Strangely, truffles are not contaminated by radioactivity

Reasons are still unclear
Even three decades after the Chernobyl nuclear disaster, some wild mushrooms in some areas are still exposed to radioactivity. But that does not apply to one of the most expensive delicacies in the world: Truffles can obviously be eaten without hesitation - at least if they come from less affected regions. Swiss scientists, together with German colleagues, had examined 82 Burgundy truffles from Western Europe, which were collected from 2010 to 2014 with the help of trained truffle dogs. The noble mushrooms came from different natural occurrences and plantations in Switzerland, in Germany, France, Italy and Hungary.
After the nuclear disaster of Chernobyl in 1986, wind and rain spread significant amounts of radioactive particles, mainly cesium 137 (137Cs), across the European continent. In many areas, the top forest soil layer is still polluted today. Mushrooms absorb these particles. Deer truffles of the genus Elaphomyces, also called "false truffles", are among the most radioactive contaminated fungi. They are often eaten by deer and wild boars, so that the game meat in some strongly affected regions too high cesium values.

Truffles not burdened. Image: dream79 - fotolia

For the burgundy truffle (Tuber aestivum), the samples showed only negligible radioactivity. The 137Cs values ​​were below the detection limit of 2 becquerels per kilogram. The limit for mushrooms is 600 becquerels per kilogram. So far, it is unclear why the underground ascomycetes are less susceptible to the uptake of radioactivity. Presumably, it is due to the mechanisms of nutrient extraction from the humus, which should be further clarified. The burgundy truffle prefers calcareous soils, and calcium carbonate could reduce the uptake of radioactive cesium. Other possible factors include the depth of the fungal plexus and the lack of 137Cs-binding pigments.

The question remains whether the all-clear for the Burgundy truffle is generally valid. Most of the truffles studied come from less affected regions. The radioactive contamination of truffles from more affected areas such as Belarus, northern Ukraine or central Austria can not be said. The investigations should therefore also be extended to other regions. (Heike Kreutz, aid)