Radon potential zoning

Radon is a radioactive gas produced by the natural decay of uranium present in rocks. Pulmonary carcinogen, it can pose a health risk when it accumulates in buildings. Knowledge of the characteristics of geological formations in the territory makes it possible to identify areas where radon at high concentrations in buildings is most likely. This work, carried out by the IRSN (Institut de Radioprotection et de Sureté Nucléaire) at the request of the Nuclear Safety Authority, has made it possible to map the radon potential covering the entire metropolitan area. This mapping leads to the classification of municipalities into 3 categories: Zone 1: areas with low radon potential Zone 2: areas with low radon potential but where particular geological factors can facilitate the transfer of radon to buildings Zone 3: areas with significant radon potential