Determination of natural radioactivity and associated radiation hazard in building materials used in Weinan, China

The concentrations of Ra-226, Th-232 and K-40 in the commonly used building materials of Weinan, China were measured using gamma-ray spectrometry. The associated radiological hazards of natural radioactivity in the studied materials were evaluated by radium equivalent activity, external hazard index, internal hazard index, indoor air absorbed dose rate and annual effective dose rate. The measurement results show that the natural radionuclides contents of the studied building materials are in the range of Chinese soil values. The radium equivalent activity and external hazard index values of glazed tile are close to or higher than the recommended limit. The internal hazard index values and the annual effective dose rate values of roof tile, glazed tile and some cement samples made from fly ash are close to or higher than unity and 1 mSv y(-1), respectively. The study shows that roof tile and glazed tile should be limited to use in the construction of building and the monitoring on the natural radioactivity level of cement made from fly ash should be intensified for avoiding unnecessary radiation exposure to residents. (C) 2014 Elsevier Ltd. All rights reserved.