Radon in Alabama: radon map by county

EPA's Map of Radon Zones puts 13 of Alabama's 67 counties in Zone 1 (predicted average indoor radon above 4 pCi/L), 33 in Zone 2 and 21 in Zone 3. Of 8,148 building tests that radon laboratories reported for 2008 to 2017, 21.3% were at or above EPA's 4 pCi/L action level, against 36.5% nationally (number 36 of 42 states with 1,000+ tests). The highest county share is Colbert County (36.2% of 578 tests).

counties in Zone 1 (above 4 pCi/L predicted)

counties in Zone 2 (2 to 4)

counties in Zone 3 (below 2)

21.3%

of 8,148 lab tests at or above 4 pCi/L

Radon by county in Alabama

EPA radon zone and radon test results for each county in Alabama
County	EPA zone	Lab tests	Median	4+ pCi/L
Autauga County	Zone 2	22	0.9	17.1%
Baldwin County	Zone 3	26	1.0	0%
Barbour County	Zone 2	2	0.6	0%
Bibb County	Zone 2	3	2.5	25%
Blount County	Zone 2	36	2.0	13.6%
Bullock County	Zone 2	n/a	n/a	n/a
Butler County	Zone 3	1	0.9	0%
Calhoun County	Zone 1	181	1.4	18.9%
Chambers County	Zone 3	3	0.8	0%
Cherokee County	Zone 2	8	1.5	10%
Chilton County	Zone 2	15	1.1	11.1%
Choctaw County	Zone 3	1	0.8	0%
Clarke County	Zone 3	1	0.4	0%
Clay County	Zone 1	32	0.9	17.9%
Cleburne County	Zone 1	60	1.5	18.8%
Coffee County	Zone 3	6	2.4	16.7%
Colbert County	Zone 1	578	2.7	36.2%
Conecuh County	Zone 3	2	0.6	0%
Coosa County	Zone 1	8	1.4	0%
Covington County	Zone 3	2	0.6	0%
Crenshaw County	Zone 3	1	1.1	0%
Cullman County	Zone 2	63	1.5	11.4%
Dale County	Zone 3	1	2.1	0%
Dallas County	Zone 2	5	0.5	0%
DeKalb County	Zone 2	57	0.9	13.2%
Elmore County	Zone 2	25	1.2	22.2%
Escambia County	Zone 3	2	1.2	0%
Etowah County	Zone 2	44	1.4	19.6%
Fayette County	Zone 2	2	1.1	0%
Franklin County	Zone 1	162	1.4	18.1%
Geneva County	Zone 3	4	1.2	0%
Greene County	Zone 2	1	0.2	0%
Hale County	Zone 2	3	3.9	50%
Henry County	Zone 3	1	2.1	0%
Houston County	Zone 3	11	1.3	23.1%
Jackson County	Zone 1	178	1.5	17.5%
Jefferson County	Zone 2	630	1.2	10.7%
Lamar County	Zone 2	1	7.5	75%
Lauderdale County	Zone 1	1,151	2.2	27.2%
Lawrence County	Zone 1	124	1.7	16.2%
Lee County	Zone 2	57	1.3	12.3%
Limestone County	Zone 1	501	1.3	10.1%
Lowndes County	Zone 2	2	0.9	0%
Macon County	Zone 2	5	0.1	22.2%
Madison County	Zone 1	2,959	1.9	25.2%
Marengo County	Zone 3	2	9.3	50%
Marion County	Zone 2	22	1.0	8%
Marshall County	Zone 2	158	1.3	15.1%
Mobile County	Zone 3	23	0.5	3.8%
Monroe County	Zone 3	1	0.2	0%
Montgomery County	Zone 2	52	0.9	9.7%
Morgan County	Zone 1	344	1.4	14.6%
Perry County	Zone 2	1	3.2	0%
Pickens County	Zone 2	2	0.9	0%
Pike County	Zone 3	8	1.7	44.4%
Randolph County	Zone 2	14	3.7	40%
Russell County	Zone 2	3	0.9	0%
Shelby County	Zone 2	283	1.3	11.3%
St. Clair County	Zone 2	70	1.2	14%
Sumter County	Zone 2	1	2.3	0%
Talladega County	Zone 1	98	1.6	18.5%
Tallapoosa County	Zone 3	12	0.9	6.3%
Tuscaloosa County	Zone 2	51	1.4	8.5%
Walker County	Zone 2	12	1.4	33.3%
Washington County	Zone 3	3	1.4	0%
Wilcox County	Zone 3	n/a	n/a	n/a
Winston County	Zone 2	11	1.6	16.7%

Lab tests: buildings tested by radon laboratories, 2008 to 2017; median in pCi/L; “4+ pCi/L” is the share of tests at or above EPA's action level. n/a: no value on file (no tests, or too few to report).

What the zones mean

Zone 1 counties have a predicted average indoor radon screening level above 4 pCi/L, Zone 2 from 2 to 4 pCi/L and Zone 3 below 2 pCi/L. The prediction is from 1993 indoor measurements, geology, aerial radioactivity, soils and foundation types. EPA: “This map should not be used to determine if individual homes need to be tested.” EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of exposure.

Radon in Alabama: questions

What radon zone is Alabama?

EPA's 1993 map does not give states one zone; it zones each county. In Alabama, 13 counties are Zone 1, 33 Zone 2 and 21 Zone 3. EPA says the map "should not be used to determine if individual homes need to be tested".

Which Alabama counties have the highest radon levels?

By the share of laboratory tests at or above 4 pCi/L for 2008 to 2017 (counties with 20 or more tests): Colbert County 36.2% (median 2.7 pCi/L, 578 tests); Lauderdale County 27.2% (median 2.2 pCi/L, 1,151 tests); Madison County 25.2% (median 1.9 pCi/L, 2,959 tests); Elmore County 22.2% (median 1.2 pCi/L, 25 tests); Etowah County 19.6% (median 1.4 pCi/L, 44 tests).

How common is high radon in Alabama?

21.3% of the 8,148 tests in the laboratory data for Alabama (2008 to 2017) were at or above 4 pCi/L; the national share was 36.5%. Buildings are tested by choice, often because of a sale or a concern, so the share describes the tests on file, not every home.

Should I test for radon in Alabama?

Yes. EPA recommends testing every home no matter where it is, fixing it at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of radon exposure.

States bordering Alabama

Radon in Florida (0 of 67 in Zone 1)Radon in Georgia (4 of 159 in Zone 1)Radon in Mississippi (0 of 82 in Zone 1)Radon in Tennessee (39 of 95 in Zone 1)

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Superfund sites in Alabama · Radon map of every state

Data compiled 2026-10-20. County-level screening information, not a radon measurement of any building.