Activity levels in the forest after the Chernobyl accident : what is the situation of berrier, mushrooms and game?

When the nuclear accident in Chernobyl occurred in april 1985, a cooperation was established between scientists at the National Defence Research Institute, FOA, and the Faculty of Forestry at the Swedish University of Agricultural Sciences, Umeå, Sweden, to study uptake and redistribution in important food-chains of radioactive caesium (134Cs and 137Cs) deposited over forest ecosystems in the county of Västerbotten. As part of this cooperation recurrent sampling in vegetation, soil and water has been performed since 1986 at the Vindeln Experimental Forest about 60 km NW of Umeå. In this report the changes in activity concentration of 137Cs in plants and fungi from 1986 to 2003 is described and discussed. Furthermore, results from these long-time series and from sampling annually (from one year prior to the Chernobyl accident till 1995) of moose meat during the autumn hunting season are also compared with predictions based on a radioacological model. Besides describing long-term trends in the material, another purpose with these series is to increase the knowledge about probable causes of the redistribution process during different periods after deposition - thereby providing increased reliability in identifying and assessing important radioecological consequences in different time-scales with focus on food-chains of particular interest to man.