The highest amounts occur in the sediments of the Bothnian Sea and the eastern Gulf of Finland.
UK Environmental Change Research Centre, University College London ( Before sending samples for analysis it is important to contact either Handong Yang or Neil Rose (see Contacts) regarding up-to-date costs and the time from receipt of samples to reporting as this can vary depending on demand.
Nonetheless, most of the radioactivity in the sediments of the Baltic Sea originates from naturally occurring radionuclides.
At present the radioactivity in the sediments is not expected to cause harmful effects to the Baltic Sea wildlife.
ii) how well we are able to quantify the multiple source inputs (atmospheric fallout, watershed erosional input, production of Pb-210 from the decay of SGD-derived Rn-222 and Ra-226, etc); iii) How well are we able to sort out a number of processes that affect the vertical profiles of both Cs-137 and Pb-210 which include sediment mixing (biological and/or physical), sediment focusing/erosion due to bottom currents and transport of sediments in subsurface environment and post-depositional mobility of Cs-137 and Pb-210.
In this presentation, the following case studies will be discussed: 1) where there is excellent as well non-agreement between Pb-210 and Cs-137-based chronologies; 2) agreement between Cs-137-based chronology with historical time-marker from Hg mining, while no chronology obtainable from Pb-210; 3) agreement between five different methods of dating in a reservoir; 4) evidence of Cs-137 diffusion in some of the sediment cores, but not in all cores in a small reservoir; and 5) evidence of long-term remineralization based on a comparison of C-14-based ages with those of Pb-210, Cs-137 and Pu-239,240-based methods.