#Airborne concentrations and chemical considerations of #radioactive #ruthenium from an undeclared major nuclear release in 2017 (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

O. Masson, G. Steinhauser, D. Zok, O. Saunier, H. Angelov, D. Babić, V. Bečková, J. Bieringer, M. Bruggeman, C. I. Burbidge, S. Conil, A. Dalheimer, L.-E. De Geer, A. de Vismes Ott, K. Eleftheriadis, S. Estier, H. Fischer, M. G. Garavaglia, C. Gasco Leonarte, K. Gorzkiewicz, D. Hainz, I. Hoffman, M. Hýža, K. Isajenko, T. Karhunen, J. Kastlander, C. Katzlberger, R. Kierepko, G.-J. Knetsch, J. Kövendiné Kónyi, M. Lecomte, J. W. Mietelski, P. Min, B. Møller, S. P. Nielsen, J. Nikolic, L. Nikolovska, I. Penev, B. Petrinec, P. P. Povinec, R. Querfeld, O. Raimondi, D. Ransby, W. Ringer, O. Romanenko, R. Rusconi, P. R. J. Saey, V. Samsonov, B. Šilobritienė, E. Simion, C. Söderström, M. Šoštarić, T. Steinkopff, P. Steinmann, I. Sýkora, L. Tabachnyi, D. Todorovic, E. Tomankiewicz, J. Tschiersch, R. Tsibranski, M. Tzortzis, K. Ungar, A. Vidic, A. Weller, H. Wershofen, P. Zagyvai, T. Zalewska, D. Zapata García, and B. Zorko

PNAS first published July 26, 2019 / DOI: https://doi.org/10.1073/pnas.1907571116

Edited by John H. Seinfeld, California Institute of Technology, Pasadena, CA, and approved June 21, 2019 (received for review May 2, 2019)

 

Significance

A massive atmospheric release of radioactive 106Ru occurred in Eurasia in 2017, which must have been caused by a sizeable, yet undeclared nuclear accident. This work presents the most compelling monitoring dataset of this release, comprising 1,100 atmospheric and 200 deposition data points from the Eurasian region. The data suggest a release from a nuclear reprocessing facility located in the Southern Urals, possibly from the Mayak nuclear complex. A release from a crashed satellite as well as a release on Romanian territory (despite high activity concentrations) can be excluded. The model age of the radioruthenium supports the hypothesis that fuel was reprocessed ≤2 years after discharge, possibly for the production of a high-specific activity 144Ce source for a neutrino experiment in Italy.

 

Abstract

In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m−3 to more than 150 mBq·m−3. The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

environmental radioactivity – ruthenium – nuclear forensics – environmental release – accidental release

Keywords: Environmental Pollution; Radiations; Radionuclides; Italy; Russia.

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In situ #measurement of #cesium-137 #contamination in #fruits from the northern #Marshall Islands (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

In situ measurement of cesium-137 contamination in fruits from the northern Marshall Islands

Carlisle E. W. Topping, Maveric K. I. L. Abella, Michael E. Berkowitz, Monica Rouco Molina, Ivana Nikolić-Hughes, Emlyn W. Hughes, and Malvin A. Ruderman

PNAS first published July 15, 2019 / DOI: https://doi.org/10.1073/pnas.1903481116

Contributed by Malvin A. Ruderman, May 15, 2019 (sent for review March 5, 2019; reviewed by Paul Cadden-Zimansky and Katrin Karbstein)

Related Articles: Radiation maps of ocean sediment from the Castle Bravo crater – Jul 10, 2019; Background gamma radiation and soil activity measurements in the northern Marshall Islands – Jul 10, 2019

 

Significance

The United States performed nuclear testing on Bikini and Enewetak Atolls in the northern Marshall Islands between 1946 and 1958. Fallout from the largest test Bravo, detonated in 1954, spread over a large area, exposing to radiation not only land and ocean but also Marshallese people living in neighboring atolls, including Rongelap and Utirik. Cesium-137, present in the fallout, has a half-life of approximately 30 y and is readily absorbed by food crops, thus representing a health hazard for island inhabitants. In situ measurements of cesium-137 content were made for fruits from 11 islands on four atolls. Contamination remains above limits set by international safety standards in some measured fruits, and several islands display contamination from this human-made radionuclide.

 

Abstract

Radioactive contamination of fruits in the northern Marshall Islands, resulting from the US nuclear weapons testing program in the 1940s and 1950s, is still a human health concern, in particular pertaining to island population resettlement and the economic benefit from farming. Over 200 fruits, primarily coconuts and pandanus, were collected on 11 islands from four atolls in the northern Marshall Islands in 2017. The energy spectra from nuclear gamma decays were measured on a research vessel for each fruit in situ. From these recordings, the level of cesium-137 (137Cs) contamination was determined for individual fruits. Comparisons of the results are made to past studies and international food safety standards. There is a broad distribution of values, ranging from below detectable radiation levels to relatively high levels; safety concerns are largest for Bikini Island. A noticeable fraction of fruits from Bikini have significantly higher levels of 137Cs contamination compared with those from all other measured islands.

Marshall Islands – food – radiation – cesium-137 – Bikini

Keywords: Environmental pollution; Environmental disasters; Radiations; Radionuclides; Marhsall Islands; Food safety.

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#Radiation #maps of #ocean #sediment from the Castle Bravo #crater (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Radiation maps of ocean sediment from the Castle Bravo crater

Emlyn W. Hughes, Monica Rouco Molina, Maveric K. I. L. Abella, Ivana Nikolić-Hughes, and Malvin A. Ruderman

PNAS first published July 15, 2019 / DOI: https://doi.org/10.1073/pnas.1903478116

Contributed by Malvin A. Ruderman, May 14, 2019 (sent for review March 1, 2019; reviewed by David Kawall and Yury G. Kolomensky)

Related Articles: In situ measurement of cesium-137 contamination in fruits from the northern Marshall Islands – Jul 10, 2019; Background gamma radiation and soil activity measurements in the northern Marshall Islands – Jul 10, 2019

 

Significance

High-yield thermonuclear explosions cause enormous radioactive contamination to the environment. These “hydrogen bombs,” when tested on small islands in the ocean, vaporize the land and produce radionuclides that settle in the ocean sediment. Even decades later, significant contamination may remain in the sediment surface and deep into the sediment layers. Measuring the radioactive contamination of the crater sediment is a first step in assessing the overall impact of nuclear weapons testing on the ocean ecosystems. We find radiation levels orders of magnitude above background for plutonium-(239,240), americium-241, and bismuth-207 in the top 25 cm of sediment across the entire Bravo bomb crater, the location of the largest aboveground US nuclear weapons test.

 

Abstract

On March 1, 1954, the United States conducted its largest thermonuclear weapon test in Bikini Atoll in the Marshall Islands; the detonation was code-named “Castle Bravo.” Radioactive deposits in the ocean sediment at the bomb crater are widespread and high levels of contamination remain today. One hundred thirty cores were collected from the top 25 cm of surface sediment at ocean depths approaching 60 m over a ∼2-km2 area, allowing for a presentation of radiation maps of the Bravo crater site. Radiochemical analyses were performed on the following radionuclides: plutonium-(239,240), plutonium-238, americium-241, bismuth-207, and cesium-137. Large values of plutonium-(239,240), americium-241, and bismuth-207 are found. Comparisons are made to core sample results from other areas in the northern Marshall Islands.

Bravo crater – Bikini Island – cesium-137 – ocean sediment – plutonium

Keywords: Environmental pollution; Environmental disasters; Radiations; Radionuclides; Marshall Islands.

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Background #gamma #radiation and #soil activity #measurements in the northern #Marshall Islands (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Background gamma radiation and soil activity measurements in the northern Marshall Islands

Maveric K. I. L. Abella, Monica Rouco Molina, Ivana Nikolić-Hughes, Emlyn W. Hughes, and Malvin A. Ruderman

PNAS first published July 15, 2019 / DOI: https://doi.org/10.1073/pnas.1903421116

Contributed by Malvin A. Ruderman, May 15, 2019 (sent for review March 1, 2019; reviewed by Joanna Kiryluk and Ernst Sichtermann)

Related Articles: Radiation maps of ocean sediment from the Castle Bravo crater – Jul 10, 2019; In situ measurement of cesium-137 contamination in fruits from the northern Marshall Islands – Jul 10, 2019

 

Significance

From 1946 to 1958, the United States tested 67 nuclear weapons in the Marshall Islands, a remote constellation of atolls in the Pacific Ocean that was then a US trust territory. Two atolls, Bikini and Enewetak, were used as ground zero for the tests, which caused unprecedented environmental contamination and, for the indigenous peoples of the islands, long-term adverse health effects. In addition to the populations of Bikini and Enewetak, the people of Rongelap and Utirik were also affected by radioactive fallout from the largest nuclear test the United States has ever conducted, the Bravo test held March 1, 1954. This article presents a picture of current radiological conditions by examining external gamma radiation and soil radionuclide activity concentrations.

 

Abstract

We report on measurements of external gamma radiation on 9 islands in 4 atolls in the northern Marshall Islands, all of which were affected by the US nuclear testing program from 1946 to 1958 (Enjebi, Ikuren, and Japtan in Enewetak Atoll; Bikini and Enyu in Bikini Atoll; Naen in Rongelap Atoll; and Aon, Elluk, and Utirik in Utirik Atoll). We also report americium-241, cesium-137, plutonium-238, and plutonium-239,240 activity concentrations in the soil samples for 11 islands in 4 northern atolls (Enewetak, Japtan, Medren, and Runit in Enewetak Atoll; Bikini and Enyu in Bikini Atoll; Naen and Rongelap in Rongelap Atoll; and Aon, Elluk, and Utirik in Utirik Atoll) and from Majuro Island, Majuro Atoll in the southern Marshall Islands. Our results show low external gamma radiation levels on some islands in the Enewetak Atoll and Utirik Atoll, and elevated levels on Enjebi Island in the Enewetak Atoll, on Bikini Atoll, and on Naen Island in the Rongelap Atoll. We perform ordinary kriging on external gamma radiation measurements to provide interpolated maps. We find that radionuclides are absent from all Majuro soil samples, and that they are present at highest activity concentrations in samples from Runit and Enjebi islands (Enewetak Atoll), Bikini Island (Bikini Atoll), and Naen Island (Rongelap Atoll). We contextualize all results by making comparisons between islands and to various standards, as well as to regions of the world affected by nuclear accidents. We also discuss implications for informed decision-making by the Marshallese and local atoll governments and their people on issues pertaining to island resettlement.

Marshall Islands – cesium-137 – external gamma radiation – soil activity – plutonium

Keywords: Environmental pollution; Environmental disasters; Radiations; Radionuclides; Marshall Islands.

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Multiradionuclide #evidence for an extreme #solar proton #event around 2,610 B.P. (∼660 BC) (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)

Paschal O’Hare, Florian Mekhaldi, Florian Adolphi, Grant Raisbeck, Ala Aldahan, Emma Anderberg, Jürg Beer, Marcus Christl, Simon Fahrni, Hans-Arno Synal, Junghun Park, Göran Possnert, John Southon, Edouard Bard, ASTER Team, and Raimund Muscheler

PNAS published ahead of print March 11, 2019 / DOI: https://doi.org/10.1073/pnas.1815725116

Edited by Lennard A. Fisk, University of Michigan, Ann Arbor, MI, and approved February 4, 2019 (received for review September 13, 2018)

 

Significance

This study provides evidence of an enormous solar storm around 2,610 B.P. It is only the third such event reliably documented and is comparable with the strongest event detected at AD 774/775. The event of 2,610 years B.P. stands out because of its particular signature in the radionuclide data [i.e., carbon-14 (14C) data alone does not allow for an unequivocal detection of the event]. It illustrates that present efforts to find such events based solely on 14C data likely lead to an underestimated number of such potentially devastating events for our society. In addition to 14C data, high-resolution records of beryllium-10 and chlorine-36 are crucial for reliable estimates of the occurrence rate and the properties of past solar proton events.

 

Abstract

Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (14C)] and ice cores [beryllium-10 (10Be), chlorine-36 (36Cl)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (∼660 BC) based on high-resolution 10Be data from two Greenland ice cores. Our conclusions are supported by modeled 14C production rates for the same period. Using existing 36Cl ice core data in conjunction with 10Be, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.

solar storms – radionuclides – ice cores – solar proton events

Keywords: Solar storm; Environmental disasters; Radiations.

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#Radiation #Contamination Following #Cremation of a Deceased #Patient Treated With a #Radiopharmaceutical (JAMA, abstract)

[Source: JAMA, full page: (LINK). Abstract, edited.]

Research Letter / February 26, 2019

Radiation Contamination Following Cremation of a Deceased Patient Treated With a Radiopharmaceutical

Nathan Y. Yu, MD1; William G. Rule, MD1; Terence T. Sio, MD, MS1; et alJonathan B. Ashman, MD, PhD1; Kevin L. Nelson, PhD2

JAMA. 2019;321(8):803-804. doi:10.1001/jama.2018.21673

 

Abstract

Radiopharmaceuticals are radioactive compounds used for diagnostic and therapeutic purposes by many medical specialties. As of 2006 (the most recently reported data), 18.6 million nuclear medicine procedures were performed in the United States, with nearly 40 million performed worldwide.1 Safety regulations are well established for radiopharmaceutical administration in living patients. However, radiopharmaceuticals present a unique and often overlooked postmortem safety challenge. Cremating an exposed patient volatilizes the radiopharmaceutical, which can then be inhaled by workers (or released into the adjacent community) and result in greater exposure than from a living patient. Regulations for cremation of exposed patients vary by state, as well as internationally, and there are no regulations at the federal level in the United States. We report radiation contamination at a crematorium.

Keywords: Cancer; Radiations; Environmental pollution.

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Exposure to #environmental #radionuclides associates with #tissue-specific impacts on #telomerase expression and telomere length (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Article | OPEN | Published: 29 January 2019

Exposure to environmental radionuclides associates with tissue-specific impacts on telomerase expression and telomere length

Jenni Kesäniemi, Anton Lavrinienko, Eugene Tukalenko, Zbyszek Boratyński, Kati Kivisaari, Tapio Mappes, Gennadi Milinevsky, Anders Pape Møller, Timothy A. Mousseau & Phillip C. Watts

Scientific Reports, volume 9, Article number: 850 (2019)

 

Abstract

Telomeres, the protective structures at the ends of chromosomes, can be shortened when individuals are exposed to stress. In some species, the enzyme telomerase is expressed in adult somatic tissues, and potentially protects or lengthens telomeres. Telomeres can be damaged by ionizing radiation and oxidative stress, although the effect of chronic exposure to elevated levels of radiation on telomere maintenance is unknown for natural populations. We quantified telomerase expression and telomere length (TL) in different tissues of the bank vole Myodes glareolus, collected from the Chernobyl Exclusion Zone, an environment heterogeneously contaminated with radionuclides, and from uncontaminated control sites elsewhere in Ukraine. Inhabiting the Chernobyl Exclusion Zone was associated with reduced TL in the liver and testis, and upregulation of telomerase in brain and liver. Thus upregulation of telomerase does not appear to associate with longer telomeres but may reflect protective functions other than telomere maintenance or an attempt to maintain shorter telomeres in a stressful environment. Tissue specific differences in the rate of telomere attrition and apparent radiosensitivity weaken the intra-individual correlation in telomere length among tissues in voles exposed to radionuclides. Our data show that ionizing radiation alters telomere homeostasis in wild animal populations in tissue specific ways.

Keywords: Environmental disasters; Environmental pollution; Radiations; Wildlife; Ukraine.

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