Liguo Cao , Zhengchao Zhou , Kexin Zhang , Ning Wang , Zhangwen Liu
{"title":"青藏高原东北部冰川冰晶中钚的测定及其来源鉴定和富集意义","authors":"Liguo Cao , Zhengchao Zhou , Kexin Zhang , Ning Wang , Zhangwen Liu","doi":"10.1016/j.scitotenv.2023.164140","DOIUrl":null,"url":null,"abstract":"<div><p>Plutonium isotopes have drawn public attention because of their high radiotoxicity and risk for internal radiation. Cryoconite, dark sediments on the surface of glaciers, is rich in anthropogenic radionuclides. Therefore, glaciers are regarded as not only a temporary sink for radioactive pollutants in the past decades, but also a secondary source during their melting. However, study on activity concentration and source of Pu isotopes in cryoconite materials in Chinese glaciers have not been studies thus far. The present study determined the <sup>239+240</sup>Pu activity concentration and <sup>240</sup>Pu/<sup>239</sup>Pu atom ratio in cryoconite and other environmental samples collected in August-one ice cap, northeast Tibetan Plateau. The results showed that the <sup>239+240</sup>Pu activity concentration in cryoconite is 2–3 orders of magnitude higher than the background value, suggesting the exceptional capacity of cryoconite to accumulate Pu isotopes. The high <sup>239+240</sup>Pu level in cryoconite in the study area was significantly correlated with organic matter and slope, indicating their dominant influence. The average values of the <sup>240</sup>Pu/<sup>239</sup>Pu atom ratio for proglacial sediments (0.175) and grassland soils (0.180) suggested that the global fallout is the dominant source of Pu isotopes pollution. In contrast, the measured <sup>240</sup>Pu/<sup>239</sup>Pu atom ratios in the cryoconite were distinctly lower at 0.064–0.199, with an average of 0.157, indicating that the close-in fallout Pu isotopes from Chinese nuclear test sites is another source. In addition, although the relatively lower activity concentrations of <sup>239+240</sup>Pu in proglacial sediments implies that most Pu isotopes are retained in this glacier instead of being redistributed along with cryoconite by meltwater, the potential health and ecotoxicological risks to the proglacial environment and downstream areas cannot be ignored. These results are important for understanding the fate of Pu isotopes in the cryosphere and can be applied as baseline data for radioactivity evaluation in the future.</p></div>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2000,"publicationDate":"2023-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Determination of plutonium in cryoconite on glacier surfaces in the northeast Tibetan Plateau: Implications for source identification and accumulation\",\"authors\":\"Liguo Cao , Zhengchao Zhou , Kexin Zhang , Ning Wang , Zhangwen Liu\",\"doi\":\"10.1016/j.scitotenv.2023.164140\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Plutonium isotopes have drawn public attention because of their high radiotoxicity and risk for internal radiation. Cryoconite, dark sediments on the surface of glaciers, is rich in anthropogenic radionuclides. Therefore, glaciers are regarded as not only a temporary sink for radioactive pollutants in the past decades, but also a secondary source during their melting. However, study on activity concentration and source of Pu isotopes in cryoconite materials in Chinese glaciers have not been studies thus far. The present study determined the <sup>239+240</sup>Pu activity concentration and <sup>240</sup>Pu/<sup>239</sup>Pu atom ratio in cryoconite and other environmental samples collected in August-one ice cap, northeast Tibetan Plateau. The results showed that the <sup>239+240</sup>Pu activity concentration in cryoconite is 2–3 orders of magnitude higher than the background value, suggesting the exceptional capacity of cryoconite to accumulate Pu isotopes. The high <sup>239+240</sup>Pu level in cryoconite in the study area was significantly correlated with organic matter and slope, indicating their dominant influence. The average values of the <sup>240</sup>Pu/<sup>239</sup>Pu atom ratio for proglacial sediments (0.175) and grassland soils (0.180) suggested that the global fallout is the dominant source of Pu isotopes pollution. In contrast, the measured <sup>240</sup>Pu/<sup>239</sup>Pu atom ratios in the cryoconite were distinctly lower at 0.064–0.199, with an average of 0.157, indicating that the close-in fallout Pu isotopes from Chinese nuclear test sites is another source. In addition, although the relatively lower activity concentrations of <sup>239+240</sup>Pu in proglacial sediments implies that most Pu isotopes are retained in this glacier instead of being redistributed along with cryoconite by meltwater, the potential health and ecotoxicological risks to the proglacial environment and downstream areas cannot be ignored. These results are important for understanding the fate of Pu isotopes in the cryosphere and can be applied as baseline data for radioactivity evaluation in the future.</p></div>\",\"PeriodicalId\":422,\"journal\":{\"name\":\"Science of the Total Environment\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":8.2000,\"publicationDate\":\"2023-08-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Science of the Total Environment\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0048969723027614\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Science of the Total Environment","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0048969723027614","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Determination of plutonium in cryoconite on glacier surfaces in the northeast Tibetan Plateau: Implications for source identification and accumulation
Plutonium isotopes have drawn public attention because of their high radiotoxicity and risk for internal radiation. Cryoconite, dark sediments on the surface of glaciers, is rich in anthropogenic radionuclides. Therefore, glaciers are regarded as not only a temporary sink for radioactive pollutants in the past decades, but also a secondary source during their melting. However, study on activity concentration and source of Pu isotopes in cryoconite materials in Chinese glaciers have not been studies thus far. The present study determined the 239+240Pu activity concentration and 240Pu/239Pu atom ratio in cryoconite and other environmental samples collected in August-one ice cap, northeast Tibetan Plateau. The results showed that the 239+240Pu activity concentration in cryoconite is 2–3 orders of magnitude higher than the background value, suggesting the exceptional capacity of cryoconite to accumulate Pu isotopes. The high 239+240Pu level in cryoconite in the study area was significantly correlated with organic matter and slope, indicating their dominant influence. The average values of the 240Pu/239Pu atom ratio for proglacial sediments (0.175) and grassland soils (0.180) suggested that the global fallout is the dominant source of Pu isotopes pollution. In contrast, the measured 240Pu/239Pu atom ratios in the cryoconite were distinctly lower at 0.064–0.199, with an average of 0.157, indicating that the close-in fallout Pu isotopes from Chinese nuclear test sites is another source. In addition, although the relatively lower activity concentrations of 239+240Pu in proglacial sediments implies that most Pu isotopes are retained in this glacier instead of being redistributed along with cryoconite by meltwater, the potential health and ecotoxicological risks to the proglacial environment and downstream areas cannot be ignored. These results are important for understanding the fate of Pu isotopes in the cryosphere and can be applied as baseline data for radioactivity evaluation in the future.
期刊介绍:
The Science of the Total Environment is an international journal dedicated to scientific research on the environment and its interaction with humanity. It covers a wide range of disciplines and seeks to publish innovative, hypothesis-driven, and impactful research that explores the entire environment, including the atmosphere, lithosphere, hydrosphere, biosphere, and anthroposphere.
The journal's updated Aims & Scope emphasizes the importance of interdisciplinary environmental research with broad impact. Priority is given to studies that advance fundamental understanding and explore the interconnectedness of multiple environmental spheres. Field studies are preferred, while laboratory experiments must demonstrate significant methodological advancements or mechanistic insights with direct relevance to the environment.