Radioactive cesium accumulation in freshwater fishes after the Fukushima nuclear accident
Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
SpringerPlus 2014, 3:479 doi:10.1186/2193-1801-3-479Published: 28 August 2014
The Fukushima Daiichi Nuclear Power Plant (F1NPP) accident released large amounts of radioactive substances into the environment and contaminated the terrestrial and marine ecosystems in East Japan. The unpredicted nuclear accident is of global concern for human health and ecosystems. Investigations of radionuclides in the local environments were performed shortly after the accident began; however the temporal and spatial effects and variations in the released radionuclides on the natural environment remain unclear. In the present study, three-year (May 2011 to March 2014) fluctuations and accumulations of total Cs, 134Cs and 137Cs in freshwater fishes in Fukushima prefecture after the F1NPP accident were examined. The total Cs, 134Cs and 137Cs concentrations decreased gradually during the three-year period that followed the F1NPP accident. However higher levels, i.e., exceeding 100 Bq kg-1, which is the interim limit of radiocesium level in Japan, were detected in several fish species. Radiocesium accumulation patterns in fishes in Fukushima prefecture varied between regions and corresponded to the environmental radiocesium levels in the Fukushima region. These radionuclides are widely distributed and remain in the natural environment. Moreover, a fresh input of radiocesium substances from the F1NPP site into the terrestrial environment remains.