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Radon Levels in Kusilvak Census Area, Alaska

EPA puts Kusilvak Census Area in Zone 3, its lowest radon zone, and only 1 radon test from it is on file with CDC (2020). 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

  • Nearest county

    14.3%

    Matanuska-Susitna Borough, 445 miles

    Matanuska-Susitna Borough
    14.3%
    Alaska
    11.5%

    Share at 4+ pCi/L, 42 tests, 2022

  • Ground above low

    99.0%

    19.8 pts above Alaska

    Kusilvak Census Area
    99.0%
    Alaska
    79.2%

    Share of land USGS rates moderate or high potential

  • Tests reported

    1

    Too few for a share

    Kusilvak Census Area
    1
    Needed
    30

    2020

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Kusilvak Census Area

Starts at EPA's action level

4.0pCi/L

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

EPA’s reading of 4.0 pCi/L

At or above 4 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 at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.

Interpret this readingWhat a fix costs

The data

Kusilvak Census Area, At a glance

Kusilvak Census Area at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Kusilvak Census Area as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Moderate across 99% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Kusilvak Census Area, 2020

CDC holds 1 reported test for Kusilvak Census Area in 2020, a result of 0.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Kusilvak Census Area beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Kusilvak Census Area over 2020, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the borough or census area nor this house.

Measured: CDC tracking data. Measured data period: 2020.

How to read these figures

Kusilvak Census Area, Compared

Kusilvak Census Area radon figures, compared

Calculated by Radon411

CDC's largest figure for Kusilvak Census Area rests on 1 test in 2020, 0 of them at or above 4 pCi/L, so each test moves its share by 100.0 points and no rank or comparison is drawn from it. Results reached as high as 0.2 pCi/L, with a middle value of 0.2 pCi/L.

The nearest counties with a figure are Matanuska-Susitna Borough (445 miles away) at 14.3%, Anchorage Municipality (474 miles away) at 3.1% and Fairbanks North Star Borough (550 miles away) at 19.4%. Pooled across 19 Alaska counties, 11.5% of reported tests reached that level; across every county in the country with a figure, 23.9%.

Statewide for the same period, Fairbanks North Star Borough reported the highest share (19.4%) and Anchorage Municipality the lowest (3.1%). EPA's 1993 map puts Kusilvak Census Area in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 99% of the county's land moderate radon potential.

Alaska, the United States and the counties around Kusilvak Census Area, 2022
AreaTestsAt or above 4 pCi/LMedian
Alaska, pooled19 counties, pooled31411.5%Not pooled
United States, pooled853 counties, pooled333,14023.9%Not pooled
Fairbanks North Star Boroughhighest in the state7219.4%1.4 pCi/L
Anchorage Municipalitylowest in the state1303.1%0.5 pCi/L
Nome Census Area, AKborders it20.0%0.9 pCi/L
The nearest Alaska counties to Kusilvak Census Area with 30 or more tests, 2022
CountyDistanceTestsAt or above 4 pCi/LMedian
Matanuska-Susitna Borough445 mi4214.3%1.1 pCi/L
Anchorage Municipality474 mi1303.1%0.5 pCi/L
Fairbanks North Star Borough550 mi7219.4%1.4 pCi/L

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

Kusilvak Census Area, Geology

The ground under Kusilvak Census Area

Predicted

USGS's geologic map puts all of Kusilvak Census Area's mapped land in one class: moderate radon potential. 99.0% of it lies in the area the map calls Central Alaska, to which USGS gives a radon index of 11, in the moderate band (9 to 11).

USGS's geologic areas under Kusilvak Census Area
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central AlaskaUraniferous granites, felsic intrusives; clastic and carbonate sedimentary rocks; metamorphic, and volcanic rocks.Moderate1199.0%

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

Kusilvak Census Area beside the ground around it

Kusilvak Census Area has more moderate-potential ground than Alaska as a whole: 99.0% of its land against 79.2%. Of the 3 boroughs and census areas that border it, 1 has more moderate-potential ground, Yukon-Koyukuk Census Area the most at 100%.

Share of land by USGS radon potential: Kusilvak Census Area, the 3 boroughs and census areas bordering it and Alaska
AreaEPA zoneLow potentialModerate potentialHigh potential
Kusilvak Census AreaZone 3None99.0%None
Bethel Census AreaZone 3None97.8%None
Nome Census AreaZone 3None96.8%None
Yukon-Koyukuk Census AreaZone 3None100%None
Alaska29 boroughs and census areas, pooled by land areaVaries19.2%79.2%None

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

Local help

Kusilvak Census Area, Local resources

Radon testing and mitigation in Kusilvak Census Area

What Alaska's program says
Phone
907-269-6401
Email
paul.goodfellow@alaska.gov

What it means

Kusilvak Census Area, Questions

Questions about radon in Kusilvak Census Area

Are radon levels high in Kusilvak Census Area?

In 2020, 0.0% of the radon tests reported to CDC for Kusilvak Census Area, Alaska were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.2 pCi/L. Of the 3 nearest counties with a figure, within 550 miles, the share of tests at or above 4 pCi/L runs from 3.1% to 19.4%.

Which counties border Kusilvak Census Area?

Kusilvak Census Area borders 3 boroughs and census areas: Bethel Census Area, Nome Census Area and Yukon-Koyukuk Census Area.

Products

Kusilvak Census Area, Products

Testing a home in Kusilvak Census Area

No CDC figure names Kusilvak Census Area; the nearest county with one, Matanuska-Susitna Borough (445 miles away), reported 14.3% of its tests at or above 4 pCi/L in 2022, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Kusilvak Census Area.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Kusilvak Census Area homes, compared

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Kusilvak Census Area, Bordering boroughs and census areas

Boroughs and census areas bordering Kusilvak Census Area

Calculated by Radon411

Kusilvak Census Area, Cities and towns

Cities and towns in Kusilvak Census Area

Kusilvak Census Area has been losing residents: from 8,367 in 2020 to 7,932 on July 1, 2025, a fall of 5.2% by the Census Bureau's estimates. Spread over its land, that is 0.5 people to the square mile. No town dominates: Hooper Bay, the largest, has 1,297 residents, 16.4% of the total. Together its 12 incorporated places hold 97.2% of those residents; the other 2.8% live outside any of them. Reported testing is thin here: 1 test over 2020, or 0.1 for every 1,000 residents (2025 estimate), where Alaska as a whole comes to 0.8.

From Hooper Bay to Nunam Iqua, CDC publishes no figure by town: each reads Kusilvak Census Area's.

The cities and towns in Kusilvak Census Area by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Hooper Bay1,297−5.6%16.4%
Chevak898−5.5%11.3%
Emmonak785−5.1%9.9%
Alakanuk718−4.9%9.1%
Kotlik624−5.0%7.9%
Pilot Station587−5.0%7.4%
Mountain Village585−5.3%7.4%
Scammon Bay574−5.0%7.2%
St. Mary's567−5.3%7.1%
Marshall468−4.9%5.9%
Russian Mission402−5.0%5.1%
Nunam Iqua207−5.0%2.6%

12 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).

Kusilvak Census Area, Homes

Homes in Kusilvak Census Area

Kusilvak Census Area is a place of houses on their own lots: 91% of its 2,341 homes are detached single-family houses, against 63% across Alaska. Half of its homes were built before 1988, close to Alaska's 1985: 2% date from before 1960 and 28% from 2000 or later. 69% of occupied homes are lived in by their owner (Alaska: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Kusilvak Census Area, Alaska, 2019 to 2023
HomesKusilvak Census AreaAlaska
Housing units2,341327,610
Detached houses91%63%
In buildings of 5 or more1%12%
Mobile homes1%4%
Built before 19602%8%
Built since 200028%25%
Middle year built19881985
Owner-occupied69%67%

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