Use of mosses and lichens for regional mapping of 137Cs fallout from the Chernobyl accident

The lichens Hypogymnia physodes and Cladonia stellaris and the moss Hylocomium splendens were studied for potential use as biomonitors of the regional distribution of 137Cs fallout in Norway from the Chernobyl accident. While Hyl. splendens and C. stellaris showed reasonable mutual agreement, the activities recorded in the epiphytic species Hyp. physodes were not consistent with those of the other species, and depended strongly on whether sampling was carried out on conifers or birch. The geographical distribution of 137Cs in the two former species was in satisfactory agreement with deposition figures obtained from analysis of surface soil, considering the heterogeneous deposition pattern of Chernobyl radioactivity. Both Hyl. splendens and C. stellaris appear well suited for regional mapping of 137Cs fallout from nuclear accidents. Regional heavy metal deposition surveys employing Hyl. splendens might be extended to include radionuclides if desirable. (Author)