Some wild boar hunted in German forests have radiation levels that exceed the limit deemed safe for human consumption

Although scientists have long known that flora and fauna in Central Europe still carry traces of radiation stemming from the 1986 meltdown at the Chernobyl nuclear power plant in Ukraine, a new study on wild boars roaming the forests of Bavaria in southern Germany has turned up unexpected findings about the radiation present in their tissue.

Given that radiation from the Chernobyl accident temporarily contaminated large swaths of Ukraine, Belarus, Russia and Central Europe, flora and fauna there have since been regularly tested to determine whether they are safe for human consumption. And Martin Steiner, a scientist at the German Federal Office for Radiation Protection who was not involved in the study, said in an interview that he and his colleagues had long known that significant radiation from mid-20th-century nuclear weapons testing remained in the environment.

But the newly published study, by researchers from Leibniz University in Hanover and the Vienna University of Technology, provides a more concrete way of quantifying the extent to which the radiation from the testing persists in boars today.

The research used a method involving the ratio of two cesium isotopes to analyze the carcasses of boars killed by hunters across Bavaria from 2019 to 2021. That relatively new method of analysis allowed the team to better understand what was behind the higher levels of contamination in wild boars in Central Europe.

In Bavaria, boar hunted in certain areas must be tested for radioactivity, and German health guidelines allow for the human consumption of such meat if the radiation is under 600 becquerels per kilogram. Torsten Reinwald, a spokesman for the German Hunting Association, said in an interview that, overall, “We have no indication that meat from wild boar in Germany is contaminated with significant radioactivity.”

But some of the boars tested in the new study carried far higher radioactivity levels, with the contamination ranging from 370 to 15,000 becquerels per kilogram of meat.

And given that nuclear reactors and nuclear weapons leave slightly different contamination signatures — with distinct ratios of cesium-135 to cesium-137 isotopes — the researchers determined that a surprising amount of radiation present in the tested boars stemmed from nuclear testing in the 1950s and 1960s.

In all, the world’s nuclear powers conducted more than 500 atmospheric tests before moving them underground to try to limit the spread of radioactivity. The new study’s findings indicate how the many decades of above-the-ground detonations continue to have ramifications.

As for why wild boars in southern Germany bear more traces of such radiation than other animals, Professor Steinhauser said that a crucial element to the mystery was a fungus — elaphomyces, or deer truffles — that boars dig up and eat but other wildlife ignores.

Although many other edible fauna are no longer significantly contaminated, the truffles, which grow inches below the Earth’s surface, store radiation particularly well. (According to Germany’s Federal Office for Radiation Protection, certain wild mushrooms can reach more than 1,000 becquerels per kilogram, although it still deems wild mushrooms safe to eat in small quantities.)