Particle samples collected by the Radiation and Nuclear Safety Authority (STUK) from the air in Rovaniemi, Kuopio and Imatra in mid-January contained levels of radioactive substances exceeding the detection limit. The concentrations were very low and posed no risk to people or the environment.
In outdoor air samples collected between 12 and 19 January, radioactive manganese (Mn-54), iron (Fe-59) and cobalt (Co-60) were found in Rovaniemi. The sample from Kuopio contained only cobalt. The sample collected in Imatra contained manganese, iron, cobalt and additionally niobium (Nb-95).
The radioactive substances now detected are generated, among other things, in nuclear power plants during operation, and may be released into the air for example during maintenance work. In many cases, the source of the radioactive substances cannot be identified. However, STUK has determined that the substances detected this time did not originate from Finnish nuclear power plants.
STUK has air-sampling stations in eight locations in Finland to monitor the concentrations of radioactive substances in the air. The samplers draw in large volumes of air, causing airborne particles to accumulate on filters. The filters can then be analysed to measure the concentrations of radioactive substances and determine which substances are present. The method allows the detection of even very small amounts of radioactive materials.
The measurement results are available on STUK’s website at: Radioactivity in outdoor air | Säteilyturvakeskus STUK
