No ruthenium-106 has been detected in air in Sweden since early October

In early October 2017, low levels of ruthenium-106 were detected in Sweden. The Swedish Radiation Safety Authority reported these monitoring results to the International Atomic Energy Agency (IAEA). Later measurements have shown no levels of ruthenium-106 in Sweden. The Swedish Defence Research Agency (FOI) is commissioned by the Swedish Radiation Safety Authority (SSM) to perform continual measurements to detect possible radioactive materials in the air.

In early October, the Swedish Defence Research Agency detected low levels of the radioactive isotope ruthenium-106 captured by air filters throughout Sweden. Between 28 September and 6 October, ruthenium-106 was captured by air filters located in Kiruna, Umeå, Gävle, Stockholm, Visby, and Ljungbyhed. The highest levels were detected in Stockholm: 17 millibecquerel per cubic metre of air (mBq/m3), that is, 0.017 becquerel per cubic metre of air (Bq/m3).

"These levels are so low that they do not pose any health risk to people or the environment," says Jan Johansson, a senior expert at the Swedish Radiation Safety Authority.

In October, when the ruthenium-106 was detected in Sweden, similar levels were detected by most other countries in Europe. The UN's International Atomic Energy Agency, the IAEA, then urged all the member countries to report their detection data. The Swedish Radiation Safety Authority has reported on the findings in Sweden. At the same time, the IAEA urged the member countries to communicate whether any domestic emergency situation might have caused a release; however, no such reports have been submitted.

"In Sweden, no levels of ruthenium-106 have been detected in the air since early October. FOI carries out continual measurements of radioactive materials in the air, and should any ruthenium-106 once again be captured by the air filters, we will communicate this fact," says Mr Johansson.

Detection data from FOI (Swedish Defence Research Agency):
Monitoring stationDetection periodAir concentration of
ruthenium-106 (mBq/m3)
Kiruna  2017-10-02 - 2017-10-06 0.09
Umeå  2017-10-02 - 2017-10-06 0.62
Gävle  2017-09-29 - 2017-10-03 4.1
Stockholm  2017-09-30 - 2017-10-01 0.03
Stockholm  2017-10-01 - 2017-10-02 17
Stockholm  2017-10-02 - 2017-10-03 9.8
Visby  2017-09-28 - 2017-10-02 5.8
Visby  2017-10-02 - 2017-10-05 5.2
Ljungbyhed  2017-09-29 – 2017-10-02 0.97

For more information, please contact: The Swedish Radiation Safety Authority's duty press officer, Tel. +46 8 799 40 20, or FOI's press officer, Tel. +46 73 371 38 38 (business hours).

Measurement and detection of radioactive materials

FOI, the Swedish Defence Research Agency, is commissioned by the Swedish Radiation Safety Authority to perform continual measurements to detect possible radioactive materials in the air. The equipment is sensitive and detects even the slightest levels of radioactive substances.

Ruthenium-106 and becquerel

Ruthenium is a chemical element that belongs to the platinum group of light metals. Ruthenium is for example used to treat certain kinds of cancer. Ruthenium-106 is not a natural component of the air.

Becquerel is the measurement unit for radioactive decay. 1 becquerel = 1 disintegration per second. This unit of measurement is used to describe the quantity of a radioactive material in (for example) the air, on the ground, or in foodstuffs. In these contexts, becquerel is stated per cubic metre of air, per square metre, or per kilo. Millibecquerel (mBq) = one-thousandth of a becquerel.