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Radionuclide distribution and transfer factors in plants are decisive parameters used to evaluate radioactive contamination in the environment and its radiological health risks to humans. In this study, the activities concentration of 226Ra, 232Th, and 40K were measured using NaI(Tl) gamma-ray spectrometry on soils and on corresponding teff and wheat plant samples analyzed collected from Sakaro gold mining area from Reji kebele, Oromia, Ethiopia. The results of mean activity concentration of 226Ra, 232Th, and 40K samples analyzedzed in soil, teff, and wheat samples were found to be 33.05 ± 0.72, 13.7 ± 0.51 and 220.18 ± 0.61 Bq.kg-1, 3.93 ± 0.4,27 ± 0.61 and 148.3 ± 0.5 Bq.kg-1 and 3.22 ± 0.43, 4.59 ± 0.64 and 229.8 ± 0.5 Bq.kg-1 respectively. Results showed that the activity concentration of radionuclides in this study area was within the limit. The transfer factors from soil to cereal crops (teff and wheat) were compared with the study done in a different country of the world and its values were below unity except for 40K in wheat samples. The absorbed dose rate, annual effective dose rate, external and internal hazards index, lifetime cancer risk, and annual effective ingestion dose were estimated and were also compared with the internationally accepted values. It was found that none of the results exceeded the recommended limit value. [ABSTRACT FROM AUTHOR]

The activity concentrations of natural radionuclides 226Ra, 232Th and 40K in 19 soil samples from Zabili uranium exploration area were measured using a low-background digital gamma-ray spectrometer equipped with broad energy germanium detector. The activity concentrations of 238U, 232Th, and 40K range from 16.5 to 1110.9 Bq.kg−1, 19.45 to 76.97 Bq.kg−1, and 3.28 to 839.5 Bq.kg−1, with their mean values of 478.0, 58.9, and 562.5, respectively. In addition, radiological hazard parameters from the activity concentrations obtained were assessed by estimating radium equivalent activity, external and internal hazard index, indoor and outdoor absorbed gamma dose rate and the corresponding annual effective dose, effective dose rate to different body organs and tissues, and excess lifetime cancer risk. Derived radiological hazard indices have been revised in accordance with relevant national and international legislation and guidelines. The radiological hazard parameter values were found to be above the relevant limit values for soils. In order to investigate the distribution of radionuclides and associated health hazard parameters in the study area, a statistical study was performed. [ABSTRACT FROM AUTHOR]

Bioindicators are living organisms that are successfully used for monitoring changes in the environmental health due to natural and/or anthropogenic influences. Dragonflies (Odonata) are considered to be good indicators of water quality; however, research on dragonflies as potential indicators of radioactivity is scarce. The aim of this study was to evaluate dragonflies as potential biological indicators of ionising radiation in nature by measuring 137Cs activity concentrations in the dragonfly and river water samples. Altogether, 11 collective samples of dragonflies were collected from the bank of the Mura–Drava–Danube Biosphere Reserve, in the area of Virovitica–Podravina County. Following the initial sample preparation, the gamma spectrometry technique, employing an ORTEC HPGe detector system, was utilised to determine the activity concentrations of 137Cs. The results show that the activity concentrations of 137Cs in the river water were in the range from 4 to 13 Bq/m3. The results of dragonfly samples showed that 137Cs was in the range from 1.7 to 3 Bq/kg. This was more than a hundred times higher than in the river Drava water. According to the obtained results, we conclude that dragonflies could be used as potential bioindicators of radioactivity. [ABSTRACT FROM AUTHOR]

The activity concentrations of 238U, 232Th, and 40K were determined at 56 sites along the East Coast of India, near the Bay of Bengal, with 31 sites in Odisha and 25 in Andhra Pradesh. In Odisha, average concentrations were 109 ± 13 Bq kg−1 for 238U, 296 ± 27 Bq kg−1 for 232Th, and 450 ± 33 Bq kg−1 for 40K, while in Andhra Pradesh, they were 51 ± 13 Bq kg−1, 149 ± 16 Bq kg−1, and 236 ± 21 Bq kg−1, respectively. Absorbed dose rates and annual effective doses were higher outdoors and indoors in Odisha compared to Andhra Pradesh. The calculated radiological parameters exhibited elevated values at certain sampling locations; however, overall, the values generally complied with regulatory standards. [ABSTRACT FROM AUTHOR]

A gamma-ray spectrometry was used to measure radium isotopes in a radium-enriched hot spring area. The activity of 224Ra was highly correlated with 228Ra in water caused by their same chemical behavior and the origin of the decay series chain. Besides, the radioactivity between radium isotopes (226Ra, 228Ra) and the selected chemical analogues in sludge exhibited moderate (Ba and Sr) to strong (Pb) correlations according to linear regression analysis. In contrast, there is less correlation between radium isotopes and 40K. These results reveal that radium isotopes may be transported and distributed together in the environment. [ABSTRACT FROM AUTHOR]

The study of radionuclide concentrations is significant for the exposure of the radiation on the livings from these radionuclides and they are transferred from plants, animals to livings, and this is important for the health of livings. In this paper, 40K concentration and elements content of wheat, barley, corn, and chick feeds, which are used as animal feed using gamma‐ray spectrometry and inductively coupled plasma‐optical emission spectrometry (ICP‐OES) were examined. The animal feeds were obtained from two different sellers for representative and to be able to compare the obtained results from studied animal feeds. The mean value of 40K radionuclide concentration for wheat, barley, and corn is smaller than the world mean value whereas it is higher for chick feeds than the world mean value. The Hin, Hex, and Iγ of studied animal feeds are lower than limit value reported in the scientific report. There are positive and significant correlations between K, Ca, Fe, Mg, Na, P, and 40K at the 0.01 level and between Cu, Mn, Ni, Zn, and 40K at 0.05 level. [ABSTRACT FROM AUTHOR]

This paper presents findings on groundwater physiochemical composition and radioactivity levels in households in Bac Lieu province, Vietnam. Through discriminant analysis, it was observed that groundwater quality exhibits spatial variations corresponding to saline intrusion zones. The paired-samples T-tests revealed significantly different ratios of Ra-224, Ra-226, and Ra-228 isotopes between Na–Cl and Ca–Na–HCO3 water types. All three water types had a ratio of Ra-226/Ra-228 of approximately one, indicating the presence of groundwater aquifers beneath the crust and fluvial marine sediment. Furthermore, strong associations between sulfate and calcium suggest that CO2 enrichment in groundwater aquifers indicates anoxic aquatic environments. Twenty-five of the thirty-three evaluated samples exceeded the national technical regulations for domestic water quality with parameters such as chloride, sulfate, sodium, gross alpha, or total dissolved solids. Fifteen samples exceeded gross alpha's allowable contamination threshold of 0.1 Bq/L. The combination of Ra-226 and Ra-228 did not surpass the U.S. Environmental Protection Agency's recommended limit of 0.185 Bq/L. However, nineteen samples exhibited annual committed effective doses of radium isotopes for infants that exceeded the WHO recommendation of 0.1 mSv/year. [ABSTRACT FROM AUTHOR]

In the city centre of Isparta, located in the southwestern part of Türkiye, indoor radon concentrations and gamma dose rate levels were observed above the world and country averages. For this reason, the determination of the natural radioactivity levels in soil samples of Isparta province is of great interest. In the present study, the activity concentrations of radionuclides (namely 226Ra,232Th, 40K and 137Cs) were investigated in the soil samples collected from 72 different points including the city centre and 12 towns of Isparta by using a gamma spectrometer with a high-purity germanium (HPGe) detector. The activity concentrations of 226Ra,232Th, 40K and 137Cs radionuclides in the samples were found in the range of 4.08 ± 0.39–69.84 ± 1.43 Bqkg−1, 2.63 ± 0.28–65.66 ± 1.41 Bqkg−1, 44.48 ± 3.17–452.38 ± 9.65 Bqkg−1 and 0.28 ± 0.18–19.10 ± 0.61 Bqkg−1 respectively. The averages of all the measurements were determined as 15.69 ± 0.72 Bqkg−1 for 226Ra, 15.40 ± 0.78 Bqkg−1 for 232Th, 210.60 ± 6.22 Bqkg−1 for 40K and 3.44 ± 0.31 Bqkg−1 for 137Cs. Although these values were below the country and world averages, it was revealed that the 226Ra and 232Th activity concentrations in the city centre exceeded the national and world averages. In addition, radiological risk maps of the analysed radionuclides were produced for the first time, covering all towns within the Isparta province. To evaluate the radiological hazards resulting from natural radionuclides, external hazard index (Hex), absorbed dose rate (D), annual effective dose equivalent (AEDE), male and female lifetime cancer risk (LCR) values were also calculated. The outcomes of this study revealed that all the radiological parameter averages for Isparta were lower than the world and country averages but the calculation results for the city centre displayed the opposite of this situation except for the external hazard index.

The present study concerned with the activity concentrations of natural radionuclides (238U, 234U, 230Th, 226Ra, 232Th, 40K and, 235U) in ten sedimentary rock samples collected from fault zone, Gabal Um Hamd, southwestern Sinai, Egypt. These samples were investigated to study their behavior during a part of geologic time. The activity concentrations were measured using γ-ray spectrometry (HPGe detector). The investigated samples were analyzed for major oxides using the XRF technique. The results demonstrated high average activity concentrations of 238U, 234U, 230Th, 226Ra, 232Th, 40K and, 235U than the worldwide average values as reported by UNSCEAR 2008. Theil diagram showed that there are accumulation and leaching of uranium in some samples in the two sides of the fault zone. It is noticed that the ages of uranium depositions for the samples collected from the downthrown of the fault zone vary from 121.5 to 440.1 ky, while for the sample collected from the upthrown of the fault is 210.9 ky. The 230Th/232Th activity ratios range between 4.55 and 91.04 for downthrown samples and between 4.75 and 6.05 for upthrown samples which are smaller than 20 except for two samples, indicating a contamination of the samples by detrital 230Th. After subtraction of the detrital 230Th, the corrected ages for downthrown samples vary from 119.1 to 231.7 ky while for upthrown samples vary from 164.4 to 390 ky.

Abstract Uranium exploration plays a pivotal role in meeting global energy demands and advancing nuclear technology. This study presents a comprehensive approach to uranium exploration in the Gebel Duwi area of the Central Eastern Desert of Egypt, utilizing remote sensing and airborne gamma-ray spectrometric data. Multispectral remote sensing techniques, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Band Ratioing (BR), are employed to identify lithological units and hydrothermal alteration zones associated with uranium deposition, such as iron oxides, argillic, propylitic, and phyllic alterations. Additionally, airborne gamma-ray spectrometry data provide insights into the spatial distribution of radioelements, including uranium (eU), thorium (eTh), and potassium (K), as well as radioelement ratios (eU/eTh, eU/K, and eTh/K). The uranium migration index map (eU-(eTh/3.5)) and the F-parameter map (K*(eU/eTh)) have been generated to investigate the movement of uranium within various geological zones and characterize anomalous uranium concentrations. Statistical analyses, including mean (X), standard deviation (S), and coefficient of variability (C.V.), are conducted to identify uranium-rich zones. The integration of these datasets enables the generation of a uranium potential map highlighting areas of elevated concentrations indicative of uranium mineralization. Field observations and mineralogical analyses of collected samples validate our findings, confirming the presence of minerals associated with uranium mineralization in mapped high-potential areas. The significance of minerals like Fe-Chlorite, Fe-Mg-Chlorite, ferrihydrite, goethite, calcite, muscovite, dolomite, actinolite, vermiculite, and gypsum in indicating potential uranium mineralization processes underscores the importance of our results.

Uranium exploration plays a pivotal role in meeting global energy demands and advancing nuclear technology. This study presents a comprehensive approach to uranium exploration in the Gebel Duwi area of the Central Eastern Desert of Egypt, utilizing remote sensing and airborne gamma-ray spectrometric data. Multispectral remote sensing techniques, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Band Ratioing (BR), are employed to identify lithological units and hydrothermal alteration zones associated with uranium deposition, such as iron oxides, argillic, propylitic, and phyllic alterations. Additionally, airborne gamma-ray spectrometry data provide insights into the spatial distribution of radioelements, including uranium (eU), thorium (eTh), and potassium (K), as well as radioelement ratios (eU/eTh, eU/K, and eTh/K). The uranium migration index map (eU-(eTh/3.5)) and the F-parameter map (K*(eU/eTh)) have been generated to investigate the movement of uranium within various geological zones and characterize anomalous uranium concentrations. Statistical analyses, including mean (X), standard deviation (S), and coefficient of variability (C.V.), are conducted to identify uranium-rich zones. The integration of these datasets enables the generation of a uranium potential map highlighting areas of elevated concentrations indicative of uranium mineralization. Field observations and mineralogical analyses of collected samples validate our findings, confirming the presence of minerals associated with uranium mineralization in mapped high-potential areas. The significance of minerals like Fe-Chlorite, Fe-Mg-Chlorite, ferrihydrite, goethite, calcite, muscovite, dolomite, actinolite, vermiculite, and gypsum in indicating potential uranium mineralization processes underscores the importance of our results. [ABSTRACT FROM AUTHOR]

The process of radiological characterization involving all the systems, structures, equipment, and components resulting from the decommissioning of the VVR-S nuclear research reactor at the Horia Hulubei National Institute for Physics and Nuclear Engineering was a continuous journey marked by ongoing research, specialized training, and the accumulation of invaluable experience. Recognizing the significance of protecting the expertise gained during this effort, this paper aims to share several key insights collected from the radiological characterization process. In particular, the focus is placed on elucidating various methodologies and techniques utilized in gamma-ray spectrometry. The aim of delving into these specific aspects is to offer practical lessons that can serve as valuable guidance for future efforts in radiological characterization within similar contexts. Through the dissemination of these insights, it is hoped that the collective knowledge and expertise amassed during the radiological characterization of the VVR-S nuclear research reactor decommissioning can be effectively preserved and utilized for the benefit of future projects in the field. [ABSTRACT FROM AUTHOR]

In this study, the current status of natural and artificial radioactivity levels in soil samples from the Büyükçekmece and Silivri districts of Istanbul, as well as the Marmara Ereğlisi district in Tekirdağ, has been determined in anticipation of a potential nuclear leakage (e.g. the Zaporizhzhia Nuclear Power Plant). Twenty soil samples were collected from the study area, and the radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs were measured using an HPGe detector. The average concentrations of 226Ra, 232Th, 40K and 137Cs were found to be 26 ± 2, 30 ± 2, 540 ± 29, 0.55 ± 0.07 Bq kg−1, respectively. [ABSTRACT FROM AUTHOR]

This study aims to assess the artificial and natural radiation dose levels in certain districts of Kocaeli province within the Marmara region, 37 years after the Chernobyl nuclear accident, and evaluate the current status prior to potential nuclear leakage events from Zaporijya or other nuclear power plants. Radioactive concentrations of 232Th, 238U, 40K and 137Cs were determined using HPGe gamma spectrometry in 26 soil samples collected from the region of interest. The average concentrations were found to be 22.35 Bqkg−1 for 238U, 26.36 Bqkg−1 for 232Th, 368.34 Bqkg−1 for 40K, and 2.44 Bqkg−1 for 137Cs. Furthermore, the study revealed an absorbed dose rate of 41.73 nGyh−1, an annual effective dose equivalent of 51.18 µSvy−1, and an excess lifetime cancer risk of 0.00018. [ABSTRACT FROM AUTHOR]

Evaluating the natural radioactivity in construction materials is significant, particularly considering the prevailing belief that our homes offer the safest living environments. To investigate this, 38 samples of building materials were collected from highly populated residential areas within the Malappuram district in Kerala, India. The levels of naturally occurring radionuclides (226Ra, 232Th, and 40K) were quantified using a NaI (Tl) detector. Radiological indices, such as radium equivalent, absorbed dose rate, effective dose rate, hazard indices, alpha index, gamma index, and cancer risk, were calculated for the samples. The activity concentrations of 226Ra, 232Th, and 40K ranged from 8.84 ± 0.3 (flooring oxide) to 46.84 ± 2.11Bq/kg (rock samples), 11.84 ± 0.2 (pumice sample) to 130.21 ± 8Bq/kg (granite sample), and 58.63 ± 4 (pumice) to 1024.32 ± 22Bq/kg (granite) with an average of 25.80 ± 4.61, 55.05 ± 6.2, and 392.30 ± 16 Bq/kg. (average ± standard deviation), respectively. As a result, all of these computed parameters fell within safe limits. The examined building materials were found to have a negligible impact on radiation exposure, posing no significant radiation risks to residents. Researchers utilized statistical techniques to understand the interrelationships and similarities among radionuclides and radiological characteristics across samples, including Pearson correlation, principal component analysis, and cluster analysis. [ABSTRACT FROM AUTHOR]

Gamma-ray spectrometry has proved to be a powerful tool in meteorite identification due to the presence of certain mid- and long-lived cosmogenic radionuclides in such samples. In particular, this technique can be made totally non-destructive by measuring each sample as-it-is and calculating the full-energy-peak efficiency through Monte Carlo simulation of the full radionuclide decay. In general, this framework can be applied whenever it is needed to characterise non-destructivery the γ-ray emission of a sample with non-standard geometry. [ABSTRACT FROM AUTHOR]

Due to the scarcity of data on both basic and toxic chemical elements in medicinal and fodder plants in Algeria, this study focused on evaluating the content of these elements in the Ampelodesma mauritanicum plant grown in the Ghardaia region of Southern Algeria. This plant is commonly used by Bedouins in traditional medicine and as fodder, and has applications in construction, decontamination, and water purification. Based on gamma-ray spectrometry for neutron activation analysis, the study identified and categorized a total of 25 mineral and trace elements into essential, non-essential, and potentially toxic groups. Essential elements exhibited varying concentrations, with potassium being the most abundant, followed by sodium, calcium, iron, zinc, chromium, cobalt, and selenium. The study also assessed potentially toxic elements, all found below the estimated permissible limits established by FAO/WHO. Quality control was ensured through the analysis of certified reference materials. The findings provide valuable insights into the elemental composition of Ampelodesma mauritanicum, offering significant implications for medicinal and nutritional applications while ensuring analytical accuracy and reliability. [ABSTRACT FROM AUTHOR]

A coaxial type HPGe detector, and two lanthanide scintillation type detectors have been modeled and characterized by means of Monte Carlo method implemented using the MCNP code. The isotope of interest is 88Rb which decays with energies up to 5 MeV, and can in theory aid in extending the efficiency calibration of the installations of interest in higher gamma rays energies. An 152Eu point source was used for the experimental validation of the MCNP models and excellent agreement was observed between the experimental data and the simulated data of both 152Eu and 88Rb point sources. After the experimental validation of the model, the efficiency calibration was extended for three different source-to-detector distances and the results are presented in this work. [ABSTRACT FROM AUTHOR]

This study aimed to estimate the, exhalation rate, and natural radioactivity in the soil of Roopnagar district, Punjab. The radon mass and surface exhalation rate ranged from 1.18 mBq kg−1 h−1 to 5.72 mBq kg−1 h−1, with an average value of 2.68 mBq kg−1 h−1, and from 4.89 mBq m−2 h−1 to 23.58 mBq m−2 h−1, with an average value of 11.09 mBq m−2 h−1, respectively. The activity concentration of 226Ra, 232Th, and 40K was found to be 31.9 Bq kg−1, 44.1 Bq kg−1, and 419.0 Bq kg−1, respectively. The air absorbed dose rates of radionuclides 226Ra, 232Th, and 40K had an average value of 14.88 nGyh−1, 27.4 nGyh−1, and 5.89 nGyh−1, respectively. The total air absorbed dose from all radionuclides ranged from 19.5 nGyh−1 to 87.7 nGyh−1, with an average value of 48.1 nGyh−1, which is discovered to be well below the levels considered dangerous by the United Nations Scientific Committee on the Effects of Atomic Radiations. [ABSTRACT FROM AUTHOR]

The distribution of the ambient dose equivalent rate (i.e., air dose rate) after a nuclear disaster is crucial for zoning contaminated areas to facilitate authorities' effective decision making. Several countries are considering a gradual characterization strategy where airborne measurement is performed first followed by ground measurement (i.e., via manborne or carborne surveys). Nonetheless, potential differences might emerge in country-specific air dose rate assessment methods. Explaining these discrepancies can improve and converge existing methodologies. The Japan Atomic Energy Agency (JAEA) and the French Institute for Radiological Protection and Nuclear Safety (IRSN), which are organizations involved in post-nuclear accident crisis management, jointly performed air dose rate measurements in 2019 at contaminated sites around the Fukushima Daiichi Nuclear Power Station. The similarities and differences between the two organizations' methods and results were quantitatively assessed by comparing the average air dose rates obtained within a grid created with a geographic information system, and the reasons for the differences between the organizations' results were investigated. The air dose rates obtained by the manborne measurements varied depending on the calibration method. Comparing the air dose rate assessment methods and mapping techniques used in different countries will contribute to developing international guidelines for recommending the best method for determining air dose rates. [ABSTRACT FROM AUTHOR]

Accurate quantitative analysis of environmental samples in laboratory settings requires knowledge of the full-energy peak (FEP) efciency for the source-detector geometries used. However, experimental determination of this parameter may prove restrictive and time-consuming. To address this issue, a Monte Carlo method based on the GEANT4 code was developed to calculate the FEP efciency of a Canberra coaxial p-type HPGe detector, tailored for 100 ml geometry sample confguration. This simulation was used to determine the FEP efciency for diferent energy levels relevant to the analysis of environmental samples. The results obtained from the Monte Carlo simulation were compared to the experimental measurements conducted under identical simulation initialization conditions. The obtained deviations (%) between simulations and experimental measurements were reliable in most cases with a maximum error of 4.17%. The proposed model exhibits a high degree of fexibility, enabling its application to diverse geometric confguration of samples. This adaptability allows for the determination of calibration coefcients across a wide range of energy, thereby enhancing the overall precision and adaptability of the analysis process for environmental samples. [ABSTRACT FROM AUTHOR]

The present study reports the first data on NORM distribution in soil and pottery samples collected from excavated sites of Erenda (Trench A1) and Bahiri (Trench YB1) located in East Medinipur, West Bengal, India. Collected potteries include grey-wares, red-wares, black-wares and black-red-wares. It was observed that 238U and 40K activities of the pottery samples are higher than that of the soil samples, which might be an indication of their different origin. 232Th activity is uniform along the depth and has similar distribution in both soil and pottery samples of Erenda and Bahiri. [ABSTRACT FROM AUTHOR]

The paper presents data on the spatial distribution of the active concentration of natural (232Th, 226Ra, and 40K) and anthropogenic (137Cs) radionuclides in the surface layer of bottom sediments in Chaun Bay of the East Siberian Sea. The measured active concentration of 232Th and 226Ra was typical of bottom sediments of the Arctic coastal shelf zone and corresponded to the global level. The level of 137Cs activity in bottom sediments showed the absence of local sources of anthropogenic pollution in Chaun Bay, while the mean 40K activity concentration was 1.8 times higher than the global. The results of statistical analysis of the data obtained showed that the dynamics of river runoff, thermal abrasion, and currents, as well as aeolian and ice transport of sedimentary matter, were the main factors that determined the differences in the behavior of the studied radionuclides in the surface bottom sediments of Chaun Bay. [ABSTRACT FROM AUTHOR]

Natural radioactivity (226Ra, 232Th, and 40K) concentrations were determined in sand samples collected from various beaches in Kadıköy-Istanbul (Turkey) at 12 sampling point for the evaluation of radiological parameters such as radiological equivalent activity and excess lifetime cancer risk. The activity concentrations of 226Ra, 232Th, and 40K were found to range between 21.08 and 49.19 Bqkg−1, 20.51–49.92 Bqkg−1, and 173.70–554.16 Bqkg−1, respectively. The selection of İstanbul as the study area is based on its high population density, indicating an increased vulnerability to potential negative effects of radiation exposure. [ABSTRACT FROM AUTHOR]

In this study, activity concentrations of natural radionuclides in 28 raw milk samples collected from different dairy farms in Dhaka city of Bangladesh were measured using a high-purity germanium (HPGe) detector for the first time. The activity concentration of 226Ra, 232Th, and 40K in the investigated fresh milk samples ranged from BDL (Below detection level) to 26 ± 1.6 Bq/kg, BDL to 11.7 ± 3.3 Bq/kg and 101 ± 17 to 384 ± 32 Bq/kg, respectively. No artificial radionuclides were found in the investigated samples. Present results show inline within the range of available data in the literature. Annual committed effective doses were estimated following the consumption characteristics of raw milk by city population, values are found within the limiting range recommended by international organizations due to consumption of foodstuffs. Additionally, real-time gamma-ray dose rate in the farms/sampling locations was found in the range of 0.12 ± 0.01–0.20 ± 0.01 μSv/h by using a digital gamma survey meter (Gamma Scout) and the calculated maximum annual effective dose due to outdoor absorbed dose was found to be 0.25 mSv/y, which shows lower than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended limit of 2.4 mSv/y. This study indicates that the concentration of radionuclides in the farm fresh milk of Dhaka city does not pose any unwanted risk to public health, and it is safe to consume by both children and adults with the current intake level.

The activity concentrations of natural radionuclides 238U, 232Th and 40K in soil samples from Kudan Local Government Area irrigation farming areas have been evaluated using gamma-ray spectrometry. The results of the activity concentrations of 238U, 232Th and 40K range between 18.15 to 34.66 Bq/kg, 16.01 to 18.83 Bq/kg and 205.51 to 461.25 Bq/kg respectively. The activity concentration of 40K was seen to be higher than the world average value of 370 Bq/kg at Kauran Wali South (GO3K) 375.25 Bq/kg, Doka (GB1K) 389.60 Bq/kg, Kauran Wali North (GB2K) 420.15 Bq/kg, Likoro (GB4K) 383.65 Bq/kg, Garu (GB5K) 461.25 Bq/kg, Zabi (GB6K) 372.76 Bq/kg and Kudan (GB7K) 382.50 Bq/kg. The activity concentrations of 238U and 232Th were observed to be high at Garu (GB5K), with values of 34.66 and 18.83 Bq/kg respectively, however, these values were still below the world average value of 40 Bq/kg as reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSEAR) in 2000. The average values for the indoor absorbed dose rate (Din), Internal Hazard Index (Hin), External Hazard Index (Hex) and Indoor Annual Effective Dose (ADE) were evaluated to be 83.07 nGy/hr, 0.35, 0.28 and 0.41 mSv respectively. The estimated radiological indices were seen to fall within the internationally acceptable limits except for the indoor absorbed dose rate (Din) whose values were all higher than the acceptable limit of 60 nGy/hr as recommended by UNSCEAR in 2000. The high values obtained from this study could be attributed to the excessive use of fertilizers by the farmers within the study area.

Gamma-ray spectrometric responses of Archean rocks were studied in order to define a characteristic signature for these rocks. As the half-life of the most frequent Thorium isotope (232Th – half life of 14.05 Ga) is more than 3 times longer relative to the Uranium isotope (238U – half life of 4.50 Ga), a low response of radiation intensity in the spectral range of decay series of Uranium relative to that of Thorium is expected for Archean rocks. Based on this theoretical aspect, associated with gamma-ray spectrometric responses parametrically studied in several Archean areas of Brazil, gamma-ray and magnetometric structural interpretation, follow-up field studies, micropetrography, lithogeochemistry, and geochronology (U-Pb in zircon), it was possible to define and identify previously unidentified Archean rocks (2.82 Ga) tectonically imbricated amid Neoproterozoic magmatic arc terrains. This discovery has geotectonic implications regarding the magnitude of the Transbrasiliano Lineamento and its potential to fragment large Archean blocks and arrange them aligned within the Tocantins Province, Central Brazil.

This study provides an in-depth analysis of the relationship between radionuclide and particle size-class abundance through an investigation of radionuclide distribution in finer sediments within surface core samples collected from two contaminated upper saltmarsh areas of the Dee estuary and Biggar marsh in north-west England. The particle size fractionation (PSF) analysis was carried out following gravitational settling and pipette method to separate all samples into six size-fractioned groups ranging from 63 to <2 µm (very coarse silt to clay), and radioactivity analysis was performed using a well-type High Purity Germanium (HPGe) detector. The highest 241Am and 137Cs activities in PSF samples were found to be 291 ± 5 and 2071 ± 16 Bq kg−1, respectively, for the Dee estuary saltmarsh and 3832 ± 14 and 4840 ± 23 Bq kg−1, respectively, for Biggar saltmarsh and found in the clay fractions for both sites. Correlation of radioactivity concentration data of three size groups ranging from 63 to <2 µm (very coarse silt to clay) confirms a strong and increasing association of radioactivity with fine particles from coarse to fine clay-size particles. Also, examination of textural and radionuclide data of all bulk core and size-fractioned samples revealed that upper saltmarshes are made up of both contaminated and uncontaminated sediments. Furthermore, the annual outdoor external effective dose range for all short core data (0.001–0.11 mSv y−1) and for PSF sample data (0.001–0.08 mSv y−1) reveal that some values exceed the world average value of 0.07 mSv y−1as reported in UNSCEAR [43], for outdoor, which are non-negligible. Thus, the total annual external effective dose associated with existing contaminated saltmarsh sediments represents a possible health risk to saltmarsh users and coastal populations living nearby these saltmarshes. [ABSTRACT FROM AUTHOR]

Oil-based mud is one of the primary wastes produced in oil industries that may contain elevated amounts of naturally occurring radioactive material. In this study, MCNPX simulations and gamma-ray spectrometry measurements were combined and a quick and sensitive method was developed for the non-destructive radiological characterization of spent oil-based mud originating from the oil industry by using a 3.81 cm x 3.81 cm LaBr3(Ce) scintillator. By this method, one cubic meter of packaged oil-based mud can be radiologically characterized in less than 20 minutes. [ABSTRACT FROM AUTHOR]

This study estimated the radiation dose in building materials (sand, cement, and granite) in Federal University Gusau, Zamfara State, Nigeria, through gamma-ray spectrometry system using a Sodium Iodide Thallium activated "NaITl" detector in a low background configuration. The range of the average activity concentration of 226Ra was found to be 56.65±0.75Bqkg-1 to 159.45±2.68Bqkg-1, which was higher than that of the world mean value for soil 35Bqkg-1, for 232Th the range was 46.65±0.45Bqkg-1 to 79.32±1.68Bqkg-1, all the samples, were found to be higher than that of the world mean for soil 30Bqkg-1. While the activity concentrations of 232Th levels of blocks, granite, and sand samples are all above the world range, except the cement which was within the worldwide range 194.84±1.31Bqkg-1 to 656.84±0.76Bqkg-1. The average activity concentration of 40K for cement, sand, and blocks was within the worldwide range, with granite samples slightly higher than the world mean value for soil 400Bqkg-1. The results have been compared with the world mean values of 35, 30, and 400Bqkg-1 specified by the UNSCEAR (2016). Concerning radiological risk to human health, the absorbed gamma dose rate (D) was estimated to be above the world average range of 55nGyh-1; the outdoor annual effective dose equivalent (AEDE) were, estimated to be below the permissible limit of 0.07mSvy-1. The values of Raeq, Hex, and Hin for all the samples in the present work are lower than the accepted safety limit value of 370Bqkg-1 and below the limit of unity, respectively. [ABSTRACT FROM AUTHOR]

Airborne spectral gamma-ray survey data were processed using Th-normalization technique for oil and gas exploration in the Qaret El-Soda area, Western Desert of Egypt. This technique was applied to suppress the effects of surface lithology, which are the main factors influencing the variation of radioelement content in rocks. Normalization of K and U by thorium yielded residual potassium and residual uranium estimates. Possible occurrences of new hydrocarbon microseepages were determined by mapping low values of residual potassium and high values of residual uranium relative to potassium, which are indicated as DRAD values, which were obtained by subtracting residual potassium from residual uranium values (eUresid – Kresid). Lower residual values of K, which were associated with higher DRAD anomaly values, highlight areas of prospective hydrocarbon accumulations. The obtained results from quantitative analysis and interpretation of aeromagnetic data show sufficiently thick sediments, probably suitable for the accumulation of hydrocarbons. This means that the study area may possess a potential for hydrocarbon exploration if supported by other detailed geophysical and geochemical exploration techniques. [ABSTRACT FROM AUTHOR]

Environmental radioactivity is present everywhere. Sometimes, anthropogenic activities may increase the background radiation level and persist for a long time in the environment. Radioactive contamination of food resources with long-lived 137Cs possess a continuous radiological hazard to human health. This review discusses worldwide reports on the distribution and activity of radio-caesium in edible biota, foodstuff and vegetation. Cumulatively, the congregated data of 137Cs activity shows an uneven spatial distribution pattern among various geographical locations. [ABSTRACT FROM AUTHOR]

In this study, the activity concentration of natural radionuclides (238U, 226Ra, 210Pb, 232Th, and 40K) in phosphogypsum were measured using a low-background digital gamma-ray spectrometer equipped with Broad Energy Germanium (BEGe) detector. The mean activity concentrations of 238U, 226Ra, 210Pb, and 232Th were found to be 88.5 ± 19.5 Bq kg−1, 879.6 ± 20.3 Bq kg−1, 755.4 ± 17.1 Bq kg−1, 4.5 ± 0.3 Bq kg−1, and below the detection limit respectively. The estimated radium equivalent activity was found to be higher than the world recommended value of 370 Bq kg−1 but is within the recommended limit of 2220 Bq kg−1 for the use of phosphogypsum in the construction of roads, bridges, and foundations of non-residential buildings. The total annual effective doses received by workers and members of the public were found to be lower than the annual limit of 1 mSv y−1, except for the scenario of a person living in a house built with building material containing phosphogypsum. [ABSTRACT FROM AUTHOR]

Activity concentrations of naturally occurring radionuclides in soil samples collected during 2013-2018 from different 53 locations around Bhabha Atomic Research Centre (BARC), Visakhapatnam, Andhra Pradesh, India, were determined using high-purity germanium gamma-ray spectrometry. An R and D center of BARC is upcoming at Visakhapatnam, North coastal Andhra Pradesh. The annual effective dose (AED) and the radiation indices from the soil activity were evaluated to generate the baseline data for this area. The average activity concentrations of the naturally occurring radionuclides 238U, 226Ra, 232Th, and 40K in the soil samples studied are 29 ± 8 Bq/kg, 31 ± 1 Bq/kg, 188 ± 2 Bq/kg, and 471 ± 10 Bq/kg, respectively. The concentration of 226Ra and 40K in the collected samples is comparable with the world average concentrations of 33 Bq/kg and 420 Bq/kg, however, 232Th is observed to be higher than the world average of 45 Bq/kg. AED due to external terrestrial radiation from the region studied is in the range the range 0.37 to 2.5 mSv/y with an average of 0.9 mSv/y. The mean radium equivalent activity values for around 70% of the studied samples are lower than the permitted levels of 370 Bq/kg. The mean external exposure index has been determined to be around the safe criterion limit of unity. The mean value of the representative level index Iγ is 2.4. Higher values in some locations are due to thorium in monazite deposits. This report will be useful as preoperational study to evaluate the impact on the environment due to ongoing and future man-made developments. [ABSTRACT FROM AUTHOR]

In situ gamma radiation measurements were performed to calculate the radiogenic heat production of sedimentary and igneous rocks from the Sabinas Basin (northeastern Mexico). The sedimentary rocks include Cretaceous shales, sandstones, and limestones. The igneous rocks consist of basalts and granodiorites (Tertiary age). The basalts belong to different volcanic fields (Las Esperanzas, Ocampo, and Las Coloradas), and the granodiorites belong to the Candela-Monclova magmatic belt (Marcelinos, Pánuco, Colorado, and Providencia intrusions). The studied rocks samples yielded values of up to 13.4 ppm, 47.3 ppm, and 9.1% for uranium (U), thorium (Th), and potassium (K), respectively, and their radiogenic heat production (RHP) values ranged from 0.11 to 6.42 µWm−3. The studied rocks were accordingly classified as having low (< 2 µWm−3), moderate (2–4 µWm−3), and high (> 4 µWm−3) RHP. Most studied rocks were characterized by a low heat production, and only 12% of the measurements indicated samples with moderate and high heat production rates. These latter rocks samples are represented by clastic sedimentary rocks such as shale of the Olmos Formation Maastrichtian age and sandstone of the Pátula Formation Hauterivian–Barremian age, and granodiorites. The highest RHP values in the sedimentary rocks are related to quartz, K-feldspars, and clay contents, and their location of deep faults. The RHP values of granodiorites are associated with their K-feldspar, sphene, zircon, and apatite contents. Such values are different in each of the intrusions and reach the highest magnitudes in the Marcelinos intrusion. The three volcanic fields reported differences in the RHP values, associated with K-feldspar and apatite, and with high and low basement blocks of the Sabinas Basin. The relationship of the RHP values with previously reported heat flow zones indicates the radiogenic contribution of the studied rocks to the heat flow in such basin. [ABSTRACT FROM AUTHOR]

In this work, a high-purity germanium (HPGe) detector in a low-background setup was used to determine the activity concentrations of 238U, 232Th, and 40K in soil samples collected in and around some gold mining areas of the Mayo-Kebbi region in Chad. Subsequently, the radiological risks due to these natural radionuclides were also assessed. The activity concentrations of 238U, 232Th, and 40K varied from 1.42 ± 0.32 to 430.88 ± 7.3 Bq / kg , 1.19 ± 0.98 - 56.61 ± 1.61 Bq / kg , and 27.38 ± 2.17 – 840.51 ± 8.99 Bq/kg with average values of 29.67 ± 15.80 (STD) Bq / kg , 11.98 ± 2.80 (STD) Bq / kg , and 234.43 ± 43.28 (STD) Bq / kg , respectively. The highest values of 238U, 232Th, and 40K concentrations were found in soil sample collected at a gold mining area of Zabili. The 232Th/238U activity ratio was consistently lower than the naturally occurring equilibrium ratio of 1.1 at the majority of the sampling sites. The assessment of the 232Th/40K mass ratio revealed the existence of montmorillonite, kaolinite, and heavy thorium-bearing minerals in the regions under investigation. The mean annual effective dose of the soil samples collected in the studied area was found to be 0.18 mSv/y. The calculated mean values of the external hazard index (Hex) and the internal hazard index (Hin) of the study area were 0.18 and 0.26, respectively. Correlation studies between 238U versus 232Th, 40K versus 238U, and 40K versus 232Th were performed. The results showed a good correlation between the pairs (238U, 232Th); however, a weak correlation was observed between the pair (238U, 40K) and (232Th, 40K). In order to investigate the statistical variation of the data and its implications on environmental exposure, the hierarchical binary cluster tree was implemented. [ABSTRACT FROM AUTHOR]

The chemical weathering intensity in Antarctica is underestimated. As the chemical weathering intensity increases, hydrological, geochemical and geophysical changes occur in the different environmental spheres and at their interfaces through reactions and energy flows. Thus, once chemical weathering rates are understood and estimated, they can be used to predict and assess changes and trends in different environmental spheres. Few studies on the chemical weathering intensity have been performed in Antarctica. We used radiometric and magnetic properties associated with terrain attributes and the chemical degree of alteration of the igneous rock to model the chemical weathering intensity in Maritime Antarctica by using machine learning. Then, we related the chemical weathering intensity and geophysical variables with periglacial processes. To do this, gamma-spectrometric and magnetic readings were carried out using proximal-field sensors at 91 points located on different lithologies in a representative area of Maritime Antarctica. A qualitative analysis of chemical alteration for the different lithologies was carried out based on field observations and rock properties, and the levels of the chemical weathering degree were established. The geophysical data associated with terrain attributes were used as input data in the modeling of the weathering intensity. Then, the levels of the rock weathering degree were used as the “y” variable in the models. The results indicated that the C5.0 algorithm had the best performance in predicting the weathering intensity, and the most important variables were eTh, 40K, 40K/eTh, 40K/eU, the magnetic susceptibility and terrain attributes. The contents of radionuclides and ferrimagnetic minerals in different lithologies, concomitantly with the intensity at which chemical weathering occurs, determine the contents of these elements. However, the stability and distribution of these elements in a cold periglacial environment are controlled by periglacial processes. The chemical weathering intensity prediction model using gamma-spectrometric and magnetic data matched the in situ estimate of the chemical degree of alteration of the rock. The pyritized andesites showed the highest intensities of weathering, followed by tuffites, diorites, andesitic basalts and basaltic andesites, and the lowest weathering intensity was shown by undifferentiated marine sediments. This work highlighted the suitability of using machine learning techniques and proximal-field sensor data to study the chemical weathering process on different rocks in these important and inhospitable areas of the cryosphere system.

The gamma-ray mass attenuation coefficient is a crucial parameter to characterize the penetration and propagation of gamma rays in complex, multiphased, and heterogeneous materials like soil. Microscopically, soils contain minerals, water, gases, and other fluids that influence gamma-ray transmission. This paper discusses the potential of the Gamma Ray Spectroscopy (GRS) technique for precise measurement of various soil properties, focusing on soil's mass attenuation coefficient and bulk density. The limitations and advantages of GRS over conventional methods are also highlighted. [ABSTRACT FROM AUTHOR]

Radium-226 detection in sediment samples is generally executed by means of gamma-ray spectrometry. Data evaluation relies (besides the 186.2 keV 226Ra gamma peak) on the combined analysis of major gamma peaks that are produced by the short-lived radon (222Rn) daughters 214Pb and 214Bi. Precondition for this detection approach is equilibrium decay of all members of the decay chain between 226Ra and 214Bi. In closed systems, this equilibrium is reached after about five half-lives of 222Rn (19 days). However, a closed system can only be guaranteed if the capsule which contains the sample prevents diffusive escape of radon. Such radon-tightness cannot be guaranteed for a wide range of plastic materials. Due to its polymer structure, plastic material generally tends to allow radon diffusion and hence radon loss from the sample resulting in a disturbance of the required decay equilibrium. The paper introduces an approach that allows quantifying radon loss from sample capsules by direct radon measurements using mobile radon detection equipment. The experimental findings are supported by theoretical considerations. An examined alternative approach based on the offset of the 186.2 keV data point from an efficiency function that is calculated exclusively from short-lived radon progeny peaks in the gamma-ray spectrum did not prove to be applicable due to a lack of supporting peaks in the low-energy section of the spectrum. [ABSTRACT FROM AUTHOR]

Three brands of NPK fertilizers that contain variable concentrations of natural radioactivity are commonly used in tobacco plantations in Kenya, Tanzania, and Uganda. Tobacco plants are known for hyper-accumulation of natural radionuclides, particularly 238U. This study investigated if the elevated radioactivity in phosphate fertilizers could enhance radioactivity in soils and tobacco plant leaves. The 232Th, 238U, and 40K radionuclide levels in NPK-fertilized soils and tobacco leaves were measured using gamma-ray spectroscopy. The research included a one-year reference experiment with tobacco growing in plots, a ten-year semi-controlled experiment in well-managed tobacco farms, and a field survey of radioactivity in soils and tobacco leaves at three traditional tobacco fields in Migori (Kenya), Urambo (Tanzania), and Kanungu (Uganda). The findings demonstrated that soils and tobacco leaves exposed to NPK fertilizers with increased radioactivity had activity concentrations of 232Th, 238U, and 40K that were considerably higher (at all sites) than in the control samples (with no use of NPK fertilizers). As the continued application of NPK fertilizers raises concentrations of 232Th, 238U, and 40K in agricultural soils, the study assessed radiological risks for humans from exposure to agricultural soils enriched with phosphate fertilizers, and it was found to be below the exposure limit of 1 mSvy-1 suggested by the International Commission on Radiological Protection (ICRP). However, tobacco consumers, both by snuffing and smoking, may face significant radiological risks, as the snuffing and smoking resulted in effective doses that were 2.41 to 6.53 and 1.14 to 2.45 times greater than the average yearly dose that the general public receives from inhalation of natural radionuclides (United Nations Scientific Committee on Atomic Radiations estimates). Furthermore, the results indicate that the lifetime excess cancer risk for tobacco snuffers and smokers ranged from 5 × 10-5 to 24.48 × 10-3 and 2.0 × 10-5 to 9.18 × 10-3, respectively. The influence of phosphorus-derived fertilizer containing relatively high natural radioactivity, potential human radiation exposure, and radiological risk due to gamma radionuclides is estimated and discussed. The results reveal that applying phosphate fertilizers enhances natural radioactivity in soil and is subsequently influenced by soil to tobacco plant uptake. Therefore, the study recommends that countries use fertilizers with lower radionuclide content to conserve soil quality and reduce gamma-emitting radionuclides in tobacco plants. [ABSTRACT FROM AUTHOR]

All types of foodstuffs contain an amount of radioactivity which can enter into the human body by the ingestion pathway. If radionuclides are deposited in the human body and concentrations of them was increase from foodstuffs, these may cause illness and a number of health hazards. Fifteen samples of different types of seeds commonly used in Albania were collected from the local markets of the city of Tirana. For this reason, the aim of this study was focused in the measurement and analysis of the activity concentrations of natural and artificial radionuclides in the seed samples. The measurements were performed by using the High Purity Germanium (HPGe) detector and the activity concentration for radionuclides of 226Ra, 232Th, 40K and 137Cs were determined by gamma-ray spectrometry method. The range of activity concentration of natural radionuclides was found to be from 0.93 ± 0.18 to 10.34 ± 1.17 Bq kg-1 for 226Ra, < MDA to 2.20 ± 0.24 Bq kg-1 for 232Th and 28.35 ± 2.08 to 446.36 ± 19.04 Bq kg-1 for 40K, respectively. The activity concentration of the artificial radionuclide of 137Cs was detected only in four seed samples with highest value of 0.65 ± 0.22 Bq kg-1. The average values of activity concentration for 226Ra and 40K were found 5.35 Bq kg-1 and 178.17 Bq kg-1. The highest values of activity for 232Th and 137Cs were found 2.20 Bq kg-1 and 0.65 Bq kg-1. The results of activity concentration of this study were compared with international reference values and the other literatures. The average values of activity concentration for seed samples were found lower than the worldwide average value, which is defined by UNSCEAR 2000 report. Therefore, the results obtained in this study for radioactivity levels show that the consumption of these seeds are safe and no harmful health effects are expected for peoples living in Albania. [ABSTRACT FROM AUTHOR]

The activity concentrations of natural radionuclides 226Ra, 232Th, and 40K in soil samples from the slopes of Mount Cameroon (South-West coastal region) have been investigated using gamma-ray spectrometry measurement-based NaI (Tl) detector. The average activity concentrations of 226Ra, 232Th, and 40K in the assessed soil samples were found to be 15.80, 43.94, and 111.68 Bq/kg, respectively. From the obtained concentrations, radiological hazard parameters such as the equivalent radium activity (Raeq), the dose rate (Dose_rate), the annual effective dose (AED), the risk indexes (Hex, Hin, Ia, Ig, ELCR), and the annual effective dose to the organs (Dorgans) were calculated. The mean values of the obtained concentrations and radiological hazard parameters are all below the world average values and suggest no radiological alarm for the local population and visitors. A statistical study consisting of descriptive analysis, Pearson correlation, principal component analysis, and cluster analysis was performed to investigate the distribution and relationship between 226Ra, 232Th, and 40K in the study area; also, to find out which factor mainly influences the calculated radiological parameters and to classify the samples according to their category or similarity. It was found that 226Ra, 232Th, and 40K follow an approximately normal distribution and that there is a very low correlation between 40K and the other radionuclides. Cluster analysis reveals four clusters which can also be compacted into two major groups suggesting that the samples are primarily from two groups of rocks. Finally, the main contributor to radiological exposure in the study area is 232Th, which is in agreement with the reference published works. [ABSTRACT FROM AUTHOR]

Natural radionuclides from building materials are one of the potential sources of external as well as internal radiation exposure to the human body. Currently, this exposure has been increasing since people spend more than their time indoors. In this study, 16 cement samples collected from Abidjan district were analyzed using a high-resolution high-purity germanium gamma spectrometry. Activity concentrations of primordial radionuclides 226Ra, 232Th, and 40K were found with mean specific activities of 9.95 ± 1.94 Bq/kg, 21.81 ± 3.2 Bq/kg, and 196.50 ± 4.5 Bq/kg, respectively. The obtained data were below world average values of 35, 30, and 400 Bq/kg. Radiological parameters such as radium equivalent activity, absorbed dose rate (D), and annual effective dose were calculated and compared to the worldwide average values. Further, statistical analyses were performed and discussed for the resulted data. The estimated radiological indices were below the recommended levels; therefore, the study shows that the measured radioactivity for cement does not pose a significant source of radiation and is safe for use in the construction of dwellings. The data from this study can be used as a reference for future studies on building materials in Côte d'Ivoire and by other researchers around the world.