Radioactive cesium levels in mushrooms can be easily reduced
Mushrooms still contain radioactive cesium that originates from the Chernobyl accident in 1986. It can be easily reduced by up to 80%, however. Fresh, dried or salted mushrooms are soaked or boiled in abundant water. You can improve the efficiency of the process by using more water than indicated in common instructions, or by repeating the process. Mushrooms that need not be boiled can be heated to release their own liquid, which is then disposed of. Most of the cesium is disposed of with the water. Just drying the mushrooms without soaking will not reduce the amount of cesium.
The new guidelines are based on the results of the research project that Evira and STUK started in 2005. The purpose of the common project was to investigate the radioactivity contained in fish and mushrooms in Vammala region in Finland. The studies showed considerable variance in the levels of cesium-137 in mushrooms, even within the same species. Reasons for this include different growing conditions and the unevenness of the fallout.
Species that contain only small amounts of cesium include chantarelle, penny bun, orange-cap boletus, sheep polyporus, ringed boletus, honey mushroom, morel, false morel and matsutake. The maximum level is often exceeded in brittlegills, funnel chanterelles, trumpet chanterelles and black chanterelles in areas that received the most fallout. Milk caps, hedgehog mushrooms, velvet boletes, gypsy mushrooms and arched woodwax, on the other hand, commonly contain more than 600 becquerels of cesium per kilogram (Bq/kg) even in areas of minor fallout.
According to the European Commission recommendation (2003/274/Euratom), the radioactive cesium content of natural products sold in the member countries may not exceed 600 Bq/kg. Mushrooms with cesium levels in excess of this maximum limit are still found in some areas in Finland.
The brochure Guidelines for handling of mushrooms is available on the web site of Evira:
More information on the Internet:
Information on fallout areas on STUK's web site: http://www.stuk.fi/sateilytietoa/sateily_ymparistossa/tshernobyl/cesiumlaskeuma/fi_FI/laskeuma/
Information on the research project on cesium-137 levels in fish and mushrooms in Vammala region:
For more information, please contact:
Ulla Karlström, Senior Officer/Evira, tel. +358 (0) 20 77 24288, +358 (0) 40 48 777 98
Eila Kostiainen, Scientist/STUK, tel. +358 (0) 9 759 88 516
STUK's information telephone outside office hours, tel. +358 (0) 10 850 4761