Migration processes of 137Cs and 90Sr in compartments of a lake ecosystem

The dispersion of radioactive substances in the environment following nuclear weapon tests in atmosphere since 1954 and accidents to nuclear plants, like that in Chernobyl in 1986, have allowed us to study the migration processes of some radionuclides in complex ecosystems such as lakes are. In the present paper the behavior of Cs-137 and Sr-90 in different compartments of the Monterosi Lake (central Italy) was assessed. The (CS)-C-137 concentration was measured in lake water as well as sediment, stream water, aquatic plant and fish samples. 90Sr concentration in water and sediments was also determined. A total inventory of 4206 +/- 76 Bq.m(-2) and 958 79 Bq.m(-2) (on 27/6/01) has been found for (CS)-C-137 and Sr-90, respectively. The experimental data presented here allow to calibrate theoretical models predicting the temporal trend of radionuclide concentration in similar ecosystems. Moreover, information on cesium and strontium migration processes can be extended to other pollutants having similar environmental behavior.