Introduction
Radon, a radioactive gas, is a significant concern when it comes to indoor air quality. It is produced naturally from the decay of uranium in the soil, and high radon levels can pose health risks, mainly when it accumulates indoors. Certain states in the United States have higher radon levels than others. Alaska and South Dakota have the highest radon levels in the US at 10.7 pCi/L and 9.6 pCi/L, respectively. Pennsylvania, Ohio, and Washington also exhibit relatively high radon levels, ranging from 7.5 pCi/L to 8.6 pCi/L.
States in the northern region, such as Alaska, South Dakota, and Pennsylvania, tend to have higher average radon levels. This could be attributed to geological factors, including the presence of uranium-rich rock formations or soil characteristics. Additionally, states in the Midwest and Mountain regions, like Ohio, Kentucky, and Montana, also exhibit elevated radon levels.
Average Radon Levels by State
# | State | Radon Levels |
---|---|---|
1 | Alaska | 10.7 pCi/L |
2 | South Dakota | 9.6 pCi/L |
3 | Pennsylvania | 8.6 pCi/L |
4 | Ohio | 7.8 pCi/L |
5 | Washington | 7.5 pCi/L |
6 | Kentucky | 7.4 pCi/L |
7 | Montana | 7.4 pCi/L |
8 | Idaho | 7.3 pCi/L |
9 | Colorado | 6.8 pCi/L |
10 | Iowa | 6.1 pCi/L |
11 | West Virginia | 6.1 pCi/L |
12 | North Dakota | 6 pCi/L |
13 | Maine | 5.9 pCi/L |
14 | Wisconsin | 5.7 pCi/L |
15 | New Hampshire | 5.6 pCi/L |
16 | Maryland | 5.4 pCi/L |
17 | Illinois | 5.3 pCi/L |
18 | Nebraska | 5.2 pCi/L |
19 | Wyoming | 5 pCi/L |
20 | Kansas | 4.9 pCi/L |
21 | Tennessee | 4.8 pCi/L |
22 | Indiana | 4.7 pCi/L |
23 | Minnesota | 4.6 pCi/L |
24 | New Jersey | 4.4 pCi/L |
25 | Utah | 4.4 pCi/L |
26 | Missouri | 4.3 pCi/L |
27 | Rhode Island | 4.3 pCi/L |
28 | New York | 4.2 pCi/L |
29 | North Carolina | 4 pCi/L |
30 | Alabama | 3.9 pCi/L |
31 | Massachusetts | 3.9 pCi/L |
32 | New Mexico | 3.9 pCi/L |
33 | Vermont | 3.7 pCi/L |
34 | Virginia | 3.6 pCi/L |
35 | Michigan | 3.5 pCi/L |
36 | Connecticut | 3.4 pCi/L |
37 | Nevada | 3.4 pCi/L |
38 | Oregon | 3.1 pCi/L |
39 | Arkansas | 2.5 pCi/L |
40 | Oklahoma | 2.5 pCi/L |
41 | Delaware | 2.4 pCi/L |
42 | South Carolina | 2.4 pCi/L |
43 | California | 2.3 pCi/L |
44 | Georgia | 2.3 pCi/L |
45 | Texas | 2.1 pCi/L |
46 | Arizona | 1.9 pCi/L |
47 | Florida | 1.8 pCi/L |
48 | Mississippi | 1.2 pCi/L |
49 | Louisiana | 1.1 pCi/L |
50 | Hawaii | 0 pCi/L |
States With Highest Radon Levels
The ten states with the highest radon levels are Alaska, South Dakota, Pennsylvania, Ohio, Washington, Kentucky, Montana, Idaho, Colorado, and Iowa. Alaska is the state with the highest radon levels in the US with 10.7 pCi/L. South Dakota is the second state with the highest radon levels with 9.6 pCi/L. Pennsylvania has the third highest radon levels with 8.6 pCi/L, while Ohio and Washington have radon levels of 7.8 pCi/L and 7.5 pCi/L, respectively. Kentucky and Montana share a radon level of 7.4 pCi/L, and Idaho follows closely with 7.3 pCi/L. Colorado is the ninth state with the highest radon levels with 6.8 pCi/L, and Iowa is the tenth state with the highest radon levels with 6.1 pCi/L.
The top ten states with the highest radon levels are:
1. Alaska – 10.7 pCi/L
2. South Dakota – 9.6 pCi/L
3. Pennsylvania – 8.6 pCi/L
4. Ohio – 7.8 pCi/L
5. Washington – 7.5 pCi/L
6. Kentucky – 7.4 pCi/L
7. Montana – 7.4 pCi/L
8. Idaho – 7.3 pCi/L
9. Colorado – 6.8 pCi/L
10. Iowa – 6.1 pCi/L
Radon Levels by State
Alabama
Radon Levels
3.9 pCi/L
Ranked in the US
#30
Alaska
Radon Levels
10.7 pCi/L
Ranked in the US
#1
Alaska has the highest radon levels in the US with 10.7 pCi/L. The state's geological composition, including uranium-rich rock formations and extensive granite deposits, contributes to the elevated radon levels.
Arizona
Radon Levels
1.9 pCi/L
Ranked in the US
#46
Arkansas
Radon Levels
2.5 pCi/L
Ranked in the US
#39
California
Radon Levels
2.3 pCi/L
Ranked in the US
#43
Colorado
Radon Levels
6.8 pCi/L
Ranked in the US
#9
Colorado has the ninth highest radon levels in the US with 6.8 pCi/L. The state's elevated radon levels are influenced by its geology, which includes a significant amount of uranium-rich rocks like granite and shale.
Connecticut
Radon Levels
3.4 pCi/L
Ranked in the US
#36
Delaware
Radon Levels
2.4 pCi/L
Ranked in the US
#41
Florida
Radon Levels
1.8 pCi/L
Ranked in the US
#47
Georgia
Radon Levels
2.3 pCi/L
Ranked in the US
#44
Hawaii
Radon Levels
0 pCi/L
Ranked in the US
#50
Idaho
Radon Levels
7.3 pCi/L
Ranked in the US
#8
Idaho has the eighth highest radon levels in the US with 7.3 pCi/L. The state's high radon levels are primarily due to its geology, as Idaho has abundant granite and volcanic rock formations that contain uranium, leading to increased radon gas levels.
Illinois
Radon Levels
5.3 pCi/L
Ranked in the US
#17
Indiana
Radon Levels
4.7 pCi/L
Ranked in the US
#22
Iowa
Radon Levels
6.1 pCi/L
Ranked in the US
#10
Iowa has the tenth highest radon levels in the US with 6.1 pCi/L. The state's radon levels are primarily attributed to its geology, as Iowa has high concentrations of uranium-rich glacial deposits and sedimentary rocks that contribute to the release of radon gas.
Kansas
Radon Levels
4.9 pCi/L
Ranked in the US
#20
Kentucky
Radon Levels
7.4 pCi/L
Ranked in the US
#6
Kentucky has the sixth highest radon levels in the US with 7.4 pCi/L. The state's high radon levels can be attributed to its geological composition, which includes soils and rock formations rich in uranium. Kentucky also has a long history of coal mining, and the presence of coal deposits and associated rocks can release radon gas into the surrounding environment.
Louisiana
Radon Levels
1.1 pCi/L
Ranked in the US
#49
Maine
Radon Levels
5.9 pCi/L
Ranked in the US
#13
Maryland
Radon Levels
5.4 pCi/L
Ranked in the US
#16
Massachusetts
Radon Levels
3.9 pCi/L
Ranked in the US
#31
Michigan
Radon Levels
3.5 pCi/L
Ranked in the US
#35
Minnesota
Radon Levels
4.6 pCi/L
Ranked in the US
#23
Mississippi
Radon Levels
1.2 pCi/L
Ranked in the US
#48
Missouri
Radon Levels
4.3 pCi/L
Ranked in the US
#26
Montana
Radon Levels
7.4 pCi/L
Ranked in the US
#7
Montana also has the sixth highest radon levels in the US with 7.4 pCi/L. The state's radon levels are primarily influenced by its geology, which includes rocks such as granite and shale that contain uranium. Montana's mountainous terrain and geological diversity contribute to the presence of uranium-rich formations, increasing the likelihood of elevated radon levels.
Nebraska
Radon Levels
5.2 pCi/L
Ranked in the US
#18
Nevada
Radon Levels
3.4 pCi/L
Ranked in the US
#37
New Hampshire
Radon Levels
5.6 pCi/L
Ranked in the US
#15
New Jersey
Radon Levels
4.4 pCi/L
Ranked in the US
#24
New Mexico
Radon Levels
3.9 pCi/L
Ranked in the US
#32
New York
Radon Levels
4.2 pCi/L
Ranked in the US
#28
North Carolina
Radon Levels
4 pCi/L
Ranked in the US
#29
North Dakota
Radon Levels
6 pCi/L
Ranked in the US
#12
Ohio
Radon Levels
7.8 pCi/L
Ranked in the US
#4
Ohio has the fourth highest radon levels in the US with 7.8 pCi/L. The state's high radon levels are linked to its geology, specifically the prevalence of glacial deposits that contain radon-producing minerals like uranium and thorium.
Oklahoma
Radon Levels
2.5 pCi/L
Ranked in the US
#40
Oregon
Radon Levels
3.1 pCi/L
Ranked in the US
#38
Pennsylvania
Radon Levels
8.6 pCi/L
Ranked in the US
#3
Pennsylvania has the third highest radon levels in the US with 8.6 pCi/L. The state's radon levels are elevated due to its geology, specifically the presence of uranium and radium in the bedrock, which results in the release of radon gas into the soil and subsequently into homes and structures.
Rhode Island
Radon Levels
4.3 pCi/L
Ranked in the US
#27
South Carolina
Radon Levels
2.4 pCi/L
Ranked in the US
#42
South Dakota
Radon Levels
9.6 pCi/L
Ranked in the US
#2
South Dakota holds the second highest radon levels with 9.6 pCi/L. The state's geology, characterized by granite and shale formations, plays a significant role in the high radon concentrations found in homes and buildings.
Tennessee
Radon Levels
4.8 pCi/L
Ranked in the US
#21
Texas
Radon Levels
2.1 pCi/L
Ranked in the US
#45
Utah
Radon Levels
4.4 pCi/L
Ranked in the US
#25
Vermont
Radon Levels
3.7 pCi/L
Ranked in the US
#33
Virginia
Radon Levels
3.6 pCi/L
Ranked in the US
#34
Washington
Radon Levels
7.5 pCi/L
Ranked in the US
#5
Washington has the fifth highest radon levels in the US with 7.5 pCi/L. The state's radon levels can be attributed to its diverse geology, including granitic rocks, which can release radon gas as they naturally decay over time.
West Virginia
Radon Levels
6.1 pCi/L
Ranked in the US
#11
Wisconsin
Radon Levels
5.7 pCi/L
Ranked in the US
#14
Wyoming
Radon Levels
5 pCi/L
Ranked in the US
#19
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