Radon levels in Freeport, New York
LowEPA Zone 3Predicted long-term basement average of 1.2 pCi/L (model estimate) across the 1 modeled ZIP codes in Freeport - about 32% below the US average of 1.8, close to the New York average of 1.4. Ranked #13 of 21 New York cities on this site. Most of the city lies in Nassau County.
Test Freeport, NY once anyway - radon varies house to house
The predicted basement average here is 1.2 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. Measured state test results are shown separately below, labeled with their source and years. How the numbers work.
1.2 ± 0.07
pCi/L predicted basement mean (model SD)
0.6 ± 0.12
pCi/L predicted upstairs (above-ground) mean
1.2-1.2
range of ZIP-level basement predictions in the city
0%
of Freeport ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)
Measured radon tests in Nassau County (New York State Department of Health, 1987-2025)
Actual results from home radon tests reported to the state, separate from the model estimate above. Coverage: 1987-2025.
- Measured mean
- 1.3 pCi/L
- Results ≥ 4 pCi/L
- 4.7%
- Basement tests, mean
- 1.5 pCi/L
- First-floor tests, mean
- 0.8 pCi/L
- Sample
- 1,083 tests
| Figure | Model (predicted) | State tests (measured) |
|---|---|---|
| Mean, pCi/L | 1.3 basement | 1.3 (1.5 basement) |
| Share ≥ 4 pCi/L | not a model output | 4.7% |
The model and the state test data land within a few tenths of a pCi/L of each other here; the model estimates a long-term basement average while the tests are voluntary, mostly short-term results.
Source: Radon Test Results By County: Beginning 1987, New York State Department of Health, Bureau of Environmental Radiation Protection. No license field on the dataset. Method and download.
What this means for Freeport
The typical Freeport home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 1.2 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). The 1993 EPA zone (3) for Nassau and the 2001-2021 model agree here.
Comparable New York cities: Schenectady (1.3), Levittown (1.3), Yonkers (1.3), Irondequoit (1.3).
ZIP codes in Freeport
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.
| ZIP | Share of city | Basement | Upstairs | Grade |
|---|---|---|---|---|
| 11520 | 100% | 1.2 ± 0.07 | 0.6 | Low |
Testing help in New York
New York's radon program page is at www.health.ny.gov and, when we checked it, offered low-cost test kits through the Radon Program. 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.
Freeport radon questions
- Is radon high in Freeport, New York?
- Low. Averaging the model's ZIP-code predictions across Freeport (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.2 pCi/L - about 32% below the US average of 1.8 and close to the New York average of 1.4. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Freeport ranks 13 of 21 New York cities on this site.
- What do actual radon tests show around Freeport?
- New York State Department of Health publishes results for Nassau County (not the city alone) covering 1987-2025 (1,083 tests): an average of 1.3 pCi/L, 4.7% of results at or above the 4 pCi/L action level. These are voluntary home tests, so they skew toward basements and toward homes where radon was suspected; the model's predicted basement average for Freeport is 1.2 pCi/L.
- Which Freeport ZIP codes have the highest radon?
- Predictions for the 1 modeled ZIP codes in Freeport range from 1.2 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 Freeport?
- Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Freeport's low predicted average describes the typical home, not yours.
- What does EPA Radon Zone 3 mean for Freeport?
- Freeport sits mainly in Nassau County, which the EPA classifies as Zone 3 - low potential (< 2 pCi/L). The zone map dates from 1993 and covers whole counties. The 2001-2021 model agrees with the zone for the city. Neither replaces a test of your own home.
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