Homebuyers in the State of Maryland are advised to get their homes tested before purchase and in Montgomery County it is the law that all homes get professionally radon tested prior to the sale of any home. Every state in the U.S. has radon gas, but homes in the Baltimore and Washington D.C. area are at particularly higher risk than many other states. Follow this link to see if you are house hunting in a high-risk zone.

What Is Radon Gas?

Radon gas is a byproduct of the underground decay of radioactive elements, such as uranium and thorium. As these substances deteriorate, the gas is released and eventually works its way to the surface of the ground and into the air we breathe. Fortunately, radon gas is so diluted in our outdoor environment it doesn’t pose a health risk.

Why Should I Be Concerned?

While radon is harmless in the low levels found outdoors, when it seeps into a home it can become concentrated in levels high enough to put residents at risk. Radon gas is measured in picocuries per liter (pCi/L), and the EPA recommends radon mitigation for all homes with radon gas levels of 4 pCi/L or higher. Radon gas is slightly heavier than air, so while it settles in basements and crawl spaces, whole-house HVAC systems have a tendency to distribute the gas throughout the entire home. That means even a second story could potentially contain high levels of radon.

What Does a Radon Test Involve?

At Old Line Home Inspections, we use the 48-hour RadonEye Pro continuous radon monitors or PicoCan 400 charcoal-filled cannisters for testing. The advantage of continuous radon monitors is that the results are available immediately after the 48-hoiur test period while charcoal cannisters need to go to a lab for further analysis and will take an additional 2-3 business days after the original 48-hour test period. Homeowner detection devices are also available, but for the purpose of a real estate contract, only professional testing results are usually considered.

Who Pays for Radon Tests and Mitigation?

While the homebuyer usually pays for the radon test, it is the seller usually pays for the mitigation and any retesting in the State of Maryland. Radon in most cases can be mitigated to an acceptable level, but seek the advice of a radon mitigation specialist if you have questions or concerns. Professional radon reduction runs $800 to $2,500, with an average cost of about $1,200.