8.5 pCi/L+60.0 points
Alachua County, FLborders it2,16235.2%2.9 pCi/L+28.5 points
Suwannee County, FLborders it210.0%1.1 pCi/L−6.7 points
Clinch County, GAborders it10.0%0.7 pCi/L−6.7 points
Gilchrist County, FLborders it100.0%0.7 pCi/L−6.7 points
Baker County, FLborders it10.0%1.0 pCi/L−6.7 points
Where Columbia County's reported results fell, 2008 to 2017, laboratory, beside Florida and the United States
ResultColumbia County testsColumbia County shareFlorida shareU.S. shareAgainst Florida
Under 2 pCi/L2376.7%45.5%39.6%+31.2 points
2 to 4 pCi/L516.7%31.8%24.7%−15.1 points
4 pCi/L and above26.7%22.7%35.7%−16.0 points
Columbia County ranked among the 40 Florida counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Pasco County15 of 4015410.4%0.8 pCi/L
Citrus County16 of 401629.9%1.6 pCi/L
Wakulla County17 of 40798.9%1.5 pCi/L
Palm Beach County18 of 409947.8%1.0 pCi/L
Broward County19 of 406567.5%1.1 pCi/L
Columbia County20 of 40306.7%1.0 pCi/L
Gadsden County21 of 401436.3%1.2 pCi/L
Jefferson County22 of 40496.1%1.4 pCi/L
St. Johns County23 of 40506.0%0.7 pCi/L
Jackson County24 of 40676.0%0.7 pCi/L
DeSoto County25 of 40454.4%0.6 pCi/L
Columbia County radon tests by year, against Florida's pooled share
YearTestsAt or above 4 pCi/LMedianHighestFlorida, pooledChange from the row before
202330.0%1.4 pCi/L3.2 pCi/L18.5%Level
2022120.0%2.4 pCi/L3.8 pCi/L22.8%Level
202140.0%1.1 pCi/L1.7 pCi/L15.4%Level
202010.0%2.2 pCi/L2.2 pCi/L23.2%Level
201930.0%2.5 pCi/L3.7 pCi/L29.6%Level
201860.0%1.4 pCi/L2.9 pCi/L23.5%−33.3 points
2017333.3%3.7 pCi/L4.8 pCi/L21.7%+33.3 points
201610.0%2.6 pCi/L2.6 pCi/L24.3%Level
2015180.0%1.6 pCi/L3.0 pCi/L26.5%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Columbia County, Geology

The ground under Columbia County

Predicted

Most of the ground under Columbia County is one class on USGS's geologic map: 77.3% of its land is low radon potential, with 22.7% moderate. The map puts 69.8% of Columbia County in the area it calls Gulf/Atlantic Lowland and Central Highland and 22.7% in Highland Anomalous areas, with one smaller area beside them. USGS gives the first a radon index of 6, in the low band (5 to 8), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Columbia County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Gulf/Atlantic Lowland and Central Highlandsand, silt, clay, gravelLow669.8%
Highland Anomalous areasPhosphate deposits.Moderate1122.7%
Northern HighlandSand, silt, clay, gravelLow67.4%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Columbia County beside the ground around it

Columbia County has more moderate-potential ground than Florida as a whole: 22.7% of its land against 7.1%. Of the 8 counties that border it, 2 have more moderate-potential ground, Union County the most at 63.8%.

Share of land by USGS radon potential: Columbia County, the 8 counties bordering it and Florida
AreaEPA zoneLow potentialModerate potentialHigh potential
Columbia CountyZone 277.3%22.7%None
Union CountyZone 236.2%63.8%None
Baker CountyZone 394.2%5.8%None
Suwannee CountyZone 3100%NoneNone
Hamilton CountyZone 3100%NoneNone
Gilchrist CountyZone 396.2%3.8%None
Echols County, GAZone 3100%NoneNone
Alachua CountyZone 252.7%47.3%None
Clinch County, GAZone 3100%NoneNone
Florida67 counties, pooled by land areaVaries89.7%7.1%None

The map rates the ground, not the air in any home.

Local help

Columbia County, Local resources

Radon testing and mitigation in Columbia County

What Florida's program says
Phone
850-245-4288
Email
PHtoxicology@FLhealth.gov
Licensing of radon professionals
Florida Statutes require the certification of businesses and individuals providing radon services or any other radon related activity.

What it means

Columbia County, Questions

Questions about radon in Columbia County

Are radon levels high in Columbia County?

In 2023, 0.0% of the radon tests reported to CDC for Columbia County, Florida were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.4 pCi/L. Of 40 Florida counties with 30 or more tests for the same period, 19 reported a higher share; pooled, the state comes to 22.7%.

Which counties border Columbia County?

Columbia County borders 8 counties: Union County, FL, Baker County, FL, Suwannee County, FL, Hamilton County, FL, Gilchrist County, FL, Echols County, GA, Alachua County, FL and Clinch County, GA.

Products

Columbia County, Products

Testing a home in Columbia County

In Columbia County, 6.7% of 30 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.7% pooled across Florida. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Columbia County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Columbia County homes, compared

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Columbia County, Bordering counties

Counties bordering Columbia County

Calculated by Radon411

Columbia County, Cities and towns

Cities and towns in Columbia County

Columbia County is growing: the Census Bureau puts it at 74,094 residents on July 1, 2025, up 6.2% from 69,758 in 2020. That works out to 93 people per square mile of land. No town dominates: Lake City, the largest, has 12,788 residents, 17.3% of the total. Together its 2 incorporated places hold 18.2% of those residents; the other 81.8% live outside any of them. Reported testing is thin here: 30 tests over 2008 to 2017, or 0.4 for every 1,000 residents (2025 estimate), where Florida as a whole comes to 2.3.

From Lake City to Fort White, CDC publishes no figure by town: each reads Columbia County's.

The cities and towns in Columbia County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Lake City12,788+3.5%17.3%
Fort White665+7.1%0.9%

2 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).

Columbia County, Homes

Homes in Columbia County

Mobile homes are 36% of Columbia County's 30,066 homes and detached houses 52%, against 55% across Florida. Half of its homes were built before 1991, close to Florida's 1988: 9% date from before 1960 and 31% from 2000 or later. 71% of occupied homes are lived in by their owner (Florida: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Columbia County, Florida, 2019 to 2023
HomesColumbia CountyFlorida
Housing units30,06610,082,356
Detached houses52%55%
In buildings of 5 or more6%25%
Mobile homes36%8%
Built before 19609%10%
Built since 200031%30%
Middle year built19911988
Owner-occupied71%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.