How Does Radon Enter A Building?

Most airborne radon is released into building from the soil or rock beneath. Radon from soil or rock enters the building through cracks and holes in a building's foundation, then can move freely through open areas.

Most radon in water can be released into buildings from contaminated groundwater (such as from a private well) used in showers, dishwashers, clothes washers, and other types of appliances.

Generally, the amount of radon released from water depends on how much radon was initially in the water, the temperature of the water (higher temperatures release more), and the amount of water surface exposed to air (the more surface exposed, the more radon is released.)

Although the alpha particles in radon can he stopped by a wall, a few sheets of paper or a person's skin, building basements or foundations are often not a completely effective barrier since they often contain cracks or holes. Pressure differentials between a building interior and exterior can also draw in radon gas.