Assessment of Radiological Safety of Ceramic Tiles Commonly Used in Polish Buildings

The concentration of natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in ceramic tiles manufactured in Poland is presented in this paper. The concentration of natural radioactive isotopes in the tested samples was determined using a low-level digital gamma ray spectrometer equipped with an HPGe semiconductor detector. The mean concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the analyzed samples were found to be 48 ± 3 Bq∙kg^-1, 49 ± 3 Bq∙kg^-1 and 476 ± 23 Bq∙kg^-1, respectively. The world mean concentrations of these radionuclides (50 Bq·kg^-1, 50 Bq·kg^-1 and 500 Bq·kg^-1, respectively) were not exceeded. Furthermore, in order to ascertain the level of gamma radiation exposure, fundamental radiation protection parameters were established: radioactivity concentration indicator/gamma ray indicator (I_γ), indoor dose rate (D_in) and annual indoor effective dose (E_in). In the case of the investigated ceramic tiles, it was established that the parameters were not higher than the limit values, except the indoor gamma radiation dose rate which was found to be 1.5 times higher than the world average. Therefore, the findings of this study indicate that the utilization of the examined ceramic tiles in constructions should be approached with a degree of caution.