129I in lakes of the Chernobyl fallout region and its environmental implications

We present seasonal results of 129I in fresh-water lakes located in central Sweden, an area over which the amount of fallout deposition from the Chernobyl accident varied significantly (2–120 kBq/m2 for 137Cs). 129I concentrations in the lakes ranged from 2.1 to 15.0×108 atoms per liter and did not show elevated concentration in lakes located in regions of high Chernobyl fallout. Apparently, the studied region is strongly influenced by 129I releases from the reprocessing facilities through precipitation. Desorption or resuspension of 129I from soils and sediments does not seem to be an active process to increase the concentration of 129I in the lakes.