Population doses from terrestrial gamma exposure in Serbia

Abstract

Background: Terrestrial radiation emitted from naturally occurring radionuclides, such as 40K and radionuclides from the 238U and 232Th series and their decay products represent the main external source of irradiation to the human body. The purpose of this study was to provide a preliminary assessment of the doses from terrestrial exposure of population in Serbia and to estimate a potential radiation hazard for population inhabiting investigated areas. Methods: The gamma dose rates, external hazard indexes, and annual effective doses due to terrestrial naturally occurring radionuclides ( 238U, 232Th and 40K) were calculated based on their activities in soil samples in Serbia as determined by gamma-ray spectrometry. Results: The total absorbed gamma dose rate due to these radionuclides varied from 16.9 to 125 nGy h-1, with a mean of 62.8 nGy h-1. Assuming a 20% occupancy factor, the corresponding annual effective dose varied from 2.07 to 15.4×10-5 Sv with the mean value of 7.7×10-5 Sv, i.e. annual effective dose was in range of the world wide average values. Conclusion: According to the values of external hazard index obtained in this study (mean Hex = 0.35), the radiation hazard was insignificant for the population living in investigated areas.