Determination of natural radiation levels and terrestrial dose rates in Bergama Kozak granite area

In the presented study, natural radioactivity due to the presence of Ra-226, Th-232 and K-40 radionuclides in soil and granite samples, collected from Bergama-Kozak Granite Area was determined by using gamma spectrometry technique. The measured activities in the granite and soil samples ranged from 29 to 111 Bq/kg, 35 to 87 Bq/kg, 698 to 1100 Bq/kg and 32 to 82 Bq/kg, 42 to 88 Bq/kg, 667 to 1127 Bq/kg for Ra-226, Th-232 and K-40, respectively. The radium equivalent activity (Ra(eq)), the external hazard index (H(ex)), the internal hazard index (H(in)), the outdoor absorbed dose rate in air and the annual effective dose rate were evaluated to assess the radiation hazard for people living in the granite area. The mean radium equivalent activity (Ra(eq)), the external hazard index (H(ex)), the internal hazard index (H(in)), terrestrial absorbed dose rate in the area under study were determined as 221 Bq/kg, 0.62, 0.79, 104 nGy/h and 214 Bq/kg, 0.60, 0.74, 100 nGy/h for granite and soil environment, respectively. The annual effective dose to the public due to granite and soil environment was estimated to be 127 ?Sv and 123 ?Sv, respectively. The results are comparable with other global radioactivity measurements and are found to be safe for public and environment.