radon in basement 3

https://subslabdepressurizationreview.moderncairn.com/posts/understanding-sub-slab-depressurization-for-radon-mitigation

My friend just bought a house and we were talking about radon in the basement. He tested for it because his neighbor had high levels. The kit was from the hardware store, pretty simple. It's not something you can see or smell, but it's a real concern, especially in our area for lung cancer risk.