In particular, the researchers examined the ratio of uranium isotopes. 235U/238U and 236U/238U – in the keratin of turtle shells. By analyzing samples taken from various places, they were able to draw some surprising conclusions about the extent of radioactive contamination. The results of the research were published in the journal PNAS Nexus.

What does the research show?

Turtles in areas close to nuclear weapons testing sites had higher 235U/238U ratios, while turtles close to nuclear fuel plants had lower ratios of the same isotopes. This particular correlation is clear evidence that turtles interact with the radioactive elements in their environment. The 236U/238U ratio also increased in both cases.

The significance of this discovery is that it can help researchers. reconstructing the history of radioactive contamination of ecosystems. The period between 1940 and 1990 saw the testing of nuclear weapons around the world, and this study highlights the long-term environmental impact of these tests.

His research methodology included collecting turtle shells from museum collections, where each sample was associated with different nuclear test sites, uranium mining sites, and nuclear fuel operations.

• For example, a green turtle shell was found in the stomach of a tiger shark near the Enewetak atoll in the Pacific Ocean, where nuclear tests were stopped in 1958.
• Similarly, the shell of a turtle from southwestern Utah found near a former testing site in Nevada had obvious signs of nuclear testing.

Scientists saw interesting links

A Sonoran tortoise from an unaffected area served as a control, while turtle shells in South Carolina, Tennessee, and Eniwetok Atoll showed abnormal uranium isotope ratios, indicating radioactive contamination. The study also revealed an increase in the level of the 236U isotope, which accumulates in the shells of turtles, unlike their natural state.

These results show that turtles can accumulate artificial radioactive isotopes in their shellseven with a small amount of keratin. Its consequences include accurate historical estimates of radioactive waste pollution in ecosystems. This work contributes to a broader understanding of the environmental consequences of nuclear testing by providing a unique perspective through the lens of these creatures.

Why is this important?

The implications of the research extend beyond turtle biology. It is consistent with other scientific efforts aimed at determining the chronology of radioactive contamination using unconventional methods. By studying the concentration of carbon-14 in the atmosphere and living organisms, scientists can determine the time of events.

Finally, the discovery of a link between turtle shells and historical nuclear testing underscores the far-reaching implications of these tests. As scientists continue to explore the complex relationships between animals and their environments, discoveries like this add to our broader understanding of the impact of human activities on the natural world.