Radioactivity in milk

Dairies send milk samples to STUK weekly or monthly. STUK combines the samples each quarter, after which they are concentrated by evaporation under infrared lamps and the residues are ashed.

The ashed samples are analyzed for cesium-137 (Cs-137) with a gamma spectrometer and for strontium-90 (Sr-90) with a liquid scintillation spectrometer. Data are published after the analyses are completed, approximately every three months. The results are also published in STUK’s Surveillance of Environmental Radiation in Finland Annual Report.

Average Cs-137 in milk produced in Southern Finland from 1960

Average cesium-137 concentration (Bq/l) in milk produced in Southern Finland from 1960. The increased concentrations are due to nuclear tests performed in the 1950s and 1960s and the Chernobyl nuclear power plant accident in 1986.

Cesium-137 and strontium-90 activity concentrations (Bq/l) in milk as quarterly averages in 2014.

Dairy 1.1.-31.3. 2014 1.4.-30.6. 2014 1.7.-30.9. 2014 1.10.-31.12. 2014
  Cs-137 Sr-90 Cs-137 Sr-90 Cs-137 Sr-90 Cs-137 Sr-90
Joensuu 0,22 0,031


0,027 0,24 0,029 0,24 0,028
Jyväskylä 0,60 0,031 0,63 0,028 1,10 0,031 1,56 0,031
Oulu 0,26 0,023 0,25 0,024 0,26 0,025 0,31 0,024
Riihimäki 0,33 0,023 0,29 0,023 0,34 0,028 0,33 0,023
Seinäjoki 0,83 0,022 0,93 0,030 0,81 0,031 0,90 0,029


Radioactive materials released into the environment during the Fukushima accident on 11 March 2011 have been detected everywhere in the northern hemisphere, including Europe. However, the concentrations in outdoor air in Finland and other European countries have been so low that no protective measures have been necessary. In Finland, the dose rates caused by radiation have been normal natural background radiation.

No radioactive materials originating from Fukushima were detected in milk produced in Finland in 2011.

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