—Large quantities of cesium (Cs) and strontium (Sr) released from the Fukushima accident in 2011 are still present in terrestrial ecosystems. This study addressed the contribution of microbial activity to the sorption of Cs and Sr into organic material, which is necessary for comparing non-sterile systems with sterile systems. The aim was to determine the contribution of microbial activity to the sorption of Cs and Sr in organic material. The complete potential of fungi to cycle Cs and Sr in the organic soil system was assessed in a series of experiments. Organic material was prepared under laboratory conditions from leaf litter to minimize the interference from competition by clay minerals. The results of an experimental system comparing biotic and abiotic systems conclusively demonstrate that soil fungi play an important role in the sorption and retention of Cs and Sr. In all experiments, the retention of both elements was greater in biotic systems than in abiotic systems. Soil and saprotrophic fungi make an important contribution to the sorption of Cs and Sr in organic systems and may partly account for the strong, irreversible binding observed in biotic systems. The single strains of Fusarium
sp., and Aspergillus sp. showed increased amounts of Cs and Sr in a fixed form compared with those found in a biotic system. This finding may partly account for the high level of retention of Cs and Sr in upland organic soil, which is not satisfactorily accounted by the physicochemical process alone. It may also partly account for the strong, irreversible binding observed in biotic systems.
—Cesium, organic soil, soil fungi, strontium.
The authors are with the Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, Japan (e-mail: firstname.lastname@example.org).
Cite: Prapamon Seeprasert, Minoru Yoneda, and Yoko Shimada, "The Influence of Soil Fungi on the Sorption of Cesium and Strontium in the Soil Organic Layer," International Journal of Environmental Science and Development vol. 7, no. 6, pp. 415-419, 2016.