Assessment of TENORM and potential radiological hazards from the main brand glazed tiles produced in China with statistical analysis

The activity concentrations of TENORM including Ra-226, Th-232 and K-40 of the ten main brands of glazed tiles produced in China and their radiological hazard parameters such radium equivalent radioactivity, alpha index, external exposure index, absorbed dose rate in air indoors, indoors annual effective dose, and activity concentration index are measured and estimated. The activity concentrations of Ra-226, Th-232, K-40 in glazed tile samples are within the international tile reference values for Ra-226 (30-200 Bq center dot kg(-1)), Th-232 (20-200 Bq center dot kg(-1)) and K-40 (160-1410 Bq center dot kg(-1)). The estimated mean values of radiological hazard parameters such as radium equivalent radioactivity, alpha index, external exposure index, indoors annual effective dose, and activity concentration index are also found to be below the international recommended limits or referenced values. The mean value of the absorbed dose rate in air indoors is within the country average range of 20-190 nGy center dot h(-1). Moreover, combined with statistical analysis, it is concluded that the activity concentrations of Ra-226 and Th-232 in glazed tile samples have a strong correlation with the calculated radiological parameters, which has a significant impact on radioactivity in glazed tiles. Finally, it can be concluded that the ten brands of glazed tiles used in decoration of building materials are identified as grade A, which are unlikely to have a significant radiological hazard to the public. Therefore, the production, marketing and use scope of glazed tiles should be not restricted, but the early monitoring and classification should be done.