UTSUNOMIYA -- Compost handled by students at an agricultural high school in Tochigi Prefecture contained 74 times more radioactive cesium than the government's safety standard.
The Tochigi prefectural board of education said on Oct. 17 that 29,600 becquerels per kilogram of radioactive soil had been found in compost used at the Tochigi Agricultural High School in Tochigi city, far above the government maximum of 400 becquerels per kilogram.
Up to 160 students at the school may have touched the contaminated material, which was supplied through a sales agent on June 27 and July 21. The school used 48 of 70 40-liter bags sourced from a firm in Kanuma, Tochigi Prefecture, for such tasks as preparing pots for seedlings.
Even after the compost from the bags was mixed with soil, the soil-compost mix contained 5,380 becquerels of radioactive cesium.
In July, high concentrations of radioactive cesium were detected in compost from the Kanuma producer by the Tochigi and Akita prefectural governments and, in late July, the Tochigi prefectural government demanded that the producer collect compost that contained excessive radioactive material. The producer did not collect all the compost.
The producer submitted a list of purchasers of the compost to the Tochigi prefectural government, but it was found to be incomplete.
No student has yet been reported to be suffering from health complications related to radioactive exposure.