scholarly journals Evaluation of environmental natural radioactivity levels in soil and ground water of Barkin Ladi, Plateau state, Nigeria

2018 ◽  
Vol 14 (3) ◽  
pp. 338-342
Author(s):  
Habu Tela Abba ◽  
Wan Muhammad Saridan Wan Hassan ◽  
Muneer Aziz saleh

Gamma spectrometry was used to measure gamma dose rate in air and to determine the activity concentration of naturally occurring radionuclides viz. 226Ra 232Th and 40K in soil samples collected across the geological formations of Barkin Ladi. Dose rates measured in-situ ranged from 5 nGy h−1 to 1265 nGy h−1 with a mean value of 325 nGy h−1. The activity concentrations of 226Ra ranged from 27 to 327 Bq kg−1, 34 to 457 Bq kg−1 for 232Th and 43 to 1055 Bq kg−1 for 40K. Their mean values are significantly higher than their corresponding global average values. Annual effective dose due to exposure to gamma dose is calculated at 0.34 mSv y−1. Mass concentrations of uranium (238U) and thorium (232Th) determined in groundwater samples using Inductive Coupled Plasma Mass Spectrometry (ICP-MS) ranged from 2.5 to 35 µg l−1 for 238U and 0.5 to 15 µg l−1 for 232Th. Ingestion effective dose varies between 10.5 and 142 mSv y−1 for 238U and between 0.34 and 10.2 mSv y−1 for 232Th. Mass concentration of three water samples exceed the toxicity limit of U in groundwater provided by WHO. The result revealed that human risk due to ingestion of groundwater is from chemical toxicity rather than radiological effects.  The results of this work will be useful for radio-geochemical investigation and groundwater resources management.

2019 ◽  
Vol 107 (6) ◽  
pp. 503-516 ◽  
Author(s):  
Muneer Aziz Saleh ◽  
Ahmad Termizi Ramli ◽  
Khaidzir Bin Hamzah ◽  
Jasman Zainal ◽  
Mohsin Mohd Sies ◽  
...  

Abstract This present study aims to obtain baseline data of environmental terrestrial radiation and to assess the corresponding health risk in the ambient environment in eastern region of Peninsular Malaysia. The measurements were taken 1 m above the soil surface using NaI [Ti] detector with a total of 2144 measured points which covered all geological formations and soil types. The measured gamma dose rates ranged from 26 nGy h−1 to 750 nGy h−1 with a mean value of 172±90 nGy h−1. The mean gamma dose rate is three times higher than world averages of 57 nGy h−1. The data of gamma dose rates show the reading of the gamma dose rates not fit to the normal distribution. The variations of gamma dose rates based on geological formation and soil types were investigated using the unbalanced one way ANOVA. The results indicated strong significant differences due to the different geological formations and soil types. The T-test of gamma dose rates for each pair of soil types or geological formations and their hypothesis test at 95 % confidential level were compared to shows the significant difference between each pairs. The results indicate that the gamma dose rates for all pairs of soil types were significant differed except the miscellaneous soil while the gamma dose rates of the pairs of geological formation were also significant differed except the intermediate and intrusive geological formations. Acid intrusive and intermediate intrusive geological formations has the highest mean values of 223 nGy h−1 and 278 nGy h−1, respectively. These values are approximately four and five times the world average. Soil type (Steep land) has the highest gamma dose rate with the mean value of 215 nGy h−1. The radiological health information which are the total annual effective dose equivalent, the collective effective dose, lifetime effective dose and the lifetime cancer risk for each person are 0.844 mSv, 3.53×103 man Sv y−1, 59.10 mSv and 3.25×10−3, respectively. The results in eastern region of Peninsular Malaysia were comparable to different areas in Malaysia, which indicate the value reported in UNSCEAR, 2000 should be adjusted to the current status in Malaysia.


2020 ◽  
Vol 190 (2) ◽  
pp. 132-138
Author(s):  
V Manić ◽  
G Manić ◽  
D Nikezić ◽  
D Krstić

Abstract The effect of buildup factors on absorbed dose rate in air and the effective dose from gamma rays of primordial radionuclides in building materials, was investigated in the article. Specific absorbed dose rates were calculated for the standard concrete room, as well as, for rooms where brick and covering building materials were used. For all room models the Harima (G-P) buildup factors were applied, while for the standard room the Berger’s and Taylor’s buildup factors were used, too. The contribution of the radiation buildup to absorbed dose rate and effective dose was determined as large as 41%.


2020 ◽  
Vol 108 (11) ◽  
pp. 913-921
Author(s):  
Nesli Bingöldağ ◽  
Pelin Otansev

AbstractThe concentrations of 226Ra, 232Th, 40K and 137Cs radionuclides in soil samples collected from 323 different regions of Nevşehir province were determined by using a gamma spectrometer with an HPGe detector. The mean gamma activity concentrations (ranges) of 226Ra, 232Th, 40K and 137Cs for districts were determined as 49.45 (7.40–193.90), 54.08 (<2.8–122.50), 698.43 (37.67–1370.20) and 8.26 (0.10–52.60) Bq kg−1, respectively. The mean activity concentrations of 226Ra, 232Th and 40K were higher than the world mean value. According to Kolmogorov–Smirnov test, distributions of 226Ra, 232Th and 137Cs show log-normal distributions. Whereas, 40K shows normal distribution. The mean radium equivalent activity was 181.68 Bq kg−1 which is lower than the recommended maximum value of 370 Bq kg−1. The mean external terrestrial gamma dose rate was found to be 85.12 nGy h−1. The calculated external hazard value was 0.49 and within the acceptable limit which is less than unity (Hex ≤ 1). Thermo Scientific RadEye NBR detector was used to determine environmental gamma dose rates. The gamma dose rates were measured at 445 points at a height of 1 m from land surface. The mean outdoor gamma dose rate (range) was found as 150.13 (50–480) nGy h−1. This mean value was found higher than world mean value. The fact that most of the Nevşehir province is based on volcanic rocks explains why the gamma dose rates are high.


2016 ◽  
Vol 17 (1) ◽  
pp. 206-211 ◽  
Author(s):  
Ali Abid Abojassim ◽  
Suha H. Kadhim ◽  
Hussien Abid Ali Mraity ◽  
Rua R. Munim

In the present work, radon concentration was measured for different types of bottled drinking water and carbonated drink samples that are available in Iraqi markets. Radon measurements were carried out using a RAD-7 electronic radon detector. Annual effective dose was also calculated. The measured radon concentration in samples of bottled drinking water ranged from 0.0354 to 0.248 Bq/l with a mean value of 0.11265 Bq/l and the measured radon concentration in the samples of the carbonated drinks lay between 0.0354 and 0.283 Bq/l with a mean value of 0.1418 Bq/l. The mean values of the effective dose in all samples of bottled drinking water and carbonated drinks were found to be 0.410844 and 1.022 μSv/y respectively. The results of this work revealed that the radon concentrations were lower than the recommended limits indicated by the World Health Organization and by the regulatory bodies of the European Union.


2017 ◽  
Vol 50 (4) ◽  
pp. 2332
Author(s):  
A. Papadopoulos ◽  
S. Altunkaynak ◽  
A. Koroneos ◽  
A. Unal ◽  
O. Kamaci

The natural radioactivity of the Western Anatolian plutonic bodies (Turkey), as well as the assessment of any potential health hazard due to their usage as decorative building materials is studied. Seventy samples from Western Anatolian plutonic bodies, including various rock-types from quartz-monzodiortie to syenogranite, have been measured for their natural radioactivity using γ-spectrometry. According to the experimental results the natural radioactivity levels were ranged up to 229.62 Bq.kg- 1 for 226Ra, up to 207.32 Bq.kg-1 for 232Th and up to 2541.95 Bq.kg-1 for 40K, with a mean value of 57.67 (±38.13), 80.30 (±42.00) and 1071.92 (±405.24) Bq.kg-1 respectively, which are below the international representative mean values for granite stones. The increment on the external γ-radiation effective dose rate appears a mean value of 0.27 (±0.19) mSv.y-1, scattering below 1 mSv.y-1. In case of the internal α-radiation a mean value of 0.14 (±0.10) mSv.y-1, scattering below 0.5 mSv.y- 1 was estimated. The majority of the samples increase the external and the internal dose less than 30% of the maximum permitted limit of the effective dose rate. Therefore, at least from radiological point of view, the plutonic rocks of Western Anatolia could be safely used as decorative building materials.


2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.


Author(s):  
Yuko Komuro ◽  
Yuji Ohta

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.


Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 816
Author(s):  
Kuei-Yuan Hou ◽  
Hao-Yuan Lu ◽  
Ching-Ching Yang

This study aimed to facilitate pseudo-CT synthesis from MRI by normalizing MRI intensity of the same tissue type to a similar intensity level. MRI intensity normalization was conducted through dividing MRI by a shading map, which is a smoothed ratio image between MRI and a three-intensity mask. Regarding pseudo-CT synthesis from MRI, a conversion model based on a three-layer convolutional neural network was trained and validated. Before MRI intensity normalization, the mean value ± standard deviation of fat tissue in 0.35 T chest MRI was 297 ± 73 (coefficient of variation (CV) = 24.58%), which was 533 ± 91 (CV = 17.07%) in 1.5 T abdominal MRI. The corresponding results were 149 ± 32 (CV = 21.48%) and 148 ± 28 (CV = 18.92%) after intensity normalization. With regards to pseudo-CT synthesis from MRI, the differences in mean values between pseudo-CT and real CT were 3, 15, and 12 HU for soft tissue, fat, and lung/air in 0.35 T chest imaging, respectively, while the corresponding results were 3, 14, and 15 HU in 1.5 T abdominal imaging. Overall, the proposed workflow is reliable in pseudo-CT synthesis from MRI and is more practicable in clinical routine practice compared with deep learning methods, which demand a high level of resources for building a conversion model.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 879
Author(s):  
Rosanna Floris ◽  
Gabriele Sanna ◽  
Cecilia Teodora Satta ◽  
Carlo Piga ◽  
Francesco Sanna ◽  
...  

Fish populations play an active role in the maintenance of aquatic ecosystems biodiversity. Their intestinal microbiota and fillet chemistry depend on abiotic and biotic factors of the water environments that they inhabit. The present study investigated the grey mullets’ gut microbiota from a transitional aquatic ecosystem (Santa Giusta Lagoon, Sardinia, Italy) by a multidisciplinary approach which refers the results of (1) gut cultivable microbiota analyses (MA), (2) the trace metal assessment of fish muscle (TM), (3) the physico-chemical water monitoring (PC). MA detected the greatest number of total aerobic heterotrophic bacteria, Enterobacteriaceae and coliforms in Autumn (mean values 1.3 × 105, 2.4 × 104, 1.1 × 104 cfu g−1, respectively) when the accumulated rain and mean values of nutrients (reactive phosphorous and silica) were the highest. Marine bacteria were more numerous in Summer (mean value 7.4 × 105 cfu g−1) when the highest mean values of water temperature and salinity were registered. The gut bacteria were identified as Pseudomonas spp. (64%), Aeromonas spp. (17%), Ochrobactrum pseudogrignonense (10%), Providencia spp. (5%), Enterobacter ludwigii (2%) and Kocuria tytonicola (2%). TM showed that Ca, Na, B and Ni increased their concentrations in Winter while maxima of P, Zn, Cu and Fe were found in muscles of fish sampled in Summer. This study highlighted that the fish intestinal microbiota and metal composition of the fillet reflected the seasonal aquatic environmental variability.


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