Journal of environmental radioactivity最新文献

{"title":"Functionalized metal organic frameworks for thorium (IV) adsorption: Mechanisms, speciation, and practical challenges","authors":"Kiruthika Manivannan,&nbsp;Meenakshi Sundaram Muthuraman","doi":"10.1016/j.jenvrad.2026.108116","DOIUrl":"10.1016/j.jenvrad.2026.108116","url":null,"abstract":"<div><div>Functionalized metal-organic frameworks (MOFs) have emerged as a promising material for Th(IV) removal from nuclear wastewater and rare earth processing effluents because of their tunable pore structures and binding environments. In these systems, the adsorption behaviour of Th(IV) is strongly influenced by hydrolysis, colloidal speciation, and competing ions, which complicate mechanistic interpretation and often limit practical separation performance. This review critically evaluates recent advances in the functionalized MOFs for Th(IV) capture by correlating aqueous thorium speciation with reported adsorption mechanisms, framework functionalization strategies, and operational performance. Pre-synthetic functionalization, post-synthetic functionalization, and defect engineering are analysed with respect to their influence on adsorption capacity, selectivity, regeneration, and framework stability. The reliability of proposed adsorption mechanisms is critically evaluated using spectroscopic and computational approaches, including EXAFS, XPS, and DFT analyses. The review highlights that adsorption capacities alone cannot explain Th(IV) uptake without simultaneous consideration of aqueous speciation, coordination environment, and competing adsorption pathways. Current limitations in the field include the absence of standardized testing protocols, limited evaluation under realistic wastewater conditions, insufficient continuous-flow and column studies, and the poor understanding of radiation-induced framework degradation and self-irradiation effects. In addition, techno-economic challenges associated with solvent-intensive synthesis, material shaping, regeneration chemistry, and scale-up feasibility are critically discussed. Future research should prioritize the integration of thorium speciation analysis, rigorous mechanistic validation, radiation stability assessment, and scalable process design to improve the practical applicability of MOF-based separation systems.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108116"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148591453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term distribution of radiocarbon in the Pacific Ocean within prevailing climate change","authors":"Jakub Kaizer","doi":"10.1016/j.jenvrad.2026.108113","DOIUrl":"10.1016/j.jenvrad.2026.108113","url":null,"abstract":"<div><div>Many studies have been already published documenting that prevailing global warming and climate change are affecting the world ocean, with some of them suggesting the Pacific Ocean being one of the most impacted basins. Among others, the physical state of the ocean can be derived from the distribution of its constituents, e.g., radionuclides with suitable characteristics. Radiocarbon (¹⁴C) was used in the past as a tracer for studying various oceanic processes such as air-sea gas exchange and thermocline ventilation. A complex image about the distribution of radiocarbon in the form of dissolved inorganic carbon (DIC) in the Pacific Ocean between 1990s and 2010s is described in the current study. Except for the northeastern part, observed accelerating decrease of a radiocarbon signal (Δ¹⁴C) in the surface seawater was quantified between 3.5 ± 0.3 and 3.9 ± 0.3‰ y⁻¹ on decadal timescale. Several factors contributing to the alteration of distribution, including fossil fuel combustion leading to Suess effect, inverted air-sea exchange of ¹⁴CO₂, and shifted ocean circulation and ventilation, were discussed as possible influences. The change was also visible for the upper mixed layer whose ¹⁴C concentration vertical profile showed fewer local maxima and was extended into greater depths, in parallel with generally higher mean penetration depth (MPD) of bomb fraction, which may be related to increasing stratification in the Pacific Ocean. The impact of environmental conditions within climate change was mainly noticeable in upper layers which is supported by a shift in the bomb radiocarbon inventories distribution in the eastern Pacific Ocean after 2000s, dominantly accumulated at the depth above 1 km.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108113"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in radioisotope geochronology for quaternary environmental and paleoclimate reconstruction","authors":"Azhagu Madhavan Sivalingam","doi":"10.1016/j.jenvrad.2026.108114","DOIUrl":"10.1016/j.jenvrad.2026.108114","url":null,"abstract":"<div><div>Reliable chronological frameworks are fundamental for reconstructing Quaternary environmental change, paleoclimate evolution, landscape development, and human history. Recent advances in radioisotope geochronology have substantially improved the accuracy, precision, and temporal resolution of dating across diverse geological and environmental archives. This review synthesizes developments in major Quaternary dating methods radiocarbon (14C), lead-210 (210 Pb), cesium-137 (137Cs), uranium-series, potassium–argon (K–Ar), argon–argon (40Ar/39Ar), and cosmogenic radionuclide techniques (10Be, 26Al, 36Cl, 81Kr) and highlights emerging analytical technologies including accelerator mass spectrometry, multi-collector ICP-MS, atom trap trace analysis, Bayesian age–depth modelling, and integrated multi-proxy approaches. Applications spanning terrestrial, marine, lacustrine, archaeological, and glacial settings demonstrate the value of combining complementary methods to build robust chronologies for sedimentation, tectonics, landscape evolution, paleoclimate reconstruction, and groundwater studies. Improvements in calibration datasets, uncertainty quantification, computational modelling, and high-resolution analytics have expanded the applicability of radioisotope geochronology to more complex systems. Persistent challenges contamination, open-system behaviour, reservoir effects, inheritance, and post-depositional alteration necessitate rigorous sample selection and methodological validation. We recommend prioritizing standardized analytical protocols, enhanced calibration frameworks, interdisciplinary integration, and adoption of machine-learning-assisted chronological modelling to further improve precision and reproducibility. Continued innovation in radioisotope geochronology promises more reliable chronological frameworks for investigating Quaternary environmental change and for reconstructing Earth's climatic, geological, and ecological conservation.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108114"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An upper limit on anthropogenic 81Kr in the atmosphere","authors":"Hao Li,&nbsp;W. Jiang,&nbsp;Z.-T. Lu,&nbsp;G.M. Yang,&nbsp;M.J. Zhang","doi":"10.1016/j.jenvrad.2026.108121","DOIUrl":"10.1016/j.jenvrad.2026.108121","url":null,"abstract":"<div><div>The cosmogenic radionuclide ⁸¹Kr (half-life 229 ka) is widely used to date groundwater and ice on 10⁴–10⁶ year timescales. Anthropogenic nuclear activities can lead to an increase of ⁸¹Kr in the atmosphere, but this contribution has not been tightly constrained experimentally. We report a precise measurement of the anthropogenic contribution using Atom Trap Trace Analysis (ATTA). A pre-nuclear atmospheric krypton sample collected in the 1940s was measured alongside a present-day atmospheric sample, acquiring over one million ⁸¹Kr atom counts for each sample. Given the measured difference of δ = (0.09 ± 0.14)% and after correcting for the cross-sample contamination, we obtain an upper limit of 0.43% (90% confidence level) for the anthropogenic contribution, validating the stability of the atmospheric ⁸¹Kr baseline for high-precision dating applications.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108121"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148648619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"137Cs in glacial meltwater on King George Island, maritime Antarctica","authors":"Michał Saniewski,&nbsp;Katarzyna Fudala,&nbsp;Robert Bialik,&nbsp;Bartłomiej Kola,&nbsp;Dominika Saniewska","doi":"10.1016/j.jenvrad.2026.108110","DOIUrl":"10.1016/j.jenvrad.2026.108110","url":null,"abstract":"<div><div>Glacierised catchments in maritime Antarctica can retain deposited atmospheric ¹³⁷Cs and remobilize it during seasonal melting. ¹³⁷Cs activity was determined in meltwater from 12 glacier outlets on King George Island (South Shetland Islands) during the austral melt season using ammonium phosphomolybdate (AMP) preconcentration and gamma spectrometry. Activities were very low: six outlets were below the detection limit (&lt;0.08-0.09 Bq m⁻³), whereas detectable values ranged from 0.12 ± 0.07 to 0.37 ± 0.07 Bq m⁻³. Suspended sediment was recovered from three visibly turbid outlets and analysed separately. Sediment-associated ¹³⁷Cs was low and heterogeneous among grain-size fractions, with the highest activity measured in the &lt;0.63 mm fraction from Penderecki Glacier (1.21 ± 0.31 Bq kg⁻¹). In sediment-rich outlets, the particulate fraction contributed substantially to total ¹³⁷Cs activity per unit volume of runoff, indicating that suspended material can act as a local carrier of fallout-derived ¹³⁷Cs.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108110"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migration mechanisms of Cs, U(VI), and Th(IV) in granite-filled fractures under competitive sorption conditions: A kinetic analysis integrating transport and desorption dynamics","authors":"Jianzheng Zang,&nbsp;Guorun Jiang,&nbsp;Haibo Yao,&nbsp;Yu Wang,&nbsp;Yan Liu,&nbsp;Hui Xu","doi":"10.1016/j.jenvrad.2026.108115","DOIUrl":"10.1016/j.jenvrad.2026.108115","url":null,"abstract":"<div><div>Accurate prediction of co-transport of multiple radionuclides within geological barriers remains a core challenge in the long-term safety assessment of high-level radioactive waste (HLW) repositories. This study investigates the co-transport of three representative nuclides—Cs, U(VI), and Th(IV)—through granite-filled single fracture, integrating breakthrough experiments with sequential desorption tests to establish a kinetic framework for their transport-desorption process. A three-site nonequilibrium kinetic model was applied to inversely simulate breakthrough curves, yielding quantitative retardation factors, sorption site distributions, and desorption rate constants for each nuclide. Results demonstrate that Cs migration is governed by reversible ion exchange coupled with interlayer diffusion, exhibiting a “high-retardation–high-recovery” signature (retardation factor = 1.77–2.64; recovery = 87.4–97.9%). U(VI) transport is dominated by energetically heterogeneous surface complexation, with occupation of strong-binding sites kinetically controlled by solid-liquid contact time; the ratio of fast-to-slow desorption rate constants during acid elution (<span><math><mrow><msub><mi>k</mi><mn>1</mn></msub></mrow></math></span>/ <span><math><msub><mi>k</mi><mrow><mn>2</mn><mspace></mspace></mrow></msub></math></span> ≈ 86–384) directly reflects site energy heterogeneity. Th(IV) retention is controlled by contact time-dependent surface precipitation, manifesting extreme flow velocity sensitivity (recovery = 57.4–93.4%) and pronounced irreversibility. In the ternary system, the distribution of U(VI) between strong- and weak-binding sites varies concurrently with Th(IV) interfacial speciation transitions (precipitate versus adsorbed phase), whereas Cs migration remains relatively unaffected owing to the spatial and chemical isolation of its primary sorption domain (interlayer sites of phyllosilicates). The coupled transport-desorption kinetic framework established herein, together with the quantified parameters and mechanistic insights, provides critical experimental constraints for developing nonequilibrium reactive transport models capable of predicting multicomponent radionuclide migration in fractured geological media.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108115"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148562299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geant4-based assessment of indoor radiation exposure in Saudi dwellings","authors":"F. Gharbi","doi":"10.1016/j.jenvrad.2026.108112","DOIUrl":"10.1016/j.jenvrad.2026.108112","url":null,"abstract":"<div><div>This study presents a Geant4-based Monte Carlo framework for assessing indoor gamma radiation in Saudi residential environments. Specific absorbed dose rate conversion factors in air (nGy h⁻¹ per Bq kg⁻¹) were calculated using Geant4 simulations for realistic Saudi room geometries, considering gamma emissions from the ²³⁸U and ²³² Th day series and from ⁴⁰K. These conversion factors were then applied to experimentally measured activity concentrations of Saudi building materials compiled from the literature to evaluate absorbed dose rates (nGy h⁻¹) and corresponding annual effective doses (mSv y⁻¹). For mean activity values, the absorbed dose rates range from 57.6 to 59.6 nGy h⁻¹, corresponding to 0.282–0.292 mSv y⁻¹. A combined deterministic and Gaussian modeling approach was developed to enable rapid dose estimation and to quantify uncertainty associated with geometric variability. The agreement between both approaches is within 1%, and the corresponding geometry-related uncertainty is approximately 1%. When considering the full variability of activity concentrations, the dose rates span a wider range (∼20–110 nGy h⁻¹), indicating that material composition is the dominant factor controlling indoor gamma exposure, while geometrical effects remain secondary. All predicted doses remain below the recommended public exposure limits, both in terms of total dose and after background correction (excess dose). The proposed framework provides a robust and practical tool for indoor dose assessment applicable to research and regulatory use.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108112"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148578940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiological risk assessment due to naturally occurring radionuclides in water and fish from gold mining-impacted regions in northern Tanzania","authors":"Dorice Rashid Seif,&nbsp;Leja Rovan Stiplošek,&nbsp;Mwingereza John Kumwenda,&nbsp;Mohamed Mazunga,&nbsp;Marko Štrok","doi":"10.1016/j.jenvrad.2026.108119","DOIUrl":"10.1016/j.jenvrad.2026.108119","url":null,"abstract":"<div><div>Many households in gold-mining regions of northern Tanzania have limited access to safe and reliable drinking water and rely on surface water, groundwater, and locally caught fish as key drinking-water and dietary sources, yet the radiological safety of these sources remains uncertain. This study evaluated age-dependent radiological risks from ingestion of naturally occurring radionuclides (²³⁴U, ²³⁸U, ²²⁶Ra, ²¹⁰Po, ²¹⁰Pb) in multiple water sources and in fish tissues (bones, gills and flesh) of African lungfish (<em>Protopterus aethiopicus</em>), Nile tilapia (<em>Oreochromis niloticus</em>) and African Catfish (<em>Clarias gariepinus</em>). Activity concentrations were determined by radiochemical separation followed by alpha spectrometry and gas-flow proportional counting. Annual effective dose (AED) and excess lifetime cancer risk (ELCR) were estimated using age-specific water and fish consumption rates. Groundwater, particularly from shallow wells, produced the highest exposures, with a maximum AED for a 5-year-old child, dominated by ²³⁴U, exceeding both the World Health Organization (WHO) screening level (0.1 mSv/y) and the International Commission on Radiological Protection (ICRP) public dose reference level (1 mSv/y). Fish consumption was the dominant pathway, with African lungfish consistently yielding the highest AEDs, followed by Tilapia and Catfish. The dose contributions were dominated by ²¹⁰Pb (75% −96%) and ²¹⁰Po (4% - 25%), while ²³⁴U, ²³⁸U, and ²²⁶Ra contributed &lt;1%. The estimated ELCRs associated with consumption of all fish species, exceeded the USEPA acceptable risk range (10⁻⁶ – 10⁻⁴). Elevated ²³⁴U/²³⁸U activity ratios (&gt;1) indicated preferential mobilisation of ²³⁴U via alpha-recoil, while low ²¹⁰Po/²¹⁰Pb ratios (&lt;1) confirmed ²¹⁰Pb predominance. These findings underscore the need for continued radiological monitoring and targeted mitigation to protect vulnerable communities.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108119"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiocesium in fallen leaves controlled by leaching and associated soil particles: litterbag experiments in Fukushima forests","authors":"Takuya Manaka,&nbsp;Tadashi Sakata,&nbsp;Yoshiki Shinomiya","doi":"10.1016/j.jenvrad.2026.108118","DOIUrl":"10.1016/j.jenvrad.2026.108118","url":null,"abstract":"<div><div>The contamination of forest ecosystems by radiocesium (¹³⁷Cs) released from the Fukushima Dai-ichi Nuclear Power Plant accident has seriously damaged forestry activities in Fukushima. Previous field-based descriptive studies have reported that a considerable proportion of ¹³⁷Cs remains in the soil O horizon, where the presence of various types of organic matter at different stages of decomposition contributes to both strong retention of ¹³⁷Cs by decomposing litter and a heterogeneous spatial distribution. To investigate the dynamics and mobility of ¹³⁷Cs during litter decomposition and to interpret our observations, we conducted litterbag experiments over approximately two years using fallen leaves of konara oak. Litterbags were deployed either suspended above the ground or placed on the forest floor. Leaching experiments were also performed on retrieved litterbag samples. In the suspended litterbags, we observed a decline of ¹³⁷Cs, mainly in the water-soluble form, likely due to washout associated with rain/snowfall and subsequent spring snowmelt. In contrast, the incorporation of soil particles by forest-floor litterbags resulted in an increase of ¹³⁷Cs relative to initial conditions, mainly in forms that were scarcely extractable, even by ammonium acetate. The large variability of residual ¹³⁷Cs revealed by comparisons with previous litterbag and equivalent experimental studies highlighted the difficulty of predicting ¹³⁷Cs activity concentrations and distributions on the forest floor. Furthermore, comparison with potassium (K), a competing alkali metal, demonstrated that ¹³⁷Cs is less mobile than K, regardless of soil particle incorporation. This low mobility likely contributes to the prolonged, strong retention of ¹³⁷Cs in the O horizon.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108118"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal variations of 40K in atmospheric fallout caused by volcanic eruptions: A case study for Kyushu Island, Japan","authors":"Yoshikazu Kikawada,&nbsp;Katsumi Hirose","doi":"10.1016/j.jenvrad.2026.108111","DOIUrl":"10.1016/j.jenvrad.2026.108111","url":null,"abstract":"<div><div>This study focused on ⁴⁰K in atmospheric-fallout monitoring data from various locations across Kyushu Island, which hosts numerous active volcanoes, including Sakurajima Volcano, one of Japan's most active volcanoes. It evaluated and verified the relationship between the fallout levels of the naturally occurring radionuclide ⁴⁰K and volcanic activity in the region. Volcanic ash contains several percent potassium, and ashfall leads to an increase in the ⁴⁰K fallout as an atmospheric deposit. A statistically significant positive correlation was found between the monthly number of explosive eruptions at Sakurajima and the monthly ⁴⁰K fallout in Miyazaki City, located 80 km away from Sakurajima, over 35 years. This finding demonstrates that Sakurajima's activity consistently causes ashfall in Miyazaki City, although no statistical data on ashfall exists. Ashfall levels there are approximately 10-20 g m⁻² per month during peak periods, estimated from ⁴⁰K fallout levels and the known potassium content in volcanic ash from Sakurajima. Furthermore, while large ⁴⁰K fallout amounts are sometimes observed on short time scales at the monitoring station in Kyushu, correlating the timing of these significant events with the eruption history of volcanoes within Kyushu led to the conclusion that most significant increases in ⁴⁰K fallout are attributable to ashfall from eruptions of specific volcanoes. Observed ⁴⁰K fallout data can reveal unrecorded volcanic ashfall events and be used to estimate ashfall amounts.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108111"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148578932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}