RADIATION EXPOSURE FROM NATURAL RADIONUCLIDES IN BUILDING MATERIALS.

Building materials from Iberian Peninsula (Portugal and Spain) were collected and analysed for 226Ra, 232Th and 40K using HPGe gamma-ray spectrometers. The results show that the highest mean value of 226Ra and 232Th activities are 2168 and 390 Bq kg-1, respectively, measured in zircon. For 40K, this value is 1290 Bq kg-1, measured in granite. The mean concentrations of the three radionuclides in the different building materials, excluding the zircon and the industrial by-products (ashes, gypsum and phosphogypsum), are 62, 31 and 519 Bq kg-1 for 226Ra, 232Th and 40K, respectively. The radiological health hazard parameters: radium equivalent activity (Raeq), activity concentration index (I) absorbed and effective dose rates, associated with these radionuclides, were evaluated. These values are within the EU recommended limits in building materials, except for same samples of aggregates, granites, ceramics, phosphogypsum and zircon. This study will contribute for the worldwide data pooling on the radioactivity of the building materials.