Accumulation of Cs by shiitake cultivated in mushroom bed

Guido-Garcia, F.; Kozai, Naofumi   ; Sakamoto, Fuminori  ; Grambow, B.

We aimed to improve the understanding of the mechanisms by which mushrooms can accumulate radiocesium within the fruit body.Cesium-137 is one of the most common fission products of uranium in nuclear reactors and was widely spread during the Fukushima incident in 2011. Nowadays, Cs is one of the main concerns in terms of contamination due to its half-life (30.1 y) and prevalence in forests. Here, cesium is accumulated by different organisms such as animals, plants and fungi. Specifically for fungi, some species have been identified that can accumulate Cs efficiently. Mushrooms are of special interest because the ingestion of contaminated species can lead to internal exposure of radioactivity. In this context, understanding the mechanisms by which cesium is accumulated by mushrooms is of particular interest and not yet fully understood. Moreover, the mechanisms by which Cs is released back into soil after mushrooms die has not been fully investigated either. In this research, we aim to improve the understanding of Cs uptake by comparing its behavior to another cation (K). For this, shiitake mushrooms were used as a model organism and exposed to Cs and K under laboratory conditions. Samples of fruit body were taken at different time points and their radioactivity analyzed by Ge detector to evaluate the uptake at different maturity stages. The results of these experiments will be shown and discussed.