Natural radioactivity in some building materials of Xi'an, China

Eight kinds of building materials collected from Xi'an, China were analyzed for the natural radioactivity of 226Ra, 232Th and 40K using γ-ray spectroscopy. The concentrations of 226Ra, 232Th and 40K in the selected building materials ranges from 19.5 to 68.3Bqkg-1, 13.4 to 51.7Bqkg-1 and 63.2 to 713.9Bqkg-1, respectively. The measured activity concentrations for these natural radionuclides were compared with the reported data of other countries and with the world average activity of soil. The radium equivalent activities (Raeq), external hazard index (Hex) and the internal radiation hazard index (Hin) associated with the natural radionuclides were calculated. The Raeq values of all building materials are lower than the limit of 370Bqkg-1, equivalent to a γ-dose of 1.5mSvyr-1. The values of Hex and Hin are less than unity.