1
|
Brown J, Teien HC, Thørring H, Skipperud L, Hosseini A, Lind OC, Oughton D, Salbu B. Transfer of radionuclides through ecological systems: Lessons learned from 10 years of research within CERAD CoE. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 940:173503. [PMID: 38821276 DOI: 10.1016/j.scitotenv.2024.173503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 06/02/2024]
Abstract
Norway's Centre of Excellence for Environmental Radioactivity (CERAD) research programme included studies on transfer of radionuclides in various ecosystems within the context of environmental risk assessment. This article provides highlights from 10 years of research within this topic and summarises lessons learnt from the process. The scope has been extensive, involving laboratory-based experiments, field studies and the implementation of transfer models quantifying radionuclide uptake directly from the surrounding environment and via food chains. Field studies have had a global span and have, inter alia, covered sites contaminated with radionuclides associated with particles, ranging from nanoparticles to fragments, due to nuclear accidents (e.g., Chornobyl and Fukushima accidents) along with sites having enhanced levels of naturally occurring radioactive materials (e.g., Fen Complex in Norway and Taboshar in Tajikistan). Focus has been put on speciation and kinetics in determining radionuclide behavior and fate as well as on the influence of environmental factors that are potentially critical for the transfer of radionuclides. In particular, seasonal factors have been shown to greatly affect the dynamics of 137Cs and 90Sr bioaccumulation and loss in freshwater fish. The work has led to the collation of organism-specific (i) parameters important for kinetic models, i.e., uptake and depuration rates, and (ii) steady-state concentration ratios, CRs, where the use of stable analogue CRs as proxies for radionuclides has been brought into question. Dynamic models have been developed and applied for radiocaesium transfer to reindeer, radionuclide transfer in Arctic marine systems, transfer to fish via water and feed and commonly used agricultural food-chain transfer models applied in the context of nuclear emergency preparedness. The CERAD programme should contribute substantially to the scientific community's understanding of radionuclide transfer in environmental systems.
Collapse
Affiliation(s)
- Justin Brown
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway.
| | - Hans Christian Teien
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Håvard Thørring
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Lindis Skipperud
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Ali Hosseini
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Ole Christian Lind
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Deborah Oughton
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Brit Salbu
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| |
Collapse
|
2
|
Yang B, Pang C, Tuo F, Zhou Q, Li Z. Radioactivity and elemental oxidation composition in soil from Yangjiang, a high background natural radiation area, China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 276:107447. [PMID: 38749216 DOI: 10.1016/j.jenvrad.2024.107447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/24/2024]
Abstract
Soil is an important source and medium of radionuclides, and the content of radioactivity in soil is crucial for radiological impact evaluation. In this study, twenty soil samples in the high background natural radiation area of Yangjiang, China were collected and analyzed for 226Ra, 232Th, 40K and 137Cs concentrations in order to evaluate the radiological health risk in the area. Results showed that the average activity concentrations of 226Ra, 232Th and 40K are 66 Bq/kg, 109 Bq/kg and 211 Bq/kg, respectively. The calculated radiological parameters of radium equivalent activity (Raeq), absorbed dose rate (D), annual effective dose equivalent (AEDE), internal and external hazard indices (Hin and Hex) show a large variation at different sampling sites. Additionally, the elemental oxidation composition and 40K/K mass ratio in the soil were analyzed to further augment the background information of the high background radiation area in Yangjiang.
Collapse
Affiliation(s)
- Baolu Yang
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Chaoya Pang
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Fei Tuo
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China.
| | - Qiang Zhou
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Zeshu Li
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| |
Collapse
|
3
|
Belykh E, Maystrenko T, Velegzhaninov I, Tavleeva M, Rasova E, Rybak A. Taxonomic Diversity and Functional Traits of Soil Bacterial Communities under Radioactive Contamination: A Review. Microorganisms 2024; 12:733. [PMID: 38674676 PMCID: PMC11051952 DOI: 10.3390/microorganisms12040733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/28/2024] Open
Abstract
Studies investigating the taxonomic diversity and structure of soil bacteria in areas with enhanced radioactive backgrounds have been ongoing for three decades. An analysis of data published from 1996 to 2024 reveals changes in the taxonomic structure of radioactively contaminated soils compared to the reference, showing that these changes are not exclusively dependent on contamination rates or pollutant compositions. High levels of radioactive exposure from external irradiation and a high radionuclide content lead to a decrease in the alpha diversity of soil bacterial communities, both in laboratory settings and environmental conditions. The effects of low or moderate exposure are not consistently pronounced or unidirectional. Functional differences among taxonomic groups that dominate in contaminated soil indicate a variety of adaptation strategies. Bacteria identified as multiple-stress tolerant; exhibiting tolerance to metals and antibiotics; producing antioxidant enzymes, low-molecular antioxidants, and radioprotectors; participating in redox reactions; and possessing thermophilic characteristics play a significant role. Changes in the taxonomic and functional structure, resulting from increased soil radionuclide content, are influenced by the combined effects of ionizing radiation, the chemical toxicity of radionuclides and co-contaminants, as well as the physical and chemical properties of the soil and the initial bacterial community composition. Currently, the quantification of the differential contributions of these factors based on the existing published studies presents a challenge.
Collapse
Affiliation(s)
- Elena Belykh
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
| | - Tatiana Maystrenko
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
| | - Ilya Velegzhaninov
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
| | - Marina Tavleeva
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
- Department of Biology, Institute of Natural Sciences, Pitirim Sorokin Syktyvkar State University, 55 Oktyabrsky Prospekt, Syktyvkar 167001, Russia
| | - Elena Rasova
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
| | - Anna Rybak
- Institute of Biology of Komi Scientific Centre, Ural Branch of Russian Academy of Sciences, 28 Kommunisticheskaya St., Syktyvkar 167982, Russia (I.V.); (E.R.)
| |
Collapse
|
4
|
Popic JM, Urso L, Michalik B. Assessing the exposure situations with naturally occurring radioactive materials across European countries by means of the e-NORM survey. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167065. [PMID: 37714339 DOI: 10.1016/j.scitotenv.2023.167065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/17/2023]
Abstract
Despite the EU states being under the umbrella of the European Directive 2013/59/Euratom, a certain degree of heterogeneity may be noticed in the implementation of EU recommendations concerning regulation and handling of NORM into national legislation and practice. This is mainly a result of the still existing incomplete international knowledge about different phenomena related to NORM. Therefore, the attempt to advance the understanding of the behaviour and exposure of NORM is at the core of the European RadoNorm project. Within this context, an international survey on NORM has been prepared. The goals of the survey were to gather information and data from European countries that will contribute making an updated and/or new (a) systematic overview of NORM exposure situations and their analysis with respect to different radiation protection aspects, (b) knowledge about applied radioecological models in a variety of NORM exposure situations to improve evaluation of possible exposure doses and risk for population and workers, as well as of environmental risk, and (c) overview of overall mitigation measures applied in NORM involving industries, and possible remediation activities applied at NORM affected legacy sites. The survey is built upon an extended list of NORM-involving industries and processes, covers general aspects of NORM, presence of multi-stressors, as well as practical procedures applied in management and regulation, also in the context of a circular economy. The survey responses were obtained from 19 countries. An analysis of survey responses proved that NORM control is still a complex issue for many countries, and the recently-introduced regulatory solutions require further interpretation for developing procedures and good practices. The present work provides a detailed analysis of the survey responses with respect to regulation, management and investigation of NORM.
Collapse
Affiliation(s)
- Jelena Mrdakovic Popic
- Norwegian Radiation and Nuclear Safety Authority (DSA), Grini Næringspark 13, 1861 Østerås, Norway.
| | - Laura Urso
- German Federal Office for Radiation Protection (BfS), Ingolstaedter Landstr. 1, 85764 Oberschleissheim, Germany
| | - Boguslaw Michalik
- Silesian Centre for Environmental Radioactivity, Central Mining Institute (GIG), Plac Gwarków 1, 4-166 Katowice, Poland
| |
Collapse
|
5
|
Mrdakovic Popic J, Haanes H, Di Carlo C, Nuccetelli C, Venoso G, Leonardi F, Trevisi R, Trotti F, Ugolini R, Dvorzhak A, Escribano A, Perez Sanchez D, Real A, Michalik B, Pannecoucke L, Blanchart P, Kallio A, Pereira R, Lourenço J, Skipperud L, Jerome S, Fevrier L. Tools for harmonized data collection at exposure situations with naturally occurring radioactive materials (NORM). ENVIRONMENT INTERNATIONAL 2023; 175:107954. [PMID: 37187003 DOI: 10.1016/j.envint.2023.107954] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/17/2023]
Abstract
Naturally occurring radioactive materials (NORM) contribute to the dose arising from radiation exposure for workers, public and non-human biota in different working and environmental conditions. Within the EURATOM Horizon 2020 RadoNorm project, work is ongoing to identify NORM exposure situations and scenarios in European countries and to collect qualitative and quantitative data of relevance for radiation protection. The data obtained will contribute to improved understanding of the extent of activities involving NORM, radionuclide behaviours and the associated radiation exposure, and will provide an insight into related scientific, practical and regulatory challenges. The development of a tiered methodology for identification of NORM exposure situations and complementary tools to support uniform data collection were the first activities in the mentioned project NORM work. While NORM identification methodology is given in Michalik et al., 2023, in this paper, the main details of tools for NORM data collection are presented and they are made publicly available. The tools are a series of NORM registers in Microsoft Excel form, that have been comprehensively designed to help (a) identify the main NORM issues of radiation protection concern at given exposure situations, (b) gain an overview of materials involved (i.e., raw materials, products, by-products, residues, effluents), c) collect qualitative and quantitative data on NORM, and (d) characterise multiple hazards exposure scenarios and make further steps towards development of an integrated risk and exposure dose assessment for workers, public and non-human biota. Furthermore, the NORM registers ensure standardised and unified characterisation of NORM situations in a manner that supports and complements the effective management and regulatory control of NORM processes, products and wastes, and related exposures to natural radiation worldwide.
Collapse
Affiliation(s)
- Jelena Mrdakovic Popic
- Norwegian Radiation and Nuclear Safety Authority (DSA), Grini Næringspark, 13, Østerås, Norway.
| | - Hallvard Haanes
- Norwegian Radiation and Nuclear Safety Authority (DSA), Grini Næringspark, 13, Østerås, Norway
| | - Christian Di Carlo
- National Institute of Health (ISS), National Centre for Radiation Protection and Computational Physics, Rome, Italy
| | - Cristina Nuccetelli
- National Institute of Health (ISS), National Centre for Radiation Protection and Computational Physics, Rome, Italy
| | - Gennaro Venoso
- National Institute of Health (ISS), National Centre for Radiation Protection and Computational Physics, Rome, Italy
| | - Federica Leonardi
- National Institute for Insurance Against Accidents at Work (INAIL), DiMEILA, Monteporzio Catone, Rome, Italy
| | - Rosabianca Trevisi
- National Institute for Insurance Against Accidents at Work (INAIL), DiMEILA, Monteporzio Catone, Rome, Italy
| | - Flavio Trotti
- Environmental Protection Agency of Veneto (ARPAV), Verona, Italy
| | | | - Alla Dvorzhak
- Research Centre on Energy, Environment and Technology (CIEMAT), Av. Complutense 40, Madrid 28040, Spain
| | - Alicia Escribano
- Research Centre on Energy, Environment and Technology (CIEMAT), Av. Complutense 40, Madrid 28040, Spain
| | - Danyl Perez Sanchez
- Research Centre on Energy, Environment and Technology (CIEMAT), Av. Complutense 40, Madrid 28040, Spain
| | - Almudena Real
- Research Centre on Energy, Environment and Technology (CIEMAT), Av. Complutense 40, Madrid 28040, Spain
| | - Boguslaw Michalik
- Central Mining Institute, Silesian Centre for Environmental Radioactivity (GIG), Plac Gwarków, 1, 40-166 Katowice, Poland
| | - Lea Pannecoucke
- Institute for Radiological Protection and Nuclear Safety, IRSN/PSE-ENV/SEDRE, 92260 Fontenay-aux-Roses, France
| | - Pascale Blanchart
- Institute for Radiological Protection and Nuclear Safety, IRSN/PSE-ENV/SEDRE, 92260 Fontenay-aux-Roses, France
| | - Antti Kallio
- Radiation and Nuclear Safety Authority, (STUK), Lähteentie 2, 96400 Rovaniemi, Finland
| | - Ruth Pereira
- GreenUPorto - Sustainable Agrifood Production Research Centre/Inov4Agro, Department of Biology, Faculty of Sciences of the University of Porto, Campus de Vairão, Rua de Agrária, 747, Vila do Conde, Portugal
| | - Joana Lourenço
- Department of Biology and CESAM, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal
| | - Lindis Skipperud
- Norwegian University of Life Sciences (NMBU), Environmental Chemistry Section, P. O. Box 5003, 1432 Aas, Norway
| | - Simon Jerome
- Norwegian University of Life Sciences (NMBU), Environmental Chemistry Section, P. O. Box 5003, 1432 Aas, Norway
| | - Laureline Fevrier
- Institute for Radiological Protection and Nuclear Safety, IRSN/PSE-ENV/SRTE, 13115 Saint Paul-lez-Durance Cedex, France
| |
Collapse
|
6
|
Rahman Z, Thomas L, Chetri SPK, Bodhankar S, Kumar V, Naidu R. A comprehensive review on chromium (Cr) contamination and Cr(VI)-resistant extremophiles in diverse extreme environments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:59163-59193. [PMID: 37046169 DOI: 10.1007/s11356-023-26624-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/20/2023] [Indexed: 05/10/2023]
Abstract
Chromium (Cr) compounds are usually toxins and exist abundantly in two different forms, Cr(VI) and Cr(III), in nature. Their contamination in any environment is a major problem. Many extreme environments including cold climate, warm climate, acidic environment, basic/alkaline environment, hypersaline environment, radiation, drought, high pressure, and anaerobic conditions have accumulated elevated Cr contamination. These harsh physicochemical conditions associated with Cr(VI) contamination damage biological systems in various ways. However, several unique microorganisms belonging to phylogenetically distant taxa (bacteria, fungi, and microalgae) owing to different and very distinct physiological characteristics can withstand extremities of Cr(VI) in different physicochemical environments. These challenging situations offer great potential and extended proficiencies in extremophiles for environmental and biotechnological applications. On these issues, the present review draws attention to Cr(VI) contamination from diverse extreme environmental regions. The study gives a detailed account on the ecology and biogeography of Cr(VI)-resistant microorganisms in inhospitable environments, and their use for detoxifying Cr(VI) and other applications. The study also focuses on physiological, multi-omics, and genetic engineering approaches of Cr(VI)-resistant extremophiles.
Collapse
Affiliation(s)
- Zeeshanur Rahman
- Department of Botany, Zakir Husain Delhi College, University of Delhi, Delhi, India.
| | - Lebin Thomas
- Department of Botany, Hansraj College, University of Delhi, Delhi, India
| | - Siva P K Chetri
- Department of Botany, Dimoria College, Gauhati University, Guwahati, Assam, India
| | - Shrey Bodhankar
- Department of Agriculture Microbiology, School of Agriculture Sciences, Anurag University, Hyderabad, Telangana, India
| | - Vikas Kumar
- Department of Botany, University of Lucknow, Lucknow, Uttar Pradesh, India
| | - Ravi Naidu
- Global Centre for Environmental Remediation, University of Newcastle, Newcastle, Australia
| |
Collapse
|
7
|
Anderson J, Caron F, Beckett P, Spiers G, Lévesque N, Charbonneau G, Halvorson B, Dufour H, Lock A. Distribution of metals and radionuclides in the lichens Cladonia rangiferina and C. mitis from the past uranium mining region of Elliot Lake, Ontario, Canada. Heliyon 2022; 8:e11863. [PMID: 36544830 PMCID: PMC9761608 DOI: 10.1016/j.heliyon.2022.e11863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/07/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
The present study was performed in the Elliot Lake area (Ontario, Canada), a site of uranium mining and milling for nearly 40 years between 1950's and 1990's. Although mining activities ceased in the mid-1990's, the site hosts several tailings management areas (TMAs) which are under ongoing rehabilitation and monitoring. Several surveys using lichens as a biomonitoring tool were completed in the 1980s and the 1990s to assess the levels of contaminants. The present survey aimed to re-visit the historical surveys, and to determine the current status of environmental recovery of the area. Our survey consisted of sampling two lichen species, Cladonia rangiferina and C. mitis, in an area covering up to 50 km from the former mining operation and the TMAs. The results reported in this work indicated that the levels of metals and radionuclides, diagnostic of mining operations, have decreased over time: particularly, the U, Th and Pb levels in both lichen species dropped by about two orders of magnitude by the 2020's compared to the 1980's. Likewise, the Cs-137 levels in both lichen species reflect present day global background. The study provides a new set of present-day regional baseline elemental concentrations for other metals that are associated with mining (Cd, As, Ti, Cs). Finally, there were weak but statistically significant differences in the levels of some elements (U, Th, Cd) between the two lichens, suggesting these two species might have different capture mechanisms or retention abilities.
Collapse
Affiliation(s)
- J. Anderson
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada,Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6 Canada
| | - F. Caron
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 13 General Crerar Cr Kingston, ON, K7K 7B4 Canada,Corresponding author.
| | - P. Beckett
- Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, P3E 2C6 Canada
| | - G.A. Spiers
- Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, P3E 2C6 Canada
| | - N. Lévesque
- School of Natural Sciences, Laurentian University, 935 Ramsey Lake Rd. Sudbury, ON, P3E 2C6 Canada
| | - G.M. Charbonneau
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada
| | - B. Halvorson
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada
| | - H. Dufour
- Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6 Canada
| | - A. Lock
- School of Natural Sciences, Laurentian University, 935 Ramsey Lake Rd. Sudbury, ON, P3E 2C6 Canada
| |
Collapse
|
8
|
Yang B, Tuo F, Zhou Q, Zhang J, Li Z, Pang C. Dietary exposure of radionuclides and heavy metals in adult residents in a high background natural radiation area using duplicate diet method. Sci Rep 2022; 12:16676. [PMID: 36202835 PMCID: PMC9537425 DOI: 10.1038/s41598-022-19979-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/07/2022] [Indexed: 11/19/2022] Open
Abstract
Intake of radionuclides and heavy metals through food consumption is one of the important pathways for long-term health considerations. In this paper, the dietary exposure to radionuclides (210Pb, 210Po, 226Ra, 228Ra, 40K, 137Cs and 129I) and heavy metals (As, Hg, Pb, Cd and U) of adult residents in the high background natural radiation area (HBNRA) in Yangjiang, China, was comprehensively assessed using duplicate diet method. The estimated effective dose received by the inhabitants in HBNRA from ingestion of radionuclides was 0.33 mSv/y, and the associated lifetime cancer risk was 1.1 × 10–3. Both the dose and cancer risk to humans were at the acceptable range, and showed no difference between the HBNRA and the control area. With respect to heavy metals, the estimated daily intake of heavy metals (DIM) values for As, Hg, Pb, Cd and U in HBNRA were 0.47, 0.03, 15.0, 0.26 and 0.04 μg/kg bw/d, respectively, and the corresponding target hazard quotient (THQ) were 1.58, 0.09, 3.7, 2.56, 0.18. The DIM and THQ of Cd and U in HBNRA were similar to the control area, but the DIM and THQ of Pb were much higher than the corresponding values of 0.39 and 0.03 in the control area. The hazard index (HI) value of heavy metals in HBNRA was almost twice that of the control area. This suggests that the inhabitants in the HBNRA may have a health risk associated with the heavy metals.
Collapse
Affiliation(s)
- Baolu Yang
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Fei Tuo
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China.
| | - Qiang Zhou
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Jing Zhang
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Zeshu Li
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| | - Chaoya Pang
- Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, 100088, China
| |
Collapse
|
9
|
Turcanu C, Perko T, Muric M, Popic JM, Geysmans R, Železnik N. Societal aspects of NORM: An overlooked research field. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 244-245:106827. [PMID: 35114639 DOI: 10.1016/j.jenvrad.2022.106827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/12/2022] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
While technical aspects of exposures to the naturally occurring radioactive material (NORM) are well explored, social science research on NORM is scarce, poorly indexed and dispersed across peer-reviewed literature, as well as various academic disciplines. Through an exploratory review of grey literature and a systematic review of scientific peer-reviewed articles published until December 2020, this paper addresses the following questions: (a) What are the societal challenges related to NORM? (b) What type of scientific research is being conducted on the societal aspects of NORM and (c) To what extent do the findings answer the identified challenges? Unfortunately, results of this study demonstrate a research gap related to the social, economic and cultural aspects of NORM management. Although the few existing studies offer some insights, for instance in relation to risk perception and risk communication, most of the societal challenges identified have not been addressed yet. This demonstrates the strong need for evidence based social science studies in order to improve the management of NORM.
Collapse
Affiliation(s)
- Catrinel Turcanu
- Belgian Nuclear Research Centre SCK CEN, Boeretang 200, 2400, Mol, Belgium.
| | - Tanja Perko
- Belgian Nuclear Research Centre SCK CEN, Boeretang 200, 2400, Mol, Belgium
| | - Melisa Muric
- Belgian Nuclear Research Centre SCK CEN, Boeretang 200, 2400, Mol, Belgium; Department of Political Science, University of Antwerp, Lange Nieuwstraat 55, 2000, Antwerpen, Belgium
| | - Jelena Mrdakovic Popic
- Norwegian Radiation and Nuclear Safety Authority (DSA), Grini næringspark 13, 1361, Østerås, Norway
| | - Robbe Geysmans
- Belgian Nuclear Research Centre SCK CEN, Boeretang 200, 2400, Mol, Belgium
| | - Nadja Železnik
- Milan Vidmar Electric Power Research Institute, Hajdrihova ulica 2, 1000, Ljubljana, Slovenia
| |
Collapse
|
10
|
Fesenko SV, Emlutina ES. Thorium Concentrations in the Environment: A Review of the Global Data. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021110030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Vanhoudt N, Van Gompel A, Vives I Batlle J. Distribution and behaviour of naturally occurring radionuclides within a Scots pine forest grown on a CaF 2 waste deposit related to the Belgian phosphate industry. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 233:106591. [PMID: 33798812 DOI: 10.1016/j.jenvrad.2021.106591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
The distribution and behaviour of naturally occurring radionuclides within a vegetated part of a CaF2 sludge heap from the Belgian phosphate industry was studied. A Scots pine forest plot was selected as study area. Trees were approximately 20 years old and showed a disturbed health state. Seasonal sampling campaigns of soil, roots, wood, inner and outer bark, needles and twigs gave insight on 238U, 226Ra, 210Pb and 210Po transfer and distribution between pine tree compartments. Soil samples were analysed for their texture, total organic and inorganic carbon, field capacity, pH and radionuclide content. Solid-liquid distribution coefficients (Kd) were experimentally determined for 238U, 226Ra (using Ba as analogue) and 210Pb based on adsorption-desorption batch tests. Results indicated higher 238U, 232Th, 226Ra, 210Pb and 210Po activity concentrations in the deeper soil layers while the first 20 cm contained less radionuclides but had a higher level of organic carbon. Additionally, results indicated no seasonal changes in the 238U:226Ra ratio in the soil while the 226Ra:210Pb ratio was significantly higher in spring compared to winter in the 20-60 cm soil layer. Pine tree roots served as natural translocation barrier for all radionuclides with high retention in the roots and low translocation to the above ground tree compartments. When considering the above ground compartments, 210Pb and 210Po were mostly present in the bark, needles and twigs. Furthermore, 238U and its progeny were highly accumulated in mosses. These results allowed us to establish more realistic soil-to-plant transfer factors. In addition, experimentally mimicking pore water acidification in the root zone resulted in lower 238U and 210Pb Kd values compared to using a standard CaCl2 solution. This study provides an integrated radioecological picture of knowledge and site specific data needed to study the long-term influence of vegetation on radionuclide dispersion in forest ecosystems.
Collapse
Affiliation(s)
- Nathalie Vanhoudt
- Biosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium.
| | - Axel Van Gompel
- Biosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
| | - Jordi Vives I Batlle
- Biosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
| |
Collapse
|
12
|
Haanes H, Gjelsvik R. Reduced soil fauna decomposition in a high background radiation area. PLoS One 2021; 16:e0247793. [PMID: 33730078 PMCID: PMC7968631 DOI: 10.1371/journal.pone.0247793] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/12/2021] [Indexed: 11/23/2022] Open
Abstract
Decomposition of litter and organic matter is a very important soil ecosystem function where soil fauna play an important role. Knowledge of the responses in decomposition and soil fauna to different stressors is therefore crucial. However, the extent to which radioactivity may affect soil fauna is not so well known. There are some results showing effects on soil fauna at uranium mines and near Chernobyl from relatively high levels of anthropogenic radionuclides. We hypothesize that naturally occurring radionuclides affect soil fauna and thus litter decomposition, which will covary with radionuclide levels when accounting for important soil parameters. We have therefore used standardised litterbags with two different mesh sizes filled with birch leaves (Betula pubescens) to assess litter decomposition in an area with enhanced levels of naturally occurring radionuclides in the thorium (232Th) and uranium (238U) decay chains while controlling for variation in important soil parameters like pH, organic matter content, moisture and large grain size. We show that decomposition rate is higher in litterbags with large mesh size compared to litterbags with a fine mesh size that excludes soil fauna. We also find that litter dried at room temperature is decomposed at a faster rate than litter dried in oven (60⁰C). This was surprising given the associated denaturation of proteins and anticipated increased nutritional level but may be explained by the increased stiffness of oven-dried litter. This result is important since different studies often use either oven-dried or room temperature-dried litter. Taking the above into account, we explore statistical models to show large and expected effects of soil parameters but also significant effects on litter decomposition of the naturally occurring radionuclide levels. We use the ERICA tool to estimate total dose rate per coarse litterbag for four different model organisms, and in subsequent different statistical models we identify that the model including the dose rates of a small tube-shape is the best statistical model. In another statistical model including soil parameters and radionuclide distributions, 226Ra (or uranium precursory radionuclides) explain variation in litter decomposition while 228Ra (and precursors) do not. This may hint to chemical toxicity effects of uranium. However, when combining this model with the best model, the resulting simplified model is equal to the tube-shape dose-rate model. There is thus a need for more research on how naturally occurring radionuclides affect soil fauna, but the study at hand show the importance of an ecosystem approach and the ecosystem parameter soil decomposition.
Collapse
Affiliation(s)
- Hallvard Haanes
- Norwegian Radiation and Nuclear Safety Authority, Østerås, Norway
- Centre for Environmental Radioactivity (CERAD CoE), NMBU, Ås, Norway
- * E-mail:
| | - Runhild Gjelsvik
- Norwegian Radiation and Nuclear Safety Authority, Østerås, Norway
- Centre for Environmental Radioactivity (CERAD CoE), NMBU, Ås, Norway
| |
Collapse
|
13
|
Popic JM, Skipperud L. Evaluation of uncertainties in environmental impact assessment of naturally occurring radiation exposure situations on example of undisturbed and legacy NORM sites in the Fen Complex, Norway. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:782. [PMID: 33236230 DOI: 10.1007/s10661-020-08747-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
The risk from naturally occurring radioactive materials (NORM) has been extensively assessed, and this has led to the integration of specific NORM radiation protection requirements within the latest EU Directive 2013/59. Nevertheless, it has been internationally recognised that remaining NORM knowledge gaps and uncertainties now present similarly significant issues in addressing recent regulatory requirements. The multi-tiered nature of environmental impact assessment (EIA) implies per se possibility for uncertainties, but when EIA at radiation exposure sites includes consideration of sites with multiple radiation and contamination sources, different ecosystem transport pathways, effects and risks by applying different parameters and models, level of overall uncertainty increases. The results of EIA study in the Fen area in Norway, comprised of undisturbed and legacy NORM sites, have been evaluated in this analysis, in order to identify all existing input uncertainties and how they may impact the final conclusions, and thus, influence any subsequent decision-making. The main uncertainties have been identified in the measurement and exposure analysis tier, and were related to the heterogeneous distribution of radionuclides, radionuclide speciation, as well as to generic variability issues in the concepts used for mobility and biota uptake analysis (such as distribution coefficient, transfer factors and concentration ratios) as well as radioecological modelling. The uncertainties in the input values to the calculation of the dose arising from radon exposure in the Fen area led to an overall elevated uncertainty of the magnitude of the radiation exposure dose of humans. It has been concluded that an integrated, ecosystem-based approach with consideration of complexity of prevailing environmental conditions and interconnections must be applied to fully understand possible radiation effects and risks.
Collapse
Affiliation(s)
| | - Lindis Skipperud
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences (NMBU), Ås, Norway
| |
Collapse
|
14
|
Thørring H, Wærsted FM, Raaness A, Skipperud L, Jensen LK. Elevated natural radioactivity in undisturbed forest and mountain areas of arctic Norway - local geology, soil characteristics, and transfer to biota. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 222:106291. [PMID: 32771855 DOI: 10.1016/j.jenvrad.2020.106291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/24/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
This study deals with the geology in areas close to a large unexploited uranium deposit and the impact of bedrock characteristics on levels of radionuclides and other elements in soil and biota. Factors influencing soil inventory and ecosystem transfer are discussed, focussing on 238U, 226Ra, and 210Pb. Field work was carried out in Salangen Valley in Northern Norway. Sampling stations for soil and biota covered different habitats - grassland, birch forest and low alpine heathland. The geological survey confirmed uranium-bearing minerals in granitic gneiss and pegmatites. There was large variation in the local occurrence of uranium, reflecting the irregular nature of the pegmatite. Activity concentrations of 238U, 226Ra, and 210Pb in surface soil were elevated at sites close to U-enhanced bedrock, compared to sites with other types of bedrock. Particularly high soil levels were found for 226Ra and 210Pb, whereas activity concentrations of 238U were more variable, depending of local soil characteristics. Levels of other natural radionuclides (40K, 232Th) merely increased with soil mineral content, and concentrations of heavy metals were generally low at all sites. External dose rate (1 m above ground surface) was closely correlated with 226Ra levels in soil. Plant levels of 238U and 226Ra varied by several orders of magnitude depending on soil level and plant species, whereas plant levels of 210Pb and 210Po were largely affected by aerial fallout. Berries generally contained lower levels of 238U and 226Ra than green plant parts. As was the case for plants, the levels of 238U in earthworms were strongly correlated with the respective concentrations in the soil. Soil-to-plant transfer was markedly higher for 226Ra than for 238U. For both radionuclides, a positive correlation was found between concentration ratios of V. myrtillus (heath) and soil organic matter content. The 238U concentration ratios for earthworms were generally two orders of magnitude higher than for plants.
Collapse
Affiliation(s)
- Håvard Thørring
- Norwegian Radiation and Nuclear Safety Authority, P.O. Box 329, Skøyen, 0213, Oslo, Norway; Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Frøydis Meen Wærsted
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Faculty of Environmental Science and Nature Resource Management, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås, Norway
| | - Agnes Raaness
- Geological Survey of Norway, P.O. Box 6315 Torgarden, NO-7491, Trondheim, Norway
| | - Lindis Skipperud
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Faculty of Environmental Science and Nature Resource Management, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås, Norway
| | - Louise Kiel Jensen
- Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Norwegian Radiation and Nuclear Safety Authority, P.O. Box 6606 Langnes, 9296, Tromsø, Norway.
| |
Collapse
|
15
|
Pandit P, Mangala P, Saini A, Bangotra P, Kumar V, Mehra R, Ghosh D. Radiological and pollution risk assessments of terrestrial radionuclides and heavy metals in a mineralized zone of the siwalik region (India). CHEMOSPHERE 2020; 254:126857. [PMID: 32353810 DOI: 10.1016/j.chemosphere.2020.126857] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 04/08/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
The present study reveals the distribution of terrestrial radionuclides (226Ra, 232Th and 40K) and heavy metals (Cr, Ni, Cu, Zn, Pb, Co) from soil samples of Una, Hamirpur and Kangra districts of Himachal Pradesh (India). The 226Ra, 232Th, 40K activity concentration in the studied region has been varied from 8 to 3593 Bq kg-1; 21-370 Bq kg-116; 62-7130 Bq kg-1 respectively. High disequilibrium factor (238U/226Ra) depicts that uranium constantly migrates from clay oxidizing zone and getting precipitated with enrichment towards south. An attempt has been made to correlate the distribution of these radionuclides and heavy metals with geology and rock type formation of Siwalik region. The concentration of Pb, Zn and Co was found higher than Indian average background value. Multiple radiological and pollution indices have been estimated for proper risk analysis in the studied region. The annual effective dose in studied region is lower than the recommended limit of 1.0 mSv a-1. The obtained geo-accumulation index and enrichment factor indicated that the sites located in the Hamirpur and Kangra regions were moderately contaminated with Pb and Co. The Nemerow pollution index and contamination security index suggested that almost 45% sites were slightly to moderately polluted. The non-carcinogenic and carcinogenic risks for both children and adults were within acceptable limits.
Collapse
Affiliation(s)
- Pragya Pandit
- Atomic Minerals Directorate for Exploration and Research, New Delhi, 110066, India.
| | - Preeti Mangala
- Atomic Minerals Directorate for Exploration and Research, New Delhi, 110066, India
| | - Atul Saini
- Department of Geography, Delhi School of Economics, University of Delhi, Delhi, 110007, India
| | - Pargin Bangotra
- Material Research Laboratory, Deptt of Physics, SBSR, Sharda University, Greater Noida, 201310, India
| | - Vinod Kumar
- Department of Botany, Government Degree College, Ramban, 182144, India
| | - Rohit Mehra
- B. R. Ambedkar National Institute of Technology, Jalandhar, 144011, India
| | - Dibakar Ghosh
- Atomic Minerals Directorate for Exploration and Research, New Delhi, 110066, India
| |
Collapse
|
16
|
Cagno S, Lind OC, Popic JM, Skipperud L, De Nolf W, Nuyts G, Vanmeert F, Jaroszewicz J, Janssens K, Salbu B. Micro-analytical characterization of thorium-rich aggregates from Norwegian NORM sites (Fen Complex, Telemark). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 219:106273. [PMID: 32339145 DOI: 10.1016/j.jenvrad.2020.106273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/05/2020] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
In this study we performed microscopic characterization of mineral particles that were collected in the thorium-rich Fen Complex in Norway and identified and isolated based on autoradiography in function of their radioactivity. For this we combined information obtained with X-ray absorption μ-CT, μ-XRF and μ-XRD, both in bi- and in three-dimensional (tomographic) mode. We demonstrate that radionuclides and metals are heterogeneously distributed both within soil samples and within individual Th-enriched aggregates, which are characterised as low-density mineral bulk particles with high density material inclusions, where Th as well as several metals are highly concentrated. For these sites, it is important to take into account how these inhomogeneous distributions could affect the overall environmental behaviour of Th and progeny upon weathering due to human or environmental factors. Moreover, the estimated size of the Th-containing inclusions as determined in this work represents information of importance for the characterization of radionuclides and toxic metals exposure, as well as for assessing the viability of mining for Th and rare-earth metals in the Fen Complex and the associated environmental impact.
Collapse
Affiliation(s)
- Simone Cagno
- Norwegian University of Life Sciences, Center of Excellence in Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1433 Ås, Norway.
| | - Ole Christian Lind
- Norwegian University of Life Sciences, Center of Excellence in Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1433 Ås, Norway
| | - Jelena Mrdakovic Popic
- Norwegian University of Life Sciences, Center of Excellence in Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1433 Ås, Norway; Norwegian Radiation and Nuclear Safety Authority (DSA), PO Box 329 Skøyen, 0213, Oslo, Norway
| | - Lindis Skipperud
- Norwegian University of Life Sciences, Center of Excellence in Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1433 Ås, Norway
| | - Wout De Nolf
- European Synchrotron Radiation Facility, Avenue des Martyrs 71, 38043, Grenoble Cedex 9, France
| | - Gert Nuyts
- AXES, University of Antwerp, Groenenborgerlaan 121, 2020, Antwerpen, Belgium
| | - Frederik Vanmeert
- AXES, University of Antwerp, Groenenborgerlaan 121, 2020, Antwerpen, Belgium
| | - Jakub Jaroszewicz
- Faculty of Materials Science, Warsaw University of Technology, Woloska 141, 02-507, Warsaw, Poland
| | - Koen Janssens
- AXES, University of Antwerp, Groenenborgerlaan 121, 2020, Antwerpen, Belgium
| | - Brit Salbu
- Norwegian University of Life Sciences, Center of Excellence in Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, 1433 Ås, Norway
| |
Collapse
|
17
|
Sneve MK, Smith K, Mrdakovic Popic J. Practical radioecology support in the management and regulatory supervision of legacy sites. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2020; 40:487-504. [PMID: 31829987 DOI: 10.1088/1361-6498/ab614e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Legacy sites are a global issue. Experience has shown that every legacy site is different and case-specific management and remediation options have to be considered. Each site presents a unique mix of physical, chemical and radiological hazards and the significance of those hazards is likely to change over time. A life-cycle approach to remediation is therefore appropriate, with priority consideration allocated according to the major hazards, as technically determined by reference to policy on protection objectives and the corresponding regulatory requirements. Additionally, consideration will typically need to be given to wider issues as may be raised by stakeholders. The remediation approach also needs to take account of the waste management options on-site or involving off-site management and disposal. Radiological and wider environmental impact assessments are a crucial part of the holistic evaluation of hazards and risks (along with economic and societal impacts), which in turn underpin project planning, regulatory and wider decision making. This paper examines the role of radioecology in the assessment process, its contribution to reduction of scientific uncertainties in modelling ecosystem processes of release, transport and fate of radionuclides and evaluation of potential ensuing impacts on humans and the environment. Relevant examples are presented to illustrate the complexities of the processes in regulatory decision making, the various conditions that significantly affect the final solutions and how radioecology can be used in these situations. Whilst a case-specific approach will usually need to be taken to legacy sites, future remediation and clean-up work can be helpfully informed through sharing of experience from other sites. Continued international collaboration between all parties involved in legacy site management is therefore needed to inform on the development of practical regulatory guidance and to ensure that radioecological research is focussed on addressing the key issues that give rise to uncertainties that challenge regulatory and wider decision making.
Collapse
Affiliation(s)
- Malgorzata K Sneve
- Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, NO-1361, Østerås, Norway
| | | | | |
Collapse
|
18
|
Mrdakovic Popic J, Oughton DH, Salbu B, Skipperud L. Transfer of naturally occurring radionuclides from soil to wild forest flora in an area with enhanced legacy and natural radioactivity in Norway. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:350-363. [PMID: 31939460 DOI: 10.1039/c9em00408d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A study of transfer of naturally occurring radioactive materials (NORM), thorium, uranium and their progeny, from soil to wild plant species was performed to evaluate the environmental impact in an area of enhanced natural and legacy radioactivity in Norway. Three sites were chosen for the study: NORM legacy mining, undisturbed 232Th-rich site and reference site. Tissue concentrations, transfer factors and radiation exposure doses were determined in nine wild plant species. High soil activity concentrations of NORM, statistically indistinguishable, were measured at legacy NORM and undisturbed 232Th-rich sites, respectively, while soil from the reference site exhibited a statistically lower activity concentration. Heterogeneous soil radionuclide distributions were observed. The mobile soil fraction of investigated radionuclides was significantly lower, but properly reflected in measured plant uptake. Plant tissue activity concentrations of NORM were significantly higher at both investigated 232Th-rich sites in comparison to the reference site and varied per plant species and analyzed radionuclide, for instance, from non-detectable 232Th in tree needles and leaves to significantly elevated values of measured 210Po in lichens. As expected, plant roots served as a natural translocation barrier, as the concentration of radionuclides in the analyzed samples was up to 88-fold higher than that in the corresponding aboveground plants. Transfer factors for 232Th, 238U, 226,228Ra and 210Po in the aboveground plants ranged broadly from 4 × 10-5 to 1 × 10-2; 1 × 10-4 to 4 × 10-2, 1.07 × 10-3 to 1.08; 2.18 × 10-2 to 9.53 × 10-2 and 9.18 × 10-2 to 9.69, respectively. Radiological exposure dose rates, calculated using the ERICA tool and site-specific data, were from 1 to 23 μGy h-1. Due to elevated NORM levels in analyzed plants, measured radiation exposure dose rates were higher than those of worldwide background biota. Still, the uptake of NORM, demonstrated in the current study, is not expected to cause significant changes at population levels in wild plant species.
Collapse
Affiliation(s)
- Jelena Mrdakovic Popic
- Norwegian Radiation and Nuclear Safety Authority (DSA), Østerås, Norway. and Centre for Environmental Radioactivity (CERAD), Ås, Norway
| | - Deborah H Oughton
- Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, Ås, Norway and Centre for Environmental Radioactivity (CERAD), Ås, Norway
| | - Brit Salbu
- Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, Ås, Norway and Centre for Environmental Radioactivity (CERAD), Ås, Norway
| | - Lindis Skipperud
- Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, Ås, Norway and Centre for Environmental Radioactivity (CERAD), Ås, Norway
| |
Collapse
|
19
|
Salbu B, Kashparov V, Lind OC, Garcia-Tenorio R, Johansen MP, Child DP, Roos P, Sancho C. Challenges associated with the behaviour of radioactive particles in the environment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 186:101-115. [PMID: 28941957 DOI: 10.1016/j.jenvrad.2017.09.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
A series of different nuclear sources associated with the nuclear weapon and fuel cycles have contributed to the release of radioactive particles to the environment. Following nuclear weapon tests, safety tests, conventional destruction of weapons, reactor explosions and fires, a major fraction of released refractory radionuclides such as uranium (U) and plutonium (Pu) were present as entities ranging from sub microns to fragments. Furthermore, radioactive particles and colloids have been released from reprocessing facilities and civil reactors, from radioactive waste dumped at sea, and from NORM sites. Thus, whenever refractory radionuclides are released to the environment following nuclear events, radioactive particles should be expected. Results from many years of research have shown that particle characteristics such as elemental composition depend on the source, while characteristics such as particle size distribution, structure, and oxidation state influencing ecosystem transfer depend also on the release scenarios. When radioactive particles are deposited in the environment, weathering processes occur and associated radionuclides are subsequently mobilized, changing the apparent Kd. Thus, particles retained in soils or sediments are unevenly distributed, and dissolution of radionuclides from particles may be partial. For areas affected by particle contamination, the inventories can therefore be underestimated, and impact and risk assessments may suffer from unacceptable large uncertainties if radioactive particles are ignored. To integrate radioactive particles into environmental impact assessments, key challenges include the linking of particle characteristics to specific sources, to ecosystem transfer, and to uptake and retention in biological systems. To elucidate these issues, the EC-funded COMET and RATE projects and the IAEA Coordinated Research Program on particles have revisited selected contaminated sites and archive samples. This COMET position paper summarizes new knowledge on key sources that have contributed to particle releases, including particle characteristics based on advanced techniques, with emphasis on particle weathering processes as well as on heterogeneities in biological samples to evaluate potential uptake and retention of radioactive particles.
Collapse
Affiliation(s)
- Brit Salbu
- CERAD CoE Environmental Radioactivity, Faculty of Environmental Sciences and Nature Resource Management, Norwegian University of Life Sciences (NMBU), 1432 Aas, Norway.
| | - Valery Kashparov
- CERAD CoE Environmental Radioactivity, Faculty of Environmental Sciences and Nature Resource Management, Norwegian University of Life Sciences (NMBU), 1432 Aas, Norway; National University of Life and Environmental Sciences of Ukraine (NUBiP of Ukraine), Ukraine
| | - Ole Christian Lind
- CERAD CoE Environmental Radioactivity, Faculty of Environmental Sciences and Nature Resource Management, Norwegian University of Life Sciences (NMBU), 1432 Aas, Norway
| | | | - Mathew P Johansen
- Australian Nuclear Science and Technology Organization (ANSTO), Australia
| | - David P Child
- Australian Nuclear Science and Technology Organization (ANSTO), Australia
| | - Per Roos
- Technical University of Denmark (DTU), Denmark
| | - Carlos Sancho
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Spain
| |
Collapse
|
20
|
Haanes H, Finne IE, Kolstad T, Mauring A, Dahlgren S, Rudjord AL. Outdoor thoron and progeny in a thorium rich area with old decommissioned mines and waste rock. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 162-163:23-32. [PMID: 27214284 DOI: 10.1016/j.jenvrad.2016.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/29/2016] [Accepted: 05/09/2016] [Indexed: 06/05/2023]
Abstract
Radon (222Rn), thoron (220Rn) and their decay products may reach high levels in areas of high natural background radiation, with increased risk associated with mining areas. Historically, the focus has mostly been placed upon radon and progeny (RnP), but recently there have been reports of significant contributions to dose from thoron progeny (TnP). However, few direct measurements of TnP exist under outdoor conditions. Therefore, we assessed the outdoor activity concentrations of radon, thoron and TnP in an area of igneous bedrock with extreme levels of radionuclides in the thorium decay series. The area is characterized by decommissioned mines and waste rock deposits, which provide a large surface area for radon and thoron emanation and high porosity enhancing exhalation. Extreme levels of thorium and thoron have previously been reported from this area and to improve dose rate estimates we also measured TnP using filter sampling and time-integrating alpha track detectors. We found high to extreme levels of thoron and TnP and the associated dose rates relevant for inhalation were up to 8 μSvh-1 at 100 cm height. Taking gamma irradiation and RnP into account, significant combined doses may result from occupancies in this area. This applies to recreational use of the area and especially previous and planned road-works, which in the worst case could involve doses as large as 23.4 mSv y-1. However, radon and thoron levels were much more intense on a hot September day than during time-integrated measurements made the subsequent colder and wetter month, especially along the ground. This may be explained by cold air observed flowing out from inside the mines through a drainage pipe adjacent to the measurement stations. During warm periods, activity concentrations may therefore be due to both local exhalation from the ground and air ventilating from the mines. However, a substantially lower level of TnP was measured on the September day using filter sampling, as compared to what was measured with time-integrative alpha track detectors. A possible explanation could be reduced filter efficiency related to the attached progeny of some aerosol sizes, but a more likely cause is an upwards bias on TnP detectors associated with assumed deposition velocity, which may be different in outdoor conditions with wind or a larger fraction of unattached progeny. There is thus a need for better instrumentation when dealing with outdoor TnP.
Collapse
Affiliation(s)
- Hallvard Haanes
- Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Østerås, Norway; Centre for Environmental Radioactivity (CERAD CoE), P.O. Box 5003, NO-1432 Ås, Norway.
| | - Ingvild E Finne
- Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Østerås, Norway
| | - Trine Kolstad
- Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Østerås, Norway
| | - Alexander Mauring
- Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Østerås, Norway
| | - Sven Dahlgren
- Buskerud Telemark Vestfold County Councils, Fylkeshuset, P.O. 2163, NO-3103 Tønsberg, Norway
| | - Anne Liv Rudjord
- Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Østerås, Norway
| |
Collapse
|
21
|
Song Y, Salbu B, Teien HC, Evensen Ø, Lind OC, Rosseland BO, Tollefsen KE. Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 562:270-279. [PMID: 27100007 DOI: 10.1016/j.scitotenv.2016.03.222] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/24/2016] [Accepted: 03/28/2016] [Indexed: 06/05/2023]
Abstract
Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using gamma radiation (Gamma) and depleted uranium (DU) as stressors, representing a combination of radiological (radiation) and chemical (metal) exposure. Juvenile Atlantic salmon (Salmo salar) were exposed to 70mGy external Gamma dose delivered over the first 5h of a 48h period (14mGy/h), 0.25mg/L DU were exposed continuously for 48h and the combination of the two stressors (Combi). Water and tissue concentrations of U were determined to assess the exposure quality and DU bioaccumulation. Hepatic gene expression changes were determined using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Effects at the higher physiological levels were determined as plasma glucose (general stress) and hepatic histological changes. The results show that bioaccumulation of DU was observed after both single DU and the combined exposure. Global transcriptional analysis showed that 3122, 2303 and 3460 differentially expressed genes (DEGs) were significantly regulated by exposure to gamma, DU and Combi, respectively. Among these, 349 genes were commonly regulated by all treatments, while the majority was found to be treatment-specific. Functional analysis of DEGs revealed that the stressors displayed similar mode of action (MoA) across treatments such as induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation, but also stressor-specific mechanisms such as cellular stress and injury, metabolic disorder, programmed cell death, immune response. No changes in plasma glucose level as an indicator of general stress and hepatic histological changes were observed. Although no direct linkage was successfully established between molecular responses and adverse effects at the organism level, the study has enhanced the understanding of the MoA of single radionuclides and mixtures of these.
Collapse
Affiliation(s)
- You Song
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway; Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
| | - Brit Salbu
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway
| | - Hans-Christian Teien
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway
| | - Øystein Evensen
- Norwegian University of Life Sciences (NMBU), Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo, Norway
| | - Ole Christian Lind
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway
| | - Bjørn Olav Rosseland
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway; Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management (INA), P.O. Box 5003, N-1432 Ås, Norway
| | - Knut Erik Tollefsen
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity (CERAD), P.O. Box 5003, N-1432 Ås, Norway; Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway
| |
Collapse
|
22
|
Wang ZT, Zheng J, Tagami K, Uchida S. Newly derived transfer factors for Th, Am, Pu, and Cl since publication of IAEA TRS No. 472: a review. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4260-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
23
|
Damascena KFR, dos Santos Amaral R, dos Santos Júnior JA, Genezini FA, da Silva AA, Menezes RSC. Rare-earth elements in uranium deposits in the municipality of Pedra, Pernambuco, Brazil. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-3934-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
24
|
On the radiological assessment of natural and fallout radioactivity in a natural high background radiation area at Odisha, India. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3814-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
25
|
Mrdakovic Popic J, Meland S, Salbu B, Skipperud L. Mobility of radionuclides and trace elements in soil from legacy NORM and undisturbed naturally 232Th-rich sites. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:1124-1134. [PMID: 24699890 DOI: 10.1039/c3em00569k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Investigation of radionuclides (232Th and 238U) and trace elements (Cr, As and Pb) in soil from two legacy NORM (former mining sites) and one undisturbed naturally 232Th-rich site was conducted as a part of the ongoing environmental impact assessment in the Fen Complex area (Norway). The major objectives were to determine the radionuclide and trace element distribution and mobility in soils as well as to analyze possible differences between legacy NORM and surrounding undisturbed naturally 232Th-rich soils. Inhomogeneous soil distribution of radionuclides and trace elements was observed for each of the investigated sites. The concentration of 232Th was high (up to 1685 mg kg(-1), i.e., ∼7000 Bq kg(-1)) and exceeded the screening value for the radioactive waste material in Norway (1 Bq g(-1)). Based on the sequential extraction results, the majority of 232Th and trace elements were rather inert, irreversibly bound to soil. Uranium was found to be potentially more mobile, as it was associated with pH-sensitive soil phases, redox-sensitive amorphous soil phases and soil organic compounds. Comparison of the sequential extraction datasets from the three investigated sites revealed increased mobility of all analyzed elements at the legacy NORM sites in comparison with the undisturbed 232Th-rich site. Similarly, the distribution coefficients Kd (232Th) and Kd (238U) suggested elevated dissolution, mobility and transportation at the legacy NORM sites, especially at the decommissioned Nb-mining site (346 and 100 L kg(-1) for 232Th and 238U, respectively), while the higher sorption of radionuclides was demonstrated at the undisturbed 232Th-rich site (10,672 and 506 L kg(-1) for 232Th and 238U, respectively). In general, although the concentration ranges of radionuclides and trace elements were similarly wide both at the legacy NORM and at the undisturbed 232Th-rich sites, the results of soil sequential extractions together with Kd values supported the expected differences between sites as the consequences of previous mining operations. Hence, mobility and possible elevated bioavailability at the legacy NORM site could be expected and further risk assessment should take this into account when decisions about the possible intervention measures are made.
Collapse
Affiliation(s)
- Jelena Mrdakovic Popic
- Norwegian University of Life Sciences, Centre for Environmental Radioactivity, 1432 Ås, Norway.
| | | | | | | |
Collapse
|
26
|
Mrdakovic Popic J, Raj Bhatt C, Salbu B, Skipperud L. Outdoor220Rn,222Rn and terrestrial gamma radiation levels: investigation study in the thorium rich Fen Complex, Norway. ACTA ACUST UNITED AC 2012; 14:193-201. [DOI: 10.1039/c1em10726g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
27
|
Mrdakovic Popic J, Salbu B, Skipperud L. Ecological transfer of radionuclides and metals to free-living earthworm species in natural habitats rich in NORM. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 414:167-176. [PMID: 22115612 DOI: 10.1016/j.scitotenv.2011.10.064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/23/2011] [Accepted: 10/25/2011] [Indexed: 05/31/2023]
Abstract
Transfer of radionuclides ((232)Th and (238)U) and associated metals (As, Cd, Pb and Cr) from soil to free-living earthworm species was investigated in a thorium ((232)Th) rich area in Norway. Sampling took place within former mining sites representing the technologically enhanced naturally occurring radioactive materials (TENORM), at undisturbed site with unique bedrock geology representing the naturally occurring radioactive materials (NORM) and at site outside the (232)Th rich area taken as reference Background site. Soil analysis revealed the elevated levels of investigated elements at NORM and TENORM sites. Based on sequential extraction, uranium ((238)U) and cadmium (Cd) were quite mobile, while the other elements were strongly associated with mineral components of soil. Four investigated earthworm species (Aporrectodea caliginosa, Aporrectodea rosea, Dendrodrilus rubidus and Lumbricus rubellus) showed large individual variability in the accumulation of radionuclides and metals. Differences in uptake by epigeic and endogeic species, as well as differences within same species from the NORM, TENORM and Background sites were also seen. Based on total concentrations in soil, the transfer factors (TF) were in ranges 0.03-0.08 and 0.09-0.25, for (232)Th and (238)U, respectively. TFs for lead (Pb), chromium (Cr) and arsenic (As) were low (less than 0.5), while TFs for Cd were higher (about 10). Using the ERICA tool, the estimated radiation exposure dose rate of the earthworms ranged from 2.2 to 3.9 μGy/h. The radiological risk for investigated earthworms was low (0.28). The obtained results demonstrated that free-living earthworm species can survive in soil containing elevated (232)Th and (238)U, as well As, Cd, Pb and Cr levels, although certain amount of radionuclides was accumulated within their bodies. The present investigation contributes to general better understanding of complex soil-to-biota transfer processes of radionuclides and metals and to assessment of risk for non-human species in the ecosystem with multiple contaminants.
Collapse
Affiliation(s)
- Jelena Mrdakovic Popic
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, N-1432 Ås, Norway.
| | | | | |
Collapse
|