Migration of 137Cs in tributaries, lake water and sediment of Lago Maggiore (Italy, Switzerland) - analysis and comparison with Lago di Lugano and other lakes

This paper describes the behaviour of Cs-137 in Lago Maggiore and other pre-alpine lakes as a consequence of atmospheric nuclear weapons testing fallout and the fallout from the nuclear accident in Chernobyl. It presents data on the Cs-137 distribution in tributaries, lake water, bottom sediments and reveals the role of Cs-137 as a marker of the sedimentation processes. The run-off of Cs-137 from the watershed to the lake is described with a simple compartment model. Measurements of the activity concentration of Cs-137 in sediments are compared with the output of a model (diffusion-convection type) which describes the input of Cs-137 into and its vertical distribution within the sediment. Varying sedimentation rates (0.05-0.90 g (cm(2) y)(-1)) in Lago Maggiore are compared with data of other authors. Sedimentation rates and total distribution coefficients (of about 10(5) L kg(-1)) in Lago Maggiore are discussed and compared with those of Lago di Lugano, Lake Constance, and Lake Vorsee. (c) 2009 Elsevier Ltd. All rights reserved.