Natural radioactivity level and radiological hazard assessment of commonly used building material in Xining, China

Natural radioactivity of the commonly used building materials in Xining of China was measured using gamma-ray spectrometer system comprising a NaI(Tl) detector. Radioactivity concentrations of Ra-226, Th-232 and K-40 in the studied samples range from 11.6 to 120.6, 10.2 to 107.1 and 228.0 to 1,036.2 Bq kg(-1), respectively. The concentrations for these natural radionuclides were compared with the reported data of other countries and the mean value for soil. Radium equivalent activity, indoor air absorbed dose rate, annual effective dose rate as well as external and internal hazard indices were calculated to assess radiological hazards for people living in dwelling made of the building materials. The radiological hazard assessment results show that the studied building materials, except for some aerated concrete block samples, are safe for use in construction of dwellings in the study area and do not pose any significant source of radiation hazard.