TOKYO, April 24 (UPI) -- A Tokyo playground was shut down after high levels of radiation were detected in the area.
Japanese authorities found one spot contained radiation of 480 microsieverts per hour, the BBC reported. That amount was equal to nearly half the recommended limit of annual exposure for one person.
Tokyo officials were alerted to the radiation traces on Wednesday, Japanese television network NHK reported. They said they believe the radiation is coming from beneath the surface of the park.
The Asahi Shimbun reported that officials said radioactive material may be buried at the location, and at a level of 480 microsieverts per hour, an individual would have to be exposed to the radiation for 40 hours before exceeding the threshold required for evacuation.
On Friday, the area was being cleaned to reassure residents.
The International Commission on Radiological Protection recommends people should not be exposed to more than 1,000 microsieverts per year.
The Tokyo playground shutdown comes days after a drone carrying a small bottle with a radioactive symbol landed on top of Prime Minister Shinzo Abe's office.
That incident also occurred on Wednesday.
Following the 2011 nuclear plant failure in Fukushima, all of Japan's nuclear reactors were taken offline.
Radioactive water continues to accumulate in the devastated nuclear plant.
In January, 600,000 tons of contaminated water was stored in tanks in Fukushima. Water purification systems that have cost Japan millions of dollars have malfunctioned and a plan to build a frozen wall of soil has been slow to progress.
