K. Kovler, Technion – Israel Institute of Technology, Israel
The chapter deals with radioactivity of building materials. The main terminology used in radiology protection is introduced. Naturally occurring radioactive materials (NORM), such as radium 226Ra, thorium 232Th, potassium 40K and radon 222Rn, are discussed. Special attention is given to radon, which is considered as the main source of natural radiation to which the building occupants are exposed. The difference between radon exhalation and emanation is explained. The role of radon diffusion length influencing the radon flux from the surface of building products and air exchange rate in living spaces is emphasized. Main experimental methods of ...