No abstract

Mamuju is one of the regions in Indonesia which retains natural conditions but has relatively high exposure to natural radiation. The goals of the present study were to characterize exposure of the entire Mamuju region as a high natural background radiation area (HNBRA) and to assess the existing exposure as a means for radiation protection of the public and the environment. A cross-sectional study method was used with cluster sampling areas by measuring all parameters that contribute to external and internal radiation exposures. It was determined that Mamuju was a unique HNBRA with the annual effective dose between 17 and 115 mSv, with an average of 32 mSv. The lifetime cumulative dose calculation suggested that Mamuju residents could receive as much as 2.2 Sv on average which is much higher than the average dose of atomic bomb survivors for which risks of cancer and non-cancer diseases are demonstrated. The study results are new scientific data allowing better understanding of health effects related to chronic low-dose-rate radiation exposure and they can be used as the main input in a future epidemiology study.

The terrestrial environment is one of the contributors to natural background radiation. Mamuju Regency, located in the Province of West Sulawesi Indonesia is known as the high natural background radiation (HNBR) area due to its high terrestrial exposure. Botteng Utara Village is one of the areas with dose rates up to 5 mSv/y in Mamuju district. For this reason, measurements were taken to determine the ambient dose received by society. In situ measurements were carried out in Botteng Utara Village using 70 OSL (Type EX-OSLD Environment) installed in 70 houses. The selection of houses is made with various types of building materials, randomly selected from 10 hamlets with each of 7 houses per sub-village. Measurements were done for ± two months from February 20, 2019 to April 12, 2019. The range of ambient dose achieved by measurement was from 51 up to 176 mRem/h. Further investigation using a larger sample number and longer time should be performed to validate this study’s results. This result will serve as a baseline for further research regarding the possibility of radiation effects on the society in Botteng Utara Village in Mamuju district.

High background radiation areas usually are correlated to the high concentration of primordial radionuclides activity from Uranium/Thorium series and 40K. This paper reported the natural radioactivity level in soil sample was taken from Botteng Utara village area. The activity of primordial radionuclide such as 226Ra, 232Th and 40K were investigated from the soil by gamma spectrometry. In order to evaluate the radioactivity levels of the area, Radium equivalent activity (Raeq), the absorb dose rate (D), the annual effective dose rate (E), the external hazard index (Hex), and internal hazard index (Hin) were calculated and compared with the internationally approved value. The concentration of 226Ra, 232Th and 40K measured by gamma spectrometry are lies in the range 268.90 to 2921.17, 993.07 to 3153.81, and 115.72 to 438.26 Bq.kg−1respectively. The average and maximum annual effective dose received by Botteng Utara resident from terrestrial gamma rays are 10.40 and 18.62 mSv y−1, which is the maximum received by resident of Tande-Tande hamlets. This present work clarify that Botteng Utara is an area with high background radiation exposure from primordial radionuclides activity.

This research aims to develop a rapid method of plutonium analysis from sediment samples using the extraction chromatography method with TRU resin. This approach will be compared with the anion exchange method with DOWEX resin previously conducted in the BATAN radioecology laboratory. Plutonium measurements was carried out using an alpha spectrometer with a PIPS detector after the separation processes. The results showed that recovery using extraction chromatography followed by the microprecipitation method resulted in an average recovery of 71.22 percent, compared to anion exchange using the electrodeposition method, which obtained about 58.89 percent. Since a combination of chromatographic extraction with electro-deposition, the recovery is still low, about 27.56 percent. The chromatographic extraction method with microprecipitation method to sediment samples from the coast of Merak resulted in an average activity of 0.14 Bq/kg dry. The activities obtained are comparable with the previous data from the Merak coastal sediment study. The advantages of using the extraction chromatography method compare to using the anion exchange method to separate plutonium from sediment samples are the shorter separation time and the less acid waste produced. Another advantage is that it is more selective to separate plutonium from other actinides. This approach is very suitable for emergency preparedness when there is an emergency response.