[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)
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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.
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.