The environmental radioactive air pollution and its transfer in forest ecosystems in Poland

Environmental monitoring of radionuclides has been performed since 1986 in the vicinity of Swierk where the research reactor facilities are placed. As a result of the nuclear power plant accident in Chernobyl the presence of radioactive isotopes of 134Cs and 137Cs in the mosses and other components of forest vegetation were performed for about 40 facilities in Poland. The transfer of these radionuclides to the soil is discussed and comparison with the air contamination detected with high volume air sampler technique is presented. Two kinds of mosses, politrichum formosum and pleurosium schreberi, were selected out of 600 kinds of moss growing in Poland in order to keep track of radioactivity accumulation and transfer. The concentration of 134Cs and 137Cs in mosses is on average about 1 kBq/kg of dry moss and it is much higher than contamination of other plants and soil in the area of study. The transfer to the soil is different for the studied places and slower than in open fields. Some coincidence with seasonal changes of electrical air conductivity is observed