Radioisotope levels in Swedish air filters normal again

At the end of June, the Swedish Radiation Safety Authority reported that low levels of radioisotopes had been measured in Sweden. The authority informed the UN’s International Atomic Energy Agency (IAEA) of the measurements. More recent measurements have shown that levels are back to normal in Sweden. The authority has reported the final measurement results to the IAEA.

In June, the Swedish Defence Research Agency (FOI) measured low amounts of several radioisotopes in air filters in Visby and Stockholm. These isotopes were caesium-134, caesium-137, cobalt-60, ruthenium-103, ruthenium-106, niobium-95 and zirconium-95.  The levels measured were so low that they posed no risk to human health or the environment.

The Swedish Radiation Safety Authority reported the measured values to the UN’s International Atomic Energy Agency (IAEA). Levels have now been normal since calendar week 27 (also reported by the authority to the IAEA).

The origin of the elevated levels is unknown. No event that could have caused the levels has been reported in Sweden. Similar measurement results have also been reported in Finland and Estonia. The IAEA has urged Member States to report whether there is knowledge of any event that could have caused these levels. However, no Member State has reported such an event.

FOI continuously monitors radioisotopes in the air in Sweden. If elevated levels are once again recorded in air filters, the Swedish Radiation Safety Authority will provide information on this.

Measurement results

Final measurement results from Visby for calendar week 24, 8-15 June. All measurement results are stated in microBq/m3.

Caesium-134 Caesium-137 Ruthenium-103 Cobalt-60
0.8 1.3 0.1 0.2

Final measurement results from Visby for calendar week 25, 15-22 June. All measurement results are stated in microBq/m3.

Caesium-134 Caesium-137 Ruthenium-103 Cobalt-60 Ruthenium-106 Niobium-95 Zirconium-95
0.6 0.7 0.7 0.4 1.4 0.8 0.6

Final measurement results from Stockholm for 21-23 June. All measurement results are stated in microBq/m3.

Cobalt-60
0.4

Final measurement results from Stockholm for 23-24 June. All measurement results are stated in microBq/m3.

Caesium-134 Caesium-137
0.3 0.7

No elevated levels were measured during the period at any other national air filter stations.

Measurement results from the CTBTO station in Stockholm for 22-23 June. All measurement results are stated in microBq/m3.

Caesium-134 Caesium-137 Ruthenium-103
9.7 9.6 4.3

For more information, please contact: Swedish Radiation Safety Authority press office, tel. +46 8 799 40 20.