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Qiao J, Cao Y, Varttic VP, Steier P. Stratigraphic records and inventories of anthropogenic 233U and 236U in Baltic Sea sediments. Sci Total Environ 2023; 901:166402. [PMID: 37598960 DOI: 10.1016/j.scitotenv.2023.166402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/16/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023]
Affiliation(s)
- Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
| | - Yiyao Cao
- Zhejiang Provincial Center for Disease Control and Prevention, 310051 Hangzhou, China
| | - Vesa-Pekka Varttic
- Measurements and Environmental Monitoring, Radiation and Nuclear Safety Authority, Finland
| | - Peter Steier
- VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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Severi M, Becagli S, Caiazzo L, Nardin R, Toccafondi A, Traversi R. The 239Pu nuclear fallout as recorded in an Antarctic ice core drilled at Dome C (East Antarctica). Chemosphere 2023; 329:138674. [PMID: 37054845 DOI: 10.1016/j.chemosphere.2023.138674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/04/2023] [Accepted: 04/10/2023] [Indexed: 05/03/2023]
Abstract
Starting from 1952 C.E. more than 540 atmospheric nuclear weapons tests (NWT) were conducted in different locations of the Earth. This lead to the injection of about 2.8 t of 239Pu in the environment, roughly corresponding to a total 239Pu radioactivity of 6.5 PBq. A semiquantitative ICP-MS method was used to measure this isotope in an ice core drilled in Dome C (East Antarctica). The age scale for the ice core studied in this work was built by searching for well-known volcanic signatures and synchronising these sulfate spikes with established ice core chronologies. The reconstructed plutonium deposition history was compared with previously published NWT records, pointing out an overall agreement. The geographical location of the tests was found to be an important parameter strongly affecting the concentration of 239Pu on the Antarctic ice sheet. Despite the low yield of the tests conducted in the 1970s, we highlight their important role in the deposition of radioactivity in Antarctica due to the relative closeness of the testing sites.
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Affiliation(s)
- Mirko Severi
- Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy; Institute of Polar Sciences, ISP-CNR, Venice-Mestre, Italy.
| | - Silvia Becagli
- Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy; Institute of Polar Sciences, ISP-CNR, Venice-Mestre, Italy
| | - Laura Caiazzo
- Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy; Ente per le Nuove Tecnologie, l'Energia e l'Ambiente, Rome, Italy
| | - Raffaello Nardin
- Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy; Institute of Polar Sciences, ISP-CNR, Venice-Mestre, Italy
| | - Alberto Toccafondi
- Department of Information Engineering and Mathematics, University of Siena, Siena, Italy
| | - Rita Traversi
- Department of Chemistry "Ugo Schiff", University of Florence, Florence, Italy; Institute of Polar Sciences, ISP-CNR, Venice-Mestre, Italy
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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. Environ Sci Pollut Res Int 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Yokoyama Y, Tims S, Froehlich M, Hirabayashi S, Aze T, Fifield LK, Koll D, Miyairi Y, Pavetich S, Kuwae M. Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene. Sci Rep 2022; 12:10068. [PMID: 35778413 DOI: 10.1038/s41598-022-14179-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 06/02/2022] [Indexed: 11/26/2022] Open
Abstract
Plutonium (Pu) has been used as a mid-twentieth century time-marker in various geological archives as a result of atmospheric nuclear tests mainly conducted in 1950s. Advancement of analytical techniques allows us to measure 239Pu and 240Pu more accurately and can thereby reconstruct the Pacific Pu signal that originated from the former Pacific Proving Grounds (PPG) in the Marshall Islands. Here, we propose a novel method that couples annual banded reef building corals and nearshore anoxic marine sediments to provide a marker to precisely determine the start of the nuclear era which is known as a part of the Anthropocene. We demonstrate the efficacy of the methods using sediment obtained from Beppu Bay, Japan, and a coral from Ishigaki Island, Japan. The sedimentary records show a clear Pu increase from 1950, peaking during the 1960s, and then showing a sharp decline during the 1970s. However, a constantly higher isotope ratio between 239Pu and 240Pu suggest an additional contribution other than global fallout via ocean currents. Furthermore, single elevations in 240Pu/239Pu provide supportive evidence of close-in-fallout similar to previous studies. Coral skeletal radiocarbon displays a clear timing with the signatures supporting the reliability of the Beppu Bay sediments as archives and demonstrates the strength of this method to capture potential Anthropocene signatures.
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Xu Y, Li C, Yu H, Fang F, Hou X, Zhang C, Li X, Xing S. Rapid determination of plutonium isotopes in small samples using single anion exchange separation and ICP-MS/MS measurement in NH 3-He mode for sediment dating. Talanta 2021; 240:123152. [PMID: 34942475 DOI: 10.1016/j.talanta.2021.123152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 10/19/2022]
Abstract
To accurately determine ultra-trace Pu isotopes in small environmental samples, we explored ICP-MS/MS in NH3-He mode, and investigated mechanism of 238U interference removal and measurement sensitivity improvement for plutonium isotopes. The interference of uranium and uranium hydrides was effectively eliminated using 0.4 mL/min NH3 as reaction gas by shifting them to U(NHm)n+ and UH(NHm)n+. The overall interference of uranium was reduced to <2.4 × 10-7, while remaining excellent 239Pu sensitivity (13,900 Mcps/(mg/L)) mainly due to ion focusing effect of Pu by helium gas. On this basis, the purification of plutonium using a single AG1- × 4 column was proved to be sufficient for accurate determination of plutonium isotopes by the developed detection method, and the detection limits for the method were estimated to be 0.16 fg (0.4 μBq) for 239Pu, 0.046 fg (0.4 μBq) for 240Pu and 0.039 fg (0.15 mBq) for 241Pu. The method was validated by analyzing plutonium isotopes in certificated reference materials and reported environmental samples of only 1-2 g. The analytical results of ultra-trace Pu isotopes in small amounts (∼1 g) of lake sediments obtained by the developed method were successfully applied to sediment dating.
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Affiliation(s)
- 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.
| | - Chen Li
- 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
| | - Haiping Yu
- 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
| | - Fengman Fang
- 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
| | - Xiaolin Hou
- Technical University of Denmark, Department of Environmental Engineering, Risø Campus, Roskilde, DK-4000, Denmark; State Key Laboratory of Loess and Quaternary Geology, 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, China
| | - Chao Zhang
- 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
| | - Xiaofei Li
- 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
| | - Shan Xing
- China Institute for Radiation Protection, Taiyuan, 030000, China.
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