Radon (chemical symbol: Rn) is a natural part of the environment. It is a radioactive gas that comes mainly from soil and rock, and is a normal part of the air we breathe.
Radon can also come from water and building materials, but the amount is usually very small.
Radon cannot be seen, and has no smell. The only way to know how much radon is in the air is to measure it.
Radon makes up the largest part of natural Sources of Radiation Exposure.
There is usually less radon outdoors than indoors, since radon can concentrate in enclosed spaces. Exposure to radon outdoors is generally not an issue, so we normally focus on Exposure to Radon at Home and in indoor workplaces.
Radon is the second leading cause of lung cancer after smoking. Exposure to higher levels of radon for a long time can increase your risk of lung cancer.
Information on measuring and, if necessary, reducing radon levels, is available for homeowners, businesses, and government authorities.