Radon Levels & Zone Map in Mathews County, VA
Direct Answer for basement and lowest-level tests: Mathews County has a lower countywide signal, but that does not clear an individual home. A real test still beats the map.
Low county risk is not a home-level clear signal
Do not let a Zone 3 label talk you out of the first test. House-by-house differences still matter.
Official source shows a highest reported county value, not a county average.
2.0-3.9 pCi/L usually means retest or track. 4.0+ is where EPA action and quote planning start to matter.
Low zone is not a free pass. Use a kit before you rule radon out.
Measured Radon Data
Mathews County evidence before the next step
Mathews County, VA has more than the EPA map: Virginia Department of Health exposes 4 reported tests, and 1.8 pCi/L high-end signal for 2016-2024.
Source window
2016-2024
County evidence type
High-end source present
County context only; your home test controls the decision.
Highest measured
1.8 pCi/L
5th percentile in-state
4.0+ signal
Not available
n/a in-state
High-end signal
1.8 pCi/L
5th percentile in-state
Official evidence dossier
Source record for Mathews County, VA
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.
Primary public source
Official county measurements
Measurement window
2016-2024
Retrieved / checked
2026-05-06
County FIPS
51115
Evidence stack
County source
Official county measurements
Primary source used for the county evidence row.
Federal map
EPA Map of Radon Zones
Zone 3 is context, not a property result.
Housing context
US Census ACS housing context
43.4% built before 1980; 5,478 housing units.
State follow-up
State radon program
Use the state source before hiring or interpreting local rules.
Primary field
1.8 pCi/L
Median field
Not available
4.0+ field
Not available
Sample / volume
4 reported tests
Metric shape
This source gives the highest measured value, not a county average. Use it to know high readings have happened locally, then verify your own home.
Source limitation
VDH says the map displays indoor air radon results received by its Radon Program from 2016-2024, using voluntary reports from five major radon test-kit vendors and professional testers after removing duplicates, post-mitigation tests, inappropriate locations, upper-floor tests, and incomplete addresses. VDH suppresses locality averages when fewer than 25 tests are available. RadonVerdict normalized the rendered VDH Tableau table because Tableau Public summary data, crosstab, and workbook export are permission-denied.
Property-level limit
Not a property-level diagnosis. The county record explains local evidence; your home's own test result controls the next decision.
County-specific interpretation
Mathews County has an official high-end county result of 1.8 pCi/L, but no county average in this source.
Mathews County is not being read from an average table here. Virginia Department of Health exposes a highest measured county value of 1.8 pCi/L, so the useful decision is proof of local spike potential: test the home directly, then use a 4.0+ property result for mitigation pricing. It ranks at the 5th percentile for high-end readings among measured counties in the state.
Real-estate use
Buyer or seller use: do not negotiate from the highest county value alone. Use it to justify requiring a fresh lowest-level property test, then price quotes or credits only from the home's own 4.0+ result.
Mathews County should be treated as a direct-test county: the official high-end value reaches 1.8 pCi/L, but the source cannot tell whether a specific home is high until that home is tested.
Use This EvidenceOfficial state path
Open the state radon program
Use state rules and local program contacts before choosing a contractor.
EPA hiring guidance
Find a qualified radon provider
EPA points homeowners to state programs and national proficiency listings.
Certified professional search
Search NRPP-certified pros
Use this after you have a valid result or need professional testing.
High-end-source answer
What does the highest reported radon result mean in Mathews County?
Virginia Department of Health reports a highest measured county value of 1.8 pCi/L for Mathews County. That is a high-end local signal, not a county average. The practical answer is to test the property and let the home's result decide mitigation, retesting, or credit math.
Enter the result. Pick the deal side. Get the route.
Official source shows a highest reported county value, not a county average.
County signal
1.8 pCi/L
At or above 4.0
Not available
Decision side
Foundation clue
Choose your next step
Start from the exact job, not another generic radon article.
Pick the situation that matches Mathews County, VA. Each route keeps the reading, deal side, or foundation clue attached so the next page answers the search instead of resetting the user.
Failed inspection
I need a repair or seller credit number
Open the local credit path with a 4.0+ buyer scenario already selected.
Open negotiation route4.0+ pCi/L
I have a high result and need the cost path
Go straight to the county estimate, quote context, and contractor checklist.
Open cost route2.0-3.9 pCi/L
I need to know if this number is bad
Use the level explanation first, then decide whether to retest, monitor, or price mitigation.
Open level routeNo test yet
I need the first valid result
Start with kit placement, timing, closed-house conditions, and result interpretation.
Open testing routePick the situation that matches you
You should not need to read the whole guide before clicking one of these. Start with the lane that matches your current stage, then come back for the deeper reference only if you still need it.
Jump into a prefilled Mathews County action plan based on the result you already have, instead of starting from a generic cost page.
I have not tested yet
Do not price mitigation blind. Get the first number, then decide whether you need monitoring, quotes, or nothing at all.
My result is 2.0-3.9
Usually confirm the reading first. If it keeps showing up, use the county evidence and official guidance before deciding whether pricing makes sense.
My result is 4.0+
This is the EPA action line. Use the local cost page before calling contractors so you know the likely scope, timing, and budget.
I am buying or selling
Turn the reading into a credit or repair number before negotiation starts. This is the faster path than arguing from a generic article.
Already tested once and need the cleanest follow-up path?
Review retesting stepsCounty Evidence Snapshot
Mathews County testing context
Mathews County has a lower predicted countywide zone signal, so direct testing matters more than the map label.
EPA map signal
Zone 3
County-level predicted indoor screening range, not a home-level test result.
Housing base
5,478
16th percentile among 133 VA counties with data.
Older housing share
43.4%
33th percentile in-state; older homes often need clearer test placement decisions.
Median home value
$355,900
Used as context for whether mitigation is a small maintenance item or a negotiation issue.
Measured Radon Data
Virginia Department of Health Radon Testing Results
2016-2024
Highest measured
1.8 pCi/L
At or above 4.0
Not available
Maximum reported
1.8 pCi/L
Reported tests
4
VDH says the map displays indoor air radon results received by its Radon Program from 2016-2024, using voluntary reports from five major radon test-kit vendors and professional testers after removing duplicates, post-mitigation tests, inappropriate locations, upper-floor tests, and incomplete addresses. VDH suppresses locality averages when fewer than 25 tests are available. RadonVerdict normalized the rendered VDH Tableau table because Tableau Public summary data, crosstab, and workbook export are permission-denied.
County evidence interpretation
High-end source present
High-end rank
5th percentile
1.8 pCi/L
4.0+ rank
n/a
Not available at or above 4.0
High-end rank
5th percentile
1.8 pCi/L
Test volume rank
8th percentile
4 reported tests
How to use this county data
Data source
Official county measurements
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.
What the numbers show
High readings have occurred
This source gives the highest measured value, not a county average. Use it to know high readings have happened locally, then verify your own home.
Nearby comparison
Nearby comparison: Closest counties by highest reported reading: Hopewell (1.8 pCi/L) is just lower, and Poquoson (1.8 pCi/L) is just higher.
How this helps
Use this to see that high readings have happened locally, then test the specific property before assuming the county value is typical.
What the data says
Mathews County, VA is measurement-backed for 2016-2024.. The high-end signal reaches 1.8 pCi/L.
Mathews County, VA sits at the n/a for measured average, n/a for 4.0+ share, 5th percentile for high-end readings, and 8th percentile for test volume among 134 measured counties in the state.
What to do with it
Mathews County should be treated as a direct-test county: the official high-end value reaches 1.8 pCi/L, but the source cannot tell whether a specific home is high until that home is tested.
Retest trigger: a 2.0-3.9 pCi/L home result should be confirmed because the official source shows local high-end readings up to 1.8 pCi/L, even though it does not publish a county average here.
Source-backed context from Virginia Department of Health based on about 4 reported tests/properties plus high-end county measurement context.
No reading yet
No reading yet: use the official high-end signal as a reason to test the home, not as a substitute for a home result.
2.0-3.9 result
2.0-3.9 pCi/L: confirm with a follow-up or longer-term test because this source proves elevated readings occur locally but does not show the full county distribution.
4.0+ result
4.0+ pCi/L: use the result for mitigation quotes, repair scope, or seller-credit negotiation; the county signal is no longer the deciding input.
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.
Direct Answer
What radon risk level should homeowners assume in Mathews County?
Mathews County is currently categorized as EPA Zone 3 (Lower Predicted Average Risk). Testing is still recommended because home-level variance can be high.
| Evidence | Value |
|---|---|
| Area | Mathews County, VA |
| EPA Zone | Zone 3 |
| Primary Recommendation | Perform direct radon testing in the lowest livable level |
Your Radon Reading
Enter your home's measured level. This county source publishes a highest reported value, so the slider does not start from a county average.
Lower Concern Range
Your reading is below the common action reference levels. Both the EPA (4.0) and WHO (2.7) thresholds are not exceeded. Mitigation is usually not the next immediate step after a confirmed low result. If you have never tested your home, use the testing guide first. If this is already a confirmed low reading, use the retesting guidance for seasonal follow-up.
Understanding Radon Levels: Complete Reference
Below 2.0 pCi/L - Lower Concern, Keep Testing
Below both the EPA (4.0) and WHO (2.7) action reference levels. This usually means mitigation is not the next immediate step after a confirmed result. The average outdoor radon level is approximately 0.4 pCi/L, and there is no known risk-free indoor level. Periodic testing is still recommended because levels can change over time due to seasonal variations, changes in home ventilation, or foundation settling.
-4.0
2.0 - 4.0 pCi/L - Elevated, Consider Action
Exceeds the World Health Organization's reference level of 2.7 pCi/L but falls below the US EPA action threshold. The EPA states that homeowners should "consider fixing" homes in this range, especially if the home has a basement used as living space, if children are present, or in connection with a real estate transaction. Practical next step: run a confirmatory long-term test, then compare mitigation quotes if levels remain elevated.
-8.0
4.0 - 8.0 pCi/L - Action Recommended
Exceeds the EPA action level of 4.0 pCi/L. The EPA and Surgeon General strongly recommend mitigation within a few months. At this level, prioritize confirmatory testing and contractor planning. Standard sub-slab depressurization systems typically reduce indoor levels by 80-99%.
Above 8.0 pCi/L - Urgent Action Required
At these levels, the EPA recommends expedited mitigation - ideally within weeks, not months. Occupants should minimize time in lower-level rooms until the system is installed. Use a certified mitigator and request priority scheduling to shorten high-exposure time. Many mitigators offer priority scheduling for homes above 8.0 pCi/L.
Why Radon is Still Relevant in Mathews County
Mathews County is classified as EPA Zone 3, with a lower predicted indoor screening range below 2.0 pCi/L. This does not mean radon is absent - it means the countywide map signal is low.
The EPA has documented elevated radon readings in every state and in homes in every zone classification. Local geological anomalies - pockets of granite, shale intrusions, or fractured bedrock - can create localized high-radon areas even within an otherwise low-risk county.
The Surgeon General and EPA recommend testing all homes, regardless of geographic zone. A simple short-term test kit ($15-$30) provides results within a few days and can give you peace of mind.
Radon & Health: What the Science Says
lung cancer
from radon
4.0 pCi/L
Radon is a Class A carcinogen - the same classification as asbestos and tobacco smoke. The National Academy of Sciences estimates that radon causes approximately 21,000 lung cancer deaths annually in the United States, making it the leading environmental cause of cancer death.
Unlike smoking, radon exposure is involuntary and often invisible. There is no safe level of radon - risk increases linearly with exposure. The good news: radon mitigation systems are highly effective, typically reducing indoor levels by 80-99% within hours of activation.
Source: US Environmental Protection Agency, "A Citizen's Guide to Radon" (EPA 402/K-12/002). National Academy of Sciences, Biological Effects of Ionizing Radiation (BEIR VI) Report, 1999.
Step 1: Test Your Home
Testing is the only way to know your home's radon level. Zone and county data tell you the regional signal, but your home could be significantly higher or lower than the countywide pattern. Start with a valid test setup before using any cost path.
State radon programs and EPA provider guidance are the right reference before hiring or confirming local requirements.
Open the state radon programAlready Know Your Level?
If your test shows 4.0 pCi/L or higher, get an itemized cost estimate specific to Mathews County - including regional labor rates and permit requirements.
Get Mitigation Cost Estimate ->VA Radon Regulations
Virginia requires sellers to complete a Residential Property Disclosure Statement covering known defects and environmental hazards including radon.
Virginia does not require specific radon licensing. NRPP or AARST certification is recommended.
How to Test for Radon in Mathews County
Buy a Test Kit
Purchase a short-term charcoal test kit online or from a local hardware store. Cost: $15-$30. Place it in the lowest livable level of your home.
Wait 2-7 Days
Keep doors and windows closed (except normal entry/exit) during the test period. Avoid running whole-house fans. Mail the kit to the lab provided.
Read Your Results
If results are below 4.0 pCi/L, re-test every 2 years or use a monitor for ongoing tracking. If above 4.0, use our cost calculator to see mitigation options.
Related Radon Resources for Mathews County
Explore Other VA Counties
Official State Resource
Virginia radon program and rules
Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.
Disclosure rule tracked
Virginia requires sellers to complete a Residential Property Disclosure Statement covering known defects and environmental hazards including radon.
Credential note
Virginia does not require specific radon licensing. NRPP or AARST certification is recommended.
Sources & Methodology
Radon zone classifications for Mathews County are sourced from the EPA's Map of Radon Zones, which uses geological surveys, indoor radon measurements, and soil permeability data to assign each county a risk tier.
Disclaimer: Zone data represents county-level screening ranges and cannot predict the radon level in any specific home. Testing is the only reliable method to determine your home's radon concentration. This content is for informational purposes and is not medical advice.
Content review: Source-level retrieval dates
Editorial and Data Transparency
- Author
- RadonVerdict Data Team (Public Data and Cost Modeling)
- Content Review
- Source-level dates shown below
- Data Retrieved At
- 2026-02-24
Primary Sources
- EPA Map of Radon Zones (retrieved 2026-02-21)
- EPA A Citizen's Guide to Radon (retrieved 2026-05-05)
- CDC Environmental Public Health Tracking - Radon Testing (retrieved 2026-05-05)
- Virginia Department of Health Radon Testing Results (retrieved 2026-05-06)
- Official VA radon program
- US Census Bureau, 2018-2022 American Community Survey 5-Year Estimates (retrieved 2026-02-24)