Researchers detected a type of radioactive plutonium in soil from three different locations in Fukushima Prefecture, although the amount is too tiny to affect human health, the team said in a report published in a science magazine.
According to the report in the March 8 edition of Scientific Reports, the team said they detected plutonium-241 in the amount of 34.8 becquerels per kilogram in soil from the town of Namie, 20.2 becquerels per kilogram in the village of Iitate and 4.52 becquerels per kilogram in the town of Naraha.
Because the half-life of plutonium-241 is 14 years, the substance likely came from the Fukushima No. 1 nuclear plant and not from fallout of past atmospheric nuclear experiments, the research report says.