Journal of environmental radioactivity最新文献

{"title":"Soil-to-rice transfer parameters for naturally occurring radionuclides and trace elements in Thai paddy fields: A national dataset","authors":"Piyawan Srikongpan,&nbsp;Michael D. Wood,&nbsp;Simon M. Hutchinson,&nbsp;Jajati Mandal,&nbsp;Thawatchai Itthipoonthanakorn,&nbsp;Daojarus Ketrot,&nbsp;Saroh Niyomdecha","doi":"10.1016/j.jenvrad.2026.108120","DOIUrl":"10.1016/j.jenvrad.2026.108120","url":null,"abstract":"<div><div>The reliability of transfer parameters in radiological assessment is essential for estimating the food chain transfer of radionuclides, which commonly uses the concentration ratio (CR_plant-soil) as a key parameter in evaluating ingestion dose exposure to humans. Rice (<em>Oryza sativa L.</em>) is a staple food consumed by half of the world's population, and it plays a particularly significant role in Thailand's diet and economy. The CR_rice-soil dataset reported by the International Atomic Energy Agency (IAEA) shows high variability across different environments (temperate and tropical), with a notable scarcity of related parameters such as soil properties within specific study sites. This scarcity is particularly evident in Thailand, where CR_rice-soil data have been reported in only a few studies. This study determined CR_rice-soil values for natural radionuclides (⁴⁰K, ²²⁶Ra, ²²⁸Ra, and ²²⁸Th) and trace elements (As, Cd, Co, Cr, Cs, Cu, Li, Ni, Pb, Rb, Se, Sr, Th, Tl, U, Y, and Zn) using 295 paired samples of soil and rice plants (root, stem, and grain) collected from Thailand's principal rice-growing areas. The arithmetic mean CR_rice-soil values from this study were generally higher than those reported in international references (IAEA TRS 472 and MODARIA II TECDOC-1979). For most elements, CR values in rice plant parts decreased in the order CR_root &gt; CR_stem &gt; CR_grain. A significant negative correlation between CR_rice-soil values and soil physicochemical properties (pH, CEC, and OM) was observed using Spearman's rho. Spatial variation in CR_rice-soil was also linked to soil texture. This study provides the first macro-scale quantification of CR_rice-soil values in Thai rice and may support radiological assessments in tropical and international contexts.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"298 ","pages":"Article 108120"},"PeriodicalIF":2.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603935","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":"Amplification of seismic stress–induced radon fluxes near surface seals: Application to earthquake precursor detection","authors":"B.K. Sahoo ,&nbsp;Y.S. Mayya ,&nbsp;Arshad Khan ,&nbsp;Ratul Dasgupta ,&nbsp;B.K. Sapra","doi":"10.1016/j.jenvrad.2026.108057","DOIUrl":"10.1016/j.jenvrad.2026.108057","url":null,"abstract":"<div><div>Reliable identification of earthquake precursors remains challenging due to weak signal amplitudes and environmental noise. Radon flux from soil is a promising indicator, but its effectiveness is often limited by low signal-to-noise ratios. In this study, we propose the use of surface seals for strengthening the signal to noise ratios of Rn-222 fluxes, based on a theory of amplification of flux signals induced by seismic stresses in their vicinity. The surface seals could either be those installed specifically for this purpose or could be the pre-existing concrete pavements, building foundations or asphalt roads. A two-dimensional advection–diffusion model is formulated and solved analytically using dual integral equation techniques to describe radon transport in partially sealed soils. The analysis demonstrates that sealed surfaces act as transport barriers, leading to subsurface radon accumulation and elevated fluxes near seal edges. Under conditions of seismic stress, the onset of Darcian flow further amplifies these fluxes relative to unsealed environments. Field measurements conducted near a concrete structure corroborate the model predictions, showing that radon flux at seal edges can increase by up to a factor of four compared to open soil. These findings establish seal-edge regions as effective passive amplifiers of radon signals, significantly improving the detectability of radon-based seismic precursors. By strategically placing radon monitors near sealed surfaces, observatories can detect seismic signals more clearly and earlier. The approach may also apply to other underground gases, opening new possibilities for earthquake research and environmental monitoring.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108057"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148054786","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":"Spatial variations in 137Cs of soil and crop within a cultivated field in Fukushima, Japan","authors":"Kotaro Saito,&nbsp;Shigeto Fujimura,&nbsp;Tatsuhiro Nishikiori","doi":"10.1016/j.jenvrad.2026.108052","DOIUrl":"10.1016/j.jenvrad.2026.108052","url":null,"abstract":"<div><div>Obtaining an accurate representative value for a field to evaluate the annual fluctuation of radiocaesium (¹³⁷Cs) concentration is critical. This study clarifies within-field spatial variability in two cultivated fields affected by fallout from the Fukushima Dai-ichi Nuclear Power Plant accident. We investigated the spatial patterns of ¹³⁷Cs in soil (two sites) and broccoli (one site), along with related parameters including the transfer factor (TF), exchangeable ¹³⁷Cs (Ex¹³⁷Cs), the ratio of Ex¹³⁷Cs to total ¹³⁷Cs in soil (Ex¹³⁷Cs%), and exchangeable potassium (ExK) using geostatistical analysis (semivariogram). In addition, we estimated the relative error of the mean at a 95% confidence interval for selected sample sizes to support monitoring design. The coefficients of variation were 19% and 29% for soil ¹³⁷Cs and broccoli inflorescence ¹³⁷Cs, respectively. Semivariograms indicated limited detectable spatial dependence for soil ¹³⁷Cs and Ex¹³⁷Cs at the sampling resolution, although crop row-aligned distributions were noted for soil ¹³⁷Cs. With five sampling points, relative errors were estimated at 16–17% and 21–31% for soil ¹³⁷Cs and Ex¹³⁷Cs, respectively, whereas five samples produced relative errors of 25–29% and 21–27% for broccoli inflorescence ¹³⁷Cs and TF, respectively. These uncertainty estimates provide practical guidance for selecting sampling intensity based on monitoring objectives and for interpreting interannual changes. Further studies are needed to establish robust sampling recommendations for cultivated fields.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108052"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148031290","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":"Distribution, bioaccumulation and radiological risks of uranium in bivalve mollusks in the tropical coastal waters of Lam Dong, Vietnam: Implications for marine monitoring and uptake pathway","authors":"Van-Hao Duong ,&nbsp;Trung-Tien Chu ,&nbsp;Thanh-Xuan Pham Thi ,&nbsp;Khai M. Nguyen ,&nbsp;Marckasagayam Priyadharshini ,&nbsp;Mohamed Saiyad Musthafa ,&nbsp;Trinh Phan Trong ,&nbsp;Duc-Thang Duong ,&nbsp;Thanh-Duong Nguyen ,&nbsp;Hue Nguyen Thanh Kim","doi":"10.1016/j.jenvrad.2026.108049","DOIUrl":"10.1016/j.jenvrad.2026.108049","url":null,"abstract":"<div><div>Natural uranium isotopes (²³⁴U and ²³⁸U) levels have been investigated in muscle and hepatopancreas tissues of twelve ecologically and economically bivalve species from a tropical coastal area, Lam Dong, Vietnam (the titanium placer area). The ²³⁴U and ²³⁸U activities were observed to be higher in the hepatopancreas organ and varied among species ranging from 0.24 <span><math><mrow><mo>±</mo></mrow></math></span> 0.02 to 13.1<span><math><mrow><mo>±</mo></mrow></math></span> 0.35 and from 0.25<span><math><mrow><mo>±</mo></mrow></math></span> 0.03 to 15.5<span><math><mrow><mo>±</mo></mrow></math></span> 1.6 Bq/kg in muscle tissues, from 0.32<span><math><mrow><mo>±</mo></mrow></math></span> 0.03 to 25.0<span><math><mrow><mo>±</mo></mrow></math></span> 2.1 and from 0.61<span><math><mrow><mo>±</mo></mrow></math></span> 0.06 to 94.7<span><math><mrow><mo>±</mo></mrow></math></span> 9.47 Bq/kg in hepatopancreas, respectively. The preferential accumulation in the hepatopancreas highlights its role in metal uptake, detoxification, and storage. Variations ²³⁴U/²³⁸U activity ratio between tissues in the range 1.0 – 3.89 and seawater indicated mixing uptake pathways, primarily through the gill and digestive tract. There was a significant negative correlation between uranium concentration in the hepatopancreas and both body weight and shell length, suggesting that morphological parameters could influence accumulation and providing valuable correction parameters and a sensitive bioindicator for marine radiological biomonitoring applications. Although three species had uranium concentration factors exceeding the IAEA guideline values, the annual effective doses for all age groups were below the guideline value, and ecological doses remained well below ERICA thresholds, indicating negligible radiological risk from uranium isotopes. These findings support the use of bivalves in marine radiation monitoring and contribute to food safety and public health management in similar tropical coastal areas worldwide.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108049"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148042675","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":"In-situ depth-resolved gamma spectrometry of natural radionuclides in central Nepal: Radiological assessment across Himalayan formations","authors":"Anita Mishra,&nbsp;Raju Khanal","doi":"10.1016/j.jenvrad.2026.108048","DOIUrl":"10.1016/j.jenvrad.2026.108048","url":null,"abstract":"<div><div>Potassium-dominated elevated natural radiation environments are exceptionally rare globally, with documented high background radiation areas typically being thorium-dominated (Kerala, India; Guarapari, Brazil) or uranium-dominated (Ramsar, Iran). This study characterizes such an environment in the Himalayan region within the Markhu Formation of central Nepal and establishes the first depth-resolved radionuclide baseline across eight geological formations from Kathmandu to Hetauda. In-situ gamma ray spectrometry at 10 cm intervals to 50 cm depth was used to quantify ⁴⁰K, ²³⁸U, and ²³²Th distributions and examine depth-dependent behavior. ²³²Th exhibited strong depth dependence reflecting bedrock-controlled immobility, ²³⁸U showed variable correlations reflecting lithological heterogeneity, and ⁴⁰K displayed intermediate patterns controlled by weathering. Dose rates exceeded world averages at all sites (84.4 ± 2.0 to 246.0 ± 6.2 nGy/h vs. 59 nGy/h), yet annual effective doses remained below the 1 mSv public limit. The Markhu Formation exhibited annual effective doses 3.6 times the world average, external hazard index exceeding unity (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>e</mi><mi>x</mi></mrow></msub></math></span> = 1.28 ± 0.31), and radium equivalent activity of 477 ± 118 Bq/kg driven by ⁴⁰K of 6.70 ± 0.82 to 9.2 ± 1.0% (four to six times global average) from biotite-rich metamorphic parent rocks. Constant activity ratios and U-Th correlation are consistent with natural geogenic origin rather than anthropogenic contamination. These findings expand the global typology of elevated natural radiation environments and demonstrate that formation-specific baselines are essential for radiological assessment in geologically diverse Himalayan terrain.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108048"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148042689","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":"From zonal containment to spot recovery: Multi-platform geostatistical reassessment of radiation risk boundaries in Fukushima (2019–2024)","authors":"Imam Ghazali Yasmint ,&nbsp;Yo Ishigaki ,&nbsp;Kayoko Yamamoto","doi":"10.1016/j.jenvrad.2026.108047","DOIUrl":"10.1016/j.jenvrad.2026.108047","url":null,"abstract":"<div><div>This study provides a spatiotemporal reassessment of the radiological landscape within the Difficult-to-Return Zone (DTRZ) surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP), integrating airborne, car-borne, and walk-borne survey data from 2019 to 2024 through Empirical Bayesian Kriging (EBK) to generate high-resolution (50-m) dose-rate surfaces. Applying the official Japanese government occupancy threshold of 3.8 μSv·h⁻¹ (equivalent to 20 mSv·y⁻¹), the 2019 DTRZ boundary demonstrated complete radiological containment, with all threshold-exceeding grid cells located within the zone boundaries in both monitoring years, but exhibited pronounced internal over-restriction: 96.2% of the 337.34 km² DTRZ area comprised grid cells that did not exceed the threshold in 2019, rising to 98.4% by 2024 as the threshold-exceeding area contracted by 56.8% from 12.74 km² to 5.50 km². Radiological assessment of the seven Specified Reconstruction and Revitalization Base Areas (SRRBA) (digitized from published cartography) revealed that mean dose rates across all patches declined from 6.45 mSv·y⁻¹ to 3.08 mSv·y⁻¹ (−52.2%), with all patches recording doses below the 20 mSv·y⁻¹ policy threshold and threshold-exceeding area contracting by 86.1%. Forest classes (Deciduous Broadleaf Forest [DBF], Deciduous Needleleaf Forest [DNF], Evergreen Broadleaf Forest [EBF], Evergreen Needleleaf Forest [ENF], and Bamboo forest) accounted for 60.2% of threshold-exceeding cells in 2019, declining to 56.5% in 2024, with a notable compositional shift from DBF (39.6% to 25.8%) toward ENF (15.1% to 22.8%) reflecting differential radioecological recovery rates. These findings empirically validate the radiological justification for the SRRBA designation and the broader transition from broad zonal restriction toward spot-based recovery management.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108047"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148138286","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":"Seasonal patterns in the relationship between gamma emitters in the ground-level atmospheric layer and total atmospheric precipitation in southern Poland (Kraków), 2022 - 2025","authors":"Sylwia Błażej,&nbsp;Jerzy W. Mietelski,&nbsp;Renata Kierepko,&nbsp;Mikołaj Wielgat","doi":"10.1016/j.jenvrad.2026.108044","DOIUrl":"10.1016/j.jenvrad.2026.108044","url":null,"abstract":"<div><div>Atmospheric physical and chemical processes significantly influence the presence of radionuclides, affecting their production (for cosmogenic isotopes), horizontal and vertical transport, and resuspension. This study presents weekly gamma-spectrometric measurements of aerosol and monthly measurements of atmospheric precipitation collected in Krakow (southern Poland) during the years 2022-2025, which is a continuation of studies initiated in 1990. For both types of samples, time series and correlations between observed activity concentrations of ⁴⁰K, ²¹⁰Pb, ⁷Be, ²²Na and ¹³⁷Cs for the whole period and in sub-sets of four seasons. Most observed trends correspond to seasonal patterns characteristic of temperate climate zones and to prevailing atmospheric phenomena during the study period. Due to increasing solar activity during the 25^th solar cycle a decreasing trend for both cosmogenic radionuclides is observed, however with a strong seasonal variation. No traces of ¹³¹I were found either in aerosol form or in gaseous form.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108044"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148150144","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":"Evaluation of radon progeny mitigation techniques (HEPA filtration, ionization, electrostatic deposition) and their potential use in caves","authors":"J.E. Martínez,&nbsp;B. Juste,&nbsp;G. Verdú","doi":"10.1016/j.jenvrad.2026.108063","DOIUrl":"10.1016/j.jenvrad.2026.108063","url":null,"abstract":"<div><div>Radon and its short-lived progeny are recognized as significant contributors to the radiological dose received indoors and are associated with increased lung cancer risk. This study evaluates the effectiveness of various air purification technologies—including HEPA filtration, ionization, electrostatic deposition, and combined systems—in reducing airborne concentrations of radon progeny (PAEC, ²¹⁸Po, and ²¹⁴Po) in a controlled, non-ventilated environment. Measurements were carried out using active and passive detectors over multiple campaigns with and without air purifiers. Statistically significant reductions were observed for all purification methods tested, with the greatest decrease found for ²¹⁴Po and PAEC, and more moderate reductions for ²¹⁸Po. The combination of HEPA filtration and ionization proved most effective, achieving reductions exceeding 40% in PAEC. The results confirm that air purification systems, particularly those using ionization and electrostatic principles, can play a crucial role in mitigating radon progeny exposure in enclosed spaces. These findings support the practical implementation of air purification strategies in high-risk environments such as underground workplaces, shelters, and laboratories.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108063"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148156762","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":"Modelling marine radioactive spills in the context of the current war in the Middle East","authors":"Raúl Periáñez","doi":"10.1016/j.jenvrad.2026.108054","DOIUrl":"10.1016/j.jenvrad.2026.108054","url":null,"abstract":"<div><div>In the current geopolitical context, the possibility of a radiological incident resulting from an attack on nuclear infrastructure or a nuclear-powered naval vessel in active maritime theaters of conflict cannot be entirely dismissed. This paper presents a suite of Lagrangian radionuclide transport models covering the marine domains most directly affected by the present Middle East war: the Red Sea, the Persian Gulf, and the Northern Indian Ocean. The models incorporate advection by currents derived from a global ocean model, three-dimensional turbulent mixing, radioactive decay, and dynamic water-sediment interactions described through reversible kinetic adsorption-release reactions. Tidal transport, which is particularly relevant in semi-enclosed basins such as the Persian Gulf and the Red Sea, can be optionally included via tidal currents obtained from a previously validated tidal propagation model. The modelling framework is consistent with the recommendations of the International Atomic Energy Agency MODARIA programme regarding the availability of marine radionuclide transport tools for rapid deployment in nuclear emergency scenarios. Some illustrative simulations of a hypothetical release of ¹³⁷Cs from a nuclear facility located in the southern Persian Gulf and from a ship in the entrance of the Gulf of Oman are presented. The models are ready to be operationally applied should a radiological emergency arise in any of these regions.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108054"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148042678","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":"Age-dependent bioaccumulation of radionuclides in pond-raised Heteroclarias catfish in Ondo State, Nigeria","authors":"Olajire Joshua Olajide,&nbsp;Oladele Samuel Ajayi","doi":"10.1016/j.jenvrad.2026.108051","DOIUrl":"10.1016/j.jenvrad.2026.108051","url":null,"abstract":"<div><div>This research investigated age-dependent distribution and bioaccumulation of natural radionuclides in pond-raised <em>Heteroclarias</em> catfish from Ondo State, Nigeria, with emphasis on sediment-water-biota interactions. Activity concentrations (dry mass) of ⁴⁰K, ²²⁶Ra, and ²³²Th were determined in 3-month-old and 14-month-old <em>Heteroclarias</em> catfish, as well as in pond water and sediments using gamma spectrometry. Radionuclide transfer factors and ingestion-related effective doses were also evaluated. Across all sampled matrices, ⁴⁰K was the dominant radionuclide. Mean ⁴⁰K activity concentrations in fish increased significantly from 181.3 ± 3 Bq kg⁻¹ in 3-month-old fish to 280 ± 4 Bq kg⁻¹ in 14-month-old fish (p &lt; 0.05), indicating cumulative uptake with age. In contrast, ²²⁶Ra and ²³²Th showed higher activity concentrations in pond sediments, confirming sediments as the main reservoir of these radionuclides. Transfer factor analysis showed higher water-to-fish transfer of ⁴⁰K and ²²⁶Ra in older fish, whereas ²³²Th exhibited greater transfer in younger fish, suggesting sediment-associated uptake during early growth stages. Estimated annual effective dose equivalents ranged from 30 to 36 μSv y⁻¹, with excess lifetime cancer risk values below internationally recommended limits. Overall, the findings indicate no significant radiological risk associated with consumption of pond-raised <em>Heteroclarias</em> catfish and underscore the importance of age and sediment-mediated processes in freshwater radioecological assessments.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"297 ","pages":"Article 108051"},"PeriodicalIF":2.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148054805","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}