41%tests ≥ 4 pCi/L
146tests on record
2.9median pCi/L
Zone 2EPA zone (1993 prediction)

Test results in St. Francois County

ResultShareEPA guidance
Below 2 pCi/L37%Below EPA's levels
2 to 4 pCi/L22%Consider fixing
4 pCi/L or more41%EPA recommends fixing

What the data shows

Where St. Francois County sits among Missouri's 115 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%20%40%60%

How St. Francois County compares

St. Francois County ranks 3 of 7 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Iron County50%Jefferson County42%St. Francois County41%Madison County39%Perry County38%Ste. Genevieve County31%Washington County26%Missouri 31%
Data table
AreaTests ≥ 4 pCi/LTests
Iron County50%14
Jefferson County42%2,652
St. Francois County41%146
Madison County39%23
Perry County38%82
Ste. Genevieve County31%74
Washington County26%38
Missouri (115 counties)31%58,525

Same source as St. Francois County.

What it means for your home

About 1 in 2 results in St. Francois 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.

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Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 146. 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