Complexation of cesium 137 by the cap pigments of the bay boletus (Xerocomus badius)

Why is 137Cs strongly enriched in bay boletus but hardly at all in cepe? This question, which arose after the reactor accident at Chernobyl, can now be answered. It was already known that bay boletus contains the unusual pigments badione A and norbadione A in the brown pileus and that these pigments are absent in cepe. The cap pigments are present in the mushroom as potassium complexes. However, the pigments can also bind cesium. Norbadione forms a 1:1 complex with CsCl. This complex can be dissociated by exposure to a strongly acidic cation exchanger. (orig.)