Assessment of gamma radiation levels of beach sands in Bitlis region of Lake Van

Natural gamma radioisotope activity concentration levels in beach sands in the Bitlis region of Lake Van, in eastern Turkey, were determined using an HPGe detector. A total of 15 different beach sand samples were collected from Ahlat, Adilcevaz, and Tatvan shoreline regions, and then 226 Ra, 232 Th, 40 K, and 137 Cs radioisotope activity concentrations were measured. Mean values of gamma emissions for each radioisotope were determined as 58.78, 65.89, 1590.25, and 4.84 Bq kg −1 for 226 Ra, 232 Th, 40 K, and 137 Cs, respectively. Mean radium equivalent activity, absorbed gamma dose rate, annual effective dose, and external hazard index values were calculated as 275.45 Bq kg −1 , 135.41 nGy h −1 , 0.17 mSv year −1 , and 0.74, respectively.