According to the Radiation and Nuclear Safety Authority (STUK), edible mushrooms such as champignons, milk caps and trumpet-shaped chanterelle can contain amounts of cesium-137 in excess of EU permitted safety levels.
The EU says mushrooms should not contain more that 600 Becquerels (Bq) of cesium -137 radiation per kilogram. The Authority says wide ranging differences exist in radioactive levels in various parts of southern Finland. It notes the highest concentrations of fallout from the 1986 Chernobyl disaster were in the districts of Pirkanmaa, Häme and the Kymi Valley.
STUK advises the public to rinse and boil mushrooms. This measure can reduce the level of cesium by more than 75 percent. Cesium-137 radiation has a half-life of 30 years.
The authority says levels of cesium-137 in forest berries such as lingonberries are considerably less and, in general, pose little risk.