Journal of environmental radioactivity最新文献

{"title":"Development and testing of a continuous maritime monitor for radionuclide aerosols","authors":"Michael E. Moore,&nbsp;Martin E. Keillor,&nbsp;Daniel Cain,&nbsp;Thomas W. Hallen,&nbsp;Jared C. Johnson,&nbsp;Dustin M. Kasparek,&nbsp;Sarah A. Mendoza,&nbsp;Cory T. Overman,&nbsp;Benjamin Q. Roberts","doi":"10.1016/j.jenvrad.2025.107777","DOIUrl":"10.1016/j.jenvrad.2025.107777","url":null,"abstract":"<div><div>Monitoring airborne concentrations of radionuclide activity may provide a timely warning to sea-based assets to avoid contamination from a radioactive plume. The development and testing of an automated aerosol monitoring system that can capture and detect radioactive particulate from marine air is presented. A custom electrostatic precipitator (ESP) was designed to capture particulate onto a reusable collection media. The collection efficiency of the ESP system for radon progeny was determined to be ∼23 %. A conservative calculation of the minimum detectable concentration of ²¹⁴Bi was estimated as 0.3–8 Bq/m³. The system was demonstrated in continuous operation, without consumables and limited maintenance, in a marine environment at the PNNL campus in Sequim, Washington. A successful 2-month deployment indicates the feasibility of the approach for continuous maritime monitoring for radionuclide aerosols.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107777"},"PeriodicalIF":2.1,"publicationDate":"2025-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757846","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":"No toxicity to the tropical marine microalgae Tisochrysis lutea from gamma radiation","authors":"Alexandra Bastick ,&nbsp;Tom Cresswell ,&nbsp;Jessica Tout-Lyon ,&nbsp;Darren Koppel ,&nbsp;Merrin Adams ,&nbsp;Rebecca Fisher ,&nbsp;Francesca Gissi","doi":"10.1016/j.jenvrad.2025.107774","DOIUrl":"10.1016/j.jenvrad.2025.107774","url":null,"abstract":"<div><div>Environmental risk assessments for contaminants require toxicological data to evaluate the potential effect on organisms and ecosystems of interest. As human activities in marine environments continue to intensify, so does the presence of contaminants such as Naturally Occurring Radionuclides and Radioactive Materials (NOR and NORM, respectively), and the risk of NORM contamination has risen globally through resource extraction. The FASSET radiation effects database (FRED) has compiled radiation toxicity data to collate the existing ionising radiation effect data for non-human species, leading to environmental thresholds such as the 10 μGy/h international screening level to protect 95 % of organisms in all ecosystems. However, approximately 6 % of the data used to derive this, and other, guideline levels pertain to marine organisms and may not accurately represent the sensitivities of marine species. NORM can accumulate in subsea infrastructure during oil and gas extraction and may persist in the environment during production and after decommissioning. If NORM contaminated infrastructure is left in situ, or repurposed as an artificial reef, local marine organisms may receive elevated radiation doses prior to infrastructure degradation due to the potential presence of gamma emitting radionuclides. As the impacts of radiation are not well understood for marine organisms, more relevant toxicity data is required to develop appropriate guidelines and risk assessments to ensure ecosystem protection during and after decommissioning. In this study, tropical marine microalga <em>Tisochrysis lutea</em> were exposed to gamma radiation from a sealed source of Cesium-137 in chronic growth inhibition toxicity assays at dose rates ranging from 0.01 to 7.9 mGy/h. Results indicated a slight hormesis response and minimal impact on the population growth of <em>T. lutea</em> up to the maximum tested dose rate, and the extrapolated No (Significant) Effect Concentration (N(S)EC) was 8.8 mGy/h. This is higher than environmentally relevant exposure levels and international dose rate screening levels for non-human biota, suggesting that this species is resilient to radiation exposure at these levels. Further investigation is recommended to identify more sensitive species and endpoints for radiation toxicity and that standard toxicity tests are conducted for a wider range of marine species to derive a water quality guideline for radiation.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107774"},"PeriodicalIF":2.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750409","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":"Chemical analogues and probabilistic functions to derive distribution coefficients of radium in soils","authors":"Joan Serra-Ventura ,&nbsp;Guillem Sabaté-Herrero ,&nbsp;Anna Rigol ,&nbsp;Miquel Vidal","doi":"10.1016/j.jenvrad.2025.107769","DOIUrl":"10.1016/j.jenvrad.2025.107769","url":null,"abstract":"<div><div>The existing data gaps in the sorption and desorption parameters of naturally occurring radionuclides (e.g., radium (Ra)) challenge the use of radioecological risk assessment models. We present two alternatives for deriving Ra distribution coefficients (K_d (Ra)) in soils when the physicochemical information on the solid and liquid phases involved is too scarce to apply parametric prediction models: the deduction of sorption parameters from those of chemical analogues (such as Ba and Sr) and the proposal of best estimate K_d (Ra) values deduced from probabilistic distribution functions of data grouped according to relevant factors affecting K_d (Ra) variability. Regarding the use of chemical analogues, partial least squares regression analysis and univariate linear correlations revealed that Ba and Ra sorption in soils was governed by the same soil properties (K_d (Ca + Mg) and Mn_am), related to exchangeable sites on the soil surface. The derivation of K_d (Ra) values from K_d (Ba) and also K_d (Sr) is feasible by applying suitable correction factors. Furthermore, several K_d (Ra) best estimates were derived from the distribution functions of K_d (Ra) datasets obtained from own and literature data. Statistical differences were noticed for the sorption and desorption datasets (the latter significantly affected by data from native Ra), leading to the proposal of distinct K_d (Ra) values (870 and 2760 L kg⁻¹, respectively) for uptake and remobilisation scenarios. Regarding the desorption data, diverse K_d (Ra) best estimates were suggested for acidic (1540 L kg⁻¹) and alkaline (6440 L kg^-1) soils. For the sorption data, statistically different K_d (Ra) best estimates were suggested according to pH (100 and 1240 L kg⁻¹ for pH &lt; 4.5 and pH ≥ 7, respectively) and water-soluble Ca + Mg content, allowing for the selection of the most appropriate best estimate values for use in risk assessment models depending on the available information.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107769"},"PeriodicalIF":2.1,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750451","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":"Tritium and 137Cs levels in marine fishes and in their host seawater around the Fukushima Daiichi Nuclear Power Plant from 2021 to 2024","authors":"Hyoe Takata ,&nbsp;Toshihiro Wada ,&nbsp;Hikaru Miura ,&nbsp;Yoshifumi Wakiyama ,&nbsp;Takuya Niida ,&nbsp;Keiri Imai ,&nbsp;Atsushi Ooki","doi":"10.1016/j.jenvrad.2025.107760","DOIUrl":"10.1016/j.jenvrad.2025.107760","url":null,"abstract":"<div><div>We examined distributions of tritium and cesium-137 (¹³⁷Cs) activity in marine fishes and in simultaneously collected host seawater in 2021–2024 around the Fukushima Daiichi Nuclear Power Plant (FDNPP). From April 2021 to June 2023 (before water treated by a multi-nuclide removal facility was first released into the ocean, hereafter, “before releases”), the mean tritium activity in bottom layer, host water of fishes, collected offshore (&gt;5 km from the FDNPP) was 0.085 Bq/L. In nearshore water (2 km south of the FDNPP), tritium activity varied with fluvial input in 2021 and 2022 and correlated with dissolved ¹³⁷Cs. After the start of treated-water releases in August 2023 (hereafter, “after releases”), at both offshore and nearshore sites, several samples deviated from the line of tritium vs dissolved ¹³⁷Cs before releases, reflecting the input of treated-water-derived tritium. Means of tissue-free-water tritium (TFWT) activities in rockfish and Japanese flounder at offshore site were 0.089 and 0.075 Bq/kg-fresh, respectively, before releases, and 0.081 and 0.13 Bq/kg-fresh, respectively, after. At nearshore site, Japanese flounder TFWT activities after releases were 0.37–0.75 Bq/kg-fresh. The elevated TFWT activities after releases could have been caused by elevated tritium activities in host seawater. There, however, was no difference in the concentration ratios (CRs) of TFWT to host seawater tritium between before releases and after releases, indicating that TFWT quickly responded to changes in host water tritium. Moreover, the CRs of TFWT + total organically bound tritium for rockfish and Japanese flounder offshore after releases were 1 or less, suggesting that tritium was not accumulated in marine fish.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107760"},"PeriodicalIF":1.9,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714545","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":"Wet deposition of radionuclides: interception under sprinkler irrigation","authors":"S. Fesenko,&nbsp;V. Kuznetsov,&nbsp;N. Sanzharova","doi":"10.1016/j.jenvrad.2025.107772","DOIUrl":"10.1016/j.jenvrad.2025.107772","url":null,"abstract":"<div><div>The paper presents novel data on the interception of radionuclides in vegetables using sprinkler irrigation as a simulator of artificial rain. This information is essential for risk evaluations during both routine operations of nuclear facilities and potential accidental events. In countries with dry climates, where irrigation is an integral part of farming technologies, data on the interception of radionuclides by vegetable crops is crucial for effectively organizing irrigation using cooling water from nuclear reactors. The experiments were conducted in the North Caucasus, a region known for intensive irrigated agriculture, utilizing common vegetable crops such as tomatoes, cucumbers, carrots, table beets, and onions. The research employed a wide range of radionuclides: ⁵⁹Fe, ⁶⁰Co, ⁶⁵Zn, ⁸⁹Sr, ¹⁰⁶Ru, ¹³⁴Cs, and ¹⁴⁴Ce. The study investigated the effects of element properties, plant development stages, and rainfall amounts on radionuclide interception in the crops. It was found that increasing rainfall from 10 to 30 mm resulted in a 1.5– to 3.2–fold increase in the concentration of ⁵⁹Fe and a 1.2– to 3.3–fold increase in the concentration of ¹³⁴Cs in the vegetative mass of plants. A further increase in rainfall, up to 70 mm, did not significantly alter the concentration of either radionuclide in the vegetative mass or the edible parts of the vegetable crops. New approximation was suggested for variations in interception factors with standing biomass of vegetable crops. Based on the strength of their fixation to plant foliage, the radionuclides can be ranked as follows: ⁶⁵Zn ≈ ¹⁴⁴Ce ≥ ⁶⁰Co ≥ ¹⁰⁶Ru &gt; ¹³⁴Cs.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107772"},"PeriodicalIF":1.9,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714544","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":"Radionuclide transfer to vegetables under sprinkler irrigation","authors":"V. Kuznetsov,&nbsp;N. Sanzharova,&nbsp;S. Fesenko","doi":"10.1016/j.jenvrad.2025.107773","DOIUrl":"10.1016/j.jenvrad.2025.107773","url":null,"abstract":"<div><div>The paper presents novel data on radionuclide transfer to vegetables under sprinkler irrigation. The experiments were conducted in the North Caucasus, a region of intensive irrigated agriculture, using common vegetable crops including tomatoes, cucumbers, carrots, table beet, onions, potatoes, and cabbage. The research utilized a wide range of radionuclides ⁵⁹Fe, ⁶⁰Co, ⁶⁵Zn, ⁸⁹Sr, ¹⁰⁶Ru, ¹³⁴Cs and ¹⁴⁴Ce. The effects of element properties, irrigation rates, and the chemical characteristics of irrigation water on radionuclide accumulation in the crops were investigated. It was found that under sprinkler irrigation ⁶⁵Zn, ¹⁴⁴Ce, and ¹³⁴Cs exhibit the highest accumulation in the vegetative tissues of vegetable crops; ⁶⁵Zn, ⁸⁹Sr and ¹³⁴Cs show the greatest accumulation in the edible parts of the plants. Increasing the irrigation rate from 10 to 50 L/m² leads to a 1.5– to 3.2-fold increase in the concentration of ⁵⁹Fe and ¹³⁴Cs in plant tissues and a 1.2– to 3.3-fold increase in edible parts of plants. The paper also considers effects of the application of mineral fertilizers as a factor regulating radionuclide transfer to vegetables under irrigation. It is shown that irrigation timing and plant development stage are key factors governing radionuclide accumulation in vegetable crops.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107773"},"PeriodicalIF":1.9,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714546","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":"Effect of different Prussian Blue compounds in feed on 137Cs uptake and excretion by silver Prussian carp","authors":"Valery Kashparov ,&nbsp;Sviatoslav Levchuk ,&nbsp;Dmytrii Holiaka ,&nbsp;Yuri Khomutinin ,&nbsp;Toshihiro Wada ,&nbsp;Marina Zhurba ,&nbsp;Polina Pavlenko ,&nbsp;Alexandra Shvardak ,&nbsp;Vasyl Yoschenko","doi":"10.1016/j.jenvrad.2025.107771","DOIUrl":"10.1016/j.jenvrad.2025.107771","url":null,"abstract":"<div><div>This paper documents that adding different hexacyanoferrate compounds, commonly referred to as Prussian Blue (PB), to feed is an effective and inexpensive countermeasure to reduce contamination of fish with ¹³⁷Cs. Laboratory aquarium experiments were conducted to investigate the effects of feed containing either 0.1 % or 1 % ammonium ferric hexacyanoferrate (AFCF, NH₄Fe [Fe(CN)₆]), potassium ferric hexacyanoferrate (KFCF, KFe [Fe(CN)₆]), or Ferrocyn (mixture of 95 % ferric hexacyanoferrate (FCF, Fe₄ [Fe(CN)₆]₃) and 5 % KFCF) on the uptake and excretion of ¹³⁷Cs by silver Prussian carp (<em>Carassius gibelio</em> (Bloch, 1782)). The experiments lasted for 2 months at a constant water temperature of 24 ± 2 °C. In each aquarium, at 9 a.m., fish received 0.2 g of feed per day (about 0.2 % of fish weight) containing 19 ± 2 Bq of ¹³⁷Cs. In addition, at 3–4 p.m., fish in different aquariums received 0.8–1.0 g of feed (about 1 % day⁻¹) containing 0 %, 0.1 % or 1 % of different PB compounds. The use of feed with 0.1 % and 1 % of PB compounds resulted in a 1.8–2.1 and 2.2–2.8-fold decrease in ¹³⁷Cs in the fish body compared to the control group of fish receiving feed without PB compounds after one month of the experiment and a 2.3–3.0 and 2.8–3.7 decrease after two months (at the end of the experiments). The reduction factors when using PB compounds can reach maximum values, 5–10, when ¹³⁷Cs activities in the treated and control groups of fish reach the maximum (stable) levels. The method of feed granulation, dry or wet, did not affect the effectiveness of PB, and no statistically significant differences were found between the efficiencies of the studied PB compounds.</div><div>The results obtained, along with the results of our previous studies, demonstrate that, unlike in mammals, the use of PB compounds in feed does not significantly reduce the resorption of radiocesium in the gut (by 1.4–1.8 times), but substantially reduces the effective half-life of ¹³⁷Cs activity in fish (from 100 to 16–28 days).</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107771"},"PeriodicalIF":1.9,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711245","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":"Effects of U stress on physiological tolerance characteristics and mineral element distribution of sunflower seedlings","authors":"Ming-Ying Zeng ,&nbsp;Yuan-Lin Yang ,&nbsp;Sheng Zheng","doi":"10.1016/j.jenvrad.2025.107770","DOIUrl":"10.1016/j.jenvrad.2025.107770","url":null,"abstract":"<div><div>The metabolism of plant mineral nutrients is crucial for plant growth and development and is a key parameter for characterising the growth state of plants in various environments. However, as a non-essential element for plants, radionuclide uranium readily accumulates in the roots, causing root toxicity and metabolic disorders of plant mineral nutrients. We used hydroponic sunflowers as experimental materials to explore the uranium tolerance features of sunflower seedlings and to compare the absorption of mineral nutrients by different root components and organs of the sunflower. The results showed that the absorption and accumulation of uranium by different sunflower varieties and various parts of sunflowers differed significantly, and uranium treatment severely damaged the sunflower root tissue. Simultaneously, uranium predominantly accumulated in the cell walls of the root tissue, contributing to sustained damage. Furthermore, antioxidant enzymes play a vital role in preventing damage caused by uranium stress. Uranium stress disrupts the photosynthetic metabolism of sunflowers. The levels of most mineral elements in the roots and leaves of sunflowers increased significantly after treatment with 0.01 mM uranium. Uranium treatment significantly reduced the Mg content of TY007 and S668 leaves by 11.03–77.68 % and 28.51–58.40 %, respectively. This study offers a scientific basis for remediating uranium contamination in urban and rural brownfield sites.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107770"},"PeriodicalIF":1.9,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702524","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":"Comparison of neutron activation analysis and passive counting for environmental radioactivity measurements","authors":"Nicholas Kaitschuck,&nbsp;JohnPeter Bekker,&nbsp;Derek Haas,&nbsp;Sheldon Landsberger","doi":"10.1016/j.jenvrad.2025.107766","DOIUrl":"10.1016/j.jenvrad.2025.107766","url":null,"abstract":"<div><div>Neutron activation analysis is not usually known used for environmental radioactivity measurements as compared to low-level passive gamma-ray counting. Texas local background samples were taken as part of a study to compare neutron activation versus passive counting. The benefits and drawbacks of each method are explored for soil samples which are in secular equilibrium, including gamma-ray self-attenuation, sample size and counting times.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107766"},"PeriodicalIF":1.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695349","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":"Assessment of the cesium-137 concentration in algae-grazing ayu Plecoglossus altivelis collected from Tomioka River in Fukushima, Japan","authors":"Takami Morita ,&nbsp;Toshihiro Wada ,&nbsp;Tsutomu Kanasashi ,&nbsp;Hyoe Takata","doi":"10.1016/j.jenvrad.2025.107759","DOIUrl":"10.1016/j.jenvrad.2025.107759","url":null,"abstract":"<div><div>Large amounts of the cesium-137 (¹³⁷Cs) released into the atmosphere during the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 had deposited on land, especially in Fukushima Prefecture. The long-term persistent ¹³⁷Cs contamination of freshwater fish has resulted in fishing activities being restricted or suspended in some rivers and lakes, mainly in the central to eastern areas of Fukushima Prefecture. The ayu <em>Plecoglossus altivelis</em>, an important inland resource in Japan, is one of the species for which fishing activities are suspended. This fish feeds on periphytic algae attached to riverbed stones, ingesting fine sediments along with the algae. Although whole-body monitoring of ayu has been conducted, whether they contain the ¹³⁷Cs concentration that allows the resumption of fishing activities is difficult to ascertain because the ¹³⁷Cs in fine sediments affects the concentration in the whole fish body. Therefore, in this study, substances (refractory portion) affecting the whole-body ¹³⁷Cs concentration were removed to gain an accurate assessment of the actual concentration. We measured the ¹³⁷Cs concentrations in the muscle, head, and internal organs of ayu individuals collected from Tomioka River in Fukushima in May and October 2022 and reconstructed the whole-body ¹³⁷Cs concentration from those measurements. Through H₂O₂–HNO₃ digestion of the fish and microalgae, we also measured the ¹³⁷Cs concentrations in the refractory portions that affect the whole-body measurement. The percentages of non-digested fish with whole-body ¹³⁷Cs concentrations exceeding the Japanese regulatory limit were 18.0 % in May and 50.0 % in October. By contrast, when the refractory portions were removed, none of the specimens showed whole-body ¹³⁷Cs concentrations that exceeded the limit. These findings suggest that the procedure for monitoring ¹³⁷Cs in ayu should be reviewed.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"289 ","pages":"Article 107759"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686302","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}