Cesium-137: Radio-Chemistry, Fate, and Transport, Remediation, and Future Concerns

In recent years, considerable interest has arisen with regard to the fate and transport of radionuclides such as iodine-131 (131I), cesium-134 (134Cs), and cesium-137 (137Cs) in aquatic environments. 137Cs is an important indicator of radioactive pollution in aquatic environments. The transport and fate of anthropogenic 137Cs is related to the chemical properties of ionic Cs (Cs+), which generally dictates a high degree of mobility and bioavailability of this radionuclide. The transport of 137Cs and its partitioning between abiotic and biotic components of aquatic ecosystems are complex processes that are considerably affected by a number of factors such as mineralogical composition of suspended and bottom sediments and the characteristic geochemistry of water. These factors influence sorption and desorption kinetics of 137Cs and the transport of particulate 137Cs. Nevertheless, substantial evidence suggests that direct biological 137Cs accumulation from the aquatic environment occurs readily in micro-organisms and aquatic plants. The evidence discussed in this work indicates that 137Cs is continuously re-circulated in biological systems for many years following a pulse of contamination. Possible remediation methods for the contaminated aquatic systems are also discussed. This review provides guidelines for future work plans for the study of the fate and transport of 137Cs in the aquatic environment in the wake of Fukushima Nuclear Power Plant disaster in 2011 and to provide answers to the urgent questions with respect to strategies for mitigating contamination and reducing radiation exposure for people living in the most affected regions of the world.