Turtle Shells Record Nuclear History - SCIENTIFIC AMERICAN

[Mary Wilson]

August 22, 2023
By Meghan Bartels​

The invention of the atom bomb has shaped both history and ecosystems across the globe. Its far-reaching impacts have even led scientists to consider using the signature of nuclear weapons to mark a new geologic age, the Anthropocene. Now a new study has shown that turtles taken from nuclear production and detonation sites encode the history of these weapons in their shell.

Using a special mass spectrometer, a device that detects the chemical makeup of a material, scientists detected minuscule levels of uranium in the shells of four turtles, including one sea and one tortoise, that lived near such sites before they were collected as natural history specimens between the 1950s and 1980s. In these samples—two taken from production sites and two taken from detonation sites—the scientists matched the signatures of uranium isotopes in the shells to the distinct profiles produced by each of these two types of nuclear activity. ...

https://www.scientificamerican.com/article/turtle-shells-record-nuclear-history/
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[Mary Wilson]

Anthropogenic uranium signatures in turtles, tortoises, and sea turtles from nuclear sites - PNAS Nexus
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August 2023

https://doi.org/10.1093/pnasnexus/pgad241​

Cyler Conrad, Jeremy Inglis, Allison Wende, Matthew Sanborn, Nilesh Mukundan, Allison Price, Travis Tenner, Kimberly Wurth, Benjamin Naes, Jeanne Fair ... Show more​

Abstract

Chelonians (turtles, tortoises, and sea turtles) grow scute keratin in sequential layers over time. Once formed, scute keratin acts as an inert reservoir of environmental information. For chelonians inhabiting areas with legacy or modern nuclear activities, their scute has the potential to act as a time-stamped record of radionuclide contamination in the environment. Here, we measure bulk (i.e. homogenized scute) and sequential samples of chelonian scute from the Republic of the Marshall Islands and throughout the United States of America, including at the Barry M. Goldwater Air Force Range, southwestern Utah, the Savannah River Site, and the Oak Ridge Reservation. We identify legacy uranium ([SUP]235[/SUP]U and [SUP]236[/SUP]U) contamination in bulk and sequential chelonian scute that matches known nuclear histories at these locations during the 20th century. Our results confirm that chelonians bioaccumulate uranium radionuclides and do so sequentially over time. This technique provides both a time series approach for reconstructing nuclear histories from significant past and present contexts throughout the world and the ability to use chelonians for long-term environmental monitoring programs (e.g. sea turtles at Enewetok and Bikini Atolls in the Republic of the Marshall Islands and in Japan near the Fukushima Daiichi reactors).​

https://watermark.silverchair.com/p...8noCVUFlccJM21wtBWaFsr-nQp-4DFS4Wpfbb4isYZkN6