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Radon Levels in DeKalb County, Georgia

EPA puts DeKalb County in Zone 1, its highest radon zone, and 18.0% of its 3,475 reported radon tests (2008 to 2017, laboratory totals) were 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

    18.0%

    6.8 pts below GA

    DeKalb
    18.0%
    Georgia
    24.8%

    3,475 tests, 2008 to 2017

  • Median result

    1.8pCi/L

    Below action level

    DeKalb
    1.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    3,475

    3rd of 57 by tests

    DeKalb
    3,475
    Fulton
    4,858

    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 Georgia

    44 of 57

    Lowest quarter

    DeKalb
    18.0%
    Barrow
    48.3%

    By share, of 57 with 30+ tests

Read a result for DeKalb County

Starts at DeKalb County's median, 1.8 pCi/L

1.8pCi/L

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

EPA’s reading of 1.8 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. DeKalb County's median reported result, 2008 to 2017.

Interpret this reading

The data

DeKalb County, At a glance

DeKalb County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of DeKalb 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 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, DeKalb County, 2008 to 2017, laboratory
Under 2 pCi/L: 53%2 to 4 pCi/L: 29%4 pCi/L and above: 18%

Of 3,475 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, DeKalb County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1,84253.0%
2 to 4 pCi/L1,00929.0%
4 pCi/L and above62418.0%
What these figures count

These are the 3,475 tests reported to CDC for DeKalb 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

DeKalb County, Compared

DeKalb County radon figures, compared

Calculated by Radon411

DeKalb County's 3,475 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 90.8 pCi/L, and 18.0% reached 4 pCi/L. Georgia as a whole (129 Georgia counties, pooled) comes to 24.8%: 6.8 points higher than here.

Among its state's counties it ranks 44th of 57 Georgia counties with 30 or more tests for the same period. Statewide for the same period, Barrow County reported the highest share (48.3%) and Richmond County the lowest (0.0%).

Below the action level, 1,842 tests (53.0%) came in under 2 pCi/L, against 44.0% statewide, and 1,009 tests (29.0%) fell between 2 and 4, against 31.2% statewide. CDC's ten-year totals for DeKalb County went from 2,510 tests (2005 to 2014) to 3,475 (2008 to 2017), the share going from 18.0% to 18.0%.

EPA's 1993 zone map puts DeKalb County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Next door, the shares run from 20.1% in Clayton County to 32.4% in Gwinnett County.

CDC also counts 430 tests taken after mitigation in DeKalb County for the same period: tests in homes where a fix was already in.

DeKalb County against Georgia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from DeKalb County
DeKalb County3,47518.0%1.8 pCi/LThis county
Georgia, pooled129 counties, pooled30,15224.8%Not pooled+6.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+17.7 points
Barrow Countyhighest in the state32148.3%3.8 pCi/L+30.3 points
Richmond Countylowest in the state320.0%1.4 pCi/L−18.0 points
Gwinnett County, GAborders it4,18732.4%2.7 pCi/L+14.4 points
Rockdale County, GAborders it24729.1%2.3 pCi/L+11.1 points
Henry County, GAborders it38422.7%2.1 pCi/L+4.7 points
Fulton County, GAborders it4,85820.8%2.2 pCi/L+2.8 points
Clayton County, GAborders it15420.1%1.6 pCi/L+2.1 points
Where DeKalb County's reported results fell, 2008 to 2017, laboratory, beside Georgia and the United States
ResultDeKalb County testsDeKalb County shareGeorgia shareU.S. shareAgainst Georgia
Under 2 pCi/L1,84253.0%44.0%39.6%+9.0 points
2 to 4 pCi/L1,00929.0%31.2%24.7%−2.2 points
4 pCi/L and above62418.0%24.8%35.7%−6.8 points
DeKalb County ranked among the 57 Georgia counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Floyd County39 of 5711619.8%1.9 pCi/L
Coweta County40 of 5754819.2%2.0 pCi/L
Oconee County41 of 5748319.0%1.8 pCi/L
Catoosa County42 of 575918.6%1.3 pCi/L
Elbert County43 of 5714518.6%1.9 pCi/L
DeKalb County44 of 573,47518.0%1.8 pCi/L
Cherokee County45 of 571,15417.6%2.0 pCi/L
Greene County46 of 577417.6%1.9 pCi/L
Morgan County47 of 575416.7%1.5 pCi/L
Cobb County48 of 573,31516.3%1.9 pCi/L
Harris County49 of 575115.7%1.9 pCi/L
DeKalb County ten-year laboratory totals, against Georgia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestGeorgia, pooledChange from the row before
2008 to 20173,47518.0%1.8 pCi/L90.8 pCi/L24.8%+0.5 points
2007 to 20163,34917.5%1.8 pCi/L34.1 pCi/L23.9%+0.1 points
2006 to 20153,11617.4%1.8 pCi/L34.1 pCi/L23.7%−0.6 points
2005 to 20142,51018.0%1.8 pCi/L34.1 pCi/L23.2%First on file

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

DeKalb County, Geology

The ground under DeKalb County

Predicted

USGS's geologic map puts all of DeKalb County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Georgiabama Thrust Stack (South), to which USGS gives a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under DeKalb County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Georgiabama Thrust Stack (South)Schist, amphibolite and granite.Moderate9100%

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

DeKalb County beside the ground around it

DeKalb County has more moderate-potential ground than Georgia as a whole: 100% of its land against 26.5%. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Clayton County comes nearest at 100%.

Share of land by USGS radon potential: DeKalb County, the 5 counties bordering it and Georgia
AreaEPA zoneLow potentialModerate potentialHigh potential
DeKalb CountyZone 1None100%None
Fulton CountyZone 1None100%None
Gwinnett CountyZone 1None100%None
Rockdale CountyZone 2None100%None
Clayton CountyZone 2None100%None
Henry CountyZone 2None100%None
Georgia159 counties, pooled by land areaVaries73.1%26.5%None

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

Local help

DeKalb County, Local resources

Radon testing and mitigation in DeKalb County

Listed radon businesses with an address in DeKalb County:

Listed radon professionals by town: Atlanta

What Georgia's program says
Licensing of radon professionals
There are no laws mandating a mitigator receive certification in Georgia, however, many mitigators choose to get certified by one of two national programs.

What it means

DeKalb County, Questions

Questions about radon in DeKalb County

Are radon levels high in DeKalb County?

Over the 2008 to 2017 laboratory totals, 18.0% of the radon tests reported to CDC for DeKalb County, Georgia were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. Of 57 Georgia counties with 30 or more tests for the same period, 43 reported a higher share; pooled, the state comes to 24.8%.

Which counties border DeKalb County?

DeKalb County borders 5 counties: Fulton County, Gwinnett County, Rockdale County, Clayton County and Henry County.

Products

DeKalb County, Products

Testing a home in DeKalb County

In DeKalb County, 18.0% of 3,475 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 24.8% pooled across Georgia. In Zone 1 the year-round level in DeKalb 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

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

Explore

DeKalb County, Bordering counties

Counties bordering DeKalb County

Calculated by Radon411

DeKalb County, Cities and towns

Cities and towns in DeKalb County

The Census Bureau estimates 774,394 residents in DeKalb County for July 1, 2025, 9,809 more than in 2020 (+1.3%). Packed into its land, that is 2,892 people per square mile. Atlanta, the largest place on its list (529,110 residents in all), extends beyond DeKalb County, so no share of the total is worked out for it. Testing is reported here more often than across the state: CDC's 3,475 reported tests for 2008 to 2017 come to 4.5 for every 1,000 residents (2025 estimate), against 2.7 for Georgia.

From Atlanta to Pine Lake, CDC publishes no figure by town: each reads DeKalb County's.

The 12 largest cities and towns in DeKalb County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Atlantaextends beyond DeKalb County529,110+5.8%Counted whole
Stonecrest61,337+3.5%7.9%
Brookhaven59,643+5.1%7.7%
Dunwoody51,792+0.4%6.7%
Tucker37,290+0.4%4.8%
Chamblee32,334+7.0%4.2%
Decatur25,276+1.4%3.3%
Doraville16,365+12.0%2.1%
Clarkston14,431−1.8%1.9%
Stone Mountain6,562−1.9%0.8%
Avondale Estates3,543−0.6%0.5%
Lithonia2,608−1.9%0.3%
  • Pine Lake

13 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond DeKalb County is counted whole, so it has no share.

DeKalb County, Homes

Homes in DeKalb County

Of DeKalb County's 328,614 homes, 56% are detached houses, against 66% across Georgia; 30% are in buildings of five or more homes. The homes are older than Georgia's as a whole: half were built before 1983 (1991 for Georgia), and 15% date from before 1960. 58% of occupied homes are lived in by their owner (Georgia: 65%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in DeKalb County, Georgia, 2019 to 2023
HomesDeKalb CountyGeorgia
Housing units328,6144,483,873
Detached houses56%66%
In buildings of 5 or more30%16%
Mobile homes1%8%
Built before 196015%12%
Built since 200025%33%
Middle year built19831991
Owner-occupied58%65%

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