Encountering a radioactive wild boar in the dark forests of Germany isn’t top of everyone’s bucket list. But, while their populations have been soaring in Europe, it’s not meeting, but rather eating them, that you need to worry about. That’s because they contain unsafe radioactive cesium (a liquid metal).
Their mysteriously high radioactivity levels have been puzzling scientists. Now we know why their radioactivity won’t go away.
The shaggy, tusked pigs roaming around the forests of Germany and Austria were thought to have been made radioactive by the 1986 Chernobyl accident. In fact, scientists from the Vienna University of Technology, in Austria, now show that Oppenheimer-style nuclear weapons testing is responsible for their long-lasting radioactivity.
“We were stunned to see that the nuclear weapons fallout still impacts the ecosystem to such great extent”, the paper’s corresponding authors Dr Georg Steinhauser and Dr Bin Feng told BBC Science Focus.
When nuclear weapons explode or nuclear energy is produced, radioactive cesium is created. When it enters the environment, it can threaten human health – and did just this when the Chernobyl power plant exploded in Ukraine almost four decades ago.
But the study, published in the journal Environmental Science & Technology, shows that the radioactive contamination affecting the boars was also caused by atmospheric nuclear weapons testing by nations across the world in the 1950s and 1960s.
Both events contaminated the radioactive boars’ food sources, including underground truffles.
Cesium-137 used to be present in other game animals, but these levels have dropped. However, the boars are plagued by cesium-135, a longer-lived form of the radioactive metal.
The scientists measured cesium levels in boar meat from southern Germany using a gamma-ray detector. They compared levels of cesium-135 and -137 using a mass spectrometer (a tool used to measure the charge of ions) to find out where the radioactivity came from.
The researchers knew that detecting a higher ratio of -135 than -137 would indicate more fallout from nuclear weapons explosions rather than nuclear reactors – and that’s what they found. Across the samples, between 10 to 68 per cent of the contamination came from nuclear weapons testing.
Eighty-eight per cent of the meat samples exceeded safe levels of radioactivity in food.
“It is a cautionary tale that the long-forgotten atmospheric nuclear weapons tests and their fallout still cast a shadow on the environment,” Steinhauser and Feng told BBC Science Focus. “Just because they took place 60 years ago doesn’t mean that they no longer impact the ecosystem.”
About our experts
Dr Georg Steinhauser is a professor of radiochemistry at the Vienna University of Technology, Austria. His research has been published in the journals Environmental Science and Technology, Journal of Hazardous Materials, and Nature Communications.
Dr Bin Feng is a professor at the Vienna University of Technology, Austria, and the Leibniz University Hannover, Germany. His research has been published in the journals Environment International, The Journal of Environmental Radioactivity, and the Journal of Agricultural and Food Chemistry.
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