Poisons of the Past

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Wild boars in southern Germany are so radioactive that they can’t be consumed and scientists have finally figured out why, Science Magazine reported.

Many scientists have suggested that the radioactivity could be blamed on the 1986 Chernobyl nuclear disaster in Ukraine, which impacted many of Europe’s forest-dwelling animals.

That nuclear meltdown released radioactive fallout that spread over the environment and contaminated areas with radioactive cesium – specifically cesium-137.

Still, this isotope of cesium has a short half-life and disappears after a few decades.

But when the research team analyzed the meat of 48 boars they found traces not only of cesium-137 but also cesium-135 in all of the samples. They explained that the more stable cesium-135 is caused by nuclear explosions and has a half-life of more than two million years.

Their findings suggest that the radioactive contamination began during the nuclear weapons testing in the 1960s: During the Cold War, more than 2,000 bombs were detonated worldwide, including 500 that were tested in the atmosphere – releasing radioactive particles that then drifted down to the ground.

Those cesium-135 particles eventually ended up in the soil. Rainfall then helped them to be absorbed deeper into the ground over the years. Eventually, those particles accumulated in fungi, including the underground truffle mushrooms that the boars love to eat.

The study paints a picture of the impact of nuclear testing and incidents on the environment and ecosystem.

“It is a cautionary tale that the long-forgotten atmospheric nuclear weapons tests and their fallout still cast a shadow on the environment,” the authors told BBC Science Focus. “Just because they took place 60 years ago doesn’t mean that they no longer impact the ecosystem.”