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Zhao X, Hou X, Huang Z, Tang L. Source, preservation and re-suspension of 239,240Pu in a well dated peat core collected from northwest China. CHEMOSPHERE 2024; 359:142267. [PMID: 38719122 DOI: 10.1016/j.chemosphere.2024.142267] [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: 11/28/2023] [Revised: 04/21/2024] [Accepted: 05/04/2024] [Indexed: 05/12/2024]
Abstract
Owning to the high radiotoxicity in high concentrations, as well as the irreplaceability in quantifying soil erosion rates, demarcating the Anthropocene, and dating of sediment, anthropogenic 239,240Pu have drawn high attention. However, the source in specific areas, preservation characteristics in different environment media, and re-distribution process after the cessation of atmospheric nuclear weapons tests, have not been fully understood, which obscures the exact start year, temporal variation, and deposition flux of 239,240Pu in sedimentary records, and hinders the wide application of 239,240Pu in environment study. A sediment core from the Yiwu peat bog with dominance of atmospheric deposition in the source material, simple sedimentary environment, and high dust deposition flux, was collected to examine the 239,240Pu, and explore the source, preservation, and re-distribution process. The double peaks of 239,240Pu in 1952 CE and 1963 CE, as well as 240Pu/239Pu ratios of 0.163-0.190 with an average of 0.177 ± 0.010 confirmed that the 239,240Pu source originated predominantly from global fallout. The minimal vertical migration of plutonium in the Yiwu peat core was attributed to the near-neutral pH condition. The high inventory of 128 ± 7 Bq m-2, as well as the atypical negative correlation between 239,240Pu concentrations and organic matter content (r = - 0.79, P < 0.01), was attributed to the contribution of 239,240Pu re-suspended with dust from the neighboring Gobi Desert, particularly in the cold and dry years. The total re-suspended 239,240Pu was estimated to be 77 Bq m-2, exceeding the direct fallout level of 51 Bq m-2 during 1945-2016 CE. In this study, the specified deposition pattern of 239,240Pu after the cessation of atmospheric nuclear weapons was established, providing an important standard for multiple environmental studies, and the re-suspended amount of 239,240Pu in a typical arid area was quantified for the first time.
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Affiliation(s)
- Xue Zhao
- State Key Laboratory of Loess Science, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, PR China; Xi'an Institute for Innovative Earth Environment Research, Xi'an, 710061, PR China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266061, PR China
| | - Xiaolin Hou
- State Key Laboratory of Loess Science, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, PR China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266061, PR China.
| | - Zhao Huang
- State Key Laboratory of Loess Science, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Lu Tang
- Xi'an Institute for Innovative Earth Environment Research, Xi'an, 710061, PR China
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Peng A, Chen M, Li X, He H. The records of 239+240Pu and 137Cs of global fallout in Lake East Dongting Sediments and Responses to watershed environmental changes. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 272:107364. [PMID: 38171109 DOI: 10.1016/j.jenvrad.2023.107364] [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: 10/26/2023] [Revised: 12/23/2023] [Accepted: 12/24/2023] [Indexed: 01/05/2024]
Abstract
Plutonium-239 + 240 and 137Cs in the environment can usually be used to track the impact of nuclear activities on the environment, and have become important tools in environmental geochemical studies. In this study, nine sediment cores (E1-E9) in Lake East Dongting were collected and measured for the activity concentration of 239+240Pu, 137Cs and the atomic ratio of 240Pu/239Pu, and then their vertical distribution characteristics were analyzed. The results show that: the activity concentrations of 137Cs and 239+240Pu in Lake East Dongting ranged from 5.26 ± 0.43 to 28.6 ± 2.23 Bq kg-1 and 0.29 ± 0.02 to 1.37 ± 0.09 Bq kg-1, with an average of 7.48 ± 0.68 Bq kg-1 and 0.39 ± 0.03 Bq kg-1, respectively. The atomic ratios of 240Pu/239Pu are 0.168 ± 0.012-0.211 ± 0.015, which are basically consistent with the global atmospheric deposition. The vertical profiles of 137Cs and 239+240Pu in sediment cores show obvious single-peak distribution in E1-E6 and bimodal distribution in E7-E9. The results of sedimentation rates calculated by 137Cs and 239+240Pu method ranged from 0.59 cm y-1 to 1.99 cm y-1 with a mean of 1.18 cm y-1 and 0.61 cm y-1 to 2.18 cm y-1 with a mean of 1.26 cm y-1. The inventories of 137Cs and 239+240Pu in nine sediment cores are 5.87-10.8 kBq m-2 and 307-545 Bq m-2, which are about 8-14 and 9-15 times the inventory in the global average atmospheric deposition at the same latitude respectively. Comparing the results of the sedimentation rates and the inventories from different sampling points indicates that extreme climatic events and human activities have a significant impact on sediment environment of Lake East Dongting.
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Affiliation(s)
- Anguo Peng
- School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China.
| | - Mengting Chen
- School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
| | - Xuebin Li
- School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
| | - Husheng He
- School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
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3
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Dowell SM, Barlow TS, Chenery SR, Humphrey OS, Isaboke J, Blake WH, Osano O, Watts MJ. Optimisation of plutonium separations using TEVA cartridges and ICP-MS/MS analysis for applicability to large-scale studies in tropical soils. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:4226-4235. [PMID: 37584161 DOI: 10.1039/d3ay01030a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
The analysis of plutonium (Pu) in soil samples can inform the understanding of soil erosion processes globally. However, there are specific challenges associated for analysis in tropical soils and so an optimal analytical methodology ensuring best sensitivity is critical. This method aimed to demonstrate the feasibility of sample preparation and analysis of Pu isotopes in African soils, considering the environmental and cost implications applicable to low-resource laboratories. The separation procedure builds upon previous work using TEVA columns, further demonstrating their usefulness for the reduction of uranium (U) interference in ICP-MS analysis with enhanced selectivity for Pu. Here several steps were optimised to enhance Pu recovery, reducing method blank concentration, and improving the separation efficiency through the determination of the elution profiles of U and Pu. The elimination of the complexing agent in the eluent, increased the spike recovery by improving matrix tolerance of the plasma, and simplified the separation procedure, improving throughput by 20%. The subsequent method was validated through the analysis of Certified Reference Material IAEA-384, where high accuracy and improved precision of measurement were demonstrated (measured value 114 ± 12 versus certified value 108 ± 13 Bq kg-1). Optimisation of the column separation, along with the analysis of the samples using O2 gas in ICP-MS/MS mode to mass shift Pu isotopes away from interfering molecular U ions provided a simple, robust, and cost-effective method with low achievable method detection limits of 0.18 pg kg-1 239+240Pu, applicable to the detection of ultra-trace fallout Pu in African soils.
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Affiliation(s)
- Sophia M Dowell
- Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Nottingham, NG12 5GG, UK.
- School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, Devon, PL4 8AA, UK
| | - Thomas S Barlow
- Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Nottingham, NG12 5GG, UK.
| | - Simon R Chenery
- Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Nottingham, NG12 5GG, UK.
| | - Olivier S Humphrey
- Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Nottingham, NG12 5GG, UK.
| | - Job Isaboke
- School of Environmental Sciences, University of Eldoret, Eldoret, Kenya
| | - William H Blake
- School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, Devon, PL4 8AA, UK
| | - Odipo Osano
- School of Environmental Sciences, University of Eldoret, Eldoret, Kenya
| | - Michael J Watts
- Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey, Nottingham, NG12 5GG, UK.
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Röllin S, Corcho-Alvarado JA, Sahli H, Putyrskaya V, Klemt E. High-resolution records of cesium, plutonium, americium, and uranium isotopes in sediment cores from Swiss lakes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:85777-85788. [PMID: 35595889 PMCID: PMC9668797 DOI: 10.1007/s11356-022-20785-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
The Aare river system in Switzerland, with two nuclear power plants on the banks of the river, and its intermediate lakes and reservoirs, provides a unique opportunity to analyze the contribution of different sources to the radioactive contamination. Sediment cores were collected from two lakes and a reservoir, all connected by the river Aare. In order to study the influence of the Chernobyl accident, one sediment core was collected from a lake in the southern part of Switzerland. The sediment cores were sliced and analyzed with gamma ray spectrometry. Plutonium, americium, and uranium were extracted radiochemically, and their concentrations were measured with a sector field ICP-MS. The uranium isotope ratios were further measured with a multi collector ICP-MS. The maximum 137Cs activity from the Chernobyl accident and the Pu and 137Cs activities associated to the 1963 global fallout maximum were well identified in sediments from all three lakes. High-resolution records of plutonium isotopes in the zone of the sediments corresponding to the period of maximum fallout from the atmospheric nuclear weapon testing showed distinct fingerprints, depending on the different test activities. Pu isotope ratios could be used to detect non-global fallout plutonium. The ratio 241Am/241Pu was used to determine the age of the plutonium. Despite of very low 241Pu and 241Am concentrations, the calculated plutonium production dates seemed to be reasonable for the sediment layers corresponding to the NWT tests. The calculated production date of the plutonium in the upper most 15 cm of the sediment core seemed to be younger. The reason for this could be additional non-global fallout plutonium. For the lake sediments, natural ratios for 235U/238U and enriched or depleted ratios for 234U/238U were measured, depending on the lake. A small increase of the 236U/238U ratio could be recognized for the NWT zone in all three lakes and, for Lake Lugano, a further distinct increase in the Chernobyl layer.
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Affiliation(s)
- Stefan Röllin
- Federal Office for Civil Protection, Spiez Laboratory, Spiez, Switzerland.
| | | | - Hans Sahli
- Federal Office for Civil Protection, Spiez Laboratory, Spiez, Switzerland
| | | | - Eckehard Klemt
- Hochschule Ravensburg-Weingarten, University of Applied Sciences, Weingarten, Germany
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Watt JH, Brunelle A, Brewer S, Bentz B, Morris J, DeRose RJ. A Holocene Record of Vegetation Change and Mountain Pine Beetle Outbreaks at Lake of the Woods, Montana, USA. WEST N AM NATURALIST 2022. [DOI: 10.3398/064.082.0308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jennifer H. Watt
- Environmental and Sustainability Studies, University of Utah, Salt Lake City, UT
| | - Andrea Brunelle
- Department of Geography, University of Utah, Salt Lake City, UT
| | - Simon Brewer
- Department of Geography, University of Utah, Salt Lake City, UT
| | - Barbara Bentz
- USDA Forest Service, Rocky Mountain Research Station, Logan, UT
| | - Jesse Morris
- Department of Geography, University of Utah, Salt Lake City, UT
| | - R. Justin DeRose
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT
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6
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Zhang H, Hou X, Qiao J, Lin J. Determination of 241Am in Environmental Samples: A Review. Molecules 2022; 27:molecules27144536. [PMID: 35889408 PMCID: PMC9315525 DOI: 10.3390/molecules27144536] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 02/04/2023] Open
Abstract
The determination of 241Am in the environment is of importance in monitoring its release and assessing its environmental impact and radiological risk. This paper aims to give an overview about the recent developments and the state-of-art analytical methods for 241Am determination in environmental samples. Thorough discussions are given in this paper covering a wide range of aspects, including sample pre-treatment and pre-concentration methods, chemical separation techniques, source preparation, radiometric and mass spectrometric measurement techniques, speciation analyses, and tracer applications. The paper focuses on some hyphenated separation methods based on different chromatographic resins, which have been developed to achieve high analytical efficiency and sample throughput for the determination of 241Am. The performances of different radiometric and mass spectrometric measurement techniques for 241Am are evaluated and compared. Tracer applications of 241Am in the environment, including speciation analyses of 241Am, and applications in nuclear forensics are also discussed.
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Affiliation(s)
- Haitao Zhang
- Northwest Institute of Nuclear Technology, Xi’an 710024, China; (H.Z.); (J.L.)
| | - Xiaolin Hou
- Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, 4000 Roskilde, Denmark;
| | - Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, 4000 Roskilde, Denmark;
- Correspondence:
| | - Jianfeng Lin
- Northwest Institute of Nuclear Technology, Xi’an 710024, China; (H.Z.); (J.L.)
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7
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Łokas E, Wachniew P, Baccolo G, Gaca P, Janko K, Milton A, Buda J, Komędera K, Zawierucha K. Unveiling the extreme environmental radioactivity of cryoconite from a Norwegian glacier. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152656. [PMID: 34954174 DOI: 10.1016/j.scitotenv.2021.152656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/29/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
This study is a first survey of the occurrence of artificial (137Cs, 241Am, 207Bi, Pu isotopes) and natural (210Pb, 228Ac, 214Bi, 40K) radionuclides in Norwegian cryoconite. Cryoconite samples were collected before (12 samples) and after (5 samples) a rainfall event, after which 7 cryoconite holes dissapeared. The concentrations of radionuclides in cryoconite samples from the Blåisen Glacier are compared with data from the Arctic and Alpine glaciers. Cryoconite samples from the studied glacier had extremely high activity concentrations of 137Cs, 241Am, 207Bi and 239+240Pu (up to 25,000 Bq/kg, 58 Bq/kg, 13 Bq/kg and 131 Bq/kg, respectively) and also high concentrations of organic matter (OM), comparing to other Scandinavian and Arctic glaciers, reaching up to ~40% of total mass. The outstandingly high concentrations of 137Cs, 241Am, Pu isotopes, and 207Bi on the Blåisen Glacier are primarily related to bioaccumulation of radionuclides in organic-rich cryoconite and might be enhanced by additional transfers of contamination from the tundra by lemmings during their population peaks. The presumed influence of intense rainfall on radionuclide concentrations in the cryoconite was not confirmed.
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Affiliation(s)
- Edyta Łokas
- Department of Mass Spectrometry, Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland.
| | - Przemysław Wachniew
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Kraków, Poland
| | - Giovanni Baccolo
- Department of Environmental and Earth Sciences, University of Milano-Bicocca, Milano, Italy
| | - Paweł Gaca
- GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton, United Kingdom
| | - Karel Janko
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Libechov, Czech Republic; Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Andrew Milton
- GAU-Radioanalytical Laboratories, Ocean and Earth Science, University of Southampton, National Oceanography Centre, European Way, Southampton, United Kingdom
| | - Jakub Buda
- Department of Animal Taxonomy and Ecology, Adam Mickiewicz Unversity, Poznań, Poland
| | - Kamila Komędera
- Mössbauer Spectroscopy Laboratory, Institute of Physics, Pedagogical University, Kraków, Poland
| | - Krzysztof Zawierucha
- Department of Animal Taxonomy and Ecology, Adam Mickiewicz Unversity, Poznań, Poland
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Feng D, Yang F, Wang X, Zhou X, Liu Z, Liao H. Distribution of plutonium isotopes in soils between two nuclear test sites: Semipalatinsk and Lop Nor. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 242:106792. [PMID: 34929510 DOI: 10.1016/j.jenvrad.2021.106792] [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: 08/20/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Plutonium (Pu) has attracted attention as an environmental tracer due to its radiotoxicity and the possibility of sources linked with nuclear accidents in recent years. Plutonium isotopes (239,240Pu) were detected at trace levels in soils collected from the Xinjiang region located between the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site. Little is known regarding the spatial variation of 239,240Pu in soils from this region. This study reports the use of Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) methods to distinguish between Pu isotopes derived from global fallout and nuclear weapon tests. We found that the 239,240Pu activity concentrations ranged from 0.035 to 1.338 mBq/g; the 240Pu/239Pu atomic ratios were 0.157-0.223 with a weighted average of 0.180 ± 0.002, corresponding with the expected average global fallout ratio of 0.180 ± 0.014. This indicated that global fallout is the major source of Pu in the study region. The 239,240Pu inventories in these soils ranged from 23.67 to 222.7 Bq/m2, corresponding with those from other areas in China and other countries within the latitude range. Our Pu isotope data was supplemented with other published Pu data for soils collected in the vicinity of the Semipalatinsk nuclear test site and Lop Nor nuclear test site. Results indicate that 239,240Pu inventories and 240Pu/239Pu atomic ratios in soils exhibit large variations with distance from the Semipalatinsk nuclear test site. High deposition and accumulation of Pu, and low 240Pu/239Pu ratios were observed in close-in fallout and downwind regions of the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site.
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Affiliation(s)
- Dongxia Feng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Fang Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Xihuang Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Xingxuan Zhou
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhiyong Liu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Centre of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, China.
| | - Haiqing Liao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Guo H, Xu Y, Pan S, Liu Z. Distinctive distribution and migration of global fallout plutonium isotopes in an alpine lake and its implications for sediment dating. CHEMOSPHERE 2021; 279:130535. [PMID: 33866096 DOI: 10.1016/j.chemosphere.2021.130535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/15/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
This work investigated plutonium (Pu) isotopes in sediment cores collected from an alpine lake (Lake Heinongpo with 3779 m above sea level) in Southwestern China. 240Pu/239Pu atom ratios in all sediment samples showed the typical global fallout values of ∼0.18 without any influences from other Pu contaminant sources. 239+240Pu activities with surface and subsurface maximums followed by exponential decline with sediment depth were respectively observed in the two sediment cores. The distinctive depth distributions of 239,240Pu in the lake sediments was attributed to the very slow sediment deposition rate due to the lack of terrestrial sediment input, while the alpine snowmelt input was the primary source of Pu in the lake sediments in addition to the direct atmospheric deposition. The total Pu inventory was estimated to be 56.3 ± 1.4 and 63.9 ± 0.8 Bq/m2 respectively in the two sediment cores. The generally higher Pu inventory in the Lake Heinongpo compared with other reported lakes in similar latitude should be mainly attributed to their different Pu input passages. The advection-diffusion equation was further applied to evaluate the downward migration of Pu isotopes in the sediment cores and predict the future evolution of Pu distribution in the sediment cores. The fitted results indicated that the diffusion effect controlled the downward migration of Pu in the sediments, but this diffusive migration will not prevent the peak of global fallout Pu in undisturbed sediment cores from being a valuable time marker for sediment dating.
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Affiliation(s)
- Haiting Guo
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China
| | - Yihong Xu
- The Key Laboratory of Earth Surface Processes and Regional Response in the Yangtze Huaihe River Basin, School of Geography and Tourism, Anhui Normal University, Wuhu, 241002, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS, Xi'an, 710061, China.
| | - Shaoming Pan
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China.
| | - Zhiyong Liu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, China
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Jaegler H, Gourgiotis A, Steier P, Golser R, Diez O, Cazala C. Pushing Limits of ICP-MS/MS for the Determination of Ultralow 236U/ 238U Isotope Ratios. Anal Chem 2020; 92:7869-7876. [PMID: 32370491 DOI: 10.1021/acs.analchem.0c01121] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Determination of uranium isotope ratios is of great expedience for assessing its origin in environmental samples. In particular, the 236U/238U isotope ratio provides a powerful tool to discriminate between the different sources of uranium (uranium ore, geochemical background, and uranium from anthropogenic activities). However, in the environment, this ratio is typically below 10-8. This low abundance of 236U and the presence in large excess of major isotopes (mainly 238U and 235U) complicates the accurate detection of 236U signal by mass spectrometry and thus highly sensitive analytical instruments providing high abundance sensitivity are required. This work pushes the limits of triple quadrupole-based ICP-MS technology for accurate detection of 236U/238U isotope ratios down to 10-10, which is so far mainly achievable by AMS. Coupled with an efficient desolvating module, N2O was used as the reaction gas in the collision reaction cell of the ICP-MS/MS. This configuration allows a significant decrease of the uranium polyatomic interferences (235UH+ ions) and an accurate determination of low 236U/238U isotope ratios. This new methodology was successfully validated through measurements of certified reference material from 10-7 to 10-9 and then through comparisons with AMS measurement results for ratios down to 10-10. This is the first time that 236U/238U isotope ratios as low as 10-10 were determined by ICP-MS/MS. The possibility of measuring low 236U/238U isotope ratios can offer a large variety of geochemical applications in particular for the determination of uranium sources in the environment.
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Affiliation(s)
- Hugo Jaegler
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SEDRE/LELI, 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France
| | - Alkiviadis Gourgiotis
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SEDRE/LELI, 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France
| | - Peter Steier
- University of Vienna, Faculty of Physics, Isotope Research and Nuclear Physics, Vienna Environmental Research Accelerator, Währinger Straße 17, 1090 Vienna, Austria
| | - Robin Golser
- University of Vienna, Faculty of Physics, Isotope Research and Nuclear Physics, Vienna Environmental Research Accelerator, Währinger Straße 17, 1090 Vienna, Austria
| | - Olivier Diez
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SEDRE/LELI, 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France
| | - Charlotte Cazala
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SEDRE/LELI, 31 Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France
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11
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Vertical distribution and migration of plutonium in the Loess Plateau, North Shaanxi, China. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06744-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Yim SA, Chae JS, Byun JI, Ko SH. Characteristics of artificial radionuclides in sedimentary soil cores from a volcanic crater lake. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 192:532-542. [PMID: 30130738 DOI: 10.1016/j.jenvrad.2018.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 08/07/2018] [Accepted: 08/07/2018] [Indexed: 06/08/2023]
Abstract
The distributions of 137Cs, 237Np, and 239+240Pu activity concentrations in sedimentary soil cores of the volcanic crater-lake have been studied. The 240Pu/239Pu atom ratios measured by MC-ICP-MS and mutual activity ratios were examined. These results were used to evaluate the sedimentation characteristics of the crater-lake (Baengnokdam of Mt. Halla, Korea). The 137Cs, 237Np, and 239+240Pu activity concentrations showed similar distribution patterns and one maximum peak was observed in each sediment core, except at St.10. For all sediment cores, the activity concentrations were in the range 1.03 × 100-1.92 × 102 Bq·kg-1 dw for 137Cs, 7.56 × 10-3 - 7.15 × 100 mBq·kg-1 dw for 237Np, and 5.20 × 10-3 - 5.13 × 100 Bq·kg-1 dw for 239+240Pu, respectively. The averaged 240Pu/239Pu atomic ratio (0.159) was slightly less than the global fallout ratio (0.176). The averaged inventories were estimated to be 9.21 × 103±5.34 × 103 Bq·m-2 for 137Cs, 2.27 × 102±1.58 × 102 Bq·m-2 for 239+240Pu, and 3.22 × 10-1±1.78 × 10-1 Bq·m-2 for 237Np. The averaged 239+240Pu/137Cs and 237Np/239+240Pu activity ratios were 2.21 × 10-2 and 2.21 × 10-3, respectively. The mean sedimentation rates calculated using 239+240Pu activity concentrations at the central area (St.30 - St.45) and at all stations (St.5 - St.75) were estimated to be 0.844 cm yr-1, and 0.767 cm yr-1, respectively. In addition, the sedimentation rates calculated using 210Pb and 226Ra were 0.856 cm yr-1 at depths of 0-35 cm and 0.204 cm yr-1 at depths of 35-55 cm. These results imply that the sedimentation in Baengnokdam was relatively slow (0.204 cm yr-1) until about 44 years ago and then became faster (0.856 cm yr-1) to the present. The excess 210Pb dating is consistent with the sedimentation rate calculated from the vertical 239+240Pu profile.
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Affiliation(s)
- Seong A Yim
- Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon, 34142, Republic of Korea.
| | - Jung-Seok Chae
- Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon, 34142, Republic of Korea
| | - Jong-In Byun
- Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon, 34142, Republic of Korea
| | - Suk-Hyung Ko
- World Heritage Office, Jeju Special Self-Coverning Province, 690-816, Republic of Korea
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13
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Xu Y, Pan S, Gao J, Hou X, Ma Y, Hao Y. Sedimentary record of plutonium in the North Yellow Sea and the response to catchment environmental changes of inflow rivers. CHEMOSPHERE 2018; 207:130-138. [PMID: 29793024 DOI: 10.1016/j.chemosphere.2018.05.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/25/2018] [Accepted: 05/13/2018] [Indexed: 06/08/2023]
Abstract
Plutonium (Pu) isotopes were first determined in surface and core sediment samples collected from the northern North Yellow Sea (NYS) to elucidate their source terms and deposition process as well as the response to catchment environmental changes of inflow rivers. 240Pu/239Pu atom ratios in all sediments showed the typical global fallout value of ∼0.18 without any influences from the nuclear weapons tests conducted recently in the North Korea or early in the Pacific Proving Ground. The large variation of 239+240Pu activities (0.022-0.515 mBq/g) observed in surface sediments should be mainly attributed to the re-suspension and transportation of fine sediments influenced by the Liaonan Costal Current. Based on the two 239+249Pu depth profiles with easily observed onset fallout levels (1952) and global fallout peaks (1963), 239+240Pu served as a valid time mark in the coastal sedimentary system. Riverine input Pu contributed only 15-27% to the total global fallout inventory (92.5-108.8 Bq/m2) in the northern NYS, much lower than that in the Yangtze River estuary (77-80%), indicating a better soil conservation in the northeast China due to higher forest coverage compared to the Yangtze River's drainage basin. The increase of riverine input Pu after 1980s reflected the more intense soil erosion degree caused by the land use and cover change due to the increment of human activities in the northeast China at the same period. Our results demonstrated that plutonium is a good indicator for studying sedimentary process and its response to the environment in the coastal area.
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Affiliation(s)
- Yihong Xu
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
| | - Shaoming Pan
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China.
| | - Jianhua Gao
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China.
| | - Xiaolin Hou
- Center for Nuclear Technologies, Technical University of Denmark, Risø Campus, DK-4000 Roskilde, Denmark; Xi'an AMS Center, SKLLQG, Institute of Earth Environment, CAS, Xi'an 710061, China
| | - Yongfu Ma
- The Key Laboratory of Environmental Radiation Monitoring of Ministry of Environmental Protection, Radiation Monitoring Department, Environmental Radiation Monitoring Technical Center of Ministry of Environmental Protection, Hangzhou 310012, China
| | - Yongpei Hao
- The Key Laboratory of Coastal and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
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14
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Abril JM, San Miguel EG, Ruiz-Canovas C, Casas-Ruiz M, Bolívar JP. From floodplain to aquatic sediments: Radiogeochronological fingerprints in a sediment core from the mining impacted Sancho Reservoir (SW Spain). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 631-632:866-878. [PMID: 29727997 DOI: 10.1016/j.scitotenv.2018.03.114] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/08/2018] [Accepted: 03/10/2018] [Indexed: 06/08/2023]
Abstract
The Sancho Reservoir (SW Spain) was built in 1962, about the time of maximum 137Cs fallout, and it has been affected by acid mine drainage (AMD) particularly since the mining cease in 2001. This is a unique scenario for studying the radiogeochronological fingerprints in AMD-affected sediments deposited over the former flood plain. A sediment core sampled in 2011 was analysed for bulk density, 137Cs, 239Pu, 240Pu, 210Pb, 226Ra, 228Ra, 234Th (238U) and 40K, and studied with various radiometric dating models. Bulk density revealed unsteady compaction and likely depositional events. The activity concentrations of 226Ra, 228Ra, 234Th (238U) and 40K were uniform down-core, but declining overall in the upper 0-25cm, revealing changes in provenance except for 238U, which increased in the top 10cm likely due to its supply by AMD. The AMD fingerprint was also found in the 239+240Pu/137Cs activity ratio, which increased in the top sediment layers. The 137Cs and 239+240Pu profiles show well defined peaks at the same depth, with inventories being about four times higher than the expected integrated atmospheric deposition in the area. The unsupported 210Pb (210Pbexc) showed a complex non-monotonic profile interrupted at several sections, particularly around the 137Cs peak. The whole dataset cannot be interpreted in terms of continuous sedimentation processes. Based upon correlated features in the bulk density and 210Pbexc profiles, a series of depositional events (likely linked to peaks in the rainfall records) have been identified in the core. These events date back to the period comprised since the construction of the dam until its increase in height in 1972, which likely displaced upstream the main depositional area of riverine loads, as inferred from sediment trap data. The CRS (with a reference date) and (a piecewise) CIC models have been used for complementing and discussing the chronology.
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Affiliation(s)
- J M Abril
- Department of Applied Physics I, ETSIA, University of Seville, Spain.
| | - E G San Miguel
- Department of Integrated Sciences, Area of Applied Physics, University of Huelva, Campus de El Carmen, 21071 Huelva, Spain; Research Center on Natural Resources, Health and the Environment (RENSMA), University of Huelva, 21071 Huelva, Spain
| | - C Ruiz-Canovas
- Department of Earth Sciences, Faculty of Experimental Sciences, University of Huelva, Spain; Research Center on Natural Resources, Health and the Environment (RENSMA), University of Huelva, 21071 Huelva, Spain
| | - M Casas-Ruiz
- Department of Applied Physics, University of Cadiz, Spain
| | - J P Bolívar
- Department of Integrated Sciences, Area of Applied Physics, University of Huelva, Campus de El Carmen, 21071 Huelva, Spain; Research Center on Natural Resources, Health and the Environment (RENSMA), University of Huelva, 21071 Huelva, Spain
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15
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Abraham J, Meusburger K, Waldis JK, Ketterer ME, Zehringer M. Fate of 137Cs, 90Sr and 239+240Pu in soil profiles at a water recharge site in Basel, Switzerland. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 182:85-94. [PMID: 29202373 DOI: 10.1016/j.jenvrad.2017.11.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/04/2017] [Accepted: 11/19/2017] [Indexed: 06/07/2023]
Abstract
An important process in the production of drinking water is the recharge of the withdrawn ground water with river water at protected recharge fields. While it is well known that undisturbed soils are efficiently filtering and adsorbing radionuclides, the goal of this study was to investigate their behaviour in an artificial recharge site that may receive rapid and additional input of radionuclides by river water (particularly when draining a catchment including nuclear power plants (NPP)). Soil profiles of recharge sites were drilled and analysed for radionuclides, specifically radiocesium (137Cs), radiostrontium (90Sr) and plutonium (239+240Pu). The distribution of the analysed radionuclides were compared with an uncultivated reference soil outside the recharge site. The main activity of 137Cs was located in the top soil (4.5-7.5 cm) and reached down to a depth of 84 cm and 48 cm for the recharge and the reference site, respectively. The found activities of 239+240Pu originate from the global fallout after 1950. 239+240Pu appeared to be strongly adsorbed onto soil particles. The shape of the depth profile was similar to 137Cs, but also similar between the recharge and the reference site. In contrast, 90Sr showed a uniform distribution over the entire depth of the recharge and reference profiles indicating that 90Sr already entered the gravel zone and the ground water. Elevated inventories of the radionuclides were observed for the recharge site. The soil of the recharge field exhibited a threefold higher activity of 137Cs compared to the reference soil. Also for 239+240Pu higher inventories where observed for the recharge sites (40%). 90Sr behaved differently, showing similar inventories between reference and recharge site. We estimate that 75-89% of the total inventory of 137Cs in the soil at the recharge site (7.000 Bq/m2) originated from the fallout of the Chernobyl accident and from emissions of Swiss NPPs. This estimate is based on the actual activity ratio of 137Cs/239+240Pu of 22 for global fallout. The investigations identified radiostrontium as potential threat to the ground water.
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Affiliation(s)
- Johannes Abraham
- State-Laboratory Basel-City, Kannenfeldstrasse 2, CH-4056 Basel, Switzerland
| | - Katrin Meusburger
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Judith Kobler Waldis
- Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Michael E Ketterer
- Metropolitan State University of Denver, Department of Chemistry, Campus Box 52, Denver, CO 80217-3362, USA
| | - Markus Zehringer
- State-Laboratory Basel-City, Kannenfeldstrasse 2, CH-4056 Basel, Switzerland.
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16
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Spencer JD, Brunelle A, Hepola T. Using Paleoecology to Inform Land Management as Climates Change: An Example from an Oak Savanna Ecosystem. ENVIRONMENTAL MANAGEMENT 2017; 60:1090-1100. [PMID: 28921004 DOI: 10.1007/s00267-017-0936-y] [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: 01/02/2017] [Accepted: 08/28/2017] [Indexed: 06/07/2023]
Abstract
Oak savanna, a transitional ecosystem between open prairie and dense oak forest, was once widespread in Minnesota. Upon European settlement much of the oak savanna was destroyed. Recently, efforts to restore this ecosystem have increased and often include the reintroduction of fire. Though fire is known to serve an important role within oak savannas, there are currently few studies which address fire regimes on timescales longer than the last century. This research presents a paleoecological history of Sherburne National Wildlife Refuge (SNWR) in MN, USA, spanning the last ~8000 years. The objectives of this study were to use charcoal, pollen, and magnetic susceptibility of lake sediments collected from Johnson Slough (JS) within the refuge to evaluate the natural range of variability and disturbance history of the oak savanna within the refuge, assess the success of current restoration strategies, and add to the regional paleoecological history. The mid/late Holocene period of the JS record shows a period of high fire activity from ca. 6500 to 2600 cal year BP, with a shift from prairie to oak savanna occurring over this same period. A (possibly agricultural) disturbance to JS sediments affected the period from ca. 2600 cal year BP to 1963 AD, which includes the time of Euro-American settlement. However, the destruction and subsequent restoration of the oak savanna is evident in a pollen ratio of Quercus:Poaceae, indicating that current restoration efforts have been successful at restoring the oak savanna to within the natural range of variability seen just prior to destruction.
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Affiliation(s)
- Jessica D Spencer
- Department of Geography, University of Utah, Salt Lake City, UT, USA.
| | - Andrea Brunelle
- Department of Geography, University of Utah, Salt Lake City, UT, USA
| | - Tim Hepola
- Regional Fire Ecologist, US Fish and Wildlife Service, Midwest Regional Office, Bloomington, MN, USA
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17
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Development and application of mass spectrometric techniques for ultra-trace determination of 236U in environmental samples-A review. Anal Chim Acta 2017; 995:1-20. [DOI: 10.1016/j.aca.2017.09.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/23/2017] [Accepted: 09/19/2017] [Indexed: 02/04/2023]
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18
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Dunne JA, Richards DA, Chen HW. Procedures for precise measurements of 135Cs/137Cs atom ratios in environmental samples at extreme dynamic ranges and ultra-trace levels by thermal ionization mass spectrometry. Talanta 2017; 174:347-356. [PMID: 28738591 DOI: 10.1016/j.talanta.2017.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/07/2017] [Accepted: 06/12/2017] [Indexed: 10/19/2022]
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19
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Mróz T, Łokas E, Kocurek J, Gąsiorek M. Atmospheric fallout radionuclides in peatland from Southern Poland. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 175-176:25-33. [PMID: 28431374 DOI: 10.1016/j.jenvrad.2017.04.012] [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: 10/28/2016] [Revised: 04/12/2017] [Accepted: 04/13/2017] [Indexed: 06/07/2023]
Abstract
Two peat profiles were collected in a peat bog located in Southern Poland and their geochronology were determined using 210Pb, 238,239+240Pu and 137Cs radiometric techniques. The 210Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the Pu isotopes and 137Cs time markers. Maximum activities of Pu isotopes were found at a depth corresponding to the early 1960s, which is the period characterized by the maximum nuclear weapon tests. The results showed that the 210Pb method is the most accurate technique for the determination age and accumulation rate of a peat. The next part of this study calculated linear accumulation rates by analyzing 238,239+240Pu and 137Cs vertical distributions in the profiles. Activities of fallout isotopes were also measured in plants covering the peatland. The highest activities of 137Cs and 210Pb were found in Calluna vulgaris samples, and 239+240Pu were found only in two samples (C. vulgaris and leaves of Oxycoccus quadripelatus).
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Affiliation(s)
- Tomasz Mróz
- Pedagogical University of Cracow, Podchorążych 2 30-084 Kraków, Poland.
| | - Edyta Łokas
- Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland.
| | - Justyna Kocurek
- AGH University of Science and Technology, Al. Mickiewicza 30, 31-120 Kraków, Poland.
| | - Michał Gąsiorek
- Department of Soil Science and Soil Protection, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120 Kraków, Poland.
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20
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Arata L, Alewell C, Frenkel E, A'Campo-Neuen A, Iurian AR, Ketterer ME, Mabit L, Meusburger K. Modelling Deposition and Erosion rates with RadioNuclides (MODERN) - Part 2: A comparison of different models to convert 239+240Pu inventories into soil redistribution rates at unploughed sites. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 162-163:97-106. [PMID: 27227561 DOI: 10.1016/j.jenvrad.2016.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/12/2016] [Accepted: 05/12/2016] [Indexed: 06/05/2023]
Abstract
Sheet erosion is one of the major threats to alpine soils. To quantify its role and impact in the degradation processes of alpine grasslands, the application of Fallout Radionuclides (FRN) showed very promising results. The specific characteristics of plutonium 239 + 240 (239+240Pu), such as the homogeneous fallout distribution, the long half-life and the cost and time effective measurements make this tracer application for investigating soil degradation in Alpine grasslands more suitable than any other FRN (e.g. 137Cs). However, the conversion of 239+240Pu inventories into soil erosion rates remains a challenge. Currently available conversion models have been developed mainly for 137Cs with later adaptation to other FRN (e.g. Excess 210Pb, and 7Be), each model being defined for specific land use (ploughed and/or unploughed) and processes (erosion or deposition). As such, they may fail in describing correctly the distribution of Pu isotopes in the soil. A new conversion model, MODERN, with an adaptable algorithm to estimate erosion and deposition rates from any FRN inventory changes was recently proposed (Arata et al., 2016). In this complementary contribution, the authors compare the application of MODERN to other available conversion models. The results show a good agreement between soil redistribution rates obtained from MODERN and from the models currently used by the FRN scientific community (i.e. the Inventory Method).
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Affiliation(s)
- Laura Arata
- Environmental Geosciences, Department of Environmental Sciences, University of Basel, Switzerland.
| | - Christine Alewell
- Environmental Geosciences, Department of Environmental Sciences, University of Basel, Switzerland
| | - Elena Frenkel
- Institute de Recherche Mathématique Avancée (IRMA), University of Strasbourg, France
| | | | - Andra-Rada Iurian
- Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania; Consolidated Radioisotope Facility, Plymouth University, Plymouth, UK
| | - Michael E Ketterer
- Chemistry Department, Metropolitan State University of Denver, Colorado, USA
| | - Lionel Mabit
- Soil and Water Management & Crop Nutrition Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, Seibersdorf, Austria
| | - Katrin Meusburger
- Environmental Geosciences, Department of Environmental Sciences, University of Basel, Switzerland
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21
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Machado W, Sanders CJ, Santos IR, Sanders LM, Silva-Filho EV, Luiz-Silva W. Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:30-35. [PMID: 26874872 DOI: 10.1016/j.envpol.2016.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 06/05/2023]
Abstract
A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C). Mercury dilution by the predominant mangrove-derived organic matter counterbalanced the positive influences of algal-derived organic matter and clay contents on Hg levels, suggesting that deleterious effects of Hg may be attenuated. Considering the current paradigm on the positive effect of organic matter on Hg concentrations in coastal sediments and the expected increase in mangrove organic matter burial due to natural and anthropogenic stimulations of primary production, predictions on the influences of organic matter on Hg accumulation in mangrove wetlands deserve caution.
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Affiliation(s)
- Wilson Machado
- Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Niterói, RJ, 24020-150, Brazil.
| | - Christian J Sanders
- National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Coffs Harbour, NSW, 2540, Australia
| | - Isaac R Santos
- National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Coffs Harbour, NSW, 2540, Australia
| | - Luciana M Sanders
- Southern Cross Geoscience, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Emmanoel V Silva-Filho
- Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Niterói, RJ, 24020-150, Brazil
| | - Wanilson Luiz-Silva
- Instituto de Geociências, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil
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Bu W, Zheng J, Guo Q, Uchida S. Vertical distribution and migration of global fallout Pu in forest soils in southwestern China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2014; 136:174-180. [PMID: 24963802 DOI: 10.1016/j.jenvrad.2014.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/30/2014] [Accepted: 06/08/2014] [Indexed: 06/03/2023]
Abstract
Soil samples collected in southwestern China were analyzed for Pu isotopes. The (240)Pu/(239)Pu atom ratios were around 0.18, which indicated the dominant source of global fallout. Consistent sub-surface maximums followed by exponential decline of (239+240)Pu activities in the soil cores were observed. Most of the Pu has still remained in the 0-10 cm layers since its deposition. Convection velocities and dispersion coefficients for Pu migration in the soils were estimated by the convection-dispersion equation (CDE) model. The effective convection velocities and effective dispersion coefficients ranged from 0.05 to 0.11 cm/y and from 0.06 to 0.29 cm(2)/y, respectively. Other factors that control the vertical migration of Pu in soil besides precipitation, soil particle size distribution and organic matter were suggested. Long-term migration behaviors of Pu in the soils were simulated. The results provide the Pu background baseline for further environmental monitoring and source identification of non-global fallout Pu inputs in the future.
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Affiliation(s)
- Wenting Bu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China; Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan
| | - Jian Zheng
- Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
| | - Qiuju Guo
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China.
| | - Shigeo Uchida
- Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan
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23
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Liao H, Bu W, Zheng J, Wu F, Yamada M. Vertical distributions of radionuclides ((239+240)Pu, (240)Pu/(239)Pu, and (137)Cs) in sediment cores of Lake Bosten in Northwestern China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3840-3846. [PMID: 24580087 DOI: 10.1021/es405364m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Artificial radionuclides ((137)Cs, (239+240)Pu, (241)Pu, (241)Am) deposited in lacustrine sediments have been used for dating as well as radionuclide source identification. In the present work, we investigated the vertical distributions of (239+240)Pu and (137)Cs activities, (240)Pu/(239)Pu atom ratios, and (239+240)Pu/(137)Cs activity ratios in sediment cores collected from Lake Bosten, which is the lake closest to the Lop Nor Chinese Nuclear Weapon Test site in northwestern China. Uniformly high concentrations of (239+240)Pu and (137)Cs were found in the upper layers deposited since 1964 in the sediment cores, and these were controlled by the resuspension of soil containing radionuclides from the nearby land surface. As the Chinese nuclear tests varied remarkably in yield, the mixing of the tropospheric deposition from these tests and the stratospheric deposition of global fallout has led to a (240)Pu/(239)Pu atom ratio that is similar to that of global fallout and to a (239+240)Pu/(137)Cs activity ratio that is slightly higher than that of global fallout. However, a low (240)Pu/(239)Pu atom ratio of 0.080 and high (239+240)Pu/(137)Cs activity ratio of 0.087, significantly different from the global fallout values, were observed in one sediment core (07BS10-2), indicating the inhomogenous tropospheric deposition from the Chinese nuclear tests in Lake Bosten during 1967-1973. These results are important to understand the influence of the CNTs on the radionuclide contamination in Lake Bosten.
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Affiliation(s)
- Haiqing Liao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences , Beijing 100012, China
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24
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Cagno S, Hellemans K, Lind OC, Skipperud L, Janssens K, Salbu B. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:306-312. [PMID: 24424783 DOI: 10.1039/c3em00531c] [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
Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples.
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Affiliation(s)
- S Cagno
- CERAD, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway.
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Bu W, Zheng J, Guo Q, Aono T, Tazoe H, Tagami K, Uchida S, Yamada M. A method of measurement of (239)Pu, (240)Pu, (241)Pu in high U content marine sediments by sector field ICP-MS and its application to Fukushima sediment samples. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 48:534-541. [PMID: 24328266 DOI: 10.1021/es403500e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site.
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Affiliation(s)
- Wenting Bu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University , Beijing 100871, China
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Bu K, Cizdziel JV, Dasher D. Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2013; 124:29-36. [PMID: 23639692 DOI: 10.1016/j.jenvrad.2013.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/28/2013] [Accepted: 03/06/2013] [Indexed: 06/02/2023]
Abstract
Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and Amchitka Island underground nuclear test site cannot be ruled out.
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Affiliation(s)
- Kaixuan Bu
- Department of Chemistry and Biochemistry, University of Mississippi, University, 116 Taylor Meadows Dr, MS 38677, USA.
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Ketterer ME, Groves AD, Strick BJ, Asplund CS, Jones VJ. Deposition of (236)U from atmospheric nuclear testing in Washington state (USA) and the Pechora region (Russian Arctic). JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2013; 118:143-149. [PMID: 23376314 DOI: 10.1016/j.jenvrad.2012.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 10/14/2012] [Accepted: 10/15/2012] [Indexed: 06/01/2023]
Abstract
Stratospheric fallout-derived (236)U has been detected by sector field ICPMS at two field locations for which our laboratory possessed available archived samples: A) four soil cores from Washington state (northwestern USA) and B) sediment cores from three small lakes in the Pechora region (Russian Arctic). Four Washington state soil cores exhibit (236)U inventories of 8.1 ± 1.3, 11.1 ± 0.9, 18 ± 2, and 30.2 ± 3.9 Tatoms/m(2); the respective (239)Pu contents are 52.9 ± 3.5, 67 ± 3, 71 ± 2, and 151 ± 2 Tatoms/m(2). A (236)U/(239)Pu atom ratio of 0.19 ± 0.04 (1 SD) has been determined from the Washington state soil cores. The three Pechora region lake cores each exhibit coincident maxima in their (236)U and (239)Pu atom concentration profiles. The (236)U/(238)U atom ratios are controlled by two independent factors; (236)U is from fallout deposition and (238)U concentrations are a property of the geochemical distribution of naturally occurring U. A (236)U/(238)U atom ratio as high as 8.9 × 10(-6) has been observed for acid-leached soils containing Pu solely derived from bomb-test fallout. Accordingly, a non-zero (236)U background from stratospheric fallout must be recognized and taken into account when detectable (236)U is used to infer specific local or regional influences of reactor-irradiated U.
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Affiliation(s)
- Michael E Ketterer
- Department of Chemistry and Biochemistry, Northern Arizona University, Box 5698, Flagstaff, AZ 86011-5698, USA.
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Isotopic Ratio of <SUP>240</SUP>Pu/<SUP>239</SUP>Pu Measurements under Interference of Uranium by Inductively Coupled Plasma-Mass Spectrometry with Direct Sampling Insertion. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2012. [DOI: 10.3724/sp.j.1096.2011.01682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ketterer ME, Zheng J, Yamada M. Applications of Transuranics as Tracers and Chronometers in the Environment. ADVANCES IN ISOTOPE GEOCHEMISTRY 2012. [DOI: 10.1007/978-3-642-10637-8_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Wu F, Zheng J, Liao H, Yamada M, Wan G. Anomalous plutonium isotopic ratios in sediments of Lake Qinghai from the Qinghai-Tibetan Plateau, China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:9188-9194. [PMID: 21950768 DOI: 10.1021/es202315c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The vertical profiles of (239+240)Pu and (137)Cs activities and (240)Pu/(239)Pu isotopic ratios are determined for three sediment cores of Lake Qinghai from the Qinghai-Tibetan Plateau, China, and compared with those in sediments of another three lakes (Lakes Bosten, Sugan, and Shuangta), the only existing ones closest to Lop Nor area, China's nuclear weapons test site in the northwestern part of the country. The mean inventory of 47.7 ± 18.7 MBq km(-2) for (239+240)Pu activity in Lake Qinghai is comparable to the average value of global fallout expected at the same latitude, yet the mean inventory of 1112.0 ± 78.0 MBq km(-2) for (137)Cs is slightly lower than that of global fallout. Anomalously low (240)Pu/(239)Pu isotopic ratios (0.038-0.125) were found in the 3-6.5 cm deep sediment layers, indicating the trace Pu input from early nuclear weapons research activities at Atomic City in the lake's watershed during the 1950-60s. Model calculation indicated that the Pu input accounted for approximately 5-16% of the total Pu inventory. The observation of low (240)Pu/(239)Pu ratio in the deep sediment layer provided a new time marker for recent sediment dating in the lake and around the area. The results are of great significance to the further understanding of sources, records, and environmental impacts of global and regional nuclear activities in the environment and provide important chronological information for further studies on the water eutrophication process and climatic change, and reconstruction of pollution history of organic contaminants and heavy metals in the watershed of Lake Qinghai.
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Affiliation(s)
- Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Wu F, Zheng J, Liao H, Yamada M. Distribution of artificial radionuclides in lacustrine sediments in China. RADIATION PROTECTION DOSIMETRY 2011; 146:291-294. [PMID: 21498412 DOI: 10.1093/rpd/ncr173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Establishing accurate historical records of the distribution, inventory and source of artificial radionuclides in the environment is important for environmental monitoring and radiological health protection due to their potential toxicity, and is also useful for identification and risk assessment of possible future environmental inputs of radionuclides from nuclear weapons tests and accidental release from the nuclear fuel reprocessing facilities or nuclear power reactors. A sector-field inductively coupled plasma mass spectrometer was used to study the recent sedimentation of Pu isotopes in 11 lakes in China. The distribution of (137)Cs was investigated using the conventional radiometric analytical methods. Based on the isotopic compositions of Pu and the activity ratio of (137)Cs/(239+240)Pu, the sources of artificial radionuclides were identified. The potential applications of Pu isotopes for sediment dating and for regional and global environmental change studies were discussed.
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Affiliation(s)
- Fengchang Wu
- Chinese Research Institute of Environmental Sciences, 8 Dayangfang, Chaoyang District, Beijing 100012, China.
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Corcho Alvarado JA, Chawla F, Froidevaux P. Determining 241Pu in environmental samples: case studies in alpine soils. RADIOCHIM ACTA 2011. [DOI: 10.1524/ract.2011.1803] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
A procedure was developed for determining 241Pu activity in environmental samples. This beta emitter isotope of plutonium was measured by ultra low level liquid scintillation, after several separation and purification steps that involved the use of a highly selective extraction chromatographic resin (Eichrom-TEVA). Due to the lack of reference material for 241Pu, the method was nevertheless validated using four IAEA reference sediments with information values for 241Pu. Next, the method was used to determine the 241Pu activity in alpine soils of Switzerland and France. The 241Pu/239,240Pu and 238Pu/239,240Pu activity ratios confirmed that Pu contamination in the tested alpine soils originated mainly from global fallout from nuclear weapon tests conducted in the fifties and sixties. Estimation of the date of the contamination, using the 241Pu/241Am age-dating method, further confirmed this origin. However, the 241Pu/241Am dating method was limited to samples where Pu-Am fractionation was insignificant. If any, the contribution of the Chernobyl accident is negligible.
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Affiliation(s)
| | - F. Chawla
- University of Lausanne, Institute of Radiation Physics, Lausanne, Schweiz
| | - P. Froidevaux
- University of Lausanne, Institute of Radiation Physics, Lausanne, Schweiz
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Wu F, Zheng J, Liao H, Yamada M. Vertical distributions of plutonium and 137Cs in lacustrine sediments in northwestern china: quantifying sediment accumulation rates and source identifications. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2911-2917. [PMID: 20302293 DOI: 10.1021/es9029649] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We investigated the vertical distributions of 239+240Pu and 137Cs activities and 240Pu/239Pu atom ratios in two lakes in northwestern China. The 240Pu/239Pu atom ratio from the Chinese nuclear test (CNT) site at Lop Nor is too complicated to identify the regional fallout source. However, radionuclides from the test site may be resolved mainly by the vertical distribution of radionuclides because there is no overlap between the global fallout peak and the local fallout peak. We analyzed Pu isotopes and 137Cs in sediments from two lakes (Sugan and Shuangta) located in northwestern China, near the CNT, and Lake Sihailongwan located in northeastern China to date recent lacustrine sediments and resolve global/local fallout sources. The apparently low 240Pu/239Pu atom ratio of 0.103 +/- 0.010 at Lake Sugan was likely representative of the fallout from the Lop Nor site. Our results also demonstrated that the 239+240Pu activity was more useful for recent chronology of lacustrine sediments, compared to 137Cs. Sediment accumulation rates of 0.651, 0.058-0.061, and 0.015 g x cm(-2) x a(-1) for sediment cores of Lake Shuangta, Lake Sugan and Lake Sihailongwan, respectively, were obtained by using the 239+240Pu fallout peak as a discrete time marker for 1964. The respective contributions of 137Cs and 239+240Pu from the CNT were estimated to be about 40 and 27% for Lake Sugan and 36 and 20% for Lake Shuangta. Plutonium isotopes in lacustrine sediments were proven to be useful for quantifying sediment accumulation rates and for source identification of the radioactive contamination.
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Affiliation(s)
- Fengchang Wu
- State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Institute of Environmental Sciences, 8 Dayangfang, Chaoyang District, Beijing 100012, China.
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Sanders CJ, Smoak JM, Sanders LM, Waters MN, Patchineelam SR, Ketterer ME. Intertidal mangrove mudflat 240+239Pu signatures, confirming a 210Pb geochronology on the southeastern coast of Brazil. J Radioanal Nucl Chem 2009. [DOI: 10.1007/s10967-009-0418-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zheng J, Wu F, Yamada M, Liao H, Liu C, Wan G. Global fallout Pu recorded in lacustrine sediments in Lake Hongfeng, SW China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2008; 152:314-21. [PMID: 17651874 DOI: 10.1016/j.envpol.2007.06.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 06/04/2007] [Accepted: 06/11/2007] [Indexed: 05/16/2023]
Abstract
Studies on the distribution and isotope compositions of fallout Pu are important for source characterization of possible future non-fallout Pu contamination in aquatic environments, and useful for dating of recent sediments to understand the pollution history of environmental contaminants. We present the historical record of atmospheric Pu fallout reconstructed from a sediment core from Lake Hongfeng, China. The Pu activity profile was in agreement with the 137Cs profile. Inventories were 50.7 Bq m(-2) for 239+240Pu and 1586 Bq m(-2) for 137Cs. The average 240Pu/239Pu atom ratio was 0.185+/-0.009, indicating that Pu originated from global stratospheric fallout rather than from direct tropospheric or close-in fallout from the Chinese nuclear testing conducted in the 1970s. Our data suggested that Lake Hongfeng would be an ideal setting for monitoring atmospheric fallout and environmental changes in this region.
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Affiliation(s)
- Jian Zheng
- Nakaminato Laboratory for Marine Radioecology, Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 3609 Isozaki-cho, Hitachinaka, Ibaraki 311-1202, Japan.
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36
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Godoy MLDP, Godoy JM, Roldão LA. Application of ICP-QMS for the determination of plutonium in environmental samples for safeguards purposes. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2007; 97:124-36. [PMID: 17543430 DOI: 10.1016/j.jenvrad.2007.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 03/02/2007] [Accepted: 03/14/2007] [Indexed: 05/15/2023]
Abstract
Aiming to determine the plutonium amount as well as its isotopic composition, in particular, in swipe samples for safeguards purposes, an analytical method was developed with a plutonium separation step based on extraction chromatography using 2 cm TEVA columns and detection with quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with membrane desolvation system. The method was successfully applied to New Brunswick plutonium certified reference materials as well as to Lawrence Livermore National Laboratory round robin samples, based on the round robin samples provided by the Institute for Reference Materials and Measurements (Belgium), as part of the Regular European Interlaboratory Measurement Evaluation Programme (REIMEP), campaign 16 (isotopic abundances of plutonium in plutonium nitrate samples), with a total plutonium amount between 1 and 0.25 ng per sample. After the introduction of an additional separation step, it was also possible to carry out precise and accurate total plutonium, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu atom ratios determination in sediment sample showing its applicability to environmental samples in general, reaching a detection limit equivalent to 5 mBq(239)Pu kg(-1).
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Affiliation(s)
- Maria Luiza D P Godoy
- Instituto de Radioproteção e Dosimetria, Caixa Postal 37750, Barra da Tijuca, 22642-970, Rio de Janeiro, Brazil.
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Pöllänen R, Ketterer ME, Lehto S, Hokkanen M, Ikäheimonen TK, Siiskonen T, Moring M, Rubio Montero MP, Martín Sánchez A. Multi-technique characterization of a nuclear bomb particle from the Palomares accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2006; 90:15-28. [PMID: 16870315 DOI: 10.1016/j.jenvrad.2006.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 04/26/2006] [Accepted: 06/03/2006] [Indexed: 05/11/2023]
Abstract
A January 1966 accident dispersed Pu and other nuclear bomb materials in the vicinity of Palomares, a village in southeastern Spain. Radioactive particles were identified in a soil sample collected in 1998 and analytical results obtained from one of the isolated particles are presented here. Isolation of the particle was performed using gamma-ray spectrometry and imaging plates. Scanning electron microscopy with X-ray microanalysis revealed the presence of U and Pu as well as Pb and Fe in the particle of approximately 10microm diameter. Radioisotopes of U, Pu, and Am were quantified using radiometric methods, inductively coupled plasma mass spectrometry and secondary ion mass spectrometry. The elevated (235)U/(238)U atom ratio indicates enriched U, and the Pu atom ratios are consistent with weapons-grade material. This work demonstrates that the analysis of individual particles provides information not available through bulk sample analysis.
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Affiliation(s)
- R Pöllänen
- STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, FIN-00881 Helsinki, Finland.
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