Radon in Marion County, Florida

About 4 in 10 homes tested here were at or above the EPA action level.

695 home tests, 2008–2017, CDC lab data
  • Below 2 pCi/L: 30%
  • 2 to 4 pCi/L: 28%
  • 4 pCi/L or more: 43%
The line marks the EPA action level, 4 pCi/L.
Median level
3.3 pCi/L
EPA radon zone
Zone 2
In Florida
1st of 44

EPA Zone 2, moderate radon potential (predicted average 2 to 4 pCi/L). The EPA zone map dates from 1993 and is meant for planning; high levels are found in every zone.

What to do next

  1. Test your home

    Radon levels vary between neighboring houses, so area data can't tell you your own home's level. A short-term test takes 2 to 7 days in the lowest lived-in floor. A long-term test (90 days or more) gives a more reliable average.

  2. If your result is 4 pCi/L or more, fix it

    Most homes are fixed with a sub-slab depressurization system: a pipe and a quiet fan that pull radon from under the foundation and vent it above the roof. We're still collecting real installation prices for Florida.

  3. Use a certified professional

    Look for a professional certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB), or by your state if it certifies radon contractors.

How Marion County compares

Share of homes tested at or above 4 pCi/L, with neighboring counties. Lab data 2008–2017, the only source that covers every state.

Share of homes tested at or above 4 pCi/L
Marion County43%
United States36%
Alachua County35%
Sumter County26%
Florida23%
Levy County13%
Citrus County10%
Lake County3%
Volusia County2%
Putnam County1%

Sources

Last updated October 2026. How we calculate these numbers.