Are we moving in the right direction?

There has been little reduction of radioactive caesium in mushrooms in the last decade. This is due to a half-life of caesium-137 of 30 years and the mushroom’s ability to take up caesium-137 from the ground.

Different kinds of mushrooms take up different amounts of caesium. Generally, the white knight, red banded webcap and gypsy mushroom absorb a lot of radioactive caesium. Species such as the penny bun, woolly milkcap, brown birch bolete, copper brittlegill and false saffron milkcap can also absorb relatively high amounts of radioactive caesium, while the sheep polypore, orange birch bolete and chantarelle absorb little radioactive caesium from the soil.

There is also great geographical variation reflecting the uneven distribution of radioactive fallout in Norway in 1986. This is shown in the radioactivity levels in mushrooms from different municipalities in Norway. The highest levels are measured in mushrooms from Dovre, Lierne, Vang, Øystre Slidre and Vestre Slidre. In the most exposed areas radioactivity from the Chernobyl accident is expected to be present in mushrooms for at least another 50 years.