Geological materials are a potential source of pollutants, among which the most widespread in the built environment is the radioactive isotope Rn-222. This isotope is the result of radioactive decay of uranium (U-238). It is emitted as a gas, which allows it to enter the human body, with the potential to affect internal organs (mostly the lungs) by alpha particles production.
While the presence of uranium in the materials is a necessary condition for the production of Rn-222, the amount of gas emitted by the material depends on other characteristics that allow the migration of the gas.
The main aim of this communication concerns the review of emission values from geological materials and their relation to physical and petrographic characteristics to assess the risk associated with them when they are in terrains or when they are used as building materials.