MOSCOW (Sputnik) — The radioactive cesium was found last week in samples collected by a STUK's monitoring station located in eastern Helsinki.
The basement of the building has been isolated and none of the STUK staff have been harmed, Yle broadcasting company reported, citing a statement by the STUK.
According to preliminary data, the leak was caused by careless handling of sealed radiation sources, the media reported. A company that handles with radioactive waste is reportedly located in the same building.
An investigation into the case is ongoing, according to the media. The test content of cesium in the air measured by the STUK last week — 4,000 microbecquerels per cubic meter of air — is about 1,000 times higher than the norm.
