radon in basement 13

https://jeffersoncountyradonpoint.alderbrief.com/posts/understanding-jefferson-county-radon-risks-and-what-homeowners-can-do

Radon in basement is a serious concern because this radioactive gas seeps up from the soil through cracks and gaps, and since basements are often the lowest point in a home, they can trap high levels of it. I once had a friend who found radon in his basement while testing the air quality; he had to install a mitigation system to reduce the risk. It's invisible and odorless, so testing is the only way to know if you're exposed, especially in older homes with more foundation gaps.