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RadonVerdict

County evidence note

Radon zone and test data for Falls Church, VA

County data can show why testing matters. It cannot tell you the radon level in a particular house. The only property-level answer comes from a valid test.

What the source supports

Falls Church is a retest-and-watch market, not a dismiss-it market.

Falls Church, VA is measurement-backed for 2016-2024. The measured average is 2.6 pCi/L. The high-end signal reaches 24.4 pCi/L.

Source hierarchy: Virginia Department of Health is used for this county, with EPA zone and Census housing data kept as supporting context. Virginia values come from VDH-received 2016-2024 indoor air radon results by locality. VDH suppresses averages below 25 tests, so test count and maximum can remain useful even when the average is unavailable.

EPA map zone: Zone 1

The EPA map predicts broad county potential; it is not a measurement for an address.

Source: Virginia Department of Health Radon Testing Results

Coverage: 2016-2024 ยท retrieved 2026-05-06

Open the original source

What to do with this information

  1. 1. Test the homeUse a valid device and record duration, placement, and conditions.
  2. 2. Interpret the resultTreat 4.0 pCi/L as the main action threshold and preserve the testing context.
  3. 3. Use qualified helpFor testing or mitigation, use state requirements and recognized proficiency programs.

Evidence profile for Falls Church

Reported average2.6 pCi/L
At or above 4.0Not available
Source test volume165 reported tests
Comparison cohort134

Virginia values come from VDH-received 2016-2024 indoor air radon results by locality. VDH suppresses averages below 25 tests, so test count and maximum can remain useful even when the average is unavailable.

Nearby comparison: Closest counties by county average: Amelia County (2.5 pCi/L) is just lower, and Fredericksburg (2.6 pCi/L) is just higher.

Editorial and Data Transparency

Author
RadonVerdict (Independent public-data software project)
Evidence Review
Official and primary sources cited below
Data Retrieved At
2026-02-24

Primary Sources