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Radon Levels in Polk County, Florida

EPA puts Polk County in Zone 2, its middle radon zone, and most reported tests there come back low, though 11.0% of 136 (2023) reached 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    11.0%

    7.5 pts below FL

    Polk
    11.0%
    Florida
    18.5%

    136 tests, 2023

  • Median result

    1.1pCi/L

    Below action level

    Polk
    1.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    136

    20th of 30 by tests

    Polk
    136
    Broward
    2,165

    Reported to CDC before any fix, 2023

  • 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

    11 of 30

    Middle half

    Polk
    11.0%
    Marion
    44.5%

    By share, of 30 with 30+ tests

Read a result for Polk County

Starts at Polk County's median, 1.1 pCi/L

1.1pCi/L

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

EPA’s reading of 1.1 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. Polk County's median reported result, 2023.

Interpret this reading

The data

Polk County, At a glance

Polk County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Polk 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 66% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Polk County, 2023

Share of reported tests at or above 4 pCi/L, by year, Polk County
Share of reported tests at or above 4 pCi/L, by year, Polk County
YearShare of reported tests at or above 4 pCi/L
201430.6%
201540.6%
201622.9%
201716.0%
201829.4%
201927.5%
202056.5%
20216.4%
202210.3%
202311.0%

2023: 11.0%. Across these years the share ran from 6.4% to 56.5%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 136 tests reported to CDC for Polk County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Polk County, Compared

Polk County radon figures, compared

Calculated by Radon411

Polk County reports fewer high tests than Florida overall. 11.0% of its 136 tests in 2023 were at or above 4 pCi/L. That is 7.5 points below the 18.5% pooled from 49 Florida counties.

Ordered from highest share down, it comes 11th of 30 Florida counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 33.4%; Polk County sits 22.4 points below it.

Next door, the shares run from 0.0% in Lake County to 11.0% in Manatee County, with Orange County, Hillsborough County and Osceola County below Polk County. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 11.0% share point the same way here.

Half the tests came in under 1.1 pCi/L and half over it; the single highest reached 25.7 pCi/L. The rest split 72.8% under 2 pCi/L and 16.2% from 2 to 4 (Florida: 57.3% and 24.2%). Year by year, 2014 opened at 30.6% and 2023 closed at 11.0% (down 19.6 points), with 2020 the high at 56.5%.

The busiest year on file was 2022, with 1,713 tests reported; the quietest, 2016, had 70.

Share of reported tests at or above 4 pCi/L by year, Polk County against Florida2014 to 2023, years with 30 or more tests: Polk County 30.6% to 11.0%, the state's pooled share 18.5% in 2023.
Polk CountyFlorida, pooled
Share of reported tests at or above 4 pCi/L by year, Polk County against Florida: data table
YearTestsPolk County, at or above 4 pCi/LFlorida, pooled
20147230.6%25.7%
201513340.6%26.5%
20167022.9%24.3%
201733216.0%21.7%
201841929.4%23.5%
201930527.5%29.6%
202016156.5%23.2%
20214046.4%15.4%
20221,71310.3%22.8%
202313611.0%18.5%
Polk County against Florida, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Polk County
Polk County13611.0%1.1 pCi/LThis county
Florida, pooled49 counties, pooled16,58918.5%Not pooled+7.5 points
United States, pooled642 counties, pooled128,74033.4%Not pooled+22.4 points
Marion Countyhighest in the state18244.5%3.6 pCi/L+33.5 points
Clay Countylowest in the state360.0%1.0 pCi/L−11.0 points
Manatee County, FLborders it26311.0%1.5 pCi/LLevel
Orange County, FLborders it1,1079.5%0.9 pCi/L−1.5 points
Hillsborough County, FLborders it9847.5%0.9 pCi/L−3.5 points
Osceola County, FLborders it701.4%1.2 pCi/L−9.6 points
Pasco County, FLborders it1640.6%0.8 pCi/L−10.4 points
Sumter County, FLborders it120.0%0.9 pCi/L−11.0 points
Lake County, FLborders it1590.0%0.6 pCi/L−11.0 points
Where Polk County's reported results fell, 2023, beside Florida and the United States
ResultPolk County testsPolk County shareFlorida shareU.S. shareAgainst Florida
Under 2 pCi/L9972.8%57.3%41.4%+15.5 points
2 to 4 pCi/L2216.2%24.2%25.2%−8.0 points
4 pCi/L and above1511.0%18.5%33.4%−7.5 points
Polk County ranked among the 30 Florida counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Alachua County6 of 3065921.4%2.4 pCi/L
Lee County7 of 301,22420.3%2.2 pCi/L
Leon County8 of 301,19619.1%1.8 pCi/L
Gadsden County9 of 309614.6%1.3 pCi/L
Sarasota County10 of 3049612.3%1.6 pCi/L
Polk County11 of 3013611.0%1.1 pCi/L
Manatee County12 of 3026311.0%1.5 pCi/L
Orange County13 of 301,1079.5%0.9 pCi/L
Broward County14 of 302,1659.4%1.7 pCi/L
Hillsborough County15 of 309847.5%0.9 pCi/L
Duval County16 of 307926.2%0.4 pCi/L
Polk County radon tests by year, against Florida's pooled share
YearTestsAt or above 4 pCi/LMedianHighestFlorida, pooledChange from the row before
202313611.0%1.1 pCi/L25.7 pCi/L18.5%+0.7 points
20221,71310.3%2.0 pCi/L20.1 pCi/L22.8%+3.9 points
20214046.4%0.5 pCi/L15.3 pCi/L15.4%−50.1 points
202016156.5%4.5 pCi/L11.8 pCi/L23.2%+29.0 points
201930527.5%2.7 pCi/L33.4 pCi/L29.6%−1.9 points
201841929.4%1.4 pCi/L16.2 pCi/L23.5%+13.4 points
201733216.0%1.6 pCi/L27.4 pCi/L21.7%−6.9 points
20167022.9%1.9 pCi/L15.4 pCi/L24.3%−17.7 points
201513340.6%2.9 pCi/L40.6 pCi/L26.5%+10.0 points
20147230.6%2.3 pCi/L15.2 pCi/L25.7%First on file

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

Polk County, Geology

The ground under Polk County

Predicted

USGS's geologic map splits Polk County: 66.3% of its land is low radon potential and 33.7% moderate. The map puts 66.3% of Polk County in the area it calls Gulf/Atlantic Lowland and Central Highland and 33.7% in Highland Anomalous areas. 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 Polk County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Gulf/Atlantic Lowland and Central Highlandsand, silt, clay, gravelLow666.3%
Highland Anomalous areasPhosphate deposits.Moderate1133.7%

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

Polk County beside the ground around it

Polk County has more moderate-potential ground than Florida as a whole: 33.7% of its land against 7.1%. Of the 10 counties that border it, 1 has more moderate-potential ground, Hillsborough County the most at 41.4%.

Share of land by USGS radon potential: Polk County, the 10 counties bordering it and Florida
AreaEPA zoneLow potentialModerate potentialHigh potential
Polk CountyZone 266.3%33.7%None
Hillsborough CountyZone 256.1%41.4%None
Hardee CountyZone 374.3%25.7%None
Osceola CountyZone 3100%NoneNone
Pasco CountyZone 376.2%23.0%None
Orange CountyZone 3100%NoneNone
Sumter CountyZone 380.6%19.4%None
Highlands CountyZone 3100%NoneNone
Lake CountyZone 3100%NoneNone
Manatee CountyZone 386.6%6.9%None
Okeechobee CountyZone 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

Polk County, Local resources

Radon testing and mitigation in Polk County

Listed radon businesses with an address in Polk County:

Listed radon professionals by town: Lakeland, Bartow

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

Polk County, Questions

Questions about radon in Polk County

Are radon levels high in Polk County?

In 2023, 11.0% of the radon tests reported to CDC for Polk County, Florida were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.1 pCi/L. Of 30 Florida counties with 30 or more tests for the same period, 10 reported a higher share; pooled, the state comes to 18.5%.

Which counties border Polk County?

Polk County borders 10 counties: Hillsborough County, Hardee County, Osceola County, Pasco County, Orange County, Sumter County, Highlands County, Lake County, Manatee County and Okeechobee County.

Products

Polk County, Products

Testing a home in Polk County

In Polk County, 11.0% of 136 tests reported to CDC in 2023 reached 4 pCi/L, against 18.5% pooled across Florida. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Polk County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Polk County homes, compared

Explore

Polk County, Bordering counties

Counties bordering Polk County

Calculated by Radon411

Polk County, Cities and towns

Cities and towns in Polk County

Polk County is growing: the Census Bureau puts it at 874,790 residents on July 1, 2025, up 19.8% from 730,148 in 2020. That works out to 487 people per square mile of land. No town dominates: Lakeland, the largest, has 125,520 residents, 14.3% of the total. Together its 17 incorporated places hold 41.0% of those residents; the other 59.0% live outside any of them. Reported testing is thin here: 136 tests over 2023, or 0.2 for every 1,000 residents (2025 estimate), where Florida as a whole comes to 0.7.

From Lakeland to Hillcrest Heights, CDC publishes no figure by town: each reads Polk County's.

The 12 largest cities and towns in Polk County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Lakeland125,520+10.2%14.3%
Winter Haven62,313+22.9%7.1%
Haines City45,973+64.9%5.3%
Bartow23,617+20.0%2.7%
Auburndale21,369+35.9%2.4%
Lake Wales18,650+14.5%2.1%
Davenport18,110+87.0%2.1%
Lake Alfred10,107+54.5%1.2%
Dundee6,424+21.9%0.7%
Eagle Lake6,415+109.2%0.7%
Fort Meade5,379+5.8%0.6%
Mulberry4,573+15.5%0.5%
  • Frostproof
  • Polk City
  • Lake Hamilton
  • Highland Park
  • Hillcrest Heights

17 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).

Polk County, Homes

Homes in Polk County

Of Polk County's 329,750 homes, 62% are detached houses, against 55% across Florida; 20% are mobile homes. Half of its homes were built before 1991, close to Florida's 1988: 11% date from before 1960 and 36% from 2000 or later. 70% 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 Polk County, Florida, 2019 to 2023
HomesPolk CountyFlorida
Housing units329,75010,082,356
Detached houses62%55%
In buildings of 5 or more9%25%
Mobile homes20%8%
Built before 196011%10%
Built since 200036%30%
Middle year built19911988
Owner-occupied70%67%

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