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

Abstract

A gamma spectrometric analysis of rock samples collected from the Precambrian Oban Massif, southeastern Nigeria, was performed to determine some primordial radioelements’ activity concentrations: U-238, Th-232, and K-40, and their associated radiological hazards. The mean activity of the primordial radionuclides was determined to be 1073.06 ± 0.65, 160.74 ± 1.32, and 250.76 ± 0.91 Bq·kg−1 for 40K, 238U, and 232Th, respectively, showing that they are inhomogeneously distributed, with activity changing with the rock type and location. The activity concentrations are highest in biotite garnet schist, quartz diorite, and biotite gneiss rock domains. The mean values of the radiological hazards are 0.08 Bq·kg−1 (alpha index), 2.15 Bq·kg−1(gamma index), 2.06 Bq·kg−1(internal) and 1.63 Bq·kg−1 (external4.30 Bq·kg−1(representative level index6), 602.23 Bq·kg−1, (radium equivalent), 780 nGy·h−1 (total absorbed dose rate), 270.91 nGy·h−1 (indoor), 509.78 nGy·h−1 (outdoor), 624.99, 1329.07 and 1954.06 mSv·yr−1 (outdoor, indoor and total annual effective dose equivalent, respectively), 6448.40 (cumulative excess lifetime cancer risk) and 248.94–3761.47 Bq·kg−1 (annual gonadal dose equivalent). These results are higher than their various permissible limits (except at Ako Community) and suggest that rocks in the area may be unsuitable for constructing dwelling places. It is strongly advised that basic safety standards and precautionary measures recommended by the European Commission should be strictly adhered to while dealing with these rocks.

Radiation Hazard from Natural Radioactivity in the Marine Sediment of Jeddah Coast, Red Sea, Saudi Arabia

“…This indicates that 40 K in common is a more prevalent radioactive element in these marine sediments. Potassium is more abundant in magmatic rocks as a major constituent of several rock-forming minerals than U and Th [75][76][77]. The activity concentration of 238 U, 232 Th, and 40 K varied site-by-site, because the physical, chemical, geochemical, and mineralogical components of the marine sediment vary greatly [78,79].…”

Assessment of the Natural Radioactivity Levels in Soils and the Associated Health Risks to the Public in Mbeya City, Tanzania

“…It takes into account all forms of gamma radiation emitted by primordial radionuclides present in soils, rocks, and plants to determine the indoor radiation dose received by an individual. The index is calculated by using Equation 7 [12].…”

An aeromagnetic denoising-decomposition-3D inversion approach for mineral exploration

“…Aeromagnetic exploration is a powerful and fast, convenient and economical technique enabling the delineation of geological structures and exploration of mineral resources. It has been applied in the exploration of geotectonics, faults, igneous rocks, craters, magnetic-related polymetallic deposits, and extraction of hydrothermal alterations (Muundjua et al, 2007;Ortiz-Alemán and Urrutia-Fucugauchi, 2010;Gao et al, 2016;Elkhateeb and Abdellatif, 2018;Sridhar et al, 2018;Eldosouky et al, 2020;Shebl et al, 2021;Xiong, 2021;Bencharef et al, 2022;Ekpe et al, 2022;ElGalladi et al, 2022;Mahdi et al, 2022;Mamouch et al, 2023). Hereinto, two factors have to be taken into account before interpretation or inversion.…”