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Radon in Scottsdale, Arizona

EPA puts Maricopa County, where Scottsdale is, in Zone 2, its middle radon zone, and 17.4% of its 2,393 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

    17.4%

    0.6 pts above AZ

    Maricopa
    17.4%
    Arizona
    16.8%

    Maricopa, 2nd of 6 in AZ, 2008 to 2017

  • Median result

    1.6pCi/L

    Below action level

    Maricopa
    1.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of Maricopa's tests, 2008 to 2017

  • Nearest county

    8.9%

    Pinal, 62 miles

    Pinal
    8.9%
    Maricopa
    17.4%

    101 tests, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    Maricopa, where Scottsdale is

  • Tests reported

    2,393

    In Maricopa

    Maricopa
    2,393
    Pinal
    101

    Reported to CDC before any fix, 2008 to 2017

Read a result for Scottsdale

Starts at Maricopa County's median, 1.6 pCi/L

1.6pCi/L

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

EPA’s reading of 1.6 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. Maricopa County's median reported result, 2008 to 2017.

Interpret this reading

The data

Scottsdale, What is published

What is published for Scottsdale

Information:

Every figure for Scottsdale is a county's

Radon data is published by county, not by city, so for Scottsdale it is Maricopa County's: its EPA zone (Zone 2) and the 2,393 tests reported to CDC for 2008 to 2017, laboratory. Only a test tells you about one home.

Scottsdale covers 184 square miles of land, all of it in Maricopa County. About 243,006 people live there, 1,321 to the square mile.

Scottsdale, Counties

The county Scottsdale lies in

Measured

Maricopa County's EPA zone and the figures CDC publishes for it, 2008 to 2017, laboratory.

Maricopa CountyZone 2Moderate predicted potential

17.4%
Reported tests at or above 4 pCi/L
1.6 pCi/L
Median reported result
2,393 tests
Tests reported to CDC
None
Yearly figures on file

Maricopa County ranks 2nd of 6 Arizona counties with 30 or more tests for that period, 0.6 points above the 16.8% pooled across Arizona's counties, 18.3 points below the national pool of 35.7%.

The counties nearest Scottsdale with a CDC figure for 2008 to 2017, laboratory, measured from the middle of the city: Pinal County (62 miles, 8.9% of 101 tests), Yavapai County (74 miles, 16.2% of 265 tests) and Pima County (110 miles, 6.8% of 410 tests). Across the 5 nearest, the share at or above 4 pCi/L runs from 4.1% to 30.0%; the farthest of them, Mohave County, is 176 miles away at 4.1%.

No business in the directory gives Scottsdale as its address; the Arizona list covers it. Arizona's other cities with a page of their own: Phoenix and Tucson.

The counties around Scottsdale

By distance from the middle of Scottsdale; counties with 30 or more tests.

Nearest counties to Scottsdale with 30 or more tests
CountyDistanceTestsAt or above 4 pCi/LMedian
Pinal County62 mi1018.9%0.9 pCi/L
Yavapai County74 mi26516.2%1.6 pCi/L
Pima County110 mi4106.8%1.1 pCi/L
Coconino County148 mi27330.0%2.3 pCi/L
Mohave County176 mi494.1%0.2 pCi/L

Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2008 to 2017, laboratory.

Scottsdale, Geology

The ground under Scottsdale

Predicted

USGS's geologic map splits Scottsdale: 60.6% of its land is moderate radon potential and 39.4% low. The map puts 60.6% of Scottsdale in the area it calls Transition Zone and 39.4% in Basin and Range/Sonoran Desert. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).

USGS's geologic areas under Scottsdale
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Transition ZonePrecambrian igneous, metamorphic and sedimentary rocks and Tertiary volcanic rocks.Moderate1060.6%
Basin and Range/Sonoran DesertQuaternary to Tertiary sediments, with uranium-bearing Tertiary volcanic rocks, highly variable volcanic, metamorphic, and sedimentary rocks, and eolian depositsLow839.4%

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

Scottsdale beside its county and Arizona

Scottsdale sits on more moderate-potential ground than Maricopa County as a whole: 60.6% of the city against 15.9% of the county. Across Arizona 0.1% of the land is rated high; none of Scottsdale's is.

Share of land by USGS radon potential: Scottsdale, the county it lies in and Arizona
AreaEPA zoneLow potentialModerate potentialHigh potential
ScottsdaleBy county39.4%60.6%None
Maricopa CountyZone 284.1%15.9%None
Arizona15 counties, pooled by land areaVaries42.8%57.1%0.1%

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

Scottsdale, Homes

Homes in Scottsdale

Fewer than six in ten of Scottsdale's 138,422 homes are detached houses (53%, against 64% across Maricopa County); the rest are attached, in shared buildings or mobile. Half of its homes were built before 1990, close to Maricopa County's 1992: 6% date from before 1960 and 26% from 2000 or later. 68% of occupied homes are lived in by their owner (Maricopa County: 65%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Scottsdale, Maricopa County, Arizona, 2019 to 2023
HomesScottsdaleMaricopa CountyArizona
Housing units138,4221,850,8623,142,443
Detached houses53%64%64%
In buildings of 5 or more29%20%16%
Mobile homes1%5%10%
Built before 19606%7%8%
Built since 200026%35%35%
Middle year built199019921992
Owner-occupied68%65%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

Scottsdale, Local resources

Local resources for Scottsdale

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

What it means

Scottsdale, Questions

Questions about radon in Scottsdale

What radon zone is Scottsdale in?

EPA's map puts Maricopa County, and with it Scottsdale, in Zone 2, the map's middle class: a predicted county average of 2 to 4 pCi/L.

What are radon levels in Scottsdale?

Maricopa County's 2,393 tests for 2008 to 2017 (laboratory totals) put 17.4% at or above 4 pCi/L: most tests near Scottsdale come back under EPA's action level, but not all. The median reported result was 1.6 pCi/L.

Should I test my home in Scottsdale?

Yes. Roughly one reported test in 6 in Maricopa County reached 4 pCi/L. That is about what Arizona as a whole reports (16.8%), and ranks Maricopa County 2nd of the 6 Arizona counties with 30 or more tests. Only a test puts a number on one house. How to test a home.

What ground is Scottsdale built on, as far as radon goes?

60.6% of Scottsdale sits on what USGS's map calls "Transition Zone", rated moderate for radon potential, radon index 10; another 39.4% is "Basin and Range/Sonoran Desert", rated low for radon potential, radon index 8. So the ground changes within Scottsdale itself.

Is radon higher in the counties around Scottsdale?

Some are and some are not. Against Maricopa County's 17.4%, 1 of the 5 nearest counties with a figure report more and 4 less, from Mohave County (4.1%, 176 miles off) to Coconino County (30.0%, 148 miles off).

The answers use the published figures of Maricopa County, the county Scottsdale lies in.

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