Mushrooms 2025 campaign

From July to November 2025, the Radiation and Nuclear Safety Authority (STUK) carried out an extensive measurement campaign on edible mushrooms. The aim of the campaign was to determine the activity concentrations of radioactive cesium (Cs-137) in mushrooms collected from different parts of Finland. We collected a total of 875 mushroom samples from across Finland, representing 60 different species. Thank you to all mushroom pickers who participated in collecting samples!

The majority of Cs-137 in Finnish nature originates from the Chernobyl nuclear power plant accident in 1986. The measurement results showed that the activity concentrations of Cs-137 in mushrooms have decreased as expected. The recommended concentration limit of 600 Bq/kg for sold, natural produce, was exceeded in less than 10% of the samples. However, there is still variation in activity concentrations between both species and regions. The highest activity concentrations were found in areas in which the fallout from Chernobyl was greatest (Kymenlaakso, Pirkanmaa, Päijät-Häme).

 

Of the edible mushrooms recommended by the Finnish Food Authority, the species that accumulate the highest amounts of cesium were the Arched woodwax, Pickle milkcap, Hedgehog mushroom, Wrinkled cort, and Velvet bolete. Previous studies have also shown that these mushroom species accumulate cesium effectively. The species that accumulated the least cesium were the Leccinum species, Boletus species and Russula species.

 

Mushrooms are superfood

Edible mushrooms growing in Finnish forests are nature’s own superfood – delicious, nutritious, and a sustainable choice for your plate. They are rich in beneficial nutrients and enhance the diet. The use of mushrooms as food does not need to be restricted due to their radioactivity. The radiation dose caused by their consumption is low, even in the case large consumption, they contribute well under one percent of the average annual radiation dose received by Finns.

STUK has been monitoring radioactivity concentrations resulting from the Chernobyl since the accident in. Mushroom samples purchased from shops or market places are measured annually within the framework of the national environmental radiation surveillance programme. This follow-up will continue after the end of Mushrooms 2025 campaign. 

Read more: 

Mushrooms 2025 -campaign report in Finnish (Julkari.fi)
Municipal measurement results in Finnish (pdf) 
Edible Mushrooms recommeded by Finnish food agency (in Finnish)