Radon levels in Casas Adobes, Arizona
LowEPA Zone 2Predicted long-term basement average of 1.8 pCi/L (model estimate) across the 3 modeled ZIP codes in Casas Adobes - close to the US average of 1.8, close to the Arizona average of 1.7. Ranked #12 of 27 Arizona cities on this site. Most of the census-designated place lies in Pima County.
Test Casas Adobes, AZ once anyway - radon varies house to house
The predicted basement average here is 1.8 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.
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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
1.8 ± 0.06
pCi/L predicted basement mean (model SD)
0.9 ± 0.08
pCi/L predicted upstairs (above-ground) mean
1.7-1.8
range of ZIP-level basement predictions in the city
0%
of Casas Adobes ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)
What this means for Casas Adobes
The typical Casas Adobes home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 1.7 to 1.8 pCi/L.
The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the census-designated place's land in each ZIP (Census 2020 ZCTA-to-place relationship file). Note that the EPA classifies Pima County as Zone 2 while the newer model predicts 1.8 pCi/L for Casas Adobes; where they disagree, we grade on the model but show both.
Comparable Arizona cities: Goodyear (1.8), Lake Havasu City (1.8), Marana (1.8), Oro Valley (1.8).
ZIP codes in Casas Adobes
ZIPs that overlap the census-designated place, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.
| ZIP | Share of city | Basement | Upstairs | Grade |
|---|---|---|---|---|
| 85704 | 50% | 1.8 ± 0.06 | 0.9 | Low |
| 85741 | 29% | 1.7 ± 0.07 | 0.8 | Low |
| 85742 | 22% | 1.8 ± 0.06 | 0.9 | Low |
Testing help in Arizona
Arizona's radon program page is at www.azdhs.gov; it lists testing and certified-mitigator guidance. EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.
Casas Adobes radon questions
- Is radon high in Casas Adobes, Arizona?
- Low. Averaging the model's ZIP-code predictions across Casas Adobes (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.8 pCi/L - close to the US average of 1.8 and close to the Arizona average of 1.7. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Casas Adobes ranks 12 of 27 Arizona cities on this site.
- Which Casas Adobes ZIP codes have the highest radon?
- Predictions for the 3 modeled ZIP codes in Casas Adobes range from 1.7 to 1.8 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. The city is fairly uniform, so the city-wide number is a reasonable guide for any neighborhood.
- Should I test for radon in Casas Adobes?
- Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Casas Adobes's low predicted average describes the typical home, not yours.
- What does EPA Radon Zone 2 mean for Casas Adobes?
- Casas Adobes sits mainly in Pima County, which the EPA classifies as Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and covers whole counties. The newer model's city average of 1.8 pCi/L does not line up with Zone 2, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.
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