Concentration of Natural Radionuclides in Soil and Assessment of External Exposure to The Public in Bangka - Belitung Islands, Indonesia

Natural radionuclides in soil such as 226Ra, 232Th and 40K are a significant component of the background exposure sources of the population- Estimation of the external exposure due to gamma-ray radiation of natural radionuclides is important because this may contribute significantly to the total annual individual dose. Bangka Belitung is known as the producer of tin and geologically, contains several tines the concentration of natural radionuclides in comparison to other common areas. The aim of this study is io detemine the radioactivity concentration of 226Ra, 232Th and 40K in soil samples collected from Bangka-Belitung province to assess their contribution to the external dose exposure. Analysis of 226Ra, 232Th and 40K has been carried out in soil samples using gamma spectrometry. The activity concentrafions of 226Ra, 232Th and 40K varied from 4.8 - 544 Bqks ', 7.3 - 21 70 Bqkg ,, s.: - :68 oqtg' with a mean value of 72.3,203 and 70.0 Bqkgi, respecfively. The absorbed alose mtes du€ to the pr€sence of 26R4 !1.h,and 4k, jn soil sanpl€s in the studied dea valy between rhe range from 7.40 to 1569 ncyh r with I Ineatr vatue of 159 ncyh'. The corresponding outdoor annual effective doses ranged between 0.05 - 11.5 msv 11 with a mean.