Radon is a radioactive gas of natural origin, colorless, odorless and inert. It is particularly present in certain geological zones and tends to accumulate in the indoor air of buildings. As a result, radon is one of the main causes of cancer in non-smokers: every year in France, this gas is the cause of 10% of lung cancer deaths.
It is possible to reduce the radon level of a building by acting on the waterproofing and ventilating daily. Control of radon levels is therefore necessary in public institutions.
Source: "Environmental expertise related to natural phenomena, radon", IRSN (Institute for Radiation Protection and Nuclear Safety) https://bit.ly/2GUjDGS [Consulté le 20/02/2019].