Radon levels in Royal Oak, Michigan

LowEPA Zone 2

Predicted long-term basement average of 1.0 pCi/L (model estimate) across the 2 modeled ZIP codes in Royal Oak - about 43% below the US average of 1.8, about 36% below the Michigan average of 1.6. Ranked #25 of 27 Michigan cities on this site. Most of the city lies in Oakland County.

Test Royal Oak, MI once anyway - radon varies house to house

The predicted basement average here is 1.0 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.

1.0 ± 0.07

pCi/L predicted basement mean (model SD)

0.8 ± 0.06

pCi/L predicted upstairs (above-ground) mean

0.9-1.2

range of ZIP-level basement predictions in the city

0%

of Royal Oak ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)

What this means for Royal Oak

The typical Royal Oak home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 0.9 to 1.2 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 city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). Note that the EPA classifies Oakland County as Zone 2 while the newer model predicts 1.0 pCi/L for Royal Oak; where they disagree, we grade on the model but show both.

Comparable Michigan cities: Detroit (1.0), Roseville (1.0), St. Clair Shores (1.1), Warren (1.1).

ZIP codes in Royal Oak

ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.

ZIPShare of cityBasementUpstairsGrade
4807361%1.2 ± 0.060.8Low
4806739%0.9 ± 0.080.8Low

Testing help in Michigan

Michigan's radon program page is at www.michigan.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.

Royal Oak radon questions

Is radon high in Royal Oak, Michigan?
Low. Averaging the model's ZIP-code predictions across Royal Oak (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.0 pCi/L - about 43% below the US average of 1.8 and about 36% below the Michigan average of 1.6. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Royal Oak ranks 25 of 27 Michigan cities on this site.
Which Royal Oak ZIP codes have the highest radon?
Predictions for the 2 modeled ZIP codes in Royal Oak range from 0.9 to 1.2 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 Royal Oak?
Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Royal Oak's low predicted average describes the typical home, not yours.
What does EPA Radon Zone 2 mean for Royal Oak?
Royal Oak sits mainly in Oakland 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 1.0 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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