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areas, and to remote sites where the birds may release the pollut- 

 ants through defecation, death, or they may be taken by hunters 

 and other predators and redistributed. Sea birds that feed on the 

 sea on a number of trophic levels in the marine system frequently 

 nest on cliffs that accumulate large amounts of bird droppings. Pol- 

 lutants in the bird droppings may enter the land system through 

 seepage and decomposition and then they're taken up by plants. 

 Feeding activities of other animals move the pollutants in feces and 

 into other components of the land-based system. 



Another route for the movement of two terrestrial system in ani- 

 mals are the small and large animals that feed on inter-tidal plants 

 and small organisms. These animals move pollutants from the 

 inter-tidal area to the local land-based systems. 



With respect to atmospheric pollutants, atmospheric-borne pol- 

 lutants fall out over wide areas through movements of air masses, 

 but they also may be concentrated to form hot spots due to local 

 precipitation such as occurred following the Chernobyl disaster. 

 Once in the terrestrial system, the effect of pollutants depend on 

 the way they're taken up and stored by plants and the rate of turn- 

 over of the chemical component, and the extent that they are then 

 used as a food resource for animals. Lichens and many mushrooms 

 preferentially take up and store some specific pollutants, and in 

 this case an example is radioactive cesium. Thus they remain a 

 source of contamination for long periods of time. In Alaska, the 

 level of pollution in lichens and mushrooms is virtually identical, 

 and which is a new finding and rather exciting biologically. Other 

 vegetation may turn over pollutants quickly and therefore they are 

 a very quick source of pollution; they are only seen briefly. Com- 

 pare, for instance, mushrooms being harvested by people and ber- 

 ries being harvested by people. Mushrooms, a long-term level, and 

 berries being there, being polluted for a rather short period of time. 



In summary, biological processes influence pathways by accel- 

 erating movement, by concentrating pollutants and redistributing 

 the pollutEints locally and worldwide by migratory movements. In 

 the Arctic, subsistence hunting and fishing is at the very core of 

 the social systems of Native Alaskans; thus in many areas people 

 may be almost completely dependent upon fish, birds and marine 

 and terrestrial mammals for meat and plant products harvested, 

 and also other plant products harvested such as berries, mush- 

 rooms and green tissues provide essential nutrients including vita- 

 mins, essential amino acids and essential fatty acids. Therefore, 

 human social systems in the Arctic are particularly vulnerable to 

 impact by pollutants. 



We're limited in our knowledge of predicting what all of these 

 impacts are going to be because the elemental kinetics in biological 

 systems in the Arctic are not well known. We predict that they 

 would be slower than in lower latitudes and therefore higher con- 

 centrations may be found in various levels of the trophic systems. 

 Radionuclides may be maintained in biological circulation longer in 

 the Arctic than elsewhere as well. 



With respect to your questions on what kind of monitoring is 

 going on and should be done, we don't know exactly how much 

 monitoring is occurring, but it probably does not address the imme- 

 diate concern for the Arctic. 



