文档介绍：Assessment of natural radioactivity levels and radiation haz ards due to cement industry Abstract The cement industry is considered as one of the basic industries that plays an important role in the national economy of developing countries. Activ ity concentrations of 226Ra, 232Th and 40K in Assiut cement and other l ocal cement types from different Egyptian factories has been measured by using γ-ray spectrometry. From the measured γ-ray spectra, specific activ ities were determined. The measured activity concentrations for these nat ural radionuclides pared with the reported data for other countries. T he average values obtained for 226Ra, 232Th and 40K activity concentrat ion in different types of cement are lower than the corresponding global v alues reported in UNSCEAR publications. The manufacturing operation r educes the radiation hazard parameters. Cement does not pose a significa nt radiological hazard when used for construction of buildings. Keywords: Natural radioactivity; Cement; Raw materials; Radiation h azards 1. Introduction The need for cement is so great. That it considered a basic industry. Work ers exposed to cement or its raw materials for a long time especially in mi nes and at manufacturing sites as well as people, that spend about 80% of their time inside offices and homes (Mollah et al., 1986; Paredes et al., 19 87) result in exposure to cement or its ra