Specific activity is the activity per unit mass of a radionuclide and is a physical property of that radionuclide. Activity is a quantity (for which the SI unit is the becquerel) related to radioactivity, and is defined as the number of radioactive transformations per second that occur in a particular radionuclide.
The average specific activity of 60Co in continental aquatic sediments is in the region of 1 Bq. kg-1 dry weight (Eyrolle et al., 2008). Cobalt distribution in the abiotic compartments of continental aquatic systems is characterised by the strong affinity of the element for sediment.
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