The Activity Concentration of Radionuclides (226Ra, 232Th and 40K) in Soil Samples and Associated Health Hazards in Natore, Kushtia and Pabna District of Bangladesh

Abstract

The study has been carried out to measure the activity concentration of natural and anthropogenic radionuclides in fifteen(15) soil samples of Natore, Kushtia and Pabna district, which are around the 30 km peripheral area of Rooppur Nuclear Power Plant, by gamma ray spectrometry system using a High Purity Germanium (HPGe) detector. It is found that the activity concentration of 226 Ra, in the collected sample was from 3.52 Bq/kg to 28.5 Bq/kg with the average value of 12.42 Bq/kg. For 232 Th, the range was from 4.18 Bq/kg to 34.5 Bq/kg with the average value of 12.6 Bq/kg. Finally, the activity concentration of 40 K, in the collected sample was in the range of 84 Bq/kg to 345 Bq/kg, and the average value was 198.9 Bq/kg. The absorbed dose rate (D) was found to be in the range of 4.59 nGy/h to 40.93 nGy/h with the mean value 21.3 nGy/h. The annual effective dose (E) was in the range of 0.006 mSv/yr to 0.152 mSv/yr with an average of 0.033 mSv/yr. The radium equivalent activity was in the range from 10.02 Bq/kg to 89 Bq/kg with an average of 44.99 Bq/kg. The external hazard index (Hex) was found to be in the range of 0.027 to 0.242 with the mean value of 0.121 and the internal hazard index (Hin) was found to be in the range of 0.044 to 0.302 with the mean value of 0.156. All the values are much below the recommended limit by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 35 Bq/kg for 226 Ra, 30 Bq/kg for 232 Th and 400 Bq/kg for 40 K. According to international and national regulation, the annual dose to members of the public, 1and Hex & Hin must be lower than unity. Moreover, no artificial radioactivity was found in the soil samples of this study area. This research concludes that the found values are within the permissible limits as required by the Nuclear Safety and Radiation Control(NSRC) Rules-1997 of Bangladesh and International Atomic Energy Agency(IAEA) Safety Standards-General Safety Requirements (GSR): Part-3.

Assessment of Natural Radionuclide Distribution Pattern and Radiological Risk from Rocks in Precambrian Oban Massif, Southeastern Nigeria

“…The alpha index varies between 0.11 and 2.73 Bq•kg −1 . The mean value of 0.80 Bq•kg −1 exceeds the exemption limit of 0.5 Bq•kg −1 proposed by [35]. Rocks emitting the highest amounts of radon gas seem to be more abundant in areas around Mfamosing (2.73 Bq•kg −1 ), Akamkpa (1.86 Bq•kg −1 ), Betem (1.16 Bq•kg −1 ), Uwet (1.05 Bq•kg −1 ), Uyanga (0.84 Bq•kg −1 ), Ekang (0.82 Bq•kg −1 ) and Awi (0.76 Bq•kg −1 ), and consequently, may not be very suitable for use in constructing dwelling places.…”

“…The primordial radionuclides comprising 226 Ra, 232 Th, and 40 K are unequally distributed in terrestrial materials due to a lack of equilibrium between 226 Ra and its progenies. The concept of radium equivalent, Ra eq , which is a weighted sum of activities from the naturally occurring radionuclides, was introduced for use in computing activities when 370 Bq•kg −1 of radium, 259 Bq•kg −1 of thorium, and 4810 Bq•kg −1 of potassium are synchronized to produce equal amounts of gamma radiation dose rates and by extension, radiation exposure [24,35]. Ra eq allows specific activity from various primordial radionuclides in terrestrial materials to be compared.…”

“…The index combines the various forms of gamma radiation emitted from primordial radionuclides in building materials (soils, rocks, and plants) to determine the indoor radiation dose delivered externally to an individual. The observed H ex values, computed using Equation (11) [35], are shown in Table 1.…”

“…Building materials are considered safe for use in constructing dwelling places if their RLI values ≤ 1 [35].…”

Primordial radionuclides in the dust samples from the educational institutions of central Bangladesh: radiological risk assessment

“…Measurements of NORMs abundances have normally been carried out by HPGe-detector which requires 100–250g solid samples. Moreover, samples required at least 28 days to attain the secular equilibrium (between short-lived daughter & long-lived parent) followed by a long time γ-ray-counting (25,000–50,000s) ( Bramha et al., 2018 ; Ehsan et al., 2019 ). If the mass of samples is lower, it requires a longer counting time.…”