radon in basements

https://theradonzone1pennsylvaniapro.novacrestiq.com/posts/radon-zone-1-pennsylvania-new-guidance-targets-high-risk-areas

You might not think about the air in your basement much, but radon is a colorless, odorless gas that can seep in through cracks in the foundation. It's a natural breakdown of uranium in soil and rock—and high levels are a serious health risk, linked to lung cancer. Testing is simple and affordable, and if levels are elevated, mitigation systems can really help.