From July until the end of November, the Radiation and Nuclear Safety Authority will organise the Mushrooms 2025 campaign, the aim of which is to examine radioactive cesium (Cs-137) concentrations and differences in concentrations in edible mushroom species in different parts of the country and in different mushroom species. During the campaign, the public can send edible mushroom samples from all over the country to the Radiation and Nuclear Safety Authority.
The Mushrooms 2025 campaign will allow STUK to analyse how the radioactivity of edible mushrooms has decreased over time, more specifically after the radioactive fallout caused by the Chernobyl Nuclear Power Plant accident in 1986.
“I really hope we’ll be sent a large number of samples of various mushroom species from different parts of the country to research,” says Head of Laboratory Sinikka Virtanen from the Radiation and Nuclear Safety Authority (STUK).
Samples sent may be either fresh or dried. Drying mushrooms will require a bit of work, but sending dried samples to STUK and their preservation is more likely to be successful than that of fresh ones.
"Fresh samples must be mailed to STUK at the beginning of the week so that they can reach us in good condition and will not get stuck in storage over the weekend," Sinikka Virtanen explains and continues with:
“This campaign marks a new way for us to collect mushroom samples. In the past, we have purchased edible mushrooms in Helsinki, Tampere and Rovaniemi to measure them,” says Sinikka Virtanen. “This is also our way of bringing science closer to people and involving everyone in monitoring the state of the environment.”
To take part in the campaign, submit a sample of an edible mushroom species you are familiar with to STUK at your own expense either by post or by bringing it to the STUK offices in Vantaa. More detailed instructions for picking, handling, packaging, and delivering of samples can be found on STUK’s website (Mushrooms 2025 campaign | Säteilyturvakeskus STUK). STUK can provide the measurement results of each person’s own mushroom sample by e-mail if an email address is provided with a submitted sample.
Measurement results will be completed as early as during the autumn and published on the campaign page. The goal is for the overall results of the campaign to be ready in April 2026.
Monitoring of cesium concentrations in edible mushrooms
Finnish mushrooms still have radioactivity resulting from the Chernobyl Nuclear Power Plant accident. However, the concentrations of radioactivity are so small that people can eat mushrooms without worry. In Finland, the recommended limit value for radioactive cesium in natural products has been set at 600 becquerels per kilo, and mushrooms crossing the limit are still sometimes found. The limit value is very conservative, meaning no one can eat such a large amount of domestic edible mushrooms that the radioactivity these contain would actually harm the person’s health.
“If you are still concerned, you can also remove potential cesium by boiling or soaking the mushrooms,” Sinikka Virtanen points out. "However, this is not necessary just due to radiation."
April next year will mark the 40th anniversary of the Chernobyl Nuclear Power Plant accident. STUK’s measurements have shown that cesium concentrations in mushrooms have decreased over the past 40 years.
