12%tests ≥ 4 pCi/L
335tests on record
1.0median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Ventura County

ResultShareEPA guidance
Below 2 pCi/L74%Below EPA's levels
2 to 4 pCi/L14%Consider fixing
4 pCi/L or more12%EPA recommends fixing

What the data shows

Where Ventura County sits among California's 56 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 Ventura County compares

Ventura County ranks 2 of 4 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Santa Barbara County18%Ventura County12%Kern County12%Los Angeles County9%California 10%
Data table
AreaTests ≥ 4 pCi/LTests
Santa Barbara County18%421
Ventura County12%335
Kern County12%121
Los Angeles County9%2,363
California (56 counties)10%9,415

Same source as Ventura County.

What it means for your home

About 1 in 8 results in Ventura 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: 335. 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