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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Effects of #fossil #fuel and total #anthropogenic #emission removal on #publichealth and #climate (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.]

Effects of fossil fuel and total anthropogenic emission removal on public health and climate

J. Lelieveld, K. Klingmüller, A. Pozzer, R. T. Burnett, A. Haines, and V. Ramanathan

PNAS published ahead of print March 25, 2019 / DOI: https://doi.org/10.1073/pnas.1819989116

Edited by Susan Solomon, Massachusetts Institute of Technology, Cambridge, MA, and approved February 27, 2019 (received for review November 27, 2018)

 

Significance

We assessed the effects of air pollution and greenhouse gases on public health, climate, and the hydrologic cycle. We combined a global atmospheric chemistry–climate model with air pollution exposure functions, based on an unmatched large number of cohort studies in many countries. We find that fossil-fuel-related emissions account for about 65% of the excess mortality rate attributable to air pollution, and 70% of the climate cooling by anthropogenic aerosols. We conclude that to save millions of lives and restore aerosol-perturbed rainfall patterns, while limiting global warming to 2 °C, a rapid phaseout of fossil-fuel-related emissions and major reductions of other anthropogenic sources are needed.

 

Abstract

Anthropogenic greenhouse gases and aerosols are associated with climate change and human health risks. We used a global model to estimate the climate and public health outcomes attributable to fossil fuel use, indicating the potential benefits of a phaseout. We show that it can avoid an excess mortality rate of 3.61 (2.96–4.21) million per year from outdoor air pollution worldwide. This could be up to 5.55 (4.52–6.52) million per year by additionally controlling nonfossil anthropogenic sources. Globally, fossil-fuel-related emissions account for about 65% of the excess mortality, and 70% of the climate cooling by anthropogenic aerosols. The chemical influence of air pollution on aeolian dust contributes to the aerosol cooling. Because aerosols affect the hydrologic cycle, removing the anthropogenic emissions in the model increases rainfall by 10–70% over densely populated regions in India and 10–30% over northern China, and by 10–40% over Central America, West Africa, and the drought-prone Sahel, thus contributing to water and food security. Since aerosols mask the anthropogenic rise in global temperature, removing fossil-fuel-generated particles liberates 0.51(±0.03) °C and all pollution particles 0.73(±0.03) °C warming, reaching around 2 °C over North America and Northeast Asia. The steep temperature increase from removing aerosols can be moderated to about 0.36(±0.06) °C globally by the simultaneous reduction of tropospheric ozone and methane. We conclude that a rapid phaseout of fossil-fuel-related emissions and major reductions of other anthropogenic sources are needed to save millions of lives, restore aerosol-perturbed rainfall patterns, and limit global warming to 2 °C.

air pollution – greenhouse gases – health impacts – climate change – hydrologic cycle

Keywords: Climate Change; Global Warming; Environmental disasters; Public Health.

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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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#Effect of #oilspills on #infant #mortality in #Nigeria (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.]

Effect of oil spills on infant mortality in Nigeria

Anna Bruederle and Roland Hodler

PNAS published ahead of print March 5, 2019 / DOI: https://doi.org/10.1073/pnas.1818303116

Edited by Anthony J. Bebbington, Clark University, Worcester, MA, and approved February 1, 2019 (received for review October 24, 2018)

 

Significance

Onshore oil spills can lead to irreversible environmental degradation and potentially pose hazards to human health, but scientific evidence on their health effects is lacking. We fill this gap by studying the causal effects of onshore oil spills on neonatal and infant mortality rates. We compare siblings conceived before and after nearby oil spills and find that nearby oil spills double the neonatal mortality rate. Given that oil spills occur with high frequency in the densely populated areas along pipelines in Nigeria, they are the cause of an alarming ongoing human tragedy. Our results suggest that efforts to prevent oil spills in the Niger Delta could save the lives of thousands of newborns every year.

 

Abstract

Oil spills can lead to irreversible environmental degradation and are a potential hazard to human health. We study how onshore oil spills affect neonatal and infant mortality by combining spatial data from the Nigerian Oil Spill Monitor with Demographic and Health Surveys. To identify a causal effect, we compare siblings born to the same mother, conceived before and after a nearby oil spill. We find that nearby oil spills that occur before conception increase neonatal mortality by 38.3 deaths per 1,000 live births, which corresponds to an increase of around 100% on the sample mean. The effect is fairly uniform across girls and boys, socio-economic backgrounds, and locations. We show that this effect is not driven by events related to oil production or violent conflict. Rather, our results are consistent with medical and epidemiological evidence showing that exposure to hydrocarbons can pose risks to fetal development. We provide further evidence suggesting that the effects of oil spills on neonatal mortality persist for several years after the occurrence of an oil spill.

onshore oil spills – infant mortality – neonatal mortality – Nigeria – sibling comparisons

Keywords: Environmental pollution; Environmental disasters; Nigeria; Pediatrics.

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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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