Researchers in Spain have studied the spread of radioactive strontium in the coastal waters of eastern Japan during the three months following the Fukushima nuclear accident, which happened in March 2011. The samples analysed show the impact of the direct release of radioactive materials into the Pacific Ocean, and indicate that the amount of strontium-90 discharged into the sea during those three months was between 90 and 900 Tbq (terabecquerels), raising levels by up to two orders of magnitude. The highest concentrations were found to the north of the Kuroshio current, which acts as a barrier preventing radioactive material from being carried to lower latitudes.

Source: Fukushima accident raised levels of...e east coast of Japan by up to 100 times