What should be done to prevent radon infiltration in buildings?

To prevent radon infiltration in buildings, installing vapor barriers is an effective and widely recommended method. Radon gas is produced naturally from the decay of uranium in soil and rock, and it can enter buildings through cracks in floors and walls, construction joints, and gaps in foundations. Vapor barriers, typically made of plastic or other impermeable materials, are designed to seal off the ground underneath a building from the air in the structure. By blocking the movement of radon gas and other soil gases, vapor barriers can significantly reduce radon levels in indoor air.

While increasing natural ventilation, sealing windows tightly, and reducing humidity levels can improve air quality and mitigate some environmental health risks, they are not as directly effective against radon infiltration as installing vapor barriers. Natural ventilation may dilute radon levels, but it does not prevent radon from entering the building in the first place. Sealing windows might reduce drafts and improve energy efficiency, but it does not address the pathways through which radon enters. Reducing humidity levels can help mitigate mold and other indoor air quality issues but does not specifically target the prevention of radon infiltration. Therefore, vapor barriers are the most effective initial measure for radon prevention in buildings.