Finnish wild mushrooms still exhibit elevated levels of caesium from Chernobyl nuclear accident
In addition to mushrooms, some hares and the predatory fish in small lakes still contain radioactive caesium.
”In the areas with the largest fallout, the level of radioactive caesium can be considerable. However, mushrooms can be eaten in moderation, even when the contents are high, exceeding the hightest permissible level recommended for commercial mushrooms”, says researcher Eila Kostiainen from the Nuclear Safety Authority (STUK).
The easiest way to reduce the caesium content is to pre-process the mushrooms with water.
”Caesium is water-soluble and can be disposed of with water. The most important thing is to soak or boil the fresh, dried or salted mushrooms in abundant water and to throw away the water after the process.”
The drying of mushrooms alone does not reduce the level of radioactive caesium.
After the Chernobyl accident, the rain and airborne discharge swept over Southeastern and Central Finland, the districts of Häme and Pirkanmaa, as well as Ostrobothnia.
Based on the severity of the caesium fallout from Chernobyl, STUK has divided the Finnish territory into five categories.
The fifth category with the maximum level of radioactive contamination includes the localities of Artjärvi, Asikkala, Elimäki, Juupajoki, Jäppilä, Kuhmoinen, Kuorevesi, Lempäälä, Längelmäki, Mänttä, Nastola, Orivesi, Padasjoki, Pieksämäki, Pirkkala, Ruotsinpyhtää, Sahalahti, Sysmä, Tampere, Viiala, Vilppula, and Ylöjärvi.
The studies showed considerable variation in the levels of caesium in wild mushrooms, even within the same region. Moreover, the caesium amount is still 60 % of the content from the Chernobyl fallout.
However, the radiation amount from food is less than 1% of all radiation an average Finn is exposed to annually.
A considerably higher amount of radiation comes from radon gas exposure in dwellings. Radon affects indoor air quality, the source of the contamination being the the ground under buildings.