Radon, a colourless and odourless radioactive gas, is produced from the natural radioactive decay of uranium in rocks and soil. It seeps into buildings from the ground on which they are built, and has been recognized as responsible for a portion of lung cancer cases in the general population and certain workers (e.g. miners). The focus over the past few years has been on managing the risk from radon through international requirements on radon in both dwellings and workplaces. Facing an excellent opportunity for primary prevention, countries have been developing policies, regulations and national action plans to respond to this indoor air pollutant. 

Over a quarter of all WHO Members States have completed a WHO radon survey conducted in 2019.