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Radon in Johnson City, Tennessee

Johnson City lies in 3 counties, in EPA Zones 1 and 2. Homes with elevated levels occur in all three zones, so the only way to know your home's level is to test it.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    47.2%

    13.9 pts above TN

    Carter
    47.2%
    Tennessee
    33.3%

    Carter, 10th of 80 in TN, 2008 to 2017

  • Median result

    3.7pCi/L

    Below action level

    Carter
    3.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of Carter's tests, 2008 to 2017

  • Highest county

    51.5%

    Sullivan

    Sullivan
    51.5%
    Washington
    26.1%

    3 counties, 3 with 30+ tests, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    Carter; Sullivan Zone 1, Washington Zone 1

  • Tests reported

    345

    In Carter

    Carter
    345
    Sullivan
    1,799

    Reported to CDC before any fix, 2008 to 2017

Read a result for Johnson City

Starts at Carter County's median, 3.7 pCi/L

3.7pCi/L

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

EPA’s reading of 3.7 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Carter County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Johnson City, What is published

What is published for Johnson City

Information:

Every figure for Johnson City is a county's

Radon data is published by county, not by city, and Johnson City reaches into 3 counties: Carter County, Sullivan County and Washington County. Each has its own EPA zone and its own CDC test figures, set side by side below and each labelled with its county. Only a test tells you about one home.

About 74,943 people live in Johnson City.

Johnson City, Counties

Johnson City's counties, side by side

Measured

Each county's own EPA zone and its own published CDC figures for 2023, the newest period any of them has. A county without a figure for that period is shown without one, never with a figure from another year.

  • Carter County
    EPA zone
    Zone 2: Moderate predicted potential
    At or above 4 pCi/L
    0.0%
    Median result
    1.2 pCi/L
    Tests reported
    9 tests
    Annual years on file
    2
  • Sullivan County
    EPA zone
    Zone 1: Highest predicted potential
    At or above 4 pCi/L
    37.0%
    Median result
    2.6 pCi/L
    Tests reported
    27 tests
    Annual years on file
    2
  • Washington County
    EPA zone
    Zone 1: Highest predicted potential
    At or above 4 pCi/L
    26.1%
    Median result
    2.3 pCi/L
    Tests reported
    46 tests
    Annual years on file
    2
The counties Johnson City lies in, each with its own EPA zone and its own published CDC figures for 2023
CountyEPA zoneReported tests at or above 4 pCi/LMedian reported resultTests reportedAnnual years on file
Carter CountyZone 2: Moderate predicted potential0.0%1.2 pCi/L9 tests2
Sullivan CountyZone 1: Highest predicted potential37.0%2.6 pCi/L27 tests2
Washington CountyZone 1: Highest predicted potential26.1%2.3 pCi/L46 tests2

Johnson City spans 3 counties, each with its own EPA zone and its own CDC figure: Carter County (Zone 2, 0.0% of 9 tests), Sullivan County (Zone 1, 37.0% of 27 tests) and Washington County (Zone 1, 26.1% of 46 tests).

Carter County ranks 10th of 80 Tennessee counties with 30 or more tests for that period, 33.3 points below the 33.3% pooled across Tennessee's counties, 35.7 points below the national pool of 35.7%. Of the city's other counties, Sullivan County reported 37.0% and Washington County reported 26.1%.

The counties nearest Carter County, one of the counties Johnson City lies in, with a CDC figure for 2008 to 2017, laboratory: Johnson County (19 miles, 34.4% of 157 tests), Unicoi County (21 miles, 37.1% of 132 tests) and Greene County (41 miles, 46.0% of 385 tests). Across the 8 nearest, the share at or above 4 pCi/L runs from 34.4% to 56.8%; the farthest of them, Grainger County, is 77 miles away at 48.2%.

No business in the directory gives Johnson City as its address; the Tennessee list covers it. Tennessee's other cities with a page of their own: Nashville, Knoxville, Chattanooga and Cleveland.

Against Tennessee and its other counties

Radon test figures for the counties Johnson City lies in
CountyTestsAt or above 4 pCi/LMedianTennessee, pooledRank in the stateEPA zone
Carter County34547.2%3.7 pCi/L33.3%10 of 80Zone 2
Sullivan County1,79951.5%4.2 pCi/L33.3%5 of 80Zone 1
Washington County4626.1%2.3 pCi/L24.9%5 of 15Zone 1

Shares of tests people chose to run and report, by county (2008 to 2017, laboratory); the state's is its counties' counts added up, calculated by Radon411. Only a test measures a home.

The counties around Johnson City

By distance from Carter County; counties with 30 or more tests.

Nearest counties to Carter County with 30 or more tests
CountyDistanceTestsAt or above 4 pCi/LMedian
Johnson County19 mi15734.4%2.3 pCi/L
Unicoi County21 mi13237.1%2.8 pCi/L
Greene County41 mi38546.0%3.6 pCi/L
Hawkins County47 mi28938.4%2.7 pCi/L
Cocke County61 mi5646.4%3.8 pCi/L
Hamblen County64 mi18645.2%3.5 pCi/L
Jefferson County76 mi14656.8%4.7 pCi/L
Grainger County77 mi5648.2%3.8 pCi/L

The median reported pre-mitigation result for 2023 was 1.2 pCi/L in Carter County, 2.6 pCi/L in Sullivan County and 2.3 pCi/L in Washington County.

Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2023.

Johnson City, Homes

Homes in Johnson City

Fewer than six in ten of Johnson City's 33,086 homes are detached houses (53%, against 68% across Carter County); the rest are attached, in shared buildings or mobile. Half of its homes were built before 1983, close to Carter County's 1977: 22% date from before 1960 and 26% from 2000 or later. Most occupied homes here are rented: owners live in 50% (Carter County: 74%). A tenant can run a test; a fix is the landlord's to make.

Homes in Johnson City, Carter County, Tennessee, 2019 to 2023
HomesJohnson CityCarter CountyTennessee
Housing units33,08627,9823,095,472
Detached houses53%68%68%
In buildings of 5 or more26%7%14%
Mobile homes4%18%8%
Built before 196022%29%18%
Built since 200026%17%29%
Middle year built198319771986
Owner-occupied50%74%67%

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

Local help

Johnson City, Local resources

Local resources for Johnson City

Who to ask in Tennessee: its radon program, test kits and professionals.

The program's own words on licensing are on the Tennessee page.

What it means

Johnson City, Questions

Questions about radon in Johnson City

What radon zone is Johnson City in?

A zone line runs through Johnson City: Sullivan County and Washington County in Zone 1 and Carter County in Zone 2. Which zone applies depends on the county an address is in.

What are radon levels in Johnson City?

Only 9 tests from Carter County are on file with CDC for 2023, 0.0% of them at or above 4 pCi/L: too few to say how Johnson City runs. Sullivan County reported 37.0% of 27 tests and Washington County reported 26.1% of 46 tests; the counties are kept apart.

Should I test my home in Johnson City?

Yes. About 12 of the 46 tests reported from Washington County were at or above 4 pCi/L. No map says which homes those are. How to test a home.

Is radon higher in the counties around Johnson City?

Yes, in every direction measured. Each of the 8 nearest counties with a figure reports a larger share of high tests than Carter County's 0.0%; the highest is Jefferson County (56.8%, 76 miles off).

The answers use the published figures of Carter County, Sullivan County and Washington County, the counties Johnson City lies in.

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