Workers have removed radioactive soil from a Tokyo playground where extremely high radiation levels had frightened local residents for days, official said.
Soil underneath a slide at the municipal park in the Ikebukuro district showed radiation readings of up to 480 microsieverts per hour.
Anyone directly exposed to this level would absorb in two hours the government’s annual maximum radiation threshold.
Contractors dug out soil from the spot on Friday, and the radiation reading returned to normal, around 0.06 microsieverts per hour, according to local reports.
Workers suspect the contamination was from radium, which is used for medical tools and glow-in-the-dark paint for watches, reports said.
Yukio Takano, the mayor of Toshima Ward, where the park is located, said in a statement that the problem, which fanned fears for the health of area children, was likely to end soon.
“The amount of radiation has been dramatically reduced after a test excavation” of the soil, said the statement, released late Friday.
The contamination came to light after a local resident reported it on Monday, but officials say they do not think it is connected to the disaster at the Fukushima No. 1 nuclear plant.
The park, Ikebukuro Honcho Densha no Mieru Koen, was built in 2013, two years after the Fukushima reactor meltdowns, on what was previously a parking lot for Tokyo’s sanitation department, a local official said.
Top soil at the lot was replaced before the land was turned into a park.
Many families in eastern Japan continue to survey the levels of radioactive contamination around their homes, distrustful of government assurances that most places were not affected by the Fukushima crisis.
Such efforts have led some people to discover radioactive materials that have been dumped in their neighborhoods. Months after the Fukushima crisis started in 2011, officials found bottles of radium discarded in Tokyo under a private house and a supermarket.