Search Results (335)

Croatian agricultural legislation acknowledges the significance of radionuclides as pollutants in agricultural lands; however, it lacks specific thresholds or reference values for contamination levels, in contrast to other contaminants. This absence highlights the necessity for a comprehensive assessment of radionuclides across various agricultural systems in Croatia. This study investigates the transfer of radionuclides ¹³⁷Cs and ⁴⁰K from soil to agricultural crops throughout Croatia and estimates the consequent annual ingestion dose for the population. The samples collected comprised food crops and animal feed, with corresponding soil samples analyzed to calculate transfer factors. Activity concentrations of ¹³⁷Cs exhibited regional and crop-type variability, reflecting the uneven distribution of fallout and differing soil properties. Transfer factors were found to range from 0.003 to 0.06 for ¹³⁷Cs and from 0.15 to 3.1 for ⁴⁰K, with the highest uptake occurring in kidney beans. The total estimated annual effective ingestion dose was calculated to be a maximum of 0.748 mSv/year for children aged 2–7, predominantly attributable to ⁴⁰K. Given the homeostatic regulation of potassium in the human body, the dose associated with ¹³⁷Cs poses a more significant radiological concern. These findings underscore the need for radionuclide-specific agricultural legislation in Croatia and offer a baseline for recommending reference values and informing future regulations regarding agricultural soil contamination. Full article

This study evaluated the activity concentrations of radionuclides in honey, bee pollen, bee bread, and propolis from multiple regions in Poland (Europe) to assess the levels of radiological contamination and their implications for public health. Furthermore, the work considers the use of bee products as bioindicators of the state of environmental contamination with radionuclides. The apiaries from which the samples were collected were selected in eight provinces in Poland, and are also complemented by reference data from soil contamination monitoring. Radionuclide measurements included both natural (e.g., ⁴⁰K, ²²⁶Ra) and anthropogenic isotopes (e.g., ¹³⁷Cs). The results show that although the overall activity concentrations were generally low, certain locations exhibited elevated levels of ¹³⁷Cs in bee products, likely reflecting historical deposition in soils. Propolis was best correlated with ¹³⁷Cs deposited in soil compared to the other products studied. The patterns observed substantiate the hypothesis that bee products, predominantly propolis, accurately reflect local radiological conditions, thereby providing a practical and non-intrusive approach to monitoring radionuclide contamination and informing risk management strategies. An assessment of potential health risks indicates that the effective dose is safe and ranges from 0.02 to 10.3 µSv per year, depending on the type of product and consumption. Full article

Bis(2-ethylhexyl) phosphate (P204) is widely used in extraction processes in the nuclear and rare earth industries. However, its high solubility in water results in high levels of total organic carbon and phosphorus in aqueous environments, and may also lead to radioactive contamination when it is used to combine with radionuclides. In this paper, we characterized a coconut shell activated carbon (CSAC) and a coal-based activated carbon (CBAC) for the adsorption of P204 and then evaluated their adsorption performance through batch and column experiments. The results found that, except for the main carbon matrix, CSAC and CBAC carried rich oxygen-containing functional groups and a small amount of inorganic substances. Both adsorbents had porous structures with pore diameters less than 4 nm. CSAC and CBAC showed good removal performance for P204 under low pH conditions, with removal efficiencies significantly higher than those of commonly used adsorption resins (XAD-4 and IRA900). The adsorption kinetics of P204 conformed to the pseudo-second-order kinetic model, and the adsorption isotherms conformed to the Langmuir model, indicating a monolayer chemical reaction mechanism. Both adsorbents exhibited strong anti-interference capabilities; their adsorption performance for P204 did not change greatly with the ambient temperature or the concentrations of common interfering ions. Column experiments demonstrated that CSAC could effectively fix dissolved P204 with a removal efficiency exceeding 90%. The fixed P204 could be desorbed with acetone. The findings provide an effective method for the recovery of P204 and the regeneration of spent activated carbon, which shows promise for practical applications in the future. Full article

In the decommissioning of nuclear facilities, activated steel often contains radionuclides such as ⁵⁵Fe and ⁶³Ni, which are categorized as hard-to-measure due to their emission of only low-energy beta particles or X-rays. In samples exhibiting very low radioactivity, close to background levels, a large quantity of steel must undergo extensive physical and chemical processing to achieve the Minimum Detectable Activity Concentration (MDC) necessary for clearance, recycling, or reuse. Italian regulations set particularly stringent clearance levels for these radionuclides (1 Bq/g for both ⁵⁵Fe and ⁶³Ni), significantly lower than those specified in the EU Directive 2013/59 (1000 Bq/g for ⁵⁵Fe and 100 Bq/g for ⁶³Ni). Additionally, Italian authorities may enforce even stricter limits depending on specific circumstances. The analytical challenge is compounded by the presence of large amounts of non-radioactive Fe and Ni, which can cause color quenching, further extending analysis times. This study presents a reliable and optimized method for the quantitative determination of ⁵⁵Fe and ⁶³Ni in steel samples with activity levels approaching regulatory thresholds. The methodology was specifically developed and applied to steel from the Frascati Tokamak Upgrade (FTU) facility, under decommissioning by ENEA. The optimization process demonstrated that achieving the required MDCs necessitates acquisition times of approximately 5 days for ⁵⁵Fe and 6 h for ⁶³Ni, ensuring compliance with stringent regulatory requirements and supporting efficient laboratory workflows. Full article

Between approximately 725 and 518 Ma, a suite of specialized felsic plutons and granitic stocks were emplaced across the Arabian Shield, many of which are now recognized as highly mineralized prospects enriched in rare earth elements (REEs), rare metals, and radioactive elements bearing mineralizations. The current investigation focused on the radiological and geochemical characterization of naturally occurring radionuclides, specifically ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K, within three strategically selected granitic prospects, namely, J. Tawlah albite granite (TW), J. Hamra (HM), and J. Abu Al Dod alkali feldspar syenite and granites (AD). Concerning the radioactivity levels of the investigated granitic stocks, specifically the activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K, the measured average values demonstrate significant variability across the TW, HM, and AD stocks. The average ²³⁸U concentrations are 195 (SD = 38.7), 88.66 (SD = 25.6), and 214.3 (SD = 140.8) Bq/kg for TW, HM, and AD granitic stocks, respectively. Corresponding ²²⁶Ra levels are recorded at 172.4 (SD = 34.6), 75.62 (SD = 25.9), and 198.4 (SD = 139.5) Bq/kg. For ²³²Th, the concentrations are markedly elevated in TW at 5453.8 (SD = 2182.9) Bq/kg, compared to 77.16 (SD = 27.02) and 160.2 (SD = 103.8) Bq/kg in HM and AD granitic stocks, respectively. Meanwhile, ⁴⁰K levels are reported at 1670 (SD = 535.9), 2846.2 (SD = 249.9), and 3225 (SD = 222.3) Bq/kg for TW, HM, and AD granitic plutons, respectively. Notably, these values exceed the global average background levels, indicating an anomalous enrichment of the studied granitic occurrences. The mean radiological hazard indices for each granitic unit generally exceed global benchmarks, except for AEDE_out in the HM and AD stocks, which remain below international limits. The geochemical disparities observed are indicative of post-magmatic alteration processes, as substantiated by the interpretation of remote sensing datasets. In light of the significant radiological burden presented by these granitic stocks, it is essential to implement a rigorous precautionary framework for any future mining. These materials must be categorically excluded from uses that entail direct human exposure, especially in residential construction or infrastructure projects. Full article

Wild-growing edible mushrooms are known to bioaccumulate radionuclides from their environment, particularly the natural isotope potassium-40 (⁴⁰K) and anthropogenic cesium-137 (¹³⁷Cs). However, region-specific data for commercially relevant species in north-eastern Poland remain limited, despite the cultural and economic importance of mushroom foraging and export. This study aimed to assess the radiological safety of wild mushrooms intended for human consumption, with particular attention to regulatory compliance and potential exposure levels. In this study, 230 mushroom samples representing 19 wild edible species were analyzed using gamma spectrometry, alongside composite soil samples collected from corresponding foraging sites. The activity concentration of ¹³⁷Cs in mushrooms ranged from 0.94 to 159.0 Bq/kg fresh mass (f.m.), and that of ⁴⁰K from 64.4 to 150.2 Bq/kg f.m. None of the samples exceeded the regulatory limit of 1250 Bq/kg f.m. for ¹³⁷Cs. The highest estimated annual effective dose was 2.32 µSv from ¹³⁷Cs and 0.93 µSv from ⁴⁰K, with no exceedance of regulatory limits observed in any sample. A strong positive correlation was observed between ¹³⁷Cs activity in soil and mushroom dry mass (Spearman’s Rho = 0.81, p = 0.042), supporting predictable transfer patterns. Additionally, the implications of mushroom drying were assessed considering Council Regulation (Euratom) 2016/52, which mandates radionuclide levels in dried products be evaluated based on their reconstituted form. After such adjustment, even the most contaminated dried samples were found to comply with food safety limits. These findings confirm the radiological safety of wild mushrooms from north-eastern Poland and contribute novel data for a region with limited prior monitoring, in the context of current food safety regulations. Full article

This review addresses the intake, distribution, and bioaccumulation of the short-lived radionuclides ⁹⁵Zr, ⁹⁵Nb, ¹⁰³Ru, and ¹⁰⁶Ru in aquatic ecosystems before and after the 1986 accident at the Chornobyl Nuclear Power Plant. Particular attention is given to a detailed analysis of these processes in fish belonging to different ecological groups, as well as in their various organs and tissues. Observational data indicate that ⁹⁵Zr and ⁹⁵Nb predominantly accumulate in external organs, with comparatively lower concentrations observed in internal organs. In contrast, ¹⁰³Ru and ¹⁰⁶Ru exhibit higher bioavailability and a marked tendency to accumulate in internal tissues. A notable feature of ¹⁰⁶Ru is its gradual increase in muscle tissue over time following the accident. These findings are critical for advancing our understanding and assessment of the ecological status of contaminated aquatic environments, for predicting the long-term impacts of accidental radionuclide release, and for informing strategies related to environmental monitoring and the safe exploitation of aquatic biological resources. Full article

Radionuclides and heavy metals pose potential risks to marine ecosystems and human health. Daya Bay, the site of China’s first commercial nuclear power plant, has experienced significant anthropogenic impacts, yet the extent of radionuclide and heavy metal contamination remains unclear. Nineteen surface sediment samples were collected in January 2024 and analyzed for natural (²¹⁰Pb, ²²⁸Th, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K) and anthropogenic (¹³⁷Cs) radionuclides, heavy metals (Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As), grain size, and total organic carbon (TOC). The surface sediments of Daya Bay were predominantly fine-grained, with TOC levels ranging from 0.41% to 1.83%, influenced significantly by riverine input from the Dan’ao River. Natural radionuclides exhibited distinct spatial patterns: ²¹⁰Pb and ²²⁸Th activity levels were higher in fine-grained sediments, and correlated with TOC, indicating adsorption and sedimentation controls. In contrast, anthropogenic ¹³⁷Cs activity was low and showed no significant impact from the nuclear power plant. Notably, the absence in the samples of key anthropogenic radionuclides typically associated with nuclear power plant operations further confirmed the negligible impact of the power plant on local sediment contamination. The results indicated that the baseline levels of both natural and anthropogenic radionuclides and heavy metals were predominantly influenced by natural processes and local anthropogenic activities rather than the operation of the nuclear power plant. This study establishes critical baselines for radioactivity and heavy metals in Daya Bay, underscoring effective pollution control measures and the resilience of local ecosystems despite anthropogenic pressures. Full article

This study was realized in the frame of an IAEA Coordinated Research Project for the evaluation of sediment dynamics, applying in-situ radiometric methods accompanied with a theoretical model. The in-situ methods were validated using lab-based high-resolution gamma-ray spectrometry. Sediment dynamics assessments were performed based on the measured and mapped activity concentrations of specific ²³⁸U progenies (²¹⁴Bi or ²¹⁴Pb), ²³²Th progenies (²⁰⁸Tl and ²²⁸Ac), and ⁴⁰K along the shoreline of the beach. The maps of the activity concentrations of natural radionuclides were produced rapidly using software tools (R language v4.5). The sediment dynamics of the studied area were also investigated through numerical simulations, applying an open source model considering land–sea interactions and meteorological conditions and the corresponding sediment processes. The assessments, which were conducted utilizing the detailed data from the natural radioactivity maps, were validated by the simulation results, since both were found to be in agreement. Generally, it was confirmed that the distribution of radionuclides reflects the selective transport processes of sediments, which are related to the corresponding processes that occur in the study area. Legrena Beach in Attica, Greece, served as a pilot area for the comparative analysis of methods and demonstration of their relevance and applicability for studying coastal processes. Full article

Multidrug resistance (MDR) represents a major obstacle to successful chemotherapy and, due to overlapping defense mechanisms, such as enhanced DNA repair and the evasion of apoptosis, can also be associated with radioresistance. In this study, we investigated whether MDR breast cancer cells (MCF-7/CMF) exhibit reduced susceptibility to radiation-induced DNA fragmentation compared to their non-resistant parental counterpart (MCF-7). Using a nucleosome-based ELISA, we quantified the chromatin fragmentation in MCF-7 and MCF-7/CMF cells following their exposure to four radiopharmaceuticals: [^99mTc]pertechnetate, [¹³¹I]NaI (sodium iodide), [¹²⁵I]NaI, and the DNA-incorporating compound [¹²⁵I]iododeoxyuridine ([¹²⁵I]IdU). Each radioactive preparation was assessed across a range of activity concentrations, using a two-way ANOVA. For [^99mTc]pertechnetate and [¹³¹I]NaI, significantly higher DNA fragmentation was observed in the sensitive cell line, whereas [¹²⁵I]NaI showed no significant difference between the two phenotypes. In contrast to the other radiopharmaceuticals, [¹²⁵I]IdU induced greater fragmentation in resistant cells. This finding was supported by the statistical analysis (a 63.7% increase) and visualized in the corresponding dose–response plots. These results highlight the critical role of the intranuclear enrichment of Auger emitters and support further development of radiopharmaceuticals in accordance with this principle. Our data suggest that radiotoxicity is governed not by linear energy transfer (LET) alone, but, fundamentally, by the spatial proximity of the radionuclide to the DNA. Targeting tumor cell DNA with precision radiotherapeutics may, therefore, offer a rational strategy to overcome MDR in breast cancer. Full article

Nowadays, much attention has been paid to the study of the specific activity of radionuclides on the surface of glaciers. This work is devoted to the study of specific activity of natural (K-40, U-235, U-238, Th-232) and anthropogenic (Cs-137) radionuclides in cryoconites of glaciers of the Central Caucasus. The work shows that the activity of the investigated natural radionuclides in the cryoconites of the glaciers we studied is comparable to data from Arctic glaciers, somewhat lower than on Mount Elbrus and Transcaucasia, and significantly lower than on Alpine glaciers. The study revealed that the glaciers of the Central Caucasus (Tsey, Skazka, and Bezengi) exhibit low values of specific activity of anthropogenic radionuclide Cs-137 and average from 0.51 Bq/kg (Bezengi) to 2.61 Bq/kg (Skazka). On the contrary, high and very high concentrations of this radionuclide were revealed in cryoconites of glaciers from other regions, especially in the Alps, the Arctic, and Transcaucasia. Thus, our data confirm the results of previous studies conducted on glaciers of the Central Caucasus, which indicated that the activity of natural radionuclides in cryoconites of glaciers of the Central Caucasus is comparable to the world average values, while the anthropogenic radionuclide Cs-137 is much lower. Full article

Nuclear accident-derived radionuclide dispersion poses critical challenges to marine ecological sustainability and human–ocean interdependence. While existing studies focus on hydrodynamic modeling of pollutant transport, the link between nuclear safety and sustainable ocean governance remains underexplored. This study investigates radionuclide diffusion patterns in semi-enclosed bays using a high-resolution coupled hydrodynamic particle-tracking model, explicitly addressing threats to marine ecosystem stability and coastal socioeconomic resilience. Simulations revealed that tidal oscillations and topographic constraints prolong pollutant retention by 40% compared to open seas, elevating local concentration peaks by 2–3× and intensifying bioaccumulation risks in benthic organisms. These findings directly inform sustainable marine resource management: the identified high-risk zones enable targeted monitoring of fishery resources, while diffusion pathways guide coastal zoning policies to decouple economic activities from contamination hotspots. Compared to Fukushima’s open-ocean dispersion models, our framework uniquely quantifies how semi-enclosed geomorphology exacerbates localized ecological degradation, providing actionable metrics for balancing nuclear energy development with UN Sustainable Development Goals (SDGs) 14 and 3. By integrating hydrodynamic specificity with ecosystem vulnerability thresholds, this work advances science-based protocols for sustainable nuclear facility siting and marine spatial planning. Full article

The combustion of hard coal and lignite in power and combined heat and power plants generates significant amounts of coal fly ash (CFA), a waste material with variable properties. CFA naturally contains radionuclides, specifically naturally occurring radioactive materials (NORMs), which pose potential radiological risks to the environment and human health during their storage and utilization, including their incorporation into building materials. Although global research on the radionuclide content in CFA is available, there is a clear gap in detailed and current data specific to Central and Eastern Europe and notably, a lack of a systematic analysis investigating the influence of installed power plant capacity on the concentration profile of these radionuclides in the generated ash. This study aimed to fill this gap and provide crucial data for the Polish energy and environmental context. The objective was to evaluate the concentrations of selected radionuclides (²³²Th, ²²⁶Ra, and ⁴⁰K) in coal fly ash samples collected between 2020 and 2023 from 19 Polish power and combined heat and power plants with varying capacities (categorized into four groups: S1–S4) and to assess the associated radiological risk. Radionuclide concentrations were determined using gamma spectrometry, and differences between groups were analyzed using non-parametric statistical methods, including PERMANOVA. The results demonstrated that plant capacity has a statistically significant influence on the concentration profiles of thorium and potassium but not radium. Calculated radiological hazard assessment factors (Ra_eq, H_ex, H_in, IAED) revealed that although most samples fall near regulatory limits (e.g., 370 Bq kg⁻¹ for Ra_eq), some exceed these limits, particularly in groups S1 (plants with a capacity less than 300 MW) and S4 (plants with a capacity higher than 300 MW). It was also found that the frequency of exceeding the annual effective dose limits (IAEDs) showed an increasing trend with the increasing installed capacity of the facility. These findings underscore the importance of plant capacity as a key factor to consider in the radiological risk assessment associated with coal fly ash. This study’s outcomes are crucial for informing environmental risk management strategies, guiding safe waste processing practices, and shaping environmental policies within the energy sector in Central and Eastern European countries, including Poland. Full article

Background: The ⁸⁹Zr radioisotope is increasingly vital in positron emission tomography (PET), especially immuno-PET, due to its long half-life of 78.4 h, allowing extended tracking of biological processes. This makes it particularly suitable for researching medicines with slow pharmacokinetics and enhances the precision of molecular imaging, especially in oncology. Despite zirconium’s potential for skeletal accumulation, effective chelation with agents like deferoxamine (DFO) enables high-resolution imaging of antigen-specific tumours, such as HER2-positive breast cancer, offering insights into tumour biology and treatment response. Methods: ⁸⁹Zr was produced at the ACSI TR-19 cyclotron via ⁸⁹Y(p,n)⁸⁹Zr reaction. Natural yttrium foils (250 μm) were irradiated with 12.9 MeV protons on target, with 100 μA·h. An HER2-targeting affibody was synthesized and conjugated with p-NCS-Bz-DFO (1:4 mass ratio) at 37 °C for 60 min (pH 9.2 ± 0.2), then purified on a PD-10 column. Radiolabelling was performed with [⁸⁹Zr]Zr-oxalate at pH ranging from 7.0 to 9.0, with concentrations from 110 to 460 MBq/mL. Results: Final activity reached 2.95 ± 0.31 GBq/batch (EOB corrected), with ≥ 99.9% radionuclide and ≥95% radiochemical purities. The anti-HER2 affibody was successfully radiolabelled with ⁸⁹Zr, resulting in a radiochemical purity of over 85% with molar activity of 26.5 ± 4.4 and 11.45 MBq/nmol at pH 7.0–7.5. In vitro tests on BT-474 and MCF-7 cell lines confirmed high uptake in HER2-positive cells, validating specificity and stability. Conclusions: The successful synthesis and labelling of the [⁸⁹Zr]Zr-p-NCS-Bz-DFO-anti-HER2 affibody are promising achievements for its further application in targeted immuno-PET imaging for HER2-positive malignancies. Further in vivo studies are needed to support its clinical translation. Full article

The Iberian Pyrite Belt (IPB) contains the world’s largest massive sulfide deposit, and, due to extensive mining developed during the last 200 years, large amounts of mining waste have been abandoned in this area, with roasted pyrite ash being the focus of this study. Polymetallic mining is also classified as a NORM (naturally occurring radioactive material) activity, thus the main objective of this work was to develop a radiological and physicochemical characterization of this waste (mineral phases, elemental and radionuclide concentrations) in order to perform a valorization diagnosis of this material. The composition of this waste strongly depends on its origin (mine), and is mainly formed by iron oxides (hematite, Fe₂O₃) and heavy metals and metalloids such as As, Pb, Zn, and Cu, in levels 2–4 orders of magnitude higher than those of undisturbed soils, depending on each particular element. However, the average natural radionuclide levels are similar to those of unperturbed soils (around 30 Bqkg⁻¹ of ²³⁸U-series, 50 Bqkg⁻¹ of ²³²Th, and 70 Bqkg⁻¹ for ⁴⁰K), thus they are below the limits established by European Union regulations to require radiological control during their future valorization. As the main potential applications of roasted pyrite ash, the valorization diagnosis indicates that it can be used as a source of Fe (FeCl₃ or FeSO₄), or an additive in the manufacturing of cements, pigments, etc. Full article