Determination of radon exhalation rate and natural radioactivity levels of building materials used in Istanbul-Turkey

Radon concentrations of 63 building materials (block-form and powder-form) used in Istanbul province were measured by using solid state nuclear track detectors (CR-39). Radon exhalation rates for each other were calculated and compared to the literature. The activity concentrations of K-40, U-238 and Th-232 for 18 powder-form building materials (cement and sand samples) were analyzed by a gamma-ray spectrometer coupled with a NaI(Tl) detector. The activity concentrations of K-40, U-238 and Th-232 ranged from 2.81 to 638.9 Bqkg(-1), 44.68 to 114.26 Bqkg(-1) and 2.02 to 34.16 Bqkg(-1), respectively. Activity of U-238 in sand samples was found as higher than the world average. The activities of K-40, U-238 and Th-232 are compared with available data from other investigations and the world average value. Radiation hazard indices (radium equivalent activity, external hazard index and indoor hazard index) were calculated by using the activity results. The results are compared to the literature.