TOKYO (Xinhua) -- Radiation levels at areas in Tokyo and Chiba prefectures were found Thursday to far exceed current levels in Fukushima prefecture, home to the crisis-hit No. 1 nuclear power plant located 200 km north of Tokyo.
An area along a sidewalk in Tokyo's Setagaya Ward, frequently used by elementary school children, was found to have airborne radiation measuring 3.35 microsieverts per hour and a children's amusement park tested positive with 5.82 microsieverts in the Funabashi district of neighboring Chiba prefecture, local authorities said Thursday.
By way of comparison, the latest readings taken from inside the evacuation zone in Fukushima prefecture, the central to the world' s worst nuclear accident in 25-years, measured 2.17 microsieverts per hour, according to local prefectural officials.
An investigation is currently underway to determine whether the troubled nuclear plant in Fukushima is responsible for the high doses of radiation detected in and around Japan's capital city and Chief Cabinet Secretary Osamu Fujimura said Thursday that nuclear agencies and government authorities will increase monitoring activities around the country.
The two hotspots have been cordoned off and authorities have attempted to reduce the concentration of radiation by using water and "other" methods, local media said, but the levels have remained worryingly high despite the counter-measures, sparking widespread panic around Japan's primary metropolis.
Compounding public fears, city officials in the neighboring port city of Yokohama said on Wednesday that radioactive Strontium above ordinary levels had been detected on the roof of a residential building in the city -- itself located 250 km south of the No. 1 plant in Fukushima prefecture.
Officials said that 195 becquerels of Strontium-90, which can cause bone cancer and leukemia, was detected in deposits on the rooftop, sparking concerns the contamination may have spread further afield.
It is the first time Strontium-90 at a concentration of more than 100 becquerels per kilogram has been detected beyond 100 km from the troubled plant in Fukushima, the officials said.
Radiation dosages of up to 47 times higher than normal levels have also been detected from processed radioactive waste at a facility used for storage in Aomori Prefecture, in northern Japan.
According to Kyushu Electric Power Co. who discharged the spent nuclear fuel rods to be processed in Britain, levels of up to 190 becquerels of both beta and gamma rays were detected in three storage canisters. The utility firms said Thursday that workers are trying to decontaminate the radioactive canisters.