Mason County, WV: EPA's radon zone, explained

EPA places Mason County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Mason County lands in the 48th percentile for radon potential.

How Mason County compares

Mason County, West Virginia is home to about 24,770 people across 430.768 square miles. Population density there runs about 58 people per square mile. By population, Mason County is the 555th largest of every county sharing its EPA zone — the 46th percentile by population within that zone. Geologically, Mason County is grouped into EPA Region 3 alongside 244 other counties that share its rock and soil setting.

Zone vs. an actual test

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Mason County's Zone 2 prediction. Middle-of-the-pack doesn't mean risk-free for any one Mason County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Mason County

For a Mason County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find West Virginia's state radon program

For Mason County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Mason County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Mason County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Mason County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.