The accident in the Fukushima-Daiichi nuclear power plant happened more than two years ago. As a consequence, the media reported about large amounts of radioactive substances released to the Pacific Ocean. One thing, which was not reported, is that radioactive substances have been dispersed through transport via air-masses and wet deposition by rainfall, the so called fallout, which has been globally measured at very low concentrations. That is the reason why radioactive substances from Fukushima nuclear power plant reached regions like the Greenland sea, which are far away from the location, where the accident happened.
Scientists from the Thuenen-Institute of Fisheries Ecology analysed catches of cod from the years 2010 and 2011 on their concentration of radioactive substances in order to check whether fish from the Greenland Sea was affected by radionuclides released through the Fukushima accident. Besides caesium-137 the isotope caesium-134 was also determined. Caesium-134 has got a short half-life of two years and hence originates from the Fukushima-fallout, while most of the caesium-137 was released by the nuclear fuel reprocessing plant at Sellafield. The discharges from the Sellafield reprocessing facility were excluded as an alternative source for caesium-134 by results from a model by which the dispersion in water and the uptake by fish is estimated. So, scientists from Thuenen-Institute were the first worldwide, able to proof the Fukushima-fallout in a sea-region far away from the place of the accident. Finally, it must be stated that the detected activity concentrations of caesium-134 of 0,0036 Bq kg-1 were extremely low and do not pose any harm to humans. This report was printed in Wissenschaft Erleben 1/2013. The results described above are part of a scientific publication published in Biogeosciences.