Reducing radioactive cesium transfer from sawdust media to Pleurotus ostreatus fruiting bodies

Abstract

The Fukushima Daiichi nuclear power plant was damaged, and radionuclides such as 137Cs were spread into the environment. Three years have passed since the accident, and ingestion of foods contaminated with radioactive material through the food chain is a health hazard of concern. Mushrooms are known for absorbing radionuclides, and methods for reducing fruiting body radioactivity are needed. We investigated radiocesium transfer activities and methods of reducing radiocesium transfer from sawdust media into fruiting bodies using Pleurotus ostreatus. Fruiting body radiocesium activity increased linearly with increasing media radioactivity. The radiocesium activities of fruiting bodies cultivated in different sawdust media were 0.2–0.9-fold (on wet-weight basis) and 1.3–3.7-fold (on dry-weight basis) higher than those of sawdust media, showing that transfer rates vary with cultivation conditions. From the reducing fruiting body radiocesium activity tests by medium additives, Prussian blue was effective and nanoparticle insoluble Prussian blue was more efficient than soluble Prussian blue. However, nanoparticle insoluble Prussian blue is more expensive than soluble Prussian blue. If mushroom growers use Prussian blue, it will be necessary to determine the type and the additional amounts that correspond to used strains, consumer needs, commercial value and cost.