Radiological assessment of natural radioactivity in a uranium deposit area: Köprübaşi, Türkiye


 In this study, the results of environmental radioactivity studies conducted in Köprübaşı, Manisa district, where Türkiye’s uranium mineral exploration and processing studies were carried out, are shared. Because this is a populated area, there is a need for radio ecological dosimetry assessment to investigate the possible risk to the population. The region where radiological monitoring is carried out is discussed in two parts as the areas where uranium mineral exploration is performed and the settlements close to these areas. It was observed that 714–4714 nGy/h values were obtained in the outdoor absorbed dose rate in air measurements taken in the areas where mineral exploration was performed and this value reached up to 22 857 nGy/h in open field mining areas. In the residential areas, it was recorded that the outdoor absorbed dose rate in air values ranged between 142 and 242 nGy/h and the indoor values ranged between 171 and 400 nGy/h. The world absorbed dose rate in air average values is 57 nGy/h (outdoor) and 75 nGy/h (indoor). The high 226Ra values in the radioactivity analyses of the soil samples draw attention. The mean values of the activity concentrations of the radionuclides 226Ra, 232Th and 40K in the soil samples are 3169, 55 and 802 Bq/kg and the world averages of these values are 35, 30 and 400 Bq/kg, respectively. It was determined that high 226Ra value in the soil in the areas close to the open field uranium mining area was passed on to the agricultural products. Radioactivity measurement results of drinking water samples did not exceed World Health Organization guidelines. According to the radon gas measurement results of 44 houses in Köprübaşı villages, the average radon concentrations in winter, spring, summer and autumn seasons were 72, 61, 50 and 55 Bq/m3, and the annual average value was 60 Bq/m3, respectively. Although these values are greater than the world average of 46 Bq/m3, they are below the recommended limit value (100 Bq/m3). By evaluating the data obtained, the total annual effective equivalent dose values (originating from outdoor–indoor absorbed dose in air, drinking water and indoor radon gas concentration) to which the people in the region are exposed were calculated as a 3.12 mSv.