Cesium-137 monitoring using mosses from Macedonia, N Greece

Cs-137 activities in mosses collected from four sites in Macedonia, N. Gree ce were measured for regular periods of time during the last decade followi ng the reactor accident in Chernobyl. Samples taken in 1985 allow to determ ine the Cs-137 contamination before the accident. A clear increase of the c esium interception was observed for about two years after the accident. Lat er a gradual decrease was detected which depended on various factors such a s moss species, location, growth rate and substrate. Higher Cs-137 amounts were observed in epilithic (Grimmia) in comparison to epiphytic or epigeic ones (Encalypta, Tortula). From the studied biotopes Mt. Vermion presented the highest C-137 activities. The high Cs-137 values found 10 yr, after Che rnobyl suggest that mosses are effective and inexpensive biological detecto rs of the distribution and burden of fallout radionuclides.