52%tests ≥ 4 pCi/L
96tests on record
4.1median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Louisa County

ResultShareEPA guidance
Below 2 pCi/L24%Below EPA's levels
2 to 4 pCi/L24%Consider fixing
4 pCi/L or more52%EPA recommends fixing

What the data shows

Where Louisa County sits among Iowa's 99 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Iowa radon test results from laboratories, 2008–2017
0%20%40%60%80%

How Louisa County compares

Louisa County ranks 2 of 6 among its neighboursShare of tests at or above 4 pCi/L · Iowa radon test results from laboratories, 2008–2017 · whisker: 95% range
Washington County55%Louisa County52%Des Moines County51%Muscatine County47%Henry County46%Johnson County42%Iowa 58%
Data table
AreaTests ≥ 4 pCi/LTests
Washington County55%1,186
Louisa County52%96
Des Moines County51%436
Muscatine County47%954
Henry County46%168
Johnson County42%7,321
Iowa (99 counties)58%95,245

Same source as Louisa County. Other bordering counties: Mercer County, Illinois, Rock Island County, Illinois.

What it means for your home

More than half of all results in Louisa 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 →

Iowa licenses radon mitigators. Source

Buying or selling here

Iowa sellers complete the Real Estate Commission's disclosure statement and must give buyers the "Iowa Radon Home-Buyers and Sellers Fact Sheet" (Iowa Admin. Code 193E). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Iowa radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 96. 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