Gamma-ray Spectrometry Method Research Articles

Statistical assessment of natural radioactivity, radon activity, and associated radiological exposure due to artisanal mining in Atiwa West district of the Eastern region, Ghana

The activity concentration of natural radionuclides, radon activity concentration, mass and area exhalation rates have been studied in soils from gold mining communities in Atiwa West district. The natural radionuclides were determined by gamma ray spectrometry method while radon concentrations were measured using CR-39 detectors. The mean activity concentrations were found to be 26.9 ± 1.7 Bq/kg, 57.5 ± 3.6 Bq/kg, 237.5 ± 17.6 Bq/kg and 560.0 ± 54 Bq/m3 for Ra-226, Th-232, K-40 and Rn-222 respectively. The evaluated mass exhalation rates ranged from 2.8 ± 0.3 to 6.5 ± 0.7 × 10−5 Bq/kg/h while the area exhalation rates were from 0.8 ± 0.09 to 2.0 ± 0.21 × 10−3 Bq/m2/h. Some mining and farming areas recorded high exhalation rates indicating that the use of soils as building materials from such areas could pose a level of radiation hazard to the population. The evaluated radiological risks were below reference levels. A good linear correlation was observed between Ra-226 and Rn-222 activity concentrations and in the investigated soils. The Pearson correlation coefficient, cluster analysis and principal component analysis were used to study the relationship between the determined parameters of the study.

Assessment of Radiation Dose Associated with Background Radionuclides in Quarry Soil at Dawakin-Kudu LGA Kano, Nigeria

Naturally occurring radioactive materials (NORMs) are present in different concentrations in the environment as well as quarry depending on the geological formation of the soil. The assessment of any release of radioactivity into the environment is crucial for safeguarding public health, particularly when this radioactivity has the potential to enter the food chain. The quarry located in Dawakin-Kudu Kano has the potential to exhibit elevated levels of natural radioactivity due to intense mining operations. This study presents the assessment of activity concentration in quarry soil at Dawakin-Kudu with a focus on the transfer mechanism from soil to plant. Soil samples were gathered from a quarry site and farmlands situated around the quarry at Dawakin-kudu, plant samples were also collected from the same farmlands and were all analyzed for natural radioactivity, specifically for 226Ra,232Th, and 40K. The gamma-ray spectrometry method, coupled with the Sodium thallium Iodide NaI (Tl) detector was used to measure the activity concentrations of 226Ra,232Th, and 40K. Activity concentrations of natural radioactivity in soil were generally higher than those recorded in plants. The mean activity concentration of the radionuclides in soil ranges from Highest-to-Lowest values as follows 226Ra: 65.24±1.92 Bqkg-1 – 42.41±1.73 Bqkg-1, 232Th: 182.71±1.44 Bqkg-1 – 114.61±1.25 Bqkg-1, 40K: 597.51±3.81 Bqkg-1 – 321.93±3.55 Bqkg-1. The radiological hazard indices were all determined to assess the radiation hazard of the quarry soil. The radionuclides transfer factor showed a higher value for 40K in the order 40K>232Th >226Ra, this implies high bioconcentration of 40K in plants. The findings suggest that consuming plants grown around the quarry location over an extended period could pose substantial health threats to the public. Consequently, the study area may not be safe for residents in the long run, emphasizing the necessity for continuous monitoring of radioactivity concentrations to mitigate the environmental health implications of accumulated...

Assessment of Activity Concentrations and Soil-to-Plant Transfer Factors of Natural Radioactivity in Rice Plant Components grown in Kano State, Nigeria

Transfer Factor (TF) depicts the percentage or fraction of natural radioactivity in the soil that is absorbed by different parts of a plant which are eventually transferred, directly or indirectly, to man during ingestion. Activity concentrations of primordial radionuclides were determined in farm soil and rice plant components (root, stem, leaf and seed) in six Local Government Areas (Bagwai, Bunkure, Dambatta, Garko, Kura and Wudil) renowned for production of rice in Kano State, Nigeria, using gamma-ray spectrometry method with sodium iodide scintillation detector. The mean activity concentrations of 40K, 238U and 232Th were: 509.51, 27.75, and 12.26 Bq.kg-1 correspondently in soil; 227.40, 14.24, and 5.19 Bq.kg-1 correspondingly in seed; 935.53, 32.73, and 7.29 Bq.kg-1 accordingly in leaf; 803.65, 16.72, and 6.76 Bq.kg-1 respectively in stem; and, 408.91, 30.03, and 10.31 Bq.kg-1 correspondingly in root. The mean concentrations of 40K reported in soil were greater than the world average of 400 Bq.kg-1, while those of 238U and 232Th were less than the world mean values of 35 Bq.kg-1 and 30 Bq.kg-1 respectively. The estimated mean of TFs of 40K, 238U and 232Th were: 0.52, 0.61, and 0.43 respectively in the seed; 1.95, 1.45, and 0.69 respectively in leaf; 1.72, 0.75, and 0.64 correspondingly in the stem; and, 0.85, 1.27, and 0.76 accordingly in the root. Except for a few plant samples where BDL were recorded for 238U and 232Th, all values of TFs were greater than the recommended values of 4.9 x 10-3 and 2.1 x10-4 given for 238U and 232Th...

Assessment of radioactivity concentration for building materials used in Babadogo Estate, Nairobi City County, Kenya.

Natural radioactive materials in certain conditions can get to hazardous radiological level. The aim of the present work was to evaluate the natural activity concentration from sampled building materials collected from different locations in Babadogo Estate within Nairobi City County. The analysis done using gamma ray spectrometer, which was put into action for spectral data acquisition and then analysis. The activity concentration levels of 238U, 232Th and 40K for the selected samples of building materials was measured by the use of gamma ray spectrometry method. The analyzed data compared with the standard acceptable values. The activity concentration in 40K varied from 55±3 to 2647±132Bq kg-1, giving an average (sum of all values divided by 33) value of 831±42Bq kg-1; 238U varied from 39±2 to 3602±180Bq kg-1, giving average figures of 378±19Bq kg-1 and 232Th ranged from 5.000±0.300 to 4213±211Bq kg-1, giving average figure of 290±15Bq kg-1. The calculated average figures for activity concentration surpassed the world average values of 420, 33 and 45Bq kg-1 in 40K, 238U and 232Th, respectively.

Environmental Radioactivity Concentrations and Assessment of Radiological Hazards in Soil Around Bandung Nuclear Area

Bandung nuclear area is an area which is nuclear reactor named TRIGA 2000 and research laboratory located. The reactor and research laboratory are utilized for training, researching and radioisotopes production that has potential to contaminate the environment. Environmental radioactivity monitoring is done periodically to find out potential radioactive release from activities inside Bandung nuclear area to surroundings. However, the assessment of radiological hazards to determine the potential radiological dangers to humans and environment around Bandung nuclear area is not done yet. The objective of this study is assessing the radiological hazards in Bandung nuclear area by comparing the data from soil samples taken in environment radiological monitoring activity with the recommendation data based on UNSCEAR and other references to find out the radiological hazards that potentially affect to humans, where this assessment has never been carried out in this area. The assessment of radiological hazards in this study is limited to Ra-226, Th-232 and K-40 nuclides because contributing to radiation dose received by human. The study was conducted by collecting soil samples from several sampling points inside and outside Bandung nuclear area. Then, the nuclides of Ra-226, Th-232 and K-40 contained in soil samples are measured by using the gamma-ray spectrometry method with high resolution detector that is HPGe (High Purity Germanium) and a computer-based Multichannel Analyzer (MCA). The results indicated that the concentration of environmental radioactivity ranged between 11.02 to 32.66 Bq/kg for Ra-226; 19.44 to 43.83 Bq/kg for Th-232 and 56.00 to 183.39 Bq/kg for K-40. This study also obtained results that the radiological hazard of the gamma dose rate ranged from 23.54 to 40.23 nGy/h, the radium equivalent was 51.77 to 89.78 Bq/kg; the external hazard index was 0.14 to 0.24 and the internal from 0.18 to 0.33; the index of radioactivity level was 0.37 to 0.63. The annual effective dose equivalent for outdoor ranged from 0.03 to 0.05 mSv/y and indoor was 0.12 to 0.20 mSv/y. The lifetime cancer risk for outdoors ranged from 0.10x10–3 to 0.17x10–3 and indoor was 0.4x10–3 to 0.69x10–3. The values of radiological hazard were below the international requirements. There is no potential risk of natural radiation of gamma ionizing radiation exposure in soil samples around the Bandung nuclear area for workers, the public, and the environment.Keywords: Environment, Radiological, Hazard, Gamma, Spectrometry.

Gamma radioactivity and Environmental radiation risks of Granitoids in Central and Western Gilgit-Baltistan, Himalayas, North Pakistan

The study analyzed the gamma radioactivity levels due to radionuclides (226Ra, 232Th, and 40K) by the Gamma-Ray spectrometry method and calculated health hazards in rocks in Central and Western Gilgit-Baltistan, North Pakistan. The results of average activity concentrations of collected rock samples were 714.82 Bq kg−1 for 40K, 44.47 Bq kg−1 for 232Th, and 56.21 Bq kg−1 for 226Ra, respectively. The values of Indoor Excessive Lifetime Cancer Risk ELCR (in) in the samples are much greater than the permissible limit of 1.19 × 10−3. The values are also higher than safe limits for building materials (0.31 × 10−3) for seven samples. According to statistical analysis, the calculation shows the correlation coefficient value higher than the safe limit. Between 226Ra and 232Th correlation coefficient value is (0.92) and 40K and 226Ra correlation coefficient value (0.97) seemed to be positively high value. For Pearson’s correlation p < 0.05 is considered a safe limit but calculations find out the values for p > 0.05. For Absorbed Dose (D), Effective dose (H), Annual Equivalent dose (E), And most important lifetime cancer risk (ELCR) R2 = 0.99 which shows a strong correlation between them. We have concluded that areas, where these rocks are exposed on a large scale, are not suitable for living. The diorite, granite, leucogranite, pegmatite, amphibolite, and gneiss are highly radioactive and should not be used as a building material..

Recognition of sedimentary environments using handheld gamma-ray spectrometry in Pleistocene Fennoscandian Ice Sheet glaciogenic basin, northern and central Poland

Gamma-ray spectrometry (GRS) is a widely applied method in geological research, useful in, e.g., stratigraphical correlation, determination of basic lithological features, and weathering processes. This paper aims to put a new perspective on the handheld gamma-ray spectrometry method, concentrated on application to the glaciogenic depositional systems in contemporary exposures. The study was held in northern and central Poland within the limit of successive Fennoscandian Ice Sheets (FIS) advances and retreats. Fifteen profiles comprising sediments deposited in typical Pleistocene environments were subjected to handheld GRS measurements. The study indicated vertical, lateral, and lithofacies variability of results and revealed the potential for determining particular sedimentary palaeoenvironments with handheld GRS. Aeolian deposits showed the lowest concentration of K, U, and Th radionuclides. Relatively low radioactivity was revealed for fluvioglacial and fluvial deposits. Notable radionuclide concentrations were indicated for glaciogenic and subaqueous fan deposits, while the highest radioactivity was found in lacustrine and loess successions. K, U, and Th concentrations also indicated weathering processes and soil profile development within glacial tills.

Field gamma ray spectrometry as a diagnostic tool for the assessment of hypothetical melt rocks from the Maâdna structure (Talemzane, Algeria): Implications for the crater formation process

AbstractAmong all geophysical methods, gamma ray spectrometry is not widely used in impact cratering studies, despite its efficiency in the investigation of physical/chemical changes in rocks. The application of gamma ray spectrometry method to data from the Maâdna crater is aimed at detection and verification of the presumed impact‐derived melt rocks or breccias, as well as discussing its implications on process of formation. The resulting information also demonstrates the potential of these specific data regarding our general understanding of impact cratering, while a few case studies have been reported in the literature to date within the impact community. Maâdna crater is dated at 2.6–3.1 Ma of ~1.7 km and is emplaced in Upper‐Cretaceous to Eocene limestones of the northern part of the Algerian Saharan platform. Although originally accepted as an impact crater, its origin is still controversial. Several thousands of field measurements were taken using a field portable gamma ray spectrometer. The measurements can be equivalently expressed by up to about 42 km footpath recordings in real‐time ground acquisitions, covering the entire structure and surrounding areas beyond the crater edge. The collected data included the total count (Tc) and the concentrations of the radionuclides calculated in wt% for K and in ppm for U and Th. The spectra rates recorded inside and outside the crater did not exceed the maximum average concentrations corresponding to 75.3 Cps, 4.94 ppm, 10.5 ppm, and 1.79 wt% for Tc, U, Th, and K, respectively. The database was processed using various gridding data methods, from which the minimum curvature was adopted as it provides a powerful visualization and interpretation of the anomalous distribution of radioactive elements and their corresponding ratios maps. In addition, an improved statistical analysis was carried out in order to extract a maximum of information about the radiometric response of each rock unit. This analysis consisted of a series of multiple linear regression, mean differencing, Q–Q (quantile–quantile) plots, and ternary mapping. Maps and plots of various models allowed us to examine the background variability in the distribution of K, Th, and U concentrations at the surface of the three distinctive litho‐type zones in the surveyed area, which are the central part, the crater edge, and the outside of the crater including the wadi deposits. Observed results of different radiometric responses clearly reflect the effect of various lithological units, especially in the areas with high K concentration. Note that this positive K‐anomaly has been observed in recent deposits that fill the Maâdna depression or external wadi beds. In contrast, the surrounding limestone rocks showed lower levels of radioelement concentrations. Relevant similarities found between the radiometric signatures of the Neogene formations inside and outside the crater can be considered as a strong argument to exclude preferential radionuclides enrichment caused by an impact event. Consequently, the natural origin of radioactive sources can be easily explained. Compared to other radiometric signatures documented on proven impact structures, the Maâdna structure has been notably discussed in the context of a diapiric hypothesis rather than a meteoritic one. Moreover, the methods used here contribute to our knowledge of the regional sedimentary history in terms of natural radioactivity.

Assessment of radiological hazards from soil samples in the Northeastern area of Burkina Faso

The activity concentrations of main naturally occurring radionuclides were determined with the aim of assessing the radiation hazards in the Northeastern part of Burkina Faso. Soil samples were taken and analyzed by the gamma-ray spectrometry method. The ranges of specific activity of 238U, 232Th and40K are 15.25 pm 2.59 , text{Bq} cdot {text{kg}^{-1}} to 109.57 pm 3.21 , text{Bq} cdot {text{kg}^{-1}}, 19.56 pm 1.65 , text{Bq} cdot {text{kg}^{-1}} to 44.88 pm 2.49 text{Bq} cdot {text{kg}^{-1}} and 125.74 pm 4.40 , text{Bq} cdot {text{kg}^{-1}} to 705.85 pm 10.79 , text{Bq} cdot {text{kg}^{-1}} respectively. Three high background radioactivity areas have been identified for Uranium, Thorium and Potassium on different places in the study area. The radiological hazards indices vary from 62.87 , text{Bq} cdot {text{kg}^{-1}} to 189.47 , text{Bq} cdot {text{kg}^{-1}} for the Radium equivalent activity (Ra_{eq}), 29.5 , eta text{Gy} cdot {text{h}^{-1}} to 86.65 , eta text{Gy} cdot {text{h}^{-1}} for the absorbed dose rate (D_R), 0.18 , text{mSv} cdot {text{y}^{-1}} to 0.53 , text{mSv} cdot {text{y}^{-1}} for the annual effective dose rate (AEDE), 0.21 to 0.81 for the internal hazard index (H_{in}), 0.17 to 0.51 for the external hazard index (H_{ex}), 1.27 times 10^{-4} to 3.73 times 10^{-4} for the Excess Lifetime Cancer Risk (ELCR) and 209.01{mkern 1mu} mu , 0.18{mkern 1mu} Sv cdot y^{{ - 1}} to 594.21 , mu text{Sv} cdot {text{y}^{-1}} for the annual gonadal dose equivalent. The average values of indices are well below their permissible limit. However, at Niapsi the obtained values for absorbed dose rate, annual effective dose rate and excess lifetime cancer risk are little above their permissible limit.

Detection of Uranium Anomalies and Alteration Zones Using Airborne Gamma-Ray Spectrometry at Gabal Attala and Its Surrounding Area, Eastern Desert, Egypt

Gamma-ray spectrometry method is widely used in various fields. The study area is located in the Central Eastern Desert of Egypt and covers about 1200 square kilometers. The rock units in the study area can be organized in ages from the Precambrian (mainly granite) to Quaternary. Airborne gamma-ray spectrometry data were collected by Aero-Service, 1984. The main objectives of this study are to detect hydrothermal alteration zones and the uranium anomalies in the study area. The processing of the data was conducted to generate radioactive element concentration maps (K, eU and eTh). Hydrothermal alteration zones such as potassic and phyllic altered areas were detected using the Potassium Ternary Composite Image map and the eTh/K map. The F-parameter technique and K ideal method were used to determine the locations of the potassium-enrichment. These locations are characteristically associated with the orogenic gold mineralization in the study area. Fourteen radioactivity zones were classified based on the Interpreted Radio-Spectrometric Zonation (IRSZ) Map. These zones were divided into high, medium and low radioactive response where zones of high radioactive response were revealed as zones 1, 6, 9 and 13. Uranium anomalies have been identified as these anomalies are abundant in eU values and also associated with higher values of eU/eTh and eU/K, where the maximum value of eU is associated with the Younger Granite with a value of 18.831 ppm. These uranium anomalies are associated with Taref Formation, Post-Hammamat felsite, Quaternary deposits and Younger Granite. The locations of uranium anomalies are considered important exploration targets, as these locations are promising and have priority for ground geophysical and geological follow-up.

A comparison of alpha-particle and gamma-ray spectrometry methods for determination of 235U, 238U and 226Ra activity concentration in samples of coal, slag and fly-ash

In order to compare alpha-particle and gamma-ray spectrometry, the activity concentrations of 235U, 238U and 226Ra in samples of coal, slag and fly-ash from the thermal power plant “Nikola Tesla A”, Serbia, were determined by these two methods. Methods were compared and discussed from the point of view of its precision, difficulty to apply and complexity. Gamma-ray spectrometry was performed with HPGe (High Purity Germanium) spectrometer, while alpha activity was measured by PIPS (Passivated Implanted Planar Silicon) detector. For the alpha-particle spectrometry, the chemical procedures applied were chromatographic resin extraction for uranium isotopes and micro-coprecipitation for 226Ra. Thin alpha sources were prepared by electrodeposition and filtration through polypropylene membrane filter for uranium determination, while filtration technique was performed for radium sources. For the evaluation of the statistical difference between individual measurement results obtained by application of two methods Z - test was used. In order to evaluate the difference between two methods used, paired samples t-test and F-test were applied. Results show that there is no statistical difference between two methods used and that gamma-ray spectrometry is a valid alternative to time consuming alpha spectrometry.

Contamination of Slovak Bilberry (Vaccinium Myrtillus L.) with Radiocaesium 137Cs in Selected Slovak Locations

Abstract The aim of this study was to determine the activity of post-Chernobyl 137Cs in Slovak bilberry (Vaccinium myrtillus L.) from selected locations of Slovakia depending upon: the season, location and the soil-plant transfer factor (TF). The 137Cs activity was determined in samples of forest soil and bilberry bushes (stems, leaves and fruits) growing on the soil in three locations: Arboretum Mlyňany (1), Hodruša-Hámre (2) and Javorníky (3). Altogether we collected 35 samples; namely 15 samples from Arboretum Mlyňany, 10 samples from Hodruša-Hámre and 10 from Javorníky. The samples of soil were examined also for the activity of 40K. The samples were collected in the spring, summer and autumn in the years 2019 and 2020 and were analysed by a gamma-ray spectrometry method. The highest levels of 137Cs activity concentrations were determined in Hodruša-Hámre in September where they reached 161 ± 13 Bq.kg−1 in the soil, 3.95 ± 1.07 Bq.kg−1 in the stems and 14.7 ± 4.26 Bq.kg−1 in the leaves. The lowest levels were determined in the Arboretum Mlyňany in October where the 137Cs activity in the soil reached 13.1 ± 1 15 Bq.kg−1, while in the stems, leaves and fruits it was lower than the minimum detectable level. In the latter location, we also determined the highest activity of 40K, the radioactive isotope physiologically and metabolically similar to 137Cs. The mass activity of 137Cs in all samples of bilberries were lower than the minimum detectable activity (MDA). The comparison of the results obtained in this study with the limit for total mass activity of radiocaesium (134Cs + 137Cs) in the food (600 Bq.kg−1) allowed us to conclude that the fruits, stems and leaves of Slovak bil-berries present neither health nor environmental risk.

Heavy metals, radionuclides activity and mineralogy of soil samples from an artisanal gold mining site in Ile-Ife, Nigeria: implications on human and environmental health

The Ife-Ilesha schist belt of the Nigerian Basement Complex is renowned for artisanal gold mining activities owing to the occurrence of gold-bearing eluvial deposits within and around the belt. However, gold mining operations in Ile-Ijesha axis are carried out haphazardly without consideration of probable health risks that might be posed to the miners and local community by heavy metals and naturally occurring radionuclides materials (NORMs) contents in the soil. This study was therefore conducted to determine the mineralogy, heavy metals contents and radionuclide activity of soil samples collected from a gold mining site in Ile-Ife with a view to assessing the consequential health and radiological risks. Thirty-five (35) soil samples were collected from abandoned and active excavating pits over the entire area using stainless-steel spade. The heavy metals and radionuclides concentrations and mineralogical compositions of the samples were obtained by Atomic Absorption Spectroscopic (AAS), gamma ray spectrometry and X-ray diffraction (XRD) methods, respectively. The contamination indices consisting of Enrichment Factor (EF) and Index of geoaccumulation (Igeo) were calculated from heavy metals concentrations. The sequence of the average concentrations of heavy metals in the soil samples decreases as follows: Pb (72.93 ± 4.60) > Cd (58.26 ± 3.25) > Cr (42.81 ± 3.00) > Zn (33.66 ± 2.71) > Mn (24.60 ± 1.80) > Ni (23.93 ± 2.51). The mean EF values of the measured heavy metals occurred in the order of Cr > Pb > Zn > Cd > Ni. The Igeo values of the measured heavy metals (except Pb) were less than one (< 1) revealing practically uncontaminated condition of the studied soil. The radiation dose and radiological hazard risks were estimated by employing absorbed dose, effective dose, radium equivalent, gamma index, external hazard index, excess life cancer risk and representative level. The hazard index values of all the measured heavy metals were < 1 indicating no significant non-carcinogenic effects. The average activity concentrations of 40 K, 238U and 232Th are 259.23 ± 84.20 Bqkg−1, 185.48 ± 73.31 Bqkg−1, 11.93 ± 4.68 Bqkg−1, respectively. All the radiological indices were below the world average values stipulated by the radiation monitoring bodies. The result of the XRD indicates the preponderance of quartz, and biotite, as well as subordinate amounts of plagioclase, kaolinite, ilmenite, andradite, actinolite and microcline in the soil samples, pointing to a schistose source rock, which is probably gold-bearing. The current study indicated practically low contamination of the Ile-Ife gold mining site soils by heavy metals, low radiological risk from NORMs and prospect of mineral exploration in the area if well-established procedure is followed.

Specific Activity and Radiation Hazard of Radionuclides in Wheat and Bean Produced Near Shazand, Iran

Introduction: Radionuclides found in foods are harmful to human health. Wheat and bean are among the most important food ingredients in the world. Therefore, this study aimed to determine the specific activity of natural radionuclides in wheat and bean produced near the refinery complex plant. Material and Methods: In order to determine the specific activity of radionuclides, the gamma-ray spectrometry method was used employing a high-purity germanium detector with a relative efficiency of 80%. Results: Our findings showed that the specific activity of the 226Ra isotope of radium had the ranges 232Th isotope of thorium was in the range of not detected (ND)-4.09 and ND-3.62 Bq/kg with the mean values of 2.19 and 2.69 Bq/kg for wheat and bean samples, respectively.The specific activity of the 40K isotope of potassium was obtained as 103.19-168.94 and 129.22-568.98 Bq/kg with the mean values of 142.21 and 458.37 Bq/kg for wheat and bean samples, respectively. The annual effective dose for wheat and bean intake was 0.11-0.52 and 0.02-0.18 mSv, respectively. Furthermore, the mean of excess lifetime cancer risk for wheat and bean samples was calculated as 1.06×10-3 and 0.11×10-3, respectively. The latter values are lower than the world average for bean samples. Conclusion: According to the results of this study, the radiological parameters of wheat were higher than the global average and reference value, which may be due to ash dispersion in this area. For bean, these parameters were lower than the mean value. As a result, it could be concluded that bean is not considered as a threat to consumer health.

Determination of natural radioactivity levels and radiological hazards in environmental samples from artisanal mining sites of Anka, North-West Nigeria

Artisanal mining of precious metals has become a lucrative venture in Anka, Zamfara State, North-West Nigeria. The use of crude methods of mining and mineral processing and the apparent ignorance of the hazards involved have been linked to some health and environmental consequences. Hence, this study focuses on the assessment of radioactivity levels in rock, soil and sediment samples as well as the radiological hazards of the artisanal mining in Anka. The gamma-ray spectrometry method was employed in the sample analysis. The results show that the estimated mean activity concentrations of 226Ra, 238U, 232Th and 40K in soil were 37.94 ± 6.01 Bqkg−1, 41.60 ± 11.06 Bqkg−1,151.15 ± 21.09 Bqkg−1 and 380.34 ± 116.41 Bqkg−1, respectively. The activity concentrations in rocks and sediments were also analyzed. The radioactivity levels were highest in rock samples. ; For rock samples, mean radium equivalent was 499.18 Bqkg−1, gamma dose rate was 221 ± 35 nGyh−1, internal and external hazard indices were 1.35 and 1.53, respectively and the radioactivity level index was 3.24. The outdoor and indoor annual effective dose equivalents were 271.03 µSvy−1 and 985.39 µSvy−1, respectively. The mean indoor and outdoor excess lifetime cancer risk for soil were 0.55 × 10−3 and 2.18 × 10−3. The evaluation of radiological health risks shows that the values obtained in this study were generally higher than admissible recommended limits and the world averages. The results obtained in this study show that the risk of exposure to ionizing radiation is linked to the artisanal mining and mineral processing in Anka.

Estimation of Natural Radionuclides’ Concentration of the Plutonic Rocks in the Sakarya Zone, Turkey Using Multivariate Statistical Methods

The study aimed to determine the natural radioactivity levels of 226Ra, 232Th, and 40K by the Gamma-Ray spectrometry method, and radiological hazard parameters of the plutonic rocks in the Western and Central Sakarya Zone and to analyze the data using multivariate statistical methods. The average radiological values of samples were determined as 40K (1295.3 Bq kg−1) &gt; 232Th (132.1 Bq kg−1) &gt; 226Ra (119.7 Bq kg−1). According to the skewness values of the distributions of the examined radionuclides, 226Ra (2.1) and 232Th (0.7) seemed to be positively right-skewed while 40K (−0.2) had a negatively right-skewed histogram. On the other hand, the following kurtosis values were calculated for the distributions: 226Ra (5.8 &gt; 3), 232Th (−0.7), and 40K (−0.8). Kolmogorov–Smirnov and Shapiro–Wilk tests were applied to the data to test their normality. Therefore, Spearman’s correlation coefficient method was performed. The radionuclides of 226Ra and 232Th were found to have a positive correlation with radiological hazard parameters of the samples. 2 (two)-related factors identified, and the cumulative value was calculated to be 98.7% on the basis of the Scree Plot. According to the hierarchical cluster analysis, the samples that are grouped with those from Camlik region are prominent. The average radioactivity values of Camlik, Sogukpinar, Karacabey, and Sogut (except for 232Th) regions were detected to be higher than the world averages while the value of 40K was also found to be higher than the average values of various countries in the world.

Aeromagnetometria e aerogamaespectrometria do Complexo Atuba e arredores, leste do estado do Paraná

As rochas do Complexo Atuba afloram na porção leste do Estado do Paraná e compreendem a região sul do Cinturão Ribeira. Situam-se a norte do Terreno Luís Alves e estão enquadradas no Terreno Curitiba. O objetivo desta pesquisa foi definir as unidades geológicas e o arcabouço estrutural da área de trabalho, junto ao mapeamento de falhas, fraturas e diques. A pesquisa foi desenvolvida por meio de aeromagnetometria e aerogamaespectrometria. A primeira permitiu interpretar os traçados de lineamentos e estabelecer o arcabouço estrutural da área de estudo, porém não conseguiu separar de forma definida o Complexo Atuba do Grupo Açungui. As grandes zonas de cisalhamento definidas pela Zona de Cisalhamento (ZC) Lancinha-Cubatão e ZC Curitiba estão encobertas e mascaradas pelos diques básicos mesozoicos. Os lineamentos com direção NE-SW são escassos e correspondem às falhas e às fraturas observadas principalmente no domínio do Complexo Atuba e da Bacia Sedimentar de Curitiba. As orientações NW-SE aparecem em grande proporção e estão relacionadas às falhas e aos diques. O método gamaespectrométrico possibilitou observar dispersão dos elementos K, Th e U, caracterizando as unidades litológicas e detectando a presença de intrusões ígneas. De acordo com esse método, foi possível identificar quatro domínios diferentes, formados pelo Complexo Atuba, pela Formação Capiru, pela Formação Guabirotuba e por granitos neoproterozoicos.

Heavy metals and radionuclides distribution and environmental risk assessment in soils of the Severodvinsk industrial district, NW Russia

The article is devoted to the study of the content of heavy metals and radionuclides in soils of the environments of the Severodvinsk industrial district (Northwest Russia). The city of Severodvinsk is the largest industrial center for the Navy in North-western Russia. Soil samples were taken in the vicinity of the Severodvinsk industrial region in the areas where there are summer cottages and gathering places for wild berries and mushrooms collected by local residents. Heavy metal content studies were performed by ICP-MS. Measurements of the activity of radionuclides were carried out via the low-background semiconductor gamma-ray spectrometry method with a detector of especially pure germanium. Assessment of the degree of soil pollution with heavy metals was performed using geo-accumulation index parameters (Igeo), contamination factor (Cf), degree of contamination (Cd), enrichment factor (EF), and ecological risk index (ERI). The radiation safety parameters of the Severodvinsk industrial region soils were calculated, as were the absorbed dose rate of gamma radiation DR, the equivalent of radium Raeq, and the external hazard index Hex. The sources of soil pollution are natural (geogenic) and anthropogenic (enterprises of the military-industrial complex, city heating systems, transport). The studies found a low level of heavy metal pollution and radionuclides in the soils of the environments of the Severodvinsk industrial region. Soils can be used by local people to grow food at their summer cottages. Also, the studied area is favorable for the collection of wild mushrooms and berries. However, closer attention should be paid to certain parts of the territory, since for some metals (As, Mn, Cd, and Pb) an increase in the parameters of the degree of soil pollution (Igeo, Cf, Cd, EF, and ERI) is observed.

Rapid in situ assessment of radiocesium wood contamination using field gamma-ray spectroscopy to optimise felling

The Chernobyl nuclear power meltdown that took place in 1986 has left a radioactive contamination legacy that currently severely limits the economic potential of impacted regions including the Polessie State Radioecology Reserve in Southern Belarus. Extensive areas of forested land could potentially become economically viable for firewood and building materials if radioactive contamination, notably 137Cs, could be characterised faster, whilst closely adhering to regulatory limits. Currently, laboursome tree coring and unreliable transfer factors derived from limited soil sampling data are routinely employed in felling decision making, which has financial repercussions owed to the large amounts of waste produced and unnecessary transportation costs. In this study, it is demonstrated that a combination of targeted mobile gamma-ray spectrometry and a newly developed, lead shielded, in situ gamma-ray spectrometry method can significantly speed up the process of characterisation of 137Cs wood activity in the field. For the in situ method, Monte Carlo calibration routines were developed alongside spectral processing procedures to unfold spectra collected in the field allowing for separation of ground and tree spectral components. Isolated contributions from the tree could then be converted to activity. The method was validated at a test facility and then demonstrated at three separate sites with differing contamination levels. This technique showed that single trees could be measured within approximately 20% of the activity compared to conventional tree core data. However, some discrepancies were found which were attributed to under sampling using the tree corer and low count rates at the lowest activity site, prompting the need for further data collection to optimise the method. It was concluded that this real-time approach could be a valuable tool for management of contaminated forested areas, releasing valuable timber and ultimately reducing the risk associated with living and working in these areas.

Reprint of “Neutron field determination of d+Be reaction for 15 MeV deuterons using the multi-foil activation technique”

At the Nuclear Physics Institute (NPI) of Czech Academy of Sciences, the d+Be source reaction was investigated for thick beryllium target (thickness of 8 mm) and 15 MeV deuteron beam extracted from the U-120M isochronous cyclotron. For neutron field measurement of the d(15)+Be source reaction in close source-to-sample distance (non-point-like geometry), the multi-foil activation technique was utilized. Sets of nine activation materials (Au, Co, Ti, In, Al, Y, Fe, Ni, Nb) were irradiated by neutrons from the d(15)+Be source, and activated dosimetry foils were analysed by means of the gamma-ray spectrometry method using HPGe detector. From obtained reaction rates, the broad neutron spectra were reconstructed employing the modified version of SAND-II unfolding code. New intensive neutron field of broad spectrum up to 20 MeV and intensity of 3×1010cm−2s−1 (close to the target) was successfully developed. The study of d(15)+Be source reaction provided new spectral data, and obtained neutron field extends the utilization of cyclotron-based fast neutron generators at the NPI and provides new experimental opportunities for future intensive irradiation experiments such as fast neutron activation analysis and radiation hardness tests of electronics and materials for nuclear energetics and aerospace industry.