Radioactive cesium from the Fukushima plant was found at 10 points in the Pacific Ocean, including a location as far as 1300 miles from the plant, less than a year after Fukushima nuclear disaster began, scientists revealed on Tuesday.
The Japan Times and Kyodo News reported that the findings were announced by researchers with the Japan Agency for Marine Earth Science and Technology at the Japan Geoscience Union meeting.
At each of the 10 points, located between Japan's Hokkaido island and Guam, cesium 134 and cesium 137 were detected in the plankton and seawater samples taken by the scientists between January and February 2012, the news agencies report.
The researchers found the highest density of cesium in seawater around latitude 36 to 40 degrees north, while plankton with the highest concentrations of cesium were found around 25 degrees north and 150 degrees east.
“Plankton are thought to play a key role in the dispersion of the cesium because they are eaten by bigger fish. We want to study further what is influencing the accumulation of radioactive cesium,” The Japan Times reports Minoru Kitamura, a marine ecologist and senior researcher at the Japan Agency for Marine Earth Science and Technology, as saying.
The high levels cesium found in the plankton around 25 degrees north presented a "concern," Kitamura added, saying, "we don’t know why the level got high around that area.”