Professional radon testing across Metro Detroit.

Understanding radon

Why radon testing matters in Michigan.

Radon is a naturally occurring radioactive gas that seeps into homes through foundation cracks, sump pits, and construction joints. It has no color, no odor, and no taste — the only way to know whether a home has elevated levels is to test. The EPA identifies radon as the second leading cause of lung cancer in the United States, and Michigan's geology makes many areas across Oakland, Macomb, and Wayne Counties particularly susceptible.

Gio uses continuous radon monitors — not passive charcoal canisters — which record hourly readings over a minimum 48-hour testing window. This method produces more reliable data and is the standard recommended by the EPA for real estate transactions. The monitor is placed in the lowest livable level of the home, and results are available as soon as the device is retrieved.

How radon testing works

• Placement: Gio places the continuous monitor in the lowest livable area — typically the basement or ground-level floor
• Testing window: The monitor records hourly readings for a minimum of 48 hours under closed-building conditions
• Retrieval and results: The device is retrieved and results are delivered in writing, with the hourly data and the average concentration
• Guidance: If levels exceed the EPA action threshold of 4.0 pCi/L, Gio explains what mitigation involves and what to expect in terms of cost and timeline

When to test for radon

The most common time to test is during a home purchase — most lenders and buyers' agents recommend it as part of the inspection process. But radon testing is also valuable for current homeowners who have never tested, homeowners who have finished a previously unfinished basement, or anyone whose home has undergone foundation work or major structural changes. Levels can shift over time, and the EPA recommends retesting every two years even in homes that previously tested below the action level.

Radon testing can be combined with your home inspection

Most clients add radon testing to their standard home inspection. Gio places the monitor at the beginning of the inspection process and retrieves it 48 hours later. This keeps everything on one timeline and avoids scheduling a separate appointment. Radon testing is also available as a standalone service for homeowners who don't need a full inspection.