Measurements of natural radioactivity and the resulting radiation doses from commercial granites.

Saudi Arabia is becoming a relatively large market for local and foreign marble and granite use in dwellings. Due to increasing concern about environmental radiological protection, different types of locally widely used granite tiles were collected from different suppliers in the Jeddah province, Saudi Arabia. The analysis for these granite tiles for gamma radiation was conducted by means of a high-resolution HPGe gamma-spectroscopy system. The activity concentrations of (232)Th, (226)Ra and 40K in the selected granite samples ranged from 4.9 to 144, 9.7 to 133 and 168 to 1806 Bq kg(-1), respectively. The data were compared with other granite types and building materials used all over the world. The absorbed dose rates, effective dose rates, radium equivalent activities as well as the radiation hazard indices were estimated. The radium equivalent activities (Ra(eq)) are lower than the limit of 370 Bq kg(-1) set by the Organisation for Economic Cooperation and Development (Exposure to radiation from the natural radioactivity in building materials. Report by a Group of Experts of the OECD, Nuclear Energy Agency, OECD, Paris, 1979) except in three samples.