Tokyo officials are to start decontamination of a 92-hectare park where high levels of radiation have been detected.
On Monday, officials tested 14 locations at Mizumoto Park in Katsushika Ward, following reports from the public about radiation hot spots there.
Thirteen of tested locations registered radiation above one microsievert per hour at one meter above ground, with the highest reading at 1.22.
According to science ministry guidelines, decontamination is required when radiation is at least one microsievert higher than surrounding areas. Based on these guidelines, 9 of the 14 surveyed places in Mizumoto Park will be decontaminated.
Since last year's accident at the Fukushima Daiichi nuclear plant, the ministry has received about 150 reports of Tokyo hot spots, as of March.