Boars carry traces of decades-old nuclear weapons tests

Wild boar, once a delicacy in Germany and Austria, has been largely off the menu since the Chernobyl power plant meltdown in 1986 spread radioactive waste across Europe, contaminating the meat. While radiation levels in other animals have declined in the ensuing decades, levels in boars have remained mysteriously steady. Researchers tracing the source of the radiation now think they know why (Environ. Sci. Technol., 2023, doi.org/10.1021/acs.est.3c03565).

Researchers from the Leibniz University Hannover and Vienna University of Technology took samples of boar meat gathered in Bavaria and tested it for cesium-135 and cesium-137, using a standard chemical purification technique and a recently developed form of mass spectrometry to obtain the ratio of the elements.

Because of the way the isotopes are produced, the ratio of ¹³⁵Cs to ¹³⁷Cs coming from a nuclear reactor tends to be low. Researchers found both low and high ratios, indicating some of the contamination came from atmospheric weapons testing in the 1950s, 60s, and 70s.

Georg Steinhauser, a professor of applied radiochemistry at TU Vienna, says that, because it takes time for cesium to migrate through the soil, the boars who root for wild truffles are getting more of the older contamination from nuclear tests than animals that eat plants on the surface. The moving “front” of Chernobyl contamination has not yet reached truffles.

“It’s still continuing,” he says. “It will be there for many years to come.”