Highest result per tested property in Cook County
| Result | Share | EPA guidance |
|---|---|---|
| Below 2 pCi/L | 34% | Below EPA's levels |
| 2 to 4 pCi/L | 26% | Consider fixing |
| 4 pCi/L or more | 41% | EPA recommends fixing |
What the data shows
- Higher share of high results than 27 of 87 Minnesota counties.
- 66% of results at or above 2 pCi/L.
- EPA's 1993 map: Zone 2, an average between 2 and 4 pCi/L. Measured average: 4.8 pCi/L.
- 1 in 20 results above 13.1 pCi/L.
- Median result 2.9 pCi/L: between the 2 and 4 pCi/L EPA levels.
How Cook County compares
Data table
| Area | Properties ≥ 4 pCi/L |
|---|---|
| Cook County | 41% |
| Lake County | 26% |
Same source as Cook County. Other bordering counties: Ashland County, Wisconsin, Keweenaw County, Michigan, Ontonagon County, Michigan.
What it means for your home
About 1 in 2 results in Cook County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.
Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.
Test your home
Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide
Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.
Prefer a digital monitor? See Airthings radon monitors, or enter code radonbycounty-10OFF at their discount store for 10% off.
Fixing high radon
No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →
Minnesota licenses radon mitigators. Source
Buying or selling here
Minnesota's Radon Awareness Act requires sellers to disclose in writing any known radon tests, results and mitigation, and to give buyers the Department of Health publication "Radon in Real Estate Transactions" (Minn. Stat. § 144.496). Source
Checked against the official text on 2026-11-03. Not legal advice.
About this data
Source: Minnesota county radon testing indicators (Minnesota Department of Health). Period: 2016–2025. Published indicators: 156 properties at or above 4 pCi/L, 255 at or above 2 pCi/L, and 38 properties tested annually on average. Read the methodology →
These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.
About this page
Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us