An unusually high level of radiation has been detected at a park in Tokyo’s Ikebukuro area, the Toshima Ward Office said Thursday, prompting speculation that hazardous material has been buried there.
The ward office has banned entry to the municipal park, which is right next to Tobu Railway Co.’s Shimoitabashi Station in the Ikebukuro-honcho district and surrounded by residences.
The name of the park is Ikebukuro Honcho Densha no Mieru Koen.
On Thursday afternoon, a radiation level of up to 480 microsieverts per hour was recorded at a spot on the ground near playground equipment, the municipality said.
That is nearly half the permitted annual dose of 1 millisievert and far in excess of the ward’s decontamination standard of 0.23 microsievert.
“Because the area in which we detect radioactivity is very limited, and readings in the surrounding areas are normal, we suspect radioactive materials of some kind are buried there,” Toshima Mayor Yukio Takano said in a statement.
The ward has fenced off the playground equipment and plans to identify the buried material, remove it and decontaminate the polluted area.
A public health center in the ward was expected to offer health consultations starting Friday to those who request them.
A 62-year-old woman who lives nearby said Thursday she is very worried to learn that a hot spot has been confirmed next to her house.
“Many children play in the park daily, so the ward office should explain the situation,” she said, adding that she had heard nothing so far.
Following a report from a resident on Monday, Toshima Ward officials probed the park Wednesday and detected 2.53 microsieverts per hour radiating from an area with playground equipment.
Based on advice from the Nuclear Regulation Authority, the ward surveyed the area again on Thursday and detected 480 microsieverts.
The park, managed by the ward, opened in March 2013. Before then, the site had been used as a parking space for garbage collection vehicles from the Tokyo Metropolitan Government.
The top soil at the lot was replaced before it was turned into a park, a Toshima Ward official said.