Table of radon concentrations
The four French “departments” of the granite-rich Auvergne region have an exposure to radon which exceeds the French national average. The average departemental radon concentrations mask wide disparities. On the basis of measurements carried out by the IRSN, it is estimated that there are 60,000 buildings in France where the concentration of radon exceeds 1,000 Bq/m3 and over 300,000 buildings with a concentration over 400 Bq/m3.
IRES/IN2P3 (source IRSN)