crawl space radon mitigation

https://future-wiki.win/index.php/How_Affordable_Radon_Mitigation_Saves_Lives_Without_Breaking_the_Bank

If you've got a crawl space, radon can seep up through the soil and get trapped under your home, slowly raising indoor levels. Sealing cracks isn't enough down there—a proper mitigation system usually involves a vent pipe and a fan that pulls the gas from below the vapor barrier and exhausts it safely above the roofline. It's a practical fix that keeps your basement air healthier without much fuss.