Baltic Marine Environment
Protection Commission

Radioactivity in the Baltic Sea keeps declining

​​The HELCOM expert group on radioactive substances has reviewed this week the latest scientific reports for the year 2015 revealing that for the first time, in the Southern Baltic in the Southern Baltic, Caesium-137 concentrations in surface waters are below the pre-Chernobyl target level of 15 Bq/m3. The decrease is most likely due to the exceptionally large saline water inflow from the North Sea into the Baltic Sea reported in December 2014*. The radioactivity levels have for long been declining in all the sub-basins of the Baltic Sea but this is the first time that the results have dropped this low, at Flensburg Fjord and Bornholm deep in the Southern Baltic.​Levels of radioactivity in the Baltic Sea are measure from e.g flounder. Photo: Petra KääriäIn their meeting in Uppsala, Sweden, the Expert Group on Monitoring of Radioactive Substances in the Baltic Sea (MORS EG) has also discussed the next thematic assessment of long-term changes in Baltic Sea radioactivity 2011–2015, with delivery now scheduled at 2017 as this will match the purposes of HOLAS II, the Second holistic Baltic-wide assessment in 2018. Further, the group will update the HELCOM core indicator “Radioactive substances: Caesium-137 in fish and surface waters” with latest data for the year 2015. In addition, the group has also reviewed and quality assured the annual data submissions to the HELCOM and , containing an unbroken time series from 1984 and 1952, respectively. The meeting, chaired by the MORS EG Chair Ms Tarja Ikäheimonen, was participated also by International Atomic Energy Association (IAEA), notifying the addition of HELCOM MORS environmental data to IAEA’s .  ​ *.   . All documents are public after the Meeting. * * * Note for editorsThe Baltic Marine Environment Protection Commission, usually referred to as , is an intergovernmental organization of the nine Baltic Sea coastal countries and the European Union working to protect the marine environment of the Baltic Sea from all sources of pollution and to ensure safety of navigation in the region. Since 1974, HELCOM has been the governing body of the ‘Convention on the Protection of the Marine Environment of the Baltic Sea Area’, more commonly known as the Helsinki Convention. * * * For more information, please contact:Tarja K. Ikäheimonen Chair of HELCOM MORS Expert Group Environmental Radiation Surveillance and Emergency Preparedness STUK – Radiation and Nuclear Safety Authority Tel. +358 400 811 254 E-mail: Tarja.Ikaheimonen(at) Johanna Laurila Information Secretary HELCOM Tel: +358 40 523 8988 Skype: helcom70 E-mail: johanna.laurila(at)

For the first time, at two monitoring sites, Caesium-137 concentrations in surface waters are below the pre-Chernobyl target level.