Pub Date : 2025-04-08DOI: 10.1016/j.jenvrad.2025.107684
Junyang Zeng , Lili Li , Yingzhe Du , Ziliang Hou , Youting Wu , Shiying Li , Hanyu Wu , Zhihao Liu , Peng Lin , Muyi Ni , Xiajie Liu
Periodic discharges from nuclear power plant (NPP) influence tritium background levels in seawater. After the Fukushima nuclear accident, radioactive wastewater discharges have introduced substantial amounts of tritium into the ocean. These events potentially threaten marine ecosystems and human health. To overcome the limitations of existing models, such as incomplete media consideration and low precision, we developed the TrOSB model (Tritium Ocean-Sediment-Biota transport Model). This high-precision model comprehensively analyzes transport and transformation across multiple marine media, including transport in seawater, interactions with sediments, transfer through the food chain, and assessment of public dose risks from seafood consumption. Results indicate that during the quarterly discharges of the Yangjiang NPP from 2019 to 2021, tritium from effluents spread across the entire South China Sea within four months, showing distinct seasonal transport patterns. Tritium concentrations in sediments were approximately ten times lower than those in near-bottom waters, with no significant enrichment observed in sediments. Organically bound tritium (OBT), the form of tritium transferred through the food chain, was found to be enriched to a higher degree in fish than in molluscs and crustaceans. The dose assessment indicates that public health risks from tritium in Yangjiang NPP effluents are negligible.
{"title":"Public dose assessment for Yangjiang nuclear power plant effluents: A multi-media numerical model of tritium transport in the South China sea","authors":"Junyang Zeng , Lili Li , Yingzhe Du , Ziliang Hou , Youting Wu , Shiying Li , Hanyu Wu , Zhihao Liu , Peng Lin , Muyi Ni , Xiajie Liu","doi":"10.1016/j.jenvrad.2025.107684","DOIUrl":"10.1016/j.jenvrad.2025.107684","url":null,"abstract":"<div><div>Periodic discharges from nuclear power plant (NPP) influence tritium background levels in seawater. After the Fukushima nuclear accident, radioactive wastewater discharges have introduced substantial amounts of tritium into the ocean. These events potentially threaten marine ecosystems and human health. To overcome the limitations of existing models, such as incomplete media consideration and low precision, we developed the TrOSB model (Tritium Ocean-Sediment-Biota transport Model). This high-precision model comprehensively analyzes transport and transformation across multiple marine media, including transport in seawater, interactions with sediments, transfer through the food chain, and assessment of public dose risks from seafood consumption. Results indicate that during the quarterly discharges of the Yangjiang NPP from 2019 to 2021, tritium from effluents spread across the entire South China Sea within four months, showing distinct seasonal transport patterns. Tritium concentrations in sediments were approximately ten times lower than those in near-bottom waters, with no significant enrichment observed in sediments. Organically bound tritium (OBT), the form of tritium transferred through the food chain, was found to be enriched to a higher degree in fish than in molluscs and crustaceans. The dose assessment indicates that public health risks from tritium in Yangjiang NPP effluents are negligible.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"286 ","pages":"Article 107684"},"PeriodicalIF":1.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792493","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}
Pub Date : 2025-04-08DOI: 10.1016/j.jenvrad.2025.107679
Mohamed A. El-Sadek
Geological interpretation and mapping-relying on existing airborne gamma-ray spectrometric data-were used to interpret from Gabal (Mountain) El-Bakriya area, Central Eastern Desert, Egypt. Log-log graphs and fractal concentration number (C-N) modeling technique were utilized to analyze the data and present them in various ways. Modeling according to C-N models removes the qualitative radioactive zones of TC, K, eU, and eTh. The lithological outcrops in the study area are then described in these qualitative radioactive zones. A geological map is created with C-N plots of TC, K, eU, and eTh to produce a comprehensive record of the radioactive signatures of all outcrops, which is tied to the radioactive signatures of K, which is the most well-known radioactive element for many rock formations. C-N fractal modeling shows great successes which perfectly simulate radioactive and lithological outcrop boundaries. The case study presented demonstrates the necessity of aerial gamma-ray spectrometry and fractal modeling for geological mapping and interpretation in difficult, and rocky terrains. The critical function in these situations is emphasized in this work. According to C-N fractal modeling of “K”, possibly indicating different cycles of granite eruption and formation in the study area. With the help of C-N model, radioactive break points can be created between rock types to indicate the transition from one lithology to another.
{"title":"Spacial variation mapping of aerial TC, K, eU, and eTh data according to concentration number (C –N) fractal modeling approach of A sample area in Egypt- A case study","authors":"Mohamed A. El-Sadek","doi":"10.1016/j.jenvrad.2025.107679","DOIUrl":"10.1016/j.jenvrad.2025.107679","url":null,"abstract":"<div><div>Geological interpretation and mapping-relying on existing airborne gamma-ray spectrometric data-were used to interpret from Gabal (Mountain) El-Bakriya area, Central Eastern Desert, Egypt. Log-log graphs and fractal concentration number (C-N) modeling technique were utilized to analyze the data and present them in various ways. Modeling according to C-N models removes the qualitative radioactive zones of TC, K, eU, and eTh. The lithological outcrops in the study area are then described in these qualitative radioactive zones. A geological map is created with C-N plots of TC, K, eU, and eTh to produce a comprehensive record of the radioactive signatures of all outcrops, which is tied to the radioactive signatures of K, which is the most well-known radioactive element for many rock formations. C-N fractal modeling shows great successes which perfectly simulate radioactive and lithological outcrop boundaries. The case study presented demonstrates the necessity of aerial gamma-ray spectrometry and fractal modeling for geological mapping and interpretation in difficult, and rocky terrains. The critical function in these situations is emphasized in this work. According to C-N fractal modeling of “K”, possibly indicating different cycles of granite eruption and formation in the study area. With the help of C-N model, radioactive break points can be created between rock types to indicate the transition from one lithology to another.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"286 ","pages":"Article 107679"},"PeriodicalIF":1.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792492","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}
Pub Date : 2025-03-31DOI: 10.1016/j.jenvrad.2025.107675
Yuan-Chao Chen , Dong Xie , Qian-Ran Jia , Jun Zeng , Guo-Jie Chen , Yang Yang
Building materials are one of the main sources of indoor radon, study of radon exhalation from building walls is of great reference significance for indoor radiation protection. Radon exhalation from building walls is comprehensively affected by environmental factors. A radon migration and exhalation model of building walls under the influence of coupled heat-moisture-air transfer was established. The radon exhalation mechanism of an aerated concrete wall under the influence of different relative humidity, temperature, relative humidity difference, temperature difference, air pressure difference and solar radiation was studied. The sensitivity of these factors to radon exhalation rate was analyzed. The results showed that the radon exhalation rate was positively correlated with relative humidity, but not with temperature; The radon exhalation rate was positively correlated with the relative humidity difference, and the temperature affected the correlation degree; The radon exhalation rate was positively correlated with the absolute temperature difference, and the relative humidity affected the correlation degree; The exhalation rate of radon was approximately linearly positive correlated with the pressure difference; Under the influence of solar radiation, the radon exhalation rate decreased; Radon parameters of material, relative humidity and solar radiation were more sensitive to radon exhalation rate than temperature, air pressure and radon concentration in air. For reducing radon exhalation rate of building walls and indoor radon concentration, we propose to use building wall materials with low radium content, keep indoor relative humidity and indoor and outdoor temperature difference low, and strengthen indoor ventilation at night, cloudy and rainy days.
{"title":"Numerical simulation study on the radon exhalation mechanism of building walls influenced by coupled heat-moisture-air transfer","authors":"Yuan-Chao Chen , Dong Xie , Qian-Ran Jia , Jun Zeng , Guo-Jie Chen , Yang Yang","doi":"10.1016/j.jenvrad.2025.107675","DOIUrl":"10.1016/j.jenvrad.2025.107675","url":null,"abstract":"<div><div>Building materials are one of the main sources of indoor radon, study of radon exhalation from building walls is of great reference significance for indoor radiation protection. Radon exhalation from building walls is comprehensively affected by environmental factors. A radon migration and exhalation model of building walls under the influence of coupled heat-moisture-air transfer was established. The radon exhalation mechanism of an aerated concrete wall under the influence of different relative humidity, temperature, relative humidity difference, temperature difference, air pressure difference and solar radiation was studied. The sensitivity of these factors to radon exhalation rate was analyzed. The results showed that the radon exhalation rate was positively correlated with relative humidity, but not with temperature; The radon exhalation rate was positively correlated with the relative humidity difference, and the temperature affected the correlation degree; The radon exhalation rate was positively correlated with the absolute temperature difference, and the relative humidity affected the correlation degree; The exhalation rate of radon was approximately linearly positive correlated with the pressure difference; Under the influence of solar radiation, the radon exhalation rate decreased; Radon parameters of material, relative humidity and solar radiation were more sensitive to radon exhalation rate than temperature, air pressure and radon concentration in air. For reducing radon exhalation rate of building walls and indoor radon concentration, we propose to use building wall materials with low radium content, keep indoor relative humidity and indoor and outdoor temperature difference low, and strengthen indoor ventilation at night, cloudy and rainy days.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107675"},"PeriodicalIF":1.9,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738797","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}
Tritium is an ubiquitous radioactive hydrogen isotope. It is found in all environmental compartments, in three different forms: tritiated water (HTO), gaseous tritium (HT) and organically bound tritium (OBT). Once internalized in the organism, it can either be found free in the tissues (TFWT) or bound to organic matter (OBT). This study aims to assess if tritiated thymidine, an organic form of tritium, induces DNA breaks once internalized in a model organism and its DNA. To do so, both experimental procedures and nanodosimetry simulations have been used. Zebrafish embryos (3.5 hpf, hours post fertilization) were exposed to three tritiated thymidine activity concentrations (7.5, 40, 110 kBq/mL, leading to internal dose rates of 22, 170 and 270 μGy/h) for four days. Individuals were sampled after 1 and 4 days of exposure and DNA break levels were assessed by the comet assay. Results showed that, even at the lowest activity concentration, tritiated thymidine induced DNA breaks in both embryos (1 dpf) and larvae (4 dpf). It was also highlighted that there was no increase nor decrease in DNA break level between 1 and 4 dpf, except in the case of the exposure to 170 μGy/h, where a slight decrease was observed. Geant4-DNA Monte Carlo simulations, performed on two spherical zebrafish nuclei of two different radii (2.5 and 5 μm), highlighted that organic tritium mainly induced single strand breaks (SSB). The results also showed that most of the damage was indirectly induced. Those results, combined with various experimentations, expose tritiated thymidine genotoxic pathways that could lead to both short- and long-term health effects.
{"title":"Experimental and computational analysis of the DNA damage induced in zebrafish, Danio rerio, early life stages after exposure to tritiated thymidine","authors":"Magali Schiano Di Lombo , Isabelle Cavalie , Virginie Camilleri , Jérôme Cachot , Yann Perrot , Beatrice Gagnaire","doi":"10.1016/j.jenvrad.2025.107682","DOIUrl":"10.1016/j.jenvrad.2025.107682","url":null,"abstract":"<div><div>Tritium is an ubiquitous radioactive hydrogen isotope. It is found in all environmental compartments, in three different forms: tritiated water (HTO), gaseous tritium (HT) and organically bound tritium (OBT). Once internalized in the organism, it can either be found free in the tissues (TFWT) or bound to organic matter (OBT). This study aims to assess if tritiated thymidine, an organic form of tritium, induces DNA breaks once internalized in a model organism and its DNA. To do so, both experimental procedures and nanodosimetry simulations have been used. Zebrafish embryos (3.5 hpf, hours post fertilization) were exposed to three tritiated thymidine activity concentrations (7.5, 40, 110 kBq/mL, leading to internal dose rates of 22, 170 and 270 μGy/h) for four days. Individuals were sampled after 1 and 4 days of exposure and DNA break levels were assessed by the comet assay. Results showed that, even at the lowest activity concentration, tritiated thymidine induced DNA breaks in both embryos (1 dpf) and larvae (4 dpf). It was also highlighted that there was no increase nor decrease in DNA break level between 1 and 4 dpf, except in the case of the exposure to 170 μGy/h, where a slight decrease was observed. Geant4-DNA Monte Carlo simulations, performed on two spherical zebrafish nuclei of two different radii (2.5 and 5 μm), highlighted that organic tritium mainly induced single strand breaks (SSB). The results also showed that most of the damage was indirectly induced. Those results, combined with various experimentations, expose tritiated thymidine genotoxic pathways that could lead to both short- and long-term health effects.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107682"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724362","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}
Pub Date : 2025-03-27DOI: 10.1016/j.jenvrad.2025.107668
Konstantin Kovler , Andrey Tsapalov , Robert Bobkier , Rob Wiegers , Wouter Schroeyers , Tibor Kovács , Edit Toth-Bodrogi , Omar El Bounagui , Arkadiusz Babczuk
This position paper deals with the critical analysis of the existing European regulation of indoor radon and NORM in building materials. It represents an opinion of the initiative group of experts created during the Workshop of European NORM Association (ENA) held in Rome, 15–17 May 2024. The main conclusions and propositions of the experts have been also discussed at the round table during the IX Terrestrial Radioisotopes in Environment International Conference on Environmental Protection, 19–22 November 2024, Vonyarcvashegy, Hungary.
The current paper lists and discusses several missing points and challenges within the European regulatory system in the field of NORM in building materials and indoor radon, consisting of three interconnecting functional levels: Legislative, Normative, and Methodological. It also serves as a Road Map for the regulatory development in the next decade.
Our analysis identifies areas for improvement. While the normative guidance (mid-tier of the hierarchical regulatory pyramid) is robust, the legislative framework has gaps, and methodological support remains underdeveloped with several serious deficiencies. These issues significantly hinder the global implementation of GRPs. To address these gaps, new harmonized standards and guidelines are necessary. It is concluded that enhancing radon and NORM regulations can be achieved by developing and globally implementing several relevant European (international) standards and guidelines within rational ISO/IEC concepts. From a legal-philosophical perspective, these findings are intended as an invitation to dialogue, not merely a critique.
{"title":"Indoor radon and NORM in building materials: Critical analysis of the current European regulation and road map for the next decade","authors":"Konstantin Kovler , Andrey Tsapalov , Robert Bobkier , Rob Wiegers , Wouter Schroeyers , Tibor Kovács , Edit Toth-Bodrogi , Omar El Bounagui , Arkadiusz Babczuk","doi":"10.1016/j.jenvrad.2025.107668","DOIUrl":"10.1016/j.jenvrad.2025.107668","url":null,"abstract":"<div><div>This position paper deals with the critical analysis of the existing European regulation of indoor radon and NORM in building materials. It represents an opinion of the initiative group of experts created during the Workshop of European NORM Association (ENA) held in Rome, 15–17 May 2024. The main conclusions and propositions of the experts have been also discussed at the round table during the IX Terrestrial Radioisotopes in Environment International Conference on Environmental Protection, 19–22 November 2024, Vonyarcvashegy, Hungary.</div><div>The current paper lists and discusses several missing points and challenges within the European regulatory system in the field of NORM in building materials and indoor radon, consisting of three interconnecting functional levels: Legislative, Normative, and Methodological. It also serves as a Road Map for the regulatory development in the next decade.</div><div>Our analysis identifies areas for improvement. While the normative guidance (mid-tier of the hierarchical regulatory pyramid) is robust, the legislative framework has gaps, and methodological support remains underdeveloped with several serious deficiencies. These issues significantly hinder the global implementation of GRPs. To address these gaps, new harmonized standards and guidelines are necessary. It is concluded that enhancing radon and NORM regulations can be achieved by developing and globally implementing several relevant European (international) standards and guidelines within rational ISO/IEC concepts. From a legal-philosophical perspective, these findings are intended as an invitation to dialogue, not merely a critique.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107668"},"PeriodicalIF":1.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705918","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}
Pub Date : 2025-03-27DOI: 10.1016/j.jenvrad.2025.107678
Jiahui He , Yang Shao , Min Luo , Xiaomeng Cheng , Lingling Ma
Recent global radiological incidents have heightened attention to environmental radioactivity. Although analytical methods for anthropogenic radionuclides in environmental samples and background research are relatively well-established on a global scale, systematic research data are still lacking in the Northwest China region. This region is not only affected by global fallout caused by nuclear weapons tests in the last century, but also the regional fallout —the Lop Nor nuclear test site, China's only nuclear testing base. The various sources, complicated climate and terrain results in the unique distribution of radionuclides. Therefore, systematically summarizing the spatial distribution characteristics of artificial radionuclides in the northwest region serves as a scientific foundation for assessing the environmental risks associated with historical nuclear test legacies. It also represents a critical component in building a global nuclear safety monitoring network. Simultaneously, it provides essential data support for regional ecological environmental protection and the development of green industries. This study reviews anthropogenic radionuclide distribution in Northwest China's environment, highlighting uneven spatial coverage, incomplete nuclide inclusion, and insufficient databases. The paper proposes future directions for systematic and long-term comprehensive research, emphasizing the need to strengthen the investigation of the links between artificial radionuclides and ecological effects as well as health risks. This paper summarizes research to enhance monitoring and improve anthropogenic radionuclide background data, offering a scientific basis for policy-making and environmental protection. The review presented in this paper offers an important reference for further exploring solutions to environmental radioactivity issues in Northwest China.
{"title":"Research progress on the distribution of anthropogenic radionuclides in Northwest China","authors":"Jiahui He , Yang Shao , Min Luo , Xiaomeng Cheng , Lingling Ma","doi":"10.1016/j.jenvrad.2025.107678","DOIUrl":"10.1016/j.jenvrad.2025.107678","url":null,"abstract":"<div><div>Recent global radiological incidents have heightened attention to environmental radioactivity. Although analytical methods for anthropogenic radionuclides in environmental samples and background research are relatively well-established on a global scale, systematic research data are still lacking in the Northwest China region. This region is not only affected by global fallout caused by nuclear weapons tests in the last century, but also the regional fallout —the Lop Nor nuclear test site, China's only nuclear testing base. The various sources, complicated climate and terrain results in the unique distribution of radionuclides. Therefore, systematically summarizing the spatial distribution characteristics of artificial radionuclides in the northwest region serves as a scientific foundation for assessing the environmental risks associated with historical nuclear test legacies. It also represents a critical component in building a global nuclear safety monitoring network. Simultaneously, it provides essential data support for regional ecological environmental protection and the development of green industries. This study reviews anthropogenic radionuclide distribution in Northwest China's environment, highlighting uneven spatial coverage, incomplete nuclide inclusion, and insufficient databases. The paper proposes future directions for systematic and long-term comprehensive research, emphasizing the need to strengthen the investigation of the links between artificial radionuclides and ecological effects as well as health risks. This paper summarizes research to enhance monitoring and improve anthropogenic radionuclide background data, offering a scientific basis for policy-making and environmental protection. The review presented in this paper offers an important reference for further exploring solutions to environmental radioactivity issues in Northwest China.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107678"},"PeriodicalIF":1.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705754","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}
Pub Date : 2025-03-24DOI: 10.1016/j.jenvrad.2025.107681
Peng Lin , Karah Greene , Wei Xing , Steven Simner , Christina Logan , Daniel I. Kaplan
<div><div>Cementitious materials are commonly used for the long-term disposal of low-level radioactive waste (LLW) in subsurface engineered disposal facilities. Iodine-129 is a key-risk driver, along with <sup>99</sup>Tc and <sup>137</sup>Cs, in proposed low- and high-level waste disposal facilities in the United States. The distribution coefficient (<em>K</em><sub><em>d</em>;</sub> concentration ratio of I<sub>solid</sub>/I<sub>liquid</sub>) is one of the key parameters used for risk assessments to estimate the risk posed by radioactive waste disposal facilities. The objective of this study is to examine iodine (I) <em>K</em><sub><em>d</em></sub> values in sandy and clayey sediment environments impacted by cementitious leachate. Batch sorption experiments were conducted using subsurface sediments from Savannah River Site (SRS) for three iodine species (iodide (I<sup>−</sup>), iodate (IO<sub>3</sub><sup>−</sup>) and organo-iodine (org-I)). Besides the SRS groundwater (pH = 5.5), three background solutions were used to simulate the cementitious leachate in different stages of cement aging, including cementitious leachate from a freshly prepared grout (Stage I of cement aging), Ca(OH)<sub>2</sub>-saturated solutions (Stage II, moderately aged grout leachate), and CaCO<sub>3</sub>-saturated solutions (Stage III, aged grout leachate). Sorption of iodide (the most common iodine species) to the sandy and clayey sediments was generally undetected in most solutions, except in groundwater (0.9–5.6 L/kg). Iodate <em>K</em><sub><em>d</em></sub> values ranged from 2.1 to 14 L/kg with sandy sediment and from 3.9 to 54 L/kg with clayey sediment, with the same background solution rankings for both sediments: Stage I < Stage III < Stage II < groundwater. Org-I demonstrated the strongest sorption to both sediments, varying from 20 to 149 L/kg to sandy sediments and from 17 to 117 L/kg on clayey sediments. Compared to groundwater conditions, the three iodine species generally demonstrated decreased sorption in the presence of cementitious leachate-impacted sediments. An important exception was org-I, which had previously been shown to comprise 45 % of the total iodine released from grout waste forms. It generally had enhanced sediment sorption in the presence of Stage II Ca(OH)<sub>2</sub> and Stage III CaCO<sub>3</sub> simulant. The fraction of iodine sorbed in the presence of cementitious leachate simulant with respect to the concentration sorbed under background groundwater conditions (calculated as <em>K</em><sub><em>d</em></sub><em>-CementLeach</em>/<em>K</em><sub><em>d</em></sub>-GW) was 0.02–0.23 for iodide, 0.07–0.88 for iodate, and 0.14–5.29 for org-I. These results provided novel insight into the importance of accounting for the change in water chemistry in nuclear waste disposal systems containing cementitious engineered barriers. Neglecting to do so may result in the underestimation of the long-term risk posed by radioiodine to the environment
{"title":"Impact of cementitious leachate on sorption of various iodine species to sediments","authors":"Peng Lin , Karah Greene , Wei Xing , Steven Simner , Christina Logan , Daniel I. Kaplan","doi":"10.1016/j.jenvrad.2025.107681","DOIUrl":"10.1016/j.jenvrad.2025.107681","url":null,"abstract":"<div><div>Cementitious materials are commonly used for the long-term disposal of low-level radioactive waste (LLW) in subsurface engineered disposal facilities. Iodine-129 is a key-risk driver, along with <sup>99</sup>Tc and <sup>137</sup>Cs, in proposed low- and high-level waste disposal facilities in the United States. The distribution coefficient (<em>K</em><sub><em>d</em>;</sub> concentration ratio of I<sub>solid</sub>/I<sub>liquid</sub>) is one of the key parameters used for risk assessments to estimate the risk posed by radioactive waste disposal facilities. The objective of this study is to examine iodine (I) <em>K</em><sub><em>d</em></sub> values in sandy and clayey sediment environments impacted by cementitious leachate. Batch sorption experiments were conducted using subsurface sediments from Savannah River Site (SRS) for three iodine species (iodide (I<sup>−</sup>), iodate (IO<sub>3</sub><sup>−</sup>) and organo-iodine (org-I)). Besides the SRS groundwater (pH = 5.5), three background solutions were used to simulate the cementitious leachate in different stages of cement aging, including cementitious leachate from a freshly prepared grout (Stage I of cement aging), Ca(OH)<sub>2</sub>-saturated solutions (Stage II, moderately aged grout leachate), and CaCO<sub>3</sub>-saturated solutions (Stage III, aged grout leachate). Sorption of iodide (the most common iodine species) to the sandy and clayey sediments was generally undetected in most solutions, except in groundwater (0.9–5.6 L/kg). Iodate <em>K</em><sub><em>d</em></sub> values ranged from 2.1 to 14 L/kg with sandy sediment and from 3.9 to 54 L/kg with clayey sediment, with the same background solution rankings for both sediments: Stage I < Stage III < Stage II < groundwater. Org-I demonstrated the strongest sorption to both sediments, varying from 20 to 149 L/kg to sandy sediments and from 17 to 117 L/kg on clayey sediments. Compared to groundwater conditions, the three iodine species generally demonstrated decreased sorption in the presence of cementitious leachate-impacted sediments. An important exception was org-I, which had previously been shown to comprise 45 % of the total iodine released from grout waste forms. It generally had enhanced sediment sorption in the presence of Stage II Ca(OH)<sub>2</sub> and Stage III CaCO<sub>3</sub> simulant. The fraction of iodine sorbed in the presence of cementitious leachate simulant with respect to the concentration sorbed under background groundwater conditions (calculated as <em>K</em><sub><em>d</em></sub><em>-CementLeach</em>/<em>K</em><sub><em>d</em></sub>-GW) was 0.02–0.23 for iodide, 0.07–0.88 for iodate, and 0.14–5.29 for org-I. These results provided novel insight into the importance of accounting for the change in water chemistry in nuclear waste disposal systems containing cementitious engineered barriers. Neglecting to do so may result in the underestimation of the long-term risk posed by radioiodine to the environment","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107681"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682952","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}
Pub Date : 2025-03-24DOI: 10.1016/j.jenvrad.2025.107672
Peter Saetre , Olle Hjerne , Ari T.K. Ikonen , Lauri Parviainen , Ulrik Kautsky , Sari Peura
In environmental impact assessments the biota-to-water concentration ratio (CR) is needed for calculating the transfer of radionuclides from water to aquatic organisms. Data are frequently missing, especially for rare elements, and various approaches are used for extrapolation of missing values. In this study we have analysed elemental concentrations in fish based on previously published data for brackish and freshwater. We grouped the fish according to their species and used a mixed linear model to calculate site- and ecosystem-specific CR values. These values were compared with values from different extrapolation methods (site, literature, element and ecosystem analogues). We also calculated edible versus whole body conversion factors.
The site-specific CR values frequently differed by an order of magnitude or more between the brackish and freshwater ecosystems. For most elements the value was affected by site, locality (within site) and fish type. Also the inclusion of bones affected some CR values. Literature analogues diverged more from the site data than site analogues, but these both performed better than element and ecosystem analogues. The ratio between edible and whole-body concentrations was typically similar in brackish and freshwater environments.
We conclude that a joint analysis of different aquatic ecosystems at similar sites allows for robust estimates of systematic and random variation associated with CR. We suggest that there are more possible analogues than the ones considered in the international recommendations, and that the choice of analogue should be based on the available data and the performance of the analogues in the specific assessment at hand.
{"title":"Concentration ratios in fish, their natural variation, and extrapolation of missing values","authors":"Peter Saetre , Olle Hjerne , Ari T.K. Ikonen , Lauri Parviainen , Ulrik Kautsky , Sari Peura","doi":"10.1016/j.jenvrad.2025.107672","DOIUrl":"10.1016/j.jenvrad.2025.107672","url":null,"abstract":"<div><div>In environmental impact assessments the biota-to-water concentration ratio (CR) is needed for calculating the transfer of radionuclides from water to aquatic organisms. Data are frequently missing, especially for rare elements, and various approaches are used for extrapolation of missing values. In this study we have analysed elemental concentrations in fish based on previously published data for brackish and freshwater. We grouped the fish according to their species and used a mixed linear model to calculate site- and ecosystem-specific CR values. These values were compared with values from different extrapolation methods (site, literature, element and ecosystem analogues). We also calculated edible versus whole body conversion factors.</div><div>The site-specific CR values frequently differed by an order of magnitude or more between the brackish and freshwater ecosystems. For most elements the value was affected by site, locality (within site) and fish type. Also the inclusion of bones affected some CR values. Literature analogues diverged more from the site data than site analogues, but these both performed better than element and ecosystem analogues. The ratio between edible and whole-body concentrations was typically similar in brackish and freshwater environments.</div><div>We conclude that a joint analysis of different aquatic ecosystems at similar sites allows for robust estimates of systematic and random variation associated with CR. We suggest that there are more possible analogues than the ones considered in the international recommendations, and that the choice of analogue should be based on the available data and the performance of the analogues in the specific assessment at hand.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107672"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682955","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}
Pub Date : 2025-03-24DOI: 10.1016/j.jenvrad.2025.107657
Hafssa Bendriss , Jaafar EL Bakkali , EL Mahjoub Chakir , Abderrahim Doudouh , Soufiyane Yachou
This paper describes the creation of a voxel-based dosimetric model of a toadfish (Halobatrachus didactylus) from available CT images in which 29 organs are identified and segmented using 3D Slicer software. To validate the present dosimetric model Specific Absorbed Fractions (SAFs) were calculated for ten vital organs as sources and all targets, for discrete energies of electrons and photons. Then, the obtained dosimetric coefficients were compared to those calculated in similar organs in a voxel-based phantom of a trout fish (Oncorhynchus mykiss). The results showed a general agreement between the comparative dosimetric data, highlighting the validity of our dosimetric model for Halobatrachus didactylus. We conclude that the current dosimetric fish model can be applied in future research to evaluate dosimetry calculations related to radiation exposure in regions surrounding the Fukushima accident site.
{"title":"Development and validation of a voxel-based computational phantom of Halobatrachus didactylus (Toadfish) to study radiation protection of the marine environment","authors":"Hafssa Bendriss , Jaafar EL Bakkali , EL Mahjoub Chakir , Abderrahim Doudouh , Soufiyane Yachou","doi":"10.1016/j.jenvrad.2025.107657","DOIUrl":"10.1016/j.jenvrad.2025.107657","url":null,"abstract":"<div><div>This paper describes the creation of a voxel-based dosimetric model of a toadfish (<em>Halobatrachus didactylus</em>) from available CT images in which 29 organs are identified and segmented using 3D Slicer software. To validate the present dosimetric model Specific Absorbed Fractions (SAFs) were calculated for ten vital organs as sources and all targets, for discrete energies of electrons and photons. Then, the obtained dosimetric coefficients were compared to those calculated in similar organs in a voxel-based phantom of a trout fish (<em>Oncorhynchus mykiss)</em>. The results showed a general agreement between the comparative dosimetric data, highlighting the validity of our dosimetric model for <em>Halobatrachus didactylus</em>. We conclude that the current dosimetric fish model can be applied in future research to evaluate dosimetry calculations related to radiation exposure in regions surrounding the Fukushima accident site.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107657"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682954","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}
Pub Date : 2025-03-24DOI: 10.1016/j.jenvrad.2025.107671
Kai Liu , Yong Liu , Hong Wang , Changshou Hong , Yifan Chen , Weiwei Yin , Chenxiao Chang
Freeze-thaw (F-T) climate causes cracking in the soil cover of uranium tailing ponds, and the exhalation of the carcinogenic gas radon needs to be monitored under the phenomenon. In laboratory experiment, cracking tests under 5 F-T cycles were carried out on 3 soil uranium tailing pond models, including Gansu loess (GS-L), Hengyang laterite (HY-L), and Hebei loess (HB-L). Each cycle consisted of −15 °C, 12 h of freezing and 15 °C, 12 h of thawing. The area, length, mean width and fractal dimension of the cracks on the soil surface were quantified using digital imaging techniques, the correlation of parameters with the radon exhalation was compared. Finally, the qualitative explanation was provided from the perspectives of visual and scanning electron microscopy (SEM). The results showed that: Fine, short and irregular cracks developed to penetrating wide cracks after the 3rd cycle. The radon barrier capacity of the soil was negatively correlated with the number of F-T cycles. After 5th cycles, the radon exhalation rates of GS-L, HY-L, and HB-L were 0.675 , 0.555 , and 0.462 , which increased by 63.8 %, 43.1 %, and 39.6 %, respectively. The mean width of cracks showed the highest correlation with radon exhalation rate: HY-L (0.91), GS-L (0.89), and HB-L (0.87). SEM results showed fewer soil internal pores mean harder radon migration. The findings are relevant to the monitoring of radioactive gas in uranium tailing ponds.
{"title":"Study on the effect of surface cracks in overburden on radon exhalation in uranium tailings ponds under freeze-thaw cycles","authors":"Kai Liu , Yong Liu , Hong Wang , Changshou Hong , Yifan Chen , Weiwei Yin , Chenxiao Chang","doi":"10.1016/j.jenvrad.2025.107671","DOIUrl":"10.1016/j.jenvrad.2025.107671","url":null,"abstract":"<div><div>Freeze-thaw (F-T) climate causes cracking in the soil cover of uranium tailing ponds, and the exhalation of the carcinogenic gas radon needs to be monitored under the phenomenon. In laboratory experiment, cracking tests under 5 F-T cycles were carried out on 3 soil uranium tailing pond models, including Gansu loess (GS-L), Hengyang laterite (HY-L), and Hebei loess (HB-L). Each cycle consisted of −15 °C, 12 h of freezing and 15 °C, 12 h of thawing. The area, length, mean width and fractal dimension of the cracks on the soil surface were quantified using digital imaging techniques, the correlation of parameters with the radon exhalation was compared. Finally, the qualitative explanation was provided from the perspectives of visual and scanning electron microscopy (SEM). The results showed that: Fine, short and irregular cracks developed to penetrating wide cracks after the 3rd cycle. The radon barrier capacity of the soil was negatively correlated with the number of F-T cycles. After 5th cycles, the radon exhalation rates of GS-L, HY-L, and HB-L were 0.675 <span><math><mrow><mi>B</mi><mi>q</mi><mo>/</mo><mrow><mo>(</mo><mrow><msup><mi>m</mi><mn>2</mn></msup><mo>·</mo><mi>s</mi></mrow><mo>)</mo></mrow></mrow></math></span>, 0.555 <span><math><mrow><mi>B</mi><mi>q</mi><mo>/</mo><mrow><mo>(</mo><mrow><msup><mi>m</mi><mn>2</mn></msup><mo>·</mo><mi>s</mi></mrow><mo>)</mo></mrow></mrow></math></span>, and 0.462 <span><math><mrow><mi>B</mi><mi>q</mi><mo>/</mo><mrow><mo>(</mo><mrow><msup><mi>m</mi><mn>2</mn></msup><mo>·</mo><mi>s</mi></mrow><mo>)</mo></mrow></mrow></math></span>, which increased by 63.8 %, 43.1 %, and 39.6 %, respectively. The mean width of cracks showed the highest correlation with radon exhalation rate: HY-L (0.91), GS-L (0.89), and HB-L (0.87). SEM results showed fewer soil internal pores mean harder radon migration. The findings are relevant to the monitoring of radioactive gas in uranium tailing ponds.</div></div>","PeriodicalId":15667,"journal":{"name":"Journal of environmental radioactivity","volume":"285 ","pages":"Article 107671"},"PeriodicalIF":1.9,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682953","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}
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