Radon Levels in Roanoke, VA: What the Data Shows

How much radon is in Roanoke-area homes? Two official sources give a local picture: the EPA Map of Radon Zones, and the indoor radon test results the Virginia Department of Health (VDH) collected from 2016 to 2024. Neither one can tell you what's in your house. Only a test can. But together they show why EPA and VDH urge every Roanoke Valley homeowner to test.

EPA radon zones for the Roanoke area

EPA's Map of Radon Zones sorts every county and independent city into three groups based on indoor measurements, geology, aerial radioactivity, soil and foundation types:

• Zone 1 (highest potential): average indoor levels may be greater than 4 pCi/L.
• Zone 2 (moderate): average indoor levels may be between 2 and 4 pCi/L.
• Zone 3 (low): average indoor levels may be less than 2 pCi/L.

In EPA's zone data, the City of Roanoke, Roanoke County, the City of Salem, Botetourt County and Craig County are all Zone 1. Neighboring Franklin and Bedford counties are Zone 2. Statewide, VDH says Virginia has 46 counties and 15 cities in Zone 1. EPA itself cautions that the map is meant for targeting resources and building codes, not for deciding whether a home needs a test: high levels have been found in all three zones.

What Virginia's test data shows

VDH's Radon Program publishes indoor air test results it received from five major test-kit vendors, covering 2016 to 2024 (VDH Radon Test Results; data on the Virginia Open Data Portal). Here are the figures for the Roanoke Valley and its neighbors:

VDH reports by county and independent city, so the Town of Vinton is counted within Roanoke County. Every locality in this table had results as low as 0.3 pCi/L as well, which is the point: neighbors can test very differently.

How to read these numbers

• Compare with the action level. EPA recommends fixing a home at 4 pCi/L or higher and considering a fix between 2 and 4 pCi/L. Every Roanoke-area average above falls in or above that 2–4 range, and Botetourt's is above 4.
• Compare with typical homes. VDH puts the average indoor radon level at about 1.3 pCi/L, and outdoor air at about 0.4 pCi/L (VDH FAQ).
• Mind the limits. VDH notes that data submission is voluntary, professional testers don't have to report, data quality varies by vendor, and the averages shouldn't be used to predict the level in any single home. VDH removes duplicates, post-mitigation tests and upper-floor tests, and doesn't calculate an average for localities with fewer than 25 results.

Why it matters

EPA calls radon the second leading cause of lung cancer in the United States (EPA), and VDH says radon exposure may contribute to almost 700 lung-cancer cases a year in Virginia (VDH). VDH's FAQ cites EPA's estimate that lifetime exposure at an average of 4 pCi/L carries a lung-cancer risk of about 7 in 1,000 for people who have never smoked, and about 62 in 1,000 for current smokers.

What to do with this information

1. Test your home, in the lowest lived-in level. VDH notes indoor radon usually peaks in the coldest months. See radon testing in Roanoke.
2. If you're at or above 4 pCi/L (after a follow-up test), plan a mitigation system. Read how systems work and what they cost in Virginia.
3. Want a certified pro to take a look? Use the form below. We'll pass your request to one independent NRPP- or NRSB-certified mitigation professional who serves your ZIP code.