Discoveries

September 06, 2023

Living with the Bomb

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There is some extensive radioactive history on the backs of turtles and tortoises, New Scientist reported.

Nuclear weapon tests and accidental waste releases create radioactive isotopes – also known as radionuclides – that can spread widely and stay in the ecosystem for a very long time.

In a new study, a research team sought to test whether these radionuclides accumulate in organisms and recently found that the shells of turtles and tortoises can store decades-long records of radioactive uranium isotopes when exposed to radioactive fallout.

Scientists explained that the shells – called scutes – exhibit layer growth similar to that of nails. However, once the nail-like scale material is deposited and it becomes distinct from other bodily tissues, it essentially gets time-stamped.

The team studied the scutes from four museum specimens: Two of which lived around areas of atomic bomb tests – the Marshall Islands and Nevada’s Mojave Desert – and two others who lived near fuel processing plants that spewed out nuclear waste.

Chemical analysis of the shells showed that all turtles and tortoises had small but elevated uranium radioactive isotopes in their scutes.

The findings are significant because they could be used to reconstruct and chronicle the histories of nuclear contamination in ecosystems.

Other scientists said the study could also pioneer the field of radioecology research using zoological collections in museums to “assess the concentration of radionuclides in feathers, bones and other tissues in specimens collected before and after nuclear tests and accidents.”

This story originally appeared in the September 06, 2023 newsletter, Cracks in the Tent Pole.