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Study area map (Inset: maps of Nigeria, Osun State and Ife Central Local Government Area)—Digitized from. 35
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The distribution of natural radioactivity levels of ²³⁸ U, ²³² Th, and ⁴⁰ K in soils overlying the 3 lithologic units within Obafemi Awolowo University, Ile-Ife, Nigeria was investigated to characterize the gamma radiation dose distribution over the lithologies and to assess the radiation hazard due to the natural radionuclides. A thallium-doped ce...
Citations
... Where 370, 259 and 4810 Bq per kg are derived from previous study (19) . There would be no significant radioactive hazard to residents if H ex was less than the unity (20) . (22) 41.0 440 33.0 32.0 Note: "< DL" means the radioactivity is below the detectable limit. ...
Monitoring radioactivity levels in the environment around nuclear power plants is of great significance to assessing environmental safety and impact. Shidaowan nuclear power plant is currently undergoing commissioning; however, the baseline soil radioactivity is unknown. The naturally occurring radionuclides 238U, 232Th, 226Ra and 40K, and artificial radionuclide (AR) 137Cs in soil samples around the Shidaowan nuclear power plant were measured to establish the baseline levels. Human health hazard indices such as external hazard indices (Hex), Radium equivalent (Raeq), outdoor absorbed dose rate (Dout), annual effective dose (AED) and excess lifetime cancer risk (ELCR) were estimated. The average concentration of 232Th, 40K, 137Cs, 238U and 226Ra were 42.6 ± 15, 581 ± 131, 0.68 ± 0.38, 40.13 ± 9.07 and 40.8 ± 12.8 Bq per kg, respectively. The average Hex, Raeq, Dout, AED and ELCR were 0.40, 146 Bq per kg, 68.8 nGy per h, 0.09 mSv per y and 3.29E-04, respectively. These data showed an acceptable level of risk to residents near the nuclear power plant and that the current radioactivity in the soil may not pose immediate harm to residents living close to the nuclear power plant. The observed lower AED and 40 K and 137Cs concentrations were comparable to other studies, whilst ELCR was higher than the world average of 2.9E-04. The commissioning of the Shidaowan nuclear power plant is potentially safe for the surrounding residents; further continuous monitoring is recommended.
... The gamma-ray detector system's detection limit (DL) refers to the ability of the detector to operate without the influence of the sample [27][28][29]. The detection limit is required to estimate the minimum detection level for appropriate determination of radionuclides in each sample were obtained using the expression [30][31][32]: ...
The activity concentration of radionuclides in soil and crop samples obtained from Irele local government area in Ondo State, Southwestern Nigeria, was evaluated using a 760 mm x 760 mm NaI(Tl) gamma-ray detector system of model 8075, and resolution of 8 % at 0.662 MeV line of 137Cs. In addition, the radionuclide transfer from soil to crops was determined as a result. In soil samples, the mean activity concentrations of 226Ra, 232Th, and 40K were (21.81 ± 3.32, 12.10 ± 4.13, 381.02 ± 11.87); (31.26 ± 3.98, 15.20 ± 3.82, 357.46 ± 14.62); (29.81 ± 2.43, 18.86 ± 2.34, 504.25 ± 20.42) and (27.44 ± 3.07, 21.54 ± 3.61, 449.48 ± 16.14) corresponding to plantain, maize, yam and cassava, respectively. The mean activity concentration of 226Ra, 232Th, and 40K for plantain, maize, yam and cassava samples are (13.27 ± 4.58, 6.48 ± 3.94, 265.81 ± 13.19); (27.03 ± 3.70, 10.72 ± 3.07, 345.70 ± 14.63); (24.03 ± 4.65, 13.79 ± 4.25, 523.53 ± 16.43) and (21.47 ± 3.57, 14.44 ± 2.20, 432.99 ± 18.56), respectively. The mean transfer factor values of 226Ra, 232Th and 40K are (0.611, 0.536, 0.700); (0.867, 0.708, 0.967); (0.807, 0.736, 1.040) and (0.785, 0.668, 0.974) for soil-to-plantain, soil-to-maize, soil-to-yam, and soil-to-cassava, respectively. The results revealed that the transfer factor of the crop samples is in the following order: yam>cassava>maize>plantain. The activity concentrations of 226Ra, 232Th, and 40K in the soil and crop samples and corresponding soil-to-crop transfer values did not cause radiation damage to human health as reported levels were below recommended limits. The results of this study may serve as the basis and future criteria for the radionuclide concentrations in soil and their migration factors for the various crops in the study area.
... The region, being a rainforest zone witnesses predominantly two seasons annually; the wet season between April and October and the dry season between November and March. Geologically, the area is underlain by clayey weathered bedrock comprising granite gneiss, banded gneiss, and mica schist rock types (Esan et al., 2022). Adepelumi and collaborators, in a study conducted in 2001, gave a detailed description of the geology of the area (Adepelumi et al., 2001). ...
... suggests that only uranium and thorium are well correlated (Table 3), therefore, activity due to K-40 could have been due to a formative process different from that of Uranium and Thorium. This is in agreement with the findings of Esan et al., (2022). The radium equivalent which is the combined activity of ionizing radiations due to all the radionuclides of interest, in this case, 238 U, 232 Th and 40 K. ...
Primordial radionuclides are, among others, sources of radiation exposure to man. In this study, dust from some 24 nursery and primary schools in Ife Central and Ife East Local Government Areas (LGA) of Osun State were collected and analysed for 238U, 232Th, and 40K using CsI scintillation detector connected to a Universal Radiation Spectrum Analyser (URSA II) for spectrum analysis. From the specific activity concentrations of 238U, 232Th, and 40K, absorbed dose rates and radiological parameters were calculated. The mean activity concentrations of 238U, 232Th, and 40K in Bq/kg were found to be (45±2, 46±2), (56±5,60±5) and (669±76, 744±86) respectively for Ife Central and Ife East LGAs, however, the difference between the data sets from the two communities were not statistically significant. The total mean ± S.D (standard deviation) calculated over the whole study area were as follows; 238U= 45±11; 232Th=58±15 and 40K=702±196. The values of these radionuclides’ activities were higher than the world averages of 33, 45, and 420 for 238U, 232Th, and 40K respectively set by UNSCEAR. The mean absorbed dose rate in the air (in nGy/h) for Ife Central was 85±7 while for Ife East was 92±8. Both values were higher than the world average of 55 nGy/h. Also, the excess lifetime cancer risk was 1.66 × 10-3 for Ife Central and 1.8 × 10-3 for Ife East LGAs. Generally, Ife East LGA has higher activity concentrations than Ife Central LGA although the difference is not statistically significant.
... Scientists around the world carry out various studies to determine the level of natural radioactivity in soil, plants, water, air, and nuclear wastes and to evaluate human exposure to ionizing radiation [4][5][6]. The average worldwide human exposure to natural resources reported by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) is 2.4 mSv y -1 [1]. ...
... Scientists around the world carry out various studies to determine the level of natural radioactivity in soil, plants, water, air, and nuclear wastes and to evaluate human exposure to ionizing radiation [4][5][6]. The average worldwide human exposure to natural resources reported by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) is 2.4 mSv y -1 [1]. ...
... Scientists around the world carry out various studies to determine the level of natural radioactivity in soil, plants, water, air, and nuclear wastes and to evaluate human exposure to ionizing radiation [4][5][6]. The average worldwide human exposure to natural resources reported by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) is 2.4 mSv y -1 [1]. ...
In this study, natural radioactivity concentrations of soil samples taken
from 9 different districts within the borders of Ankara were determined using
thallium-doped sodium iodide NaI(Tl) gamma spectrometry. As a result of
the study, 226Ra, 232Th, and 40K radioactivity concentration ranges of the soil
samples were found to be 16.1 ± 1.7 (Gölbaşı) – 41.5 ± 3.5 Bq kg-1 (Kızılca�hamam), 26.2 ± 1.7 (Kahramankazan) – 45.6 ± 2.9 Bqkg-1 (Kızılcahamam),
and 284.2 ±26.7 (Beypazarı)- 580.6 ± 37.4 Bq kg-1 (Haymana), respectively.
Average activity concentrations in soil in the areas of interest were found
to be 25.1± 1.9, 32.3 ± 2.3, and 426.6± 33.1 Bq kg-1 for 226Ra, 232Th, and 40K,
respectively. The results obtained in this study have been compared with
the results of similar studies conducted in different regions of Turkey and
different regions of the world, and these results can be a reference for similar
evaluations to be made in the future.
This study aims to examine the physicochemical and radiological properties of some inorganic materials which are perlite, vermiculite, pumice, rock wool, zeolite, expanded clay aggregate, volcanic tuff, and sepiolite used in soilless agriculture. Water saturation, pH, electrical conductivity, calcium carbonate equivalent, available potassium, available phosphorus, and organic matter analyses were implemented for inorganic materials. The elemental contents of the components for studied inorganic materials were obtained using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Furthermore, natural and artificial radionuclides of studied inorganic materials were calculated using gamma‐ray spectrometry. The pumice has the highest ²²⁶ Ra activity concentration, and the zeolite has the highest ²³² Th and ⁴⁰ K activity concentrations. The ¹³⁷ Cs activity concentration is the maximum for perlite and it is the minimum for expanded clay aggregate. The zeolite has the highest radiological hazard parameters whereas those are the smallest for the rock wool. The Fe, Na, B, Ca, K, Si, P, S, and Mn are the primary components of the inorganic materials used in soilless agriculture. Consequently, this study is contributed to environmental and health problems of livings. In the future, transferred radionuclides from plant to livings assessment can be carried out for these inorganic materials used in soilless agriculture.
