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Radon Levels in Bourbon County, Kentucky

EPA puts Bourbon County in Zone 1, its highest radon zone, and high results are common there: 53.5% of the 127 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

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  • Share at 4+ pCi/L

    53.5%

    9.8 pts above KY

    Bourbon
    53.5%
    Kentucky
    43.7%

    127 tests, 2008 to 2017

  • Median result

    4.8pCi/L

    Action level reached

    Bourbon
    4.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    127

    30th of 69 by tests

    Bourbon
    127
    Jefferson
    6,590

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Kentucky

    12 of 69

    Top quarter

    Bourbon
    53.5%
    Meade
    68.4%

    By share, of 69 with 30+ tests

Read a result for Bourbon County

Starts at Bourbon County's median, 4.8 pCi/L

4.8pCi/L

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

EPA’s reading of 4.8 pCi/L

At or above 4 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 at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Bourbon County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Bourbon County, At a glance

Bourbon County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Bourbon County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: Moderate across 56% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Bourbon County, 2008 to 2017, laboratory

Reported results by concentration band, Bourbon County, 2008 to 2017, laboratory
Under 2 pCi/L: 26%2 to 4 pCi/L: 21%4 pCi/L and above: 53%

Of 127 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Bourbon County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3326.0%
2 to 4 pCi/L2620.5%
4 pCi/L and above6853.5%
What these figures count

These are the 127 tests reported to CDC for Bourbon 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).

How to read these figures

Bourbon County, Compared

Bourbon County radon figures, compared

Calculated by Radon411

More than half: 53.5% of the 127 radon tests reported to CDC for Bourbon County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 12th of 69 Kentucky counties with 30 or more tests for the same period. That is 9.8 points above the 43.7% pooled from 120 Kentucky counties.

The median result, 4.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 153.7 pCi/L. The rest split 26.0% under 2 pCi/L and 20.5% from 2 to 4 (Kentucky: 33.2% and 23.1%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 53.5% share point the same way here.

1 of its 5 bordering counties with figures ran higher, led by Fayette County at 54.5%; Clark County reported 29.0%. Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%).

CDC's ten-year totals for Bourbon County went from 81 tests (2005 to 2014) to 127 (2008 to 2017), the share going from 53.1% to 53.5%.

Nationally, every county with a figure for the same period pools to 35.7%; Bourbon County sits 17.8 points above it. CDC also counts 13 tests taken after mitigation in Bourbon County for the same period: tests in homes where a fix was already in.

Bourbon County against Kentucky, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Bourbon County
Bourbon County12753.5%4.8 pCi/LThis county
Kentucky, pooled120 counties, pooled28,79343.7%Not pooled−9.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−17.8 points
Meade Countyhighest in the state11768.4%8.2 pCi/L+14.9 points
Hopkins Countylowest in the state429.5%1.7 pCi/L−44.0 points
Fayette County, KYborders it5,26354.5%4.5 pCi/L+1.0 points
Montgomery County, KYborders it10551.4%4.1 pCi/L−2.1 points
Scott County, KYborders it87546.9%3.6 pCi/L−6.6 points
Harrison County, KYborders it11146.8%3.4 pCi/L−6.7 points
Bath County, KYborders it1241.7%3.1 pCi/L−11.8 points
Clark County, KYborders it23129.0%2.4 pCi/L−24.5 points
Nicholas County, KYborders it2010.0%1.9 pCi/L−43.5 points
Where Bourbon County's reported results fell, 2008 to 2017, laboratory, beside Kentucky and the United States
ResultBourbon County testsBourbon County shareKentucky shareU.S. shareAgainst Kentucky
Under 2 pCi/L3326.0%33.2%39.6%−7.2 points
2 to 4 pCi/L2620.5%23.1%24.7%−2.6 points
4 pCi/L and above6853.5%43.7%35.7%+9.8 points
Bourbon County ranked among the 69 Kentucky counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Woodford County7 of 6934257.9%4.9 pCi/L
Taylor County8 of 699157.1%4.4 pCi/L
Jessamine County9 of 6978955.5%4.7 pCi/L
Fayette County10 of 695,26354.5%4.5 pCi/L
Boyle County11 of 6949253.9%4.4 pCi/L
Bourbon County12 of 6912753.5%4.8 pCi/L
Monroe County13 of 698752.9%4.6 pCi/L
Barren County14 of 6918651.6%4.0 pCi/L
Montgomery County15 of 6910551.4%4.1 pCi/L
Hardin County16 of 6942950.3%4.0 pCi/L
Marion County17 of 6917748.6%3.9 pCi/L
Bourbon County ten-year laboratory totals, against Kentucky's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestKentucky, pooledChange from the row before
2008 to 201712753.5%4.8 pCi/L153.7 pCi/L43.7%−1.9 points
2007 to 201611255.4%4.9 pCi/L153.7 pCi/L45.1%+1.9 points
2006 to 20159953.5%4.9 pCi/L153.7 pCi/L46.4%+0.4 points
2005 to 20148153.1%4.9 pCi/L55.8 pCi/L47.3%First on file

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

Bourbon County, Geology

The ground under Bourbon County

Predicted

USGS's geologic map splits Bourbon County: 55.9% of its land is moderate radon potential and 44.1% high. The map puts 55.9% of Bourbon County in the area it calls Outer Bluegrass and 44.1% in Inner Bluegrass. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 13, in the high band (12 to 17).

USGS's geologic areas under Bourbon County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Outer BluegrassOrdovician-Devonian limestone and shale.Moderate1155.9%
Inner BluegrassOrdovician limestones, dolomites and shales.High1344.1%

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

Bourbon County beside the ground around it

Bourbon County has more high-potential ground than Kentucky as a whole: 44.1% of its land against 18.2%. Of the 7 counties that border it, 2 have more high-potential ground, Fayette County the most at 76.8%.

Share of land by USGS radon potential: Bourbon County, the 7 counties bordering it and Kentucky
AreaEPA zoneLow potentialModerate potentialHigh potential
Bourbon CountyZone 1None55.9%44.1%
Harrison CountyZone 1None65.3%34.7%
Nicholas CountyZone 2None97.3%2.7%
Clark CountyZone 1None73.0%27.0%
Fayette CountyZone 1None23.2%76.8%
Montgomery CountyZone 2None61.3%38.7%
Scott CountyZone 1None49.3%50.7%
Bath CountyZone 2None64.6%35.4%
Kentucky120 counties, pooled by land areaVaries5.7%76.1%18.2%

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

Local help

Bourbon County, Local resources

Radon testing and mitigation in Bourbon County

What Kentucky's program says
Phone
502-782-2782
Email
Radon@ky.gov

What it means

Bourbon County, Questions

Questions about radon in Bourbon County

Are radon levels high in Bourbon County?

Over the 2008 to 2017 laboratory totals, 53.5% of the radon tests reported to CDC for Bourbon County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.8 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 11 reported a higher share; pooled, the state comes to 43.7%.

Which counties border Bourbon County?

Bourbon County borders 7 counties: Harrison County, Nicholas County, Clark County, Fayette County, Montgomery County, Scott County and Bath County.

Products

Bourbon County, Products

Testing a home in Bourbon County

In Bourbon County, 53.5% of 127 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 1 the year-round level in Bourbon 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

Bourbon County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Bourbon County

Explore

Bourbon County, Bordering counties

Counties bordering Bourbon County

Calculated by Radon411

Bourbon County, Cities and towns

Cities and towns in Bourbon County

Bourbon County's population has barely moved since 2020: 20,243 residents on July 1, 2025 against 20,299 then, by the Census Bureau's estimates. That works out to 70 people per square mile of land. Paris alone is home to 10,130 of them, 50.0% of the total. CDC's 127 reported tests for 2008 to 2017 work out to 6.3 per 1,000 residents (2025 estimate), close to Kentucky's 6.3.

From Paris to North Middletown, CDC publishes no figure by town: each reads Bourbon County's.

The cities and towns in Bourbon County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Paris10,130−0.7%50.0%
Millersburgextends beyond Bourbon County745−0.7%Counted whole
North Middletown606Level3.0%

3 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 Bourbon County is counted whole, so it has no share.

Bourbon County, Homes

Homes in Bourbon County

Of Bourbon County's 9,148 homes, 74% are detached houses, against 68% across Kentucky; 6% are mobile homes. Half of its homes were built before 1977, close to Kentucky's 1982: 33% date from before 1960 and 19% from 2000 or later. 65% of occupied homes are lived in by their owner (Kentucky: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Bourbon County, Kentucky, 2019 to 2023
HomesBourbon CountyKentucky
Housing units9,1482,010,655
Detached houses74%68%
In buildings of 5 or more5%12%
Mobile homes6%11%
Built before 196033%22%
Built since 200019%24%
Middle year built19771982
Owner-occupied65%68%

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