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Each nuclear weapon test contributes to a global burden of released radioactivity. Between 1945 and 1996, more than 2,000 nuclear tests were conducted, three-quarters of which were underground. Underground nuclear tests involved placing the nuclear device in a cavity drilled or excavated beneath the surface. The goal was to contain the explosion and its effects to the immediate vicinity of the detonation point, ultimately minimizing the release of radioactive materials into the atmosphere. While these tests successfully curtailed the atmospheric release and radioactive fallout, they created dynamic responses within crustal formations caused by local shock waves from the explosion. This paper discusses the legacy of underground nuclear testing, addressing issues from containment failure to the phenomenological effects after underground detonations and the pathways of subsequent dispersal of radionuclides to the environment. [ABSTRACT FROM AUTHOR]

Brazil nuts are well known for their extraordinarily high selenium content. For this reason, they are frequently recommended as a kind of natural selenium ‘supplement’, particularly for certain population groups such as vegetarians and vegans in regions with low soil selenium levels. Typically, an intake of one or two Brazil nuts per day is recommended. Brazil nuts, however, also stand out from other nuts in terms of their high (albeit highly variable) radium content. The radium isotopes Ra‐226 and Ra‐228 emit alpha‐ and beta‐radiation, with this type of radiation being particularly harmful when ingested. Consequently, it is important to consider radium levels in Brazil nuts before formulating recommendations for a long‐term, daily intake of these nuts. To date, however, no comprehensive overview of radium levels in Brazil nuts has been published. Therefore, a literature review without time or language restrictions was conducted, including unpublished original data from Germany. The literature review (including the German data) indicated mean Ra‐226 and Ra‐228 levels of 49 (range: 17–205) mBq/g and 67 (range: 12–235) mBq/g, respectively. Assuming a consistent daily intake of one or two Brazil nuts, this would result in an effective dose of ~88–220 μSv/year. This level of exposure appears to be neither clearly harmful nor clearly harmless. As increased radioactivity exposure (at least at higher doses) is associated with increased cancer risk, randomised controlled trials assessing the effect of Brazil nuts on cancer risk biomarkers are needed. [ABSTRACT FROM AUTHOR]

238U and 234U concentrations, 238U/234U ratios and Na, Ca, Mg, K, Al, As, Cd concentrations were measured in selected surface waters (streams, rivers and lakes), ground waters (dug wells) and underground waters (drill wells and thermal waters) in Quang Nam and Da Nang provinces, Central Vietnam. The mineralization was < 500 mg L−1 and Al, As, Cd contents were a few tenths of µg L−1. 234U and 238U activities were between 0.47–27.6 mBq L−1 and 0.6–15.0 mBq L−1 respectively, these values are lower than WHO recommended limits. Uranium contents trended as Urivers < Ustreams < Ulakes < Udig wells < Uthermal water < Udrill wells. The 234U/238U ratio ranged from 0.69 to 2.31 with 1.26 on average. For groundwaters, the ratio scattered around one. Effects of Nong Son uranium deposit located in Quang Nam region were not observed. [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]

The natural radionuclides in ancient El-Qasr village located in the El-Dakhla oasis (EDO), Egypt's Western Desert were measured using gamma-ray spectrometry equipped with a NaI (Tl) detector. The findings indicate that the samples' mean activity concentrations were 18.61 ± 1.02, 16.67 ± 0.9, and 137.67 ± 6.9 Bq kg−1 for 226Ra, 232Th, and 40K, respectively. The values of Raeq, D, AED, Hex, Hin, Iγ, and ELCR for the samples ranged anywhere from 34.1 to 83.9 Bq kg−1, 15.7 to 37 nGy h−1, 19.26 to 45.384 Sv y−1, 0.09 to 0.23, 0.12 to 0.23, 0.25 to 0.59, and 6.74E−05 to 1.59E−04, respectively. These values are significantly lower than the international limit of 370 Bq kg−1 for Raeq, 59 nGy h−1 for D, 70 Sv y−1 for AED, 1 for Hex and Hin, 2 for Iγ, and 29E−03 for ELCR. According to the obtained data, none of the samples seemed to be a significant risk when it came to radiation exposure. Using these data, we will determine the baseline level of radionuclides that occur naturally in the area that is the subject of the inquiry. [ABSTRACT FROM AUTHOR]

Neutron activated concrete reference material for measurement of residual radioactivity by gamma-ray spectrometry has been prepared. The main radionuclides were 60Co, 152Eu, 54Mn, 154Eu and 134Cs. One-way ANOVA homogeneity test has shown that the samples are homogeneous. The activity concentrations of 54Mn, 59Fe, 154Eu and 134Cs were relatively low; only 60Co activity concentration was found to be higher therefor it was considered as the main target isotope. The prepared sample can be used as a tool to prove compliance to radiation protection and environmental regulations during decommissioning of cyclotron buildings or other irradiation facilities that produce residual radioactivity. [ABSTRACT FROM AUTHOR]

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The present study investigates gross alpha (GA) radioactivity levels in hazelnut kernels purchased from markets in Türkiye. 10 different hazelnut samples were crushed and made ready for counting. The alpha counts were obtained via ELSEC 7286 low level alpha counter with ZnS scintillator and EMI 6097B photomultiplier tube. The samples were placed in front of the detector to acquire the counts. All samples were counted isochronously. In addition to the GA activity measurement, total annual effective dose (AED) value for different age groups owing to ingestion was calculated for each sample. It was observed that the GA radioactivity levels in the samples were quite low, and total AED values were considerably lower than the WHO worldwide average AED value (290 μSv/year). [ABSTRACT FROM AUTHOR]

Objectives: This work aims to establish a dataset of ratios between tissue free water tritium (TFWT) and organically bound tritium (OBT) (containing both exchangeable and non-exchangeable OBT) in different types of seafood from Zhejiang province, China, thus to provide references for rapid screening of potential contamination of tritium in biological samples. Methods: Five types of seafood (fish, prawn, mussel, crab and kelp) were collected from Jiaxing, Ningbo, Zhoushan, Taizhou and Wenzhou city in Zhejiang Province in 2022, and measured for TFWT and OBT using tube furnace combustion system and liquid scintillation counting. Results: The observed activity concentrations of TFWT and OBT in this study were within the range of 1.01-10.09 Bq/L and 0.51-7.61 Bq/L, respectively. No significant difference in OBT/TFWT ratio was observed among different types of seafood (p > 0.05), among the geographic distribution of the five cities (p > 0.05), nor among the area of coastline, fishing ground and island (p > 0.05). Additionally, there was no significant difference in the OBT/TFWT ratio between seafood from area with and without nuclear power plant operation (p > 0.05). The mean OBT/TFWT ratio of fish, prawn, mussel, crab and kelp was 0.37 ± 0.19, 0.48 ± 0.27, 0.63 ± 0.33, 0.82 ± 0.50, and 0.64 ± 0.37, respectively. The mean and range of OBT/TFWT ratios were 0.59 ± 0.37 and 0.15-2.09 in all seafood collected from the five cities in Zhejiang Province, respectively. Conclusions: Our results indicate that tritium in seafood from coastal cities in Zhejiang Province is at the background level, and the operation of nuclear power plants in the province has no notable impact on the radioactivity levels of tritium in local marine biota. This study filled the gap in OBT/TFWT ratios in seafood, which provides new dataset for rapid detection of tritium contamination in nuclear emergencies. [ABSTRACT FROM AUTHOR]

The Coulomb and Proximity potential Model (CPPM) is improved by introducing an accurate empirical expression for the nuclear surface diffuseness parameter in the expression for the proximity potential. Within the improved CPPM, the decay half-lives of experimentally detected cluster emissions from heavy elements are calculated. The results of the calculations using the Universal Decay Law (UDL) [Qi et al., Phys. Rev. Lett. 103 (2009) 072501], the improved empirical formula of Sahu et al. (ImSahuB) [Wang et al., Chin. Phys. C 45 (2021) 044111], and the empirical formula of Horoi [J. Phys. G. Nucl. Part. Phys. 30 (2004) 945] are compared with the predictions of the improved CPPM. The lowest standard deviation is obtained for the predictions using the improved CPPM. The model’s predictive power increases significantly when the proximity potential is modified by including the diffuseness parameter. Furthermore, improved CPPM is employed to calculate the decay half-lives of undiscovered cluster emissions from heavy elements, a valuable information for upcoming experimental investigations. The calculated values are compared with the predictions of the UDL, Horoi formula and the improved empirical formula of Sahu et al. (ImSahuB). There is a high degree of agreement between the improved CPPM, UDL, and Horoi formula predictions. The ImSahuB formula predict decay half-life one or two order magnitudes lower than the predictions of the other models. [ABSTRACT FROM AUTHOR]

This study investigates the levels of natural and artificial radioactivity in rice samples collected from various local markets in Islamabad, Pakistan. The 226Ra, 232Th, and 40K activity concentrations were measured through gamma-ray spectrometry with a NaI(Tl) detector. The average activity concentrations were 1.67 ± 1.19 Bq kg−1 for 226Ra, 3.31 ± 1.83 Bq kg−1 for 232Th, and 88.51 ± 11.65 Bq kg−1 for 40K. Calculated radium equivalent (Raeq) values ranged from 7.35 to 18.08 Bq kg−1, with a mean value of 11.11 Bq kg−1, all below the permissible maximum of 370 Bq kg−1. The absorbed dose rates ranged from 6.85 to 16.39 nGy h−1, with an average of 10.64 nGy h−1, falling below the acceptable limit of 51 nGy h−1. The outdoor and indoor radiation hazard indices (Hex and Hin) had mean values of 0.03, both below the threshold value of one. The external and internal hazard indices (Iγ and Iα) were both 0.088, also below the critical value of one. The excess lifetime cancer risk (ELCR) ranged from 0.28 to 0.11, with a mean value of 0.18, which is less than the critical value of one. Overall, the radioactivity levels in the analyzed rice samples are within the acceptable limits set by the International Commission on Radiological Protection and are below global averages. These results offer important insights into the radiological safety of rice consumption in the study area. [ABSTRACT FROM AUTHOR]

This study evaluates the levels of natural radioactivity in sediment and water samples from Lake Victoria in Jinja, Uganda, with a focus on the radionuclides potassium-40 (40 K), radium-226 (226Ra), and thorium-232 (232Th). We investigated four distinct zones around the lake: fishing (Zone A), farming (Zone B), domestic/livestock (Zone C), and a control zone (Zone D). A total of 15 sediment samples and 15 water samples were collected and analyzed. Sediment samples were obtained using a gravity corer, with a maximum penetration depth of 50 cm. 40 K ranged from 170.479 to 524.883 Bqkg−1 across all zones, 226Ra ranges from 1.51 to 56.78 Bqkg−1 across all zones, and 232Th ranges from 18.18 to 73.10 Bqkg−1 across all zones. 40 K concentrations were highest in the farming zone, likely due to the use of nitrogen, phosphorus, and potassium (NPK) fertilizers. 226Ra and 232Th levels were also elevated in the farming zone, suggesting potential contributions from phosphate fertilizers. Absorbed dose rates varied across the zones, ranging from 28.33 to 58.17 nGyh-1. The measured absorbed dose rates across all zones were within the global average of 59 nGyh−1. The effective annual dose rate ranged from 0.35 to 0.91 mSvy−1 across all zones. Effective annual dose rates did not exceed the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended limit of 1 mSv y−1, indicating low risks to public health from sediment radioactivity. The external index was below the safety threshold, suggesting minimal health risks. In water samples, gross alpha and beta activity concentrations were analyzed. Zone B had the highest average alpha activity concentration (0.64 BqL−1) and beta activity concentration (0.72 BqL−1), while Zone A had the lowest for both alpha (0.16 BqL−1) and beta (0.25 BqL−1) activity concentrations. Gross beta activity was generally higher than gross alpha activity, reflecting potential anthropogenic influences. Most water samples were within the UNSCEAR recommended limits for drinking water quality, except in areas affected by agricultural runoff. This study demonstrates that while the sediments of Lake Victoria in Jinja, Uganda, exhibit varying levels of naturally occurring radionuclides influenced by farming practices, the overall radiation exposure remains within safe limits. Continuous monitoring and regulatory measures are essential to maintain these safety levels and mitigate potential risks from increasing agricultural activities. [ABSTRACT FROM AUTHOR]

The development of the nuclear industry in the countries of the Arabian Gulf demands an investigation of its potential impact on the environment and human activities. It should involve routine monitoring of radionuclide from existing nuclear facilities as well as modelling of accidental release of radioactivity. Agriculture is usually considered the human activity which is the most endangered with radioactive pollution. Although the traditional concept of low-developed agriculture in the United Arab Emirates has been already described from a radioecological point of view, herein, the recent trends of agriculture are recorded. Due to climatic changes and population increase, the use of saline lands will be more pressing. Apart from it, the risk assessment for nuclear events, which was formed mainly for temperate zones, neglected another aspect of arid zones which is underground water reservoirs refilled with episodic heavy rains. The sandy or saline soils are not an effective barrier for the migration of radionuclide deposited in topsoil. A hypersaline environment could prevent the adsorption of radionuclide on soil particles and allow their high bioavailability for halophyte plants. The new principal challenges in radioecological research in arid zones are impacts on (i) saline agriculture, (ii) underground water reservoirs, and (iii) proposal for countermeasures in order to minimise the impact of radioactive contamination. [ABSTRACT FROM AUTHOR]

Natural radioactivity was first discovered in 1896 by the French physicist Beck Kerelem. As a result of recent research, Pierre and Marie Curie discovered that the nucleus of atoms of some elements spontaneously transforms into the nucleus of atoms of other elements, and during this, the radiation of particles occurs. Most naturally occurring radioactive elements form a radioactive family in which each radioactive element originates from the preceding radioactive element and in turn transforms into the next radioactive element. The transformations continue until the end product is an isotope of a stable element. In nature, there are also radioactive elements that this transformation occurs only once . In 1934, French scientists Irene and Fredrik Joluo-Curie irradiated aluminum, boron and manganese with particles and obtained isotopes of phosphorus, nitrogen and silicon elements, which do not exist in nature. This type of radioactivity is called artificial radioactivity. Later, by irradiating various elements with proton, deuteron and neutron particles, they obtained isotopes of all chemical elements in the Mendeleev table. [ABSTRACT FROM AUTHOR]

Zavegepant, a high‐affinity, selective, small‐molecule calcitonin gene‐related peptide receptor antagonist, is approved as a nasal spray for acute treatment of migraine in adults. This phase I, open‐label, single‐center, single‐period, nonrandomized study in six healthy male subjects assessed mass balance recovery after a single 15‐min intravenous (IV) infusion dose of carbon‐14 ([14C])‐zavegepant. Blood, urine, and fecal samples were collected over 192 h for analysis of zavegepant in plasma and urine; total radioactivity (TR) in plasma, whole blood, urine, and feces; and zavegepant metabolite profiling and structural identification in plasma, urine, and feces. An average of 96.6% of radioactivity administered was recovered in excreta. Most TR (mean 84.9%) was recovered in the feces, indicating that biliary/fecal elimination was the main route. Volume of distribution of zavegepant based on the terminal phase (129 L) was higher than total body water (42 L), indicating substantial distribution into tissue. Total plasma clearance of zavegepant (220 mL/min) is identical to whole blood clearance given the blood/plasma partition ratio of 1, lower than typical hepatic blood flow (1450 mL/min). The observed plasma terminal half‐life of zavegepant was 6.8 h. Exposure to zavegepant accounted for ~90% of circulating plasma TR, suggesting that very low levels of uncharacterized circulating metabolites were present. Metabolite profiling did not identify any metabolites representing ≥10% of radioactivity in plasma, urine, or feces. A single IV infusion of 5 mg [14C]‐zavegepant was well tolerated in healthy male subjects. Disposition findings of IV [14C]‐zavegepant are applicable to the disposition of the approved zavegepant nasal spray. [ABSTRACT FROM AUTHOR]

In this study, the mass balance, pharmacokinetics (PK) and metabolism of atuliflapon, a novel 5‐lipoxygenase‐activating protein inhibitor, were investigated in healthy male subjects. A single oral dose of 200 mg [14C]atuliflapon suspension was administered to six healthy male subjects. Mass balance, PK and metabolite profiles of atuliflapon were analyzed using radioactivity monitoring and liquid chromatography with mass spectrometry analysis. The safety of atuliflapon was assessed during the study. Atuliflapon was rapidly absorbed with a median tmax of 1.5 h, followed by a biphasic decline in plasma exposure rendering a terminal half‐life of ~20 h. Unchanged atuliflapon was the predominant radioactive component in plasma, accounting for 40.1% of the total drug‐related exposure (DRE), while a direct N‐glucuronide was the only metabolite exceeding 10% of DRE, accounting for 20.9%. Renal excretion of intact atuliflapon accounted for <1% of the administered dose. In total 85.2% of administered radioactivity was recovered over 312 h with 79.3% and 5.9% in feces and urine, respectively. Parent atuliflapon contributed to approximately 40% of the recovered dose in excreta, while metabolites resulting from phase 1 oxidative pathways accounted for more than 30% of the excreted dose. Overall, a single oral dose of 200 mg [14C]atuliflapon suspension was well tolerated in healthy male subjects. The human metabolism and disposition data obtained will support future development and submissions of atuliflapon as a potential candidate drug for the treatment of cardiovascular, cardiorenal, and respiratory indications. [ABSTRACT FROM AUTHOR]

Aficamten, a cardiac myosin inhibitor, is being developed for the treatment of patients with symptomatic hypertrophic cardiomyopathy (HCM). The purpose of this study was to determine the absorption, metabolism, and excretion of aficamten. Eight healthy male participants received a single oral dose of 20 mg aficamten (containing approximately 100 μCi of radiocarbon). Blood, urine, and feces samples were collected up to a maximum of Day 26. The pharmacokinetics of aficamten were characterized by moderate absorption, with a median tmax of 2.0 h postdose. The median t1/2 of aficamten was 99.6 h with similar t1/2 observed for metabolites and total radioactivity in plasma and whole blood. The overall total recovery of administered total radioactivity was 89.7% with 57.7% of the dose recovered in feces and 32.0% in urine. The main circulating metabolites in plasma included monohydroxylated metabolites M1a (CK‐3834282) and M1b (CK‐3834283) accounting for 10.5% and 36.4% of the total radioactivity AUC both with a median tmax of 5 h. The other major plasma metabolite was M5 (an oxygen‐linked glucuronide conjugate of M1a), which accounted for 10.3% of the total plasma radioactivity exposure, with a tmax of 24 h. In urine, M5 was the most abundant metabolite with 8.02% total radioactive dose (TRD), followed by M1a and M1b with 6.16% and 2.85% TRD, respectively; however, there were no metabolites in urine observed at >10% of dose. The major metabolite in feces was M18 representing 44.1% of the radioactive dose. These findings indicated that aficamten was eliminated by metabolism, and to a minor extent, by fecal excretion of unchanged aficamten with renal excretion playing a minor role. Feces were the principal route of excretion of the radioactive dose. [ABSTRACT FROM AUTHOR]

Background: Historically, [131I]I has been a common isotope in radionuclide therapy, with [177Lu]Lu‐labelled radiopharmaceuticals now seeing a surge in use. These can include no‐carrier‐added or carrier‐added [177Lu]Lu with slight impurities of [177mLu]Lu with a significantly longer half‐life than [131I]I. Wastewater from therapy wards can contain a mixture of these radioisotopes. In some countries, national regulations require wastewater to be stored in dedicated systems before it is discharged into the public sewage system. To fulfill legal requirements, the nuclide specific activity concentration must be verified. Purpose: We evaluate a method for determining the activity concentration of [177mLu]Lu /[177Lu]Lu at equilibrium and [131I]I in pure and mixed samples in order to prove that the determined values are reliably below the limits for release. Methods: We analysed the emitted energy spectrum of 1 L samples with a wastewater counter using an energy window‐based approach by evaluating measurements from two different time points. Based on the law of decay and the time and energy‐dependent measured values, equation systems were set up to calculate the count rates for [131I]I and [177mLu]Lu, which were converted into activity concentration using calibration factors. Results: There is strong linear correlation between the nominal and determined activity concentrations (correlation coefficients R = 0.99; coefficient of determinations R2 = 0.99). We underestimate the actual activity concentration by a median of −1.4% for [177mLu]Lu and overestimate the activity concentration for [131I]I by a median of 7.1%. Conclusion: We show that an undercut of the clearance levels for material release is measurable. We analyse and determine activity concentrations of mixed samples consisting of [131I]I and [177mLu]Lu/[177Lu]Lu in equilibrium. The method is simple to implement using a conventional wastewater counter, however with a slightly increased effort, as two samples and measurements are required. The methodology can be adapted for the analysis of other nuclide mixtures. [ABSTRACT FROM AUTHOR]

Naturally occurring radionuclides rocks are one of the possible sources of indoor and outdoor radiation. Samples were taken from Kolar taluk in Karnataka in order to evaluate the radioactive hazards and natural radioactivity levels in those samples. The activity concentrations of 226Ra, 232Th, and 40K in these samples were determined using NaI(Tl) gamma ray spectroscopy. The measured ranged from 5.05 to 171.43 (Bq kg-1); 5.04 to 274.64 (Bq kg-1); 287.23 to 2603.45 (Bq kg-1) for 226Ra, 232Th, and 40K. In this study, the yearly effective radiation dosage, air absorbed gamma radiation dose rate, and hazard index (Hin, Hex), gamma index, activity utilization index, annual gonald dose equivalent were estimated. The study's demonstrate that potassium (40K), a naturally occurring radionuclide, is higher than radium and thorium. The levels of the computed radionuclides were compared to other places in Karnataka and world average value. The relationship between radionuclides was examined using correlation and statistical methods, radiation parameters were also computed. Information on background radioactivity levels and the impacts of radiation on locals in the research area under inquiry is what this study aims to deliver. [ABSTRACT FROM AUTHOR]

Determinations of radioactivity and stable element contents in outlet waters taken from dams (Çamlıdere, Kurtboğazı, Kesikköprü, Çubuk-2) and drinking waters from water treatment plants (İvedik, Pursaklar and Çubuk) of Ankara Water and Sewerage Administration (ASKİ) were performed by using MPC-9604 multi-detector alpha/beta (α/β) counting system, inductively coupled plasma–mass–mass spectrometer and graphite furnace atomic absorption spectrometer. Gross alpha and beta activity levels and element concentrations found in samples were compared with maximum permissible values given by World Health Organization, United State Environmental Protection Agency, Turkish Standards and Türkiye Regulation on Water for Human Consumption. [ABSTRACT FROM AUTHOR]

To analyze groundwater contamination with uranium, groundwater samples were collected from the major industrial area of Jalandhar, Punjab, India (as the industrial effluent is found to contain a large number of heavy metals) and analyzed using ICPMS (Inductively Coupled Plasma Mass Spectrometer) for uranium-238. Uranium-238 concentrations in groundwater ranged from 4.96 µg/L and 38.52 µg/L, with an average of 17.0 µg/L. All the values of uranium concentration and uranium activity concentration in the samples were found within the permissible range by the World Health Organization (WHO). The hazard quotient for all the samples is found to be below one, indicating very low or no risk to the population. [ABSTRACT FROM AUTHOR]

The tritium content in the surface water of the Suifen River in China was measured using an ultra low-level liquid scintillation spectrometer. In August and October, a total of 30 samples were collected (15 per month) The measured 3H activity concentration ranged from 5.08 to 9.75 Bq L−1, and the annual effective dose ranged from 0.07 to 0.13 μSv. These values are below WHO's recommendations, indicating no risk to human health. Although the 3H activity concentration was higher in October than in August, statistical analysis did not show a significant difference between the two months. [ABSTRACT FROM AUTHOR]

Cobalt-60 is usually used for calibration standard that nowadays, it hard to fabricated. This research aims to fabricate of Sealed Source 46Sc as alternative Calibration Standard. Sealed source 46Sc radioactivity was 1.17 ± 0.08 µCi, sealed with an aluminum label. Radiation exposure on the surface opened container is 19.27 ± 0.09 µSv/h, a closed is 10.78 ± 0.15 µSv/h and the distance of 1 m from an open container is 4.40 ± 0.04 µSv/h whereas closed has 2.40 ± 0.04 µSv/h. Multi-channel analyzer γ-spectrometry showed the 46Sc gamma spectrum similar with characteristics from standard 60Co source. [ABSTRACT FROM AUTHOR]

Abstract The metabolism and disposition of zamicastat, a reversible dopamine β-hydroxylase (DβH) inhibitor, developed for treatment of Pulmonary Arterial Hypertension (PAH), were investigated in rats after oral and intravenous administration of [14C]-zamicastat.Zamicastat was rapidly absorbed and widely distributed to peripheral tissues, with total radioactivity almost completely recovered 168 h post-dose. Its main route of excretion was via faeces, whilst urine and expired air had minor roles.Maximum plasma concentration of zamicastat-related radioactivity occurred in the first hours, remaining quantifiable up to 144 h. The unchanged zamicastat plasma peak was 2 h post-dose and declined to low levels over 24 h.Zamicastat metabolism occurs largely during the first 8 h with only one metabolite identified in the latest time-point (96 h), the isothiocyanic acid/thiocyanic acid (tautomeric forms). Zamicastat metabolic pathway involved multiple reactions comprising desulphurisation, oxidative desulphurisation, N-debenzylation followed by further oxidation or N-acetylation, and the unexpected multistep metabolic pathway leading to isothiocyanic acid/thiocyanic acid.The metabolism and disposition of zamicastat, a reversible dopamine β-hydroxylase (DβH) inhibitor, developed for treatment of Pulmonary Arterial Hypertension (PAH), were investigated in rats after oral and intravenous administration of [14C]-zamicastat.Zamicastat was rapidly absorbed and widely distributed to peripheral tissues, with total radioactivity almost completely recovered 168 h post-dose. Its main route of excretion was via faeces, whilst urine and expired air had minor roles.Maximum plasma concentration of zamicastat-related radioactivity occurred in the first hours, remaining quantifiable up to 144 h. The unchanged zamicastat plasma peak was 2 h post-dose and declined to low levels over 24 h.Zamicastat metabolism occurs largely during the first 8 h with only one metabolite identified in the latest time-point (96 h), the isothiocyanic acid/thiocyanic acid (tautomeric forms). Zamicastat metabolic pathway involved multiple reactions comprising desulphurisation, oxidative desulphurisation, N-debenzylation followed by further oxidation or N-acetylation, and the unexpected multistep metabolic pathway leading to isothiocyanic acid/thiocyanic acid. [ABSTRACT FROM AUTHOR]

On October 22, 1934, in a fateful experiment, Enrico Fermi and his associates at the University of Rome discovered that neutrons in hydrogen-rich media slow down and acquire enhanced capability for nuclear reactions. The utilization of this phenomenon had far-reaching implications in science and world events. [ABSTRACT FROM AUTHOR]

The study was carried out to evaluate the radioactivity concentrations of 40K, 232Th and 238U in five maize samples collected from maize farms within Ekiti State, Nigeria. The activity concentration measurements were determined using n -- type co-axial HPGe detectors for the state. The activity concentrations were found to vary from 994.67 - 2457.01 Bq Kg-1 for 40K, 32.84 - 91.88 Bq kg-1 for 232Th and 43.21 - 97.77 Bq kg-1 for 238U respectively. The annual effective dose to individuals from the consumption of the Maize was estimated on the basis of the measured radionuclides content in the food crop which ranged between 0.41 and 1.51 m Svy-1 respectively. The value 1.04 m Svy-1 were obtained for the state as the mean total annual effective dose. The mean excess life time cancer risk was also calculated to be 2.06x10-9. The value was compared with the internationally acceptable limits and found to be far less to the maximum permissible dose of 1.0 x10-3 recommended for the public by the United Nations Scientific Committee on the Effects of Atomic Radiation. Hence, the maize was found to be safe for human consumption. [ABSTRACT FROM AUTHOR]

Laboratory-scale experiments were conducted on Carboniferous Limestone gravels from the Mendip Hills area, England; sandstones from the Pirambóia and Botucatu formations, Paraná sedimentary basin, Brazil; samples of schist and quartzite from Caldas Novas Hydrothermal Complex, Brazil; and the minerals tantalite, cassiterite, and columbite from mining areas at Rio Grande do Norte State, Brazil, with the purpose of evaluating the release of 222Rn to the water phase. The specific surface area of the samples corresponded to 1.69–81.36 cm2g−1, which provided values of 0.001–1.68 dpm/g and 3.18 × 10−6 to 0.59 for the radon released and radon emanation coefficient, respectively. These results allowed us to calculate the radon flux with respect to the radon leakage, which corresponded to values of 0.00016–0.00158 Bq/m2/d for the denser materials and 0.018–0.43 Bq/m2/d for limestones and sandstones. They also permitted us to find an inverse, significant relationship between the radon generated by the minerals/rocks and the radon flux into the water phase, which was tested for sediments in coastal and inland Brazilian areas, demonstrating utility for evaluating the diffusive radon flux from the sediments, which is an important parameter to monitor submarine groundwater discharge (SGD) by means of radon as a natural tracer. [ABSTRACT FROM AUTHOR]

Monitoring radioactivity around nuclear power plants is important to avoid the risks of radiation. This study provides an overview of the radioactive emission impact on the near surroundings of the Metsamor nuclear power plant in Armenia. In this context, 29 soil samples were collected from the 40, 80, 120, 160 km radius areas determined in the direction of Iğdır province by accepting the Metsamor nuclear power plant as the center. The activity concentrations of 226Ra, 232Th, 40K and 137Cs in soil samples ranged from 7.90 to 23.44, 7.11 to 33.55, 132.54 to 502.69 and 0.33 to 17.61 Bq/kg, respectively. In addition, the radioactivity concentrations in some agricultural products and the transfer factors from soil to plant were determined. As a result, there is no significant radiological risk in terms of studied radioisotopes for people living in this region. [ABSTRACT FROM AUTHOR]

The study assessed the concentration of natural radionuclides in soil samples from the Bambasi district in Ethiopia's Benishangul Gumuz region using a gamma‐ray spectrometer equipped with a high‐purity germanium (HPGe) detector. The measured activity concentrations of 238U, 232Th, and 40K in soil samples varied from 46.2 ± 2.25 to 88.49 ± 5.73 Bq/kg, 73.4 ± 4.12 to 119.65 ± 8.45 Bq/kg, and 176.78 ± 8.63 to 396.71 ± 25.39 Bq/kg, respectively. The average concentration of 238U and 232Th exceeded the recommended worldwide population weighted average values of 32.0 and 45.0 Bq/kg, respectively, while the average concentration of 40K was below the recommended value of 420.0 Bq/kg. The mean absorbed dose rate was calculated to be 91.6 ± 5.1 nGy/h, which is above the recommended safe value of 59 nGy/h. The average annual effective dose equivalents for indoor and outdoor exposure were determined to be 2.65 ± 0.14 mSv/y and 0.66 ± 0.1 mSv/y, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index across all soil samples were 0.72 ± 0.05, 0.55 ± 0.02, and 0.72 ± 0.02, respectively, all below the recommended safe threshold of one. These findings suggest that the activity concentrations observed in the soil samples exceed safe levels, indicating the necessity for further investigation into radioactivity levels and epidemiological studies regarding potential hazards from high background radiation. [ABSTRACT FROM AUTHOR]

This study introduces a technique for decontaminating radioactive surfaces by employing a gel, herein termed as radiation decontamination gel with eutectic liquids (RADGEL), composed of a deep eutectic solvent and polyvinyl alcohol, with the goal of enabling reuse of the surface post‐decontamination. The decontamination effectiveness of RADGEL underwent thorough evaluation through trials conducted on different simulated surfaces, achieving decontamination efficiency up to 99.9% for alpha as well as gamma radionuclides. The various parameters influencing decontamination factors such as amount of complexing agent used, polymer film thickness, nature, and magnitude of radioactivity, as well as surface characteristics of substrates to be decontaminated were optimized. Additionally excellent mechanical strength of RADGEL, affirms its potential as practically efficient, cost‐effective, and safe option for surface decontamination. The Fourier‐transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis suggest RADGELs capability for both physical and chemical interactions with contaminants, thus highlighting its comprehensive decontamination efficacy. The outcomes of this study carry substantial implications for the decontamination of surfaces contaminated with various types of radionuclides. [ABSTRACT FROM AUTHOR]

The pharmacokinetics, metabolism, excretion, mass balance, and tissue distribution of [14C]aficamten were evaluated following oral administration of an 8 mg/kg dose in Sprague Dawley rats and in a quantitative whole-body autoradiography study in Long Evans rats. [14C]Aficamten accounted for ∼80% and a hydroxylated metabolite (M1) accounted for ∼12% of total radioactivity in plasma over 48-h (AUC0–48). Plasma tmax was 4-h and the t1/2 of total plasma radioactivity was 5.8-h. Tissues showing highest Cmax exposures were myocardium and semitendinosus muscle. Most [14C]aficamten-derived radioactivity was excreted within 48-h post-administration. Mean cumulative recovery in urine and faeces over 168-h was 8.3% and 90.7%, respectively. In urine and bile, unchanged aficamten was detected at <0.1 and <0.2% of dose, respectively; however, based on total radioactivity excreted in urine (8.0%) and bile (51.7%), approximately 60% of dose was absorbed. [14C]Aficamten was metabolised by hydroxylation with subsequent glucuronidation where the most abundant metabolite recovered in bile was M5 (35.2%), the oxygen-linked glucuronide of hydroxylated aficamten (M1a). The major metabolite detected in faeces was a 1,2,4-oxadiazole moiety ring-cleaved metabolite (M18, 35.3%), shown to be formed from the metabolism of M5 in incubations with rat intestinal contents solution. [ABSTRACT FROM AUTHOR]

Background: An ultra‐high dose rate (UHDR) electron accelerator for FLASH radiotherapy (RT) produces very intense bremsstrahlung by the interaction of the electron beam with objects both inside and outside of the accelerator. The bremsstrahlung dose per pulse is typically 1–2 orders of magnitude larger than that of conventional RT x‐ray treatment of the same energy, and for electron energies above 10 MeV, the bremsstrahlung produces substantially more induced radioactivity outside the accelerator than for conventional RT. Therefore, a thorough radiation safety assessment is mandatory prior to the operation of a UHDR electron accelerator. Purpose: To evaluate the radiation safety of a prototype FLASH‐enabled Varian TrueBeam accelerator and to develop a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator for FLASH RT. Methods: Production of bremsstrahlung and induced radioactivity by a UHDR electron accelerator is modeled by various analytical methods. The analytical modeling is compared with National Institute of Standards and Technology (NIST) bremsstrahlung yield data as well as measurements of primary bremsstrahlung outside the bunker and induced radioactivity of irradiated thick targets for a FLASH‐enabled 16 MeV Varian TrueBeam electron accelerator. In addition, the analytical modeling is complemented by measurements of secondary bremsstrahlung inside/outside the bunker and neutrons at the maze entrance. Results: Calculated bremsstrahlung yields deviate maximum 8.5% from NIST data, and all measurements of primary bremsstrahlung and induced radioactivity agree with calculations, validating the analytical tools. In addition, it is found that scattering foil bremsstrahlung dominates primary bremsstrahlung and the main source of secondary bremsstrahlung is the irradiated object outside the accelerator. It follows that primary and secondary bremsstrahlung outside the bunker can be calculated using the same simple formalism as that used for conventional RT. Measured primary bremsstrahlung tenth‐value layers for concrete of the simple formalism are in good agreement with NCRP and IAEA data, while measured secondary bremsstrahlung tenth‐value layers for concrete are considerably lower than NCRP and IAEA data. All calculations and measurements form a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator. Conclusions: The FLASH‐enabled Varian TrueBeam accelerator is safe for normal operation (max. 99 pulses per irradiation) in a bunker designed for at least 15 MV conventional x‐ray treatment unless the UHDR workload is much larger than the x‐ray workload. A similar finding applies to other UHDR electron accelerators. However, during beam tuning, radiation survey, or other tests with extended irradiation time, the UHDR workload may become very large, necessitating the implementation of additional safety measures. [ABSTRACT FROM AUTHOR]

Background and Objective: Tinengotinib, a novel multi-target small molecule kinase inhibitor, is currently undergoing phase II clinical trial in the USA and China. The purpose of this open-label study was to investigate the absorption, metabolism, and excretion of [14C]tinengotinib following a single oral dose in healthy subjects. Methods: Six healthy male subjects received a single oral dose of [14C]tinengotinib capsules at 10 mg/100 µCi, and blood, urine, and feces samples were collected. Phenotyping experiments were further conducted to confirm the enzymes involved in its metabolism. Results: Tinengotinib was rapidly absorbed in plasma with a time to peak drug concentration (Tmax) of 1.0–4.0 h post-dose and a long terminal half-life (t½) of 23.7 h. Blood-to-plasma radioactivity concentration ratios across timepoints ranged from 0.780 to 0.827, which indicated minimal association of radioactivity with blood cells. The mean cumulative excreted radioactivity was 99.57% of the dose, including 92.46% (68.65% as unchanged) in feces and 7.11% (0.28% as unchanged) in urine. In addition to unchanged tinengotinib, a total of 11 radioactive metabolites were identified in plasma, urine, and feces. The most abundant circulating radioactivity was the parent drug in plasma, which comprised 88.23% of the total radioactivity area under the concentration–time curve (AUC). Metabolite M410-3 was a major circulating metabolite, accounting for 5.38% of the parent drug exposure and 4.75% of the total drug-related exposure, respectively. All excreted metabolites accounted for less than 5.10% and 1.82% of the dose in feces and urine, respectively. In addition, no unique metabolites were observed in humans. Tinengotinib was metabolized mainly via CYP3A4. Conclusions: Overall, tinengotinib demonstrated a complete mass balance with limited renal excretion, no disproportionate blood metabolism, and slow elimination, primarily through the fecal route. The results of this study provide evidence to support the rational use of tinengotinib as a pharmacotherapeutic agent. Registration: ChinadrugTrials.org.cn identifier: CTR20212852. [ABSTRACT FROM AUTHOR]

In this study, the results showed that the soil radioactivity concentrations of 232Th and 40K were higher than the reference values given by UNSCEAR, but still within radiologically safe limits. Heavy metal concentrations were within allowable limit according to Vietnamese standards. Radioactivity and metal concentrations in the topsoil did not increase compared with the 30 cm depth after a period of operation. After one year of operation, the gamma dose rates of the area around the plant showed no difference according to the one-way ANOVA test (p = 0.944). The results indicated that after a period of operation, the coal-fired thermal power plant did not shown any significant impact of radioactivity and metals from the fly ash on the surrounding environment. [ABSTRACT FROM AUTHOR]

Microplastics have become a ubiquitous contaminant, but their fate in food animals is largely unknown. In this study, [14C]-polystyrene microplastic (PS-MP) particles were orally dosed to lactating sheep to evaluate their absorption and disposition. Elimination of the [14C]-PS-MP was predominately through faeces with faecal radioactivity peaking at 24 h post-dosing but continuing to be present throughout the entire 72 h study period. Only a small fraction (≤ 1%) of the dosed [14C]-PS-MP was present in blood, milk, and urine. Pharmacokinetic analysis of blood plasma radioactivity, using non-compartment modeling, indicated rapid absorption (T1/2 0.4 to 3 h) with slow elimination (T1/2 37 to 48 h). Radioactivity in milk and urine had similar elimination patterns with radiocarbon activities peaking 24 h post-dosing with detectable elimination throughout the 72 h study period. No radioactivity was quantifiable in tissues at the 72 h withdrawal period. [ABSTRACT FROM AUTHOR]

As a result of firing pulverized coal in thermal power plants, enormous amounts of fly ash (FA) are produced as industrial waste. The release into the atmosphere and storage of this industrial waste remains one of the major environmental problems that threaten human health by contributing to air, water, and soil pollution. The recovery and reuse of FA in the construction industry is the only economic solution to the existing problem. In this study, the potential radiological risk caused by the usage of FA in concrete and cement production as a main component and its storage in landfill sites was evaluated for people and works by estimating radiological parameters (activity concentration and alpha index, annual effective doses, and the corresponding excess lifetime cancer risks) based on activity concentrations of terrestrial radionuclides in FA. Also, the radiological risk to the workers working in the FA landfill site was evaluated using the Residual Radioactivity Onsite 7.2 code. The average activity concentrations of terrestrial radionuclides in FA samples from the Tunçbilek lignite coal-fired thermal power plant at Kütahya province of Turkey were measured as 417, 156 and 454 Bq kg−1 for 226Ra, 232Th and 40K, respectively. When using up to 35% by mass of FA in cement and concrete, the average values of the radiological parameters revealed that they were within the recommended safety limits. However, code estimations showed that a regular worker in FA storage would be exposed to a total effective dose rate greater than 3 mSv y−1. [ABSTRACT FROM AUTHOR]

Purpose: It has been known for many decades that radiation exposure of the developing embryo or fetus may cause two fundamentally different types of severe health effects: on the one hand, radiation may interfere with the normal intrauterine development, on the other hand, radiation may induce leukemia and cancer which become manifest in childhood. A large amount of epidemiological and experimental data has recently been presented which might be used to improve our understanding of underlying mechanisms and setting radiation protection standards. Yet, ecological studies in the populations exposed to increased levels of radiation in regions contaminated by radioactivity released from reactor accidents (Chernobyl, Fukushima) do not provide solid evidence which would contribute to this aim. On the other hand, well designed experimental studies demonstrated the multifactorial mechanisms which lead to different health effects after radiation exposure in utero. Conclusion: There is no convincing evidence, neither from epidemiological nor experimental data of the existence of a dose threshold for developmental defects after radiation exposure in utero. This must be taken into account in the revision of rules and regulations of radiation protection in medicine. [ABSTRACT FROM AUTHOR]

The main objective of this study is to measure the levels of radioactivity in certain construction material samples by quantifying the amounts of natural radionuclides (238U, 232Th, 40K) and 137Sc using gamma-ray spectroscopy with a High Purity Germanium (HPGe) detector. The selected samples were collected and examined to ascertain the mean quantities of radionuclides present. Subsequently, these findings were juxtaposed with global benchmarks for additional examination. The efficiency results unveiled a spectrum of concentrations for different radionuclides, encompassing 238U with a concentration range of (2.53 - 8.2 Bq/kg) and an average concentration of (4.93 Bq/kg). Similarly, the concentration of 232Th ranged from (0.655 - 3.45 Bq/kg), with an average concentration of (1.74 Bq/kg). The radionuclide 40k exhibited a concentration range of (3.5 -1500 Bq/kg), with an average value of (386.4 Bq/kg). Furthermore, 137Sc displayed a concentration range of (0.51-0.22 Bq/kg) with an average concentration of (0.53 Bq/kg). The radium equivalent concentration was determined to be (40.45 Bq/kg), whereas the absorbed dosage was measured at (18.67 nGy/h). The external hazard index (Hout) was measured to equal (0.11 mSv/y), whereas the internal hazard index (Hin) was determined to be (0.17 mSv/y). Furthermore, the annual equivalent effective dose (AEDEout) was calculated to be (0.09 mSv/year). The annual dosage of (AEDEin) was determined to be (0.02 mSv/year). The gamma radiation index, denoted as Iγ, was determined to be (0.28 Bq/kg). The study results imply that the amounts of radionuclides fall within the defined normal limits worldwide, indicating that the natural radioactivity levels are within the internationally acceptable range. Quantification of both natural and artificial radioactivity in specific building materials employed in constructing dwellings inside Salah Al-Din Governorate. A selection of seven distinct models was made. (Plaster, Bork, and Dust). The concentration of gamma-ray-emitting radionuclides in both the uranium-radium and thorium series, as well as 40K and 137Sc, was measured using a high-purity germanium (HpGe) detector. Subsequently, the spectrum underwent analysis for 3600 seconds. The concentrations of the radionuclides being investigated were determined to be as follows: The mean concentrations of 238U range from (2.53 - 8.2 Bq/kg), while for 232Th the range from (0.65 to 3.45 Bq/kg). The concentrations of potassium 40K range from (3.5 to 1500 Bq/kg), and for 137 Sc the range from 0.51 to 0.22 Bq/kg. [ABSTRACT FROM AUTHOR]

In the last decade, cases of radioactive isotope theft have been observed more frequently in Mexico, endangering human health, biodiversity, and the environment due to the risks of mishandling radioactive isotopes. The aim of this study was to analyze the theft of radioactive isotopes in Mexico in the period 2011–2023 from the perspective of green criminology through official data and radiological emergency bulletins. The results show that the most frequently stolen isotopes were 192Ir, 137Cs, and 131I in this study period, and it was also identified that the isotopes are stolen unintentionally, since it is the vehicles that transport them that are stolen, most of the time without knowing what they contain. It is concluded that the theft of radioactive isotopes in Mexico is a crime linked to vehicle theft, which in turn stems from the conditions of public insecurity but puts the health, safety and well-being of people, biodiversity, and the country's ecosystems at risk, so that institutional actions must be oriented considering the conditions of public insecurity to improve nuclear safety in the country. [ABSTRACT FROM AUTHOR]

The use of a Monte Carlo code in the assessment of residual radioactivity for decommissioning of a medical cyclotron facility requires a reasonable approximation to the facility's history of operations. A periodic irradiation scenario simulating the cyclotron's daily operation for radioisotope production is generally considered reasonable, but its implementation in the code's input file can be cumbersome because more than thousands of irradiation cycles must be modeled. In practice, two simplified scenarios with continuous irradiation are commonly used instead: (i) omitting the downtime between two irradiation periods and (ii) extending the irradiation duration across the entire operational lifespan of the facility, albeit with a reduced beam current to maintain workload consistency. A systematic comparison of residual radionuclide productions across various half-lives under these three scenarios was performed. This technical note presents the resulting correction factors for the two simplified continuous irradiation models, enhancing their applicability in estimating radioactive inventories under a range of circumstances. [ABSTRACT FROM AUTHOR]

Using gamma and alpha spectrometers, the radioactive isotopes 226Ra, 210Pb, 232Th, and 40K were determined in three sediment cores from the Tam Giang-Cau Hai (TG), Thi Nai (TN), and Nai (DN) lagoons, and radiation risk indices were computed. The radioactivity concentrations of 210Pb, 40K, 232Th, and 226Ra were 55.46 Bq/kg, 675.78 Bq/kg, 67.22 Bq/kg, and 34.15 Bq/kg, respectively. The Raeq, ADR, AEDE, Iγr, AUI, Hex, and AGDE indices were 182.31 Bq/kg, 84.46 nGy/h, 0.10 mSV/y, 1.35, 1, 18, 0.49, and 598.71 µSV/y, respectively; the values of 40K, 232Th, AEDE, ADR, Iγr, and AGDE were greater than the global average and UNSCEAR values. The radioactivity and radiation risk indices decreased in the order DN > TN > TG. [ABSTRACT FROM AUTHOR]

The occurrence of sand and dust storms (SDS) in Iran has raised many concerns about the possibility of environmental and public health hazards caused by dust particles and pollutants existed in these particles. Therefore, the purpose of this study was to investigate the possibility of contamination of surface soil, river sediments, and roadside deposits with radioactive materials, especially depleted uranium (DU) in the areas affected by SDS. The radioactive activity of the samples was measured by gamma spectroscopy with a high-purity germanium detector. The average activity concentrations of 226Ra, 232Th, and 40 K were 11.19, 8.05, and 76.05 Bq/kg. The average ratio of 238U/235U was 89 indicating the possibility of the presence of DU in the soil samples. The average values of Rm (the share of 235U in total uranium) and DUm were 0.55% (lower than natural uranium, 0.72) and 33% (indicating the presence of 33% DU on average in the samples). Based on 238U/226Ra activity, two samples (S11 and S12) should be considered as DU-contaminated. Almost the obtained results for all radiological risk indices showed lower values than the world average and the possibility of creating a low risk for working people, residents, visitors, and travelers passing through these areas. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess natural activity in soil to estimate potential radiological risks for the population. Given that soil is inherently radioactive and can reach hazardous levels, it is crucial to determine the activities of radionuclides such as Potassium-40 and Uranium-238 descendants at different depths and geographical positions. For this work, gamma spectrometry method was employed to analyze soil samples collected at three different positions in the Missour region. Each position was sampled at five different depths, spaced 5 cm apart, resulting in a total of 15 samples. The activity of Potassium-40 and Uranium238 descendants in the soil was accurately assessed using Lvis software, enabling the estimation of radiological doses. [ABSTRACT FROM AUTHOR]

Abstract This study evaluates the levels of natural radioactivity in sediment and water samples from Lake Victoria in Jinja, Uganda, with a focus on the radionuclides potassium-40 (40 K), radium-226 (226Ra), and thorium-232 (232Th). We investigated four distinct zones around the lake: fishing (Zone A), farming (Zone B), domestic/livestock (Zone C), and a control zone (Zone D). A total of 15 sediment samples and 15 water samples were collected and analyzed. Sediment samples were obtained using a gravity corer, with a maximum penetration depth of 50 cm. 40 K ranged from 170.479 to 524.883 Bqkg−1 across all zones, 226Ra ranges from 1.51 to 56.78 Bqkg−1 across all zones, and 232Th ranges from 18.18 to 73.10 Bqkg−1 across all zones. 40 K concentrations were highest in the farming zone, likely due to the use of nitrogen, phosphorus, and potassium (NPK) fertilizers. 226Ra and 232Th levels were also elevated in the farming zone, suggesting potential contributions from phosphate fertilizers. Absorbed dose rates varied across the zones, ranging from 28.33 to 58.17 nGyh-1. The measured absorbed dose rates across all zones were within the global average of 59 nGyh−1. The effective annual dose rate ranged from 0.35 to 0.91 mSvy−1 across all zones. Effective annual dose rates did not exceed the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended limit of 1 mSv y−1, indicating low risks to public health from sediment radioactivity. The external index was below the safety threshold, suggesting minimal health risks. In water samples, gross alpha and beta activity concentrations were analyzed. Zone B had the highest average alpha activity concentration (0.64 BqL−1) and beta activity concentration (0.72 BqL−1), while Zone A had the lowest for both alpha (0.16 BqL−1) and beta (0.25 BqL−1) activity concentrations. Gross beta activity was generally higher than gross alpha activity, reflecting potential anthropogenic influences. Most water samples were within the UNSCEAR recommended limits for drinking water quality, except in areas affected by agricultural runoff. This study demonstrates that while the sediments of Lake Victoria in Jinja, Uganda, exhibit varying levels of naturally occurring radionuclides influenced by farming practices, the overall radiation exposure remains within safe limits. Continuous monitoring and regulatory measures are essential to maintain these safety levels and mitigate potential risks from increasing agricultural activities.

There have been potential public health risks associated with the use of soil and rock from mining locations in North-Eastern Nigeria. This research evaluates the natural hazard parameters of soil and rock specimens obtained from mining locations in North-Eastern Nigeria, using grammar-ray spectroscopy. A total of twenty-eight samples were systematically gathered from Nahuta and Kashere locations. Through gamma spectrometry employing a NaI (TI) detector, the natural radioactivity levels of 238U, 232Th and 40K were determined for each sample. The findings indicated that the mean activity concentrations of 226Ra, 232Th, and 40K in Nahuta are 46.13±4.78 Bq/Kg, 34.10±3.02 Bq/Kg and 473.94±5.41 Bq/Kg for the soil samples respectively, and 32.91±0.49 Bq/Kg, 40.70±0.41 Bq/Kg, and 578.18±4.28 Bq/Kg for the rock samples respectively. The corresponding mean activity concentrations of 226Ra, 232Th, and 40K in Kashere are 17.99±4.18 Bq/Kg, 23.73±1.78Bq/Kg, and 191.65±3.15 Bq/Kg, for the soil samples, and 20.24±3.72 Bq/Kg, 29.09±1.78 Bq/Kg, and 148.36±3.15 Bq/Kg, for the rock samples respectively. An analysis of radiation risk parameters (D, AEDE, Raeq, Hex, Hin, AGDE, and ELCR) has been explored. While the samples from the Kashere region fall within the international recommended levels, elevated readings of certain radiation health parameters are observed in the Nahuta region, posing serious public health risks due to the utilization of the soil and rock from this area in construction activities.

Source term investigation is a critically important aspect of reactor decommissioning, particularly as the range of nuclides under consideration expands beyond the capabilities of existing analysis methods. In this study, we try to propose a methodology to indirectly determine the radioactivity of long-lived nuclides which are non-γ or low energy in various nuclear waste materials by measuring the radioactivity of 60Co. The critical point of this method is to establish relationship between some easy to measure (ETM) key nuclides, such as certain γ emitters (like 60Co), and the difficult to measure (DTM) nuclides to derive information for the DTM nuclides of interest. To begin, we calculate nuclide bulk densities of 55Fe, 60Co, 63Ni and 152Eu in nuclear waste materials. By constructing inversion matrices and analyzing the intensity matrices of characteristic γ lines emitted by 60Co, we can extract the radioactivity of non-γ radionuclides (55Fe, 63Ni, and 152Eu) present in the nuclear waste materials that are contained within a specific container. Furthermore, our methodology accounts for the influence of voids within the container, thereby ensuring the reliability and validity of the obtained results. This innovative approach offers a promising avenue for efficiently sorting nuclear waste.

ABSTRACTThe Unumherin community in Nigeria’s Niger Delta is home to coastal marine polluted zones, and this research examines the radioactivity distributions and biohazard in the coastal environment. The activity concentrations of 40K, 238U, 232Th, as well as the outdoor dose rate of contaminated coastlines were measured using a calibrated RS-125 Gamma-Spec and a NaI(Tl) gamma-detector. The laboratory examination of sediments, water, and fish from the same coastal region – Clarias gariepinus Pseudotropheus elongated Oreochromis niloticus and Stromateus fiatola – was combined with the in-situ observations of gamma dose rates. With a value of [Formula: see text], the hotspot at site 4 is shown by the geographic distribution of gamma dose rates. The findings showed that the activities of the primordial radionuclides varied, with average values for the sediments and water exceeding suggested limits. Similarly, the corresponding mean hazard indices mostly exceeds the allowable limits. The species specificity of the fish species accounts for the variation in the mean concentrations of 40K, 238U and 232Th. C. gariepinus, having accumulated higher concentrations of 40K and 238U, may be the first to elicit health hazards in the future if pollution continues unmonitored. Hence, continuous monitoring of the aquatic environment alongside is highly recommended.

The present work deals with identifying and determining the activity levels of naturally occurring radionuclides 226Ra and 232Th series, their decay products and 40K in chemical and organic fertilisers used in the Chattogram area, Bangladesh. A total of 39 samples collected from retail markets were investigated, out of which 28 are chemical fertilisers and the others are organic fertilisers. The average activity concentration of 226Ra and 232Th found in TSP fertiliser are 304.57 ± 36.0 and 19.1 ± 6.8 Bq kg−1 respectively and the average activity concentration of 40K in MOP fertiliser is found as 10,311.11 ± 1168 Bq kg−1. In the organic fertiliser samples, the mean concentration of 226Ra, 232Th and 40K are 17.35 ± 3.11, 7.20 ± 1.74 and 437.14 ± 42.58 Bq kg−1, respectively. The mean absorbed dose rates were measured after the end of our experiment, and the value was found to be 91.39 nGy h−1. The combined (indoor + outdoor) annual effective dose equivalent was also estimated as 0.322 mSv year−1. The mean radium equivalent activity found to be 190.15 ± 26.74 Bq kg−1 is well below the recommended level of 370 Bq kg1. The internal hazard index, external hazard index, and radioactivity level index of the investigated fertiliser samples were found as 0.56 ± 0.034, 0.54 ± 0.08 and 0.69 ± 0.10, respectively. From the calculated hazard parameters, the excess lifetime cancer risk (ELCR) was found to be higher than the world average in most of the chemical fertilisers except in DAP and BOR, while the organic fertilisers show lower than the world average. The obtained results reveal that there are no significant radiation hazards due to natural radionuclides of the fertiliser samples in the studied area, but the higher concentration of 40K in MOP suggests strengthening the regulatory work. Overall, this study highly recommends the use of organic fertilisers, as these kinds have hazard parameters lower than the recommended levels. [ABSTRACT FROM AUTHOR]

Natural radionuclide activity concentrations were measured in ceramic, gypsum, and brick samples from manufacturers, dealers, and construction sites in and around Addis Ababa, Ethiopia, using an HPGe detector. The study's main aim is to assess the activity concentration of building materials and their health impacts. Average activity concentrations (Bq kg−1) for 226Ra in ceramic, gypsum, and brick samples were obtained as 81 ± 1, 1.34 ± 0.17, and 39 ± 1, respectively. In ceramic, gypsum, and brick, concentrations of 232Th were obtained as 166 ± 4, 0.68 ± 0.18, and 103 ± 3, respectively, while concentrations of 40K were found to be 755 ± 16,15 ± 1, and 921 ± 24, respectively. Some of the materials that were tested, especially the ceramic samples, had slightly higher concentrations of radionuclides in comparison to other analysed samples. In all samples except ceramic, Raeq was < 370 Bq kg−1, which is the recommended limiting dose for bulk medium. Furthermore, the corresponding radiological parameters, such as absorbed dose, annual effective dose equivalent, excess lifetime cancer risk (ELCR), internal (Hin) and external (Hex) hazard indexes, gamma index (Iγ), and alpha index (Iα) were determined. The ELCR average values in this study are slightly higher than the global average, and the indoor and outdoor absorbed dose rates are greater than the limiting criteria of 84 and 59 n Gy h−1, respectively. Therefore, it is important to assess the potential radiation risk of ceramic samples, which should be used in a controlled manner to reduce gamma exposure to residents. Finally, the computed data could be used as a baseline to assess any future radiation exposure from construction materials. [ABSTRACT FROM AUTHOR]