Estimating Cs-137 fallout inventories in Iceland from precipitation data

Iceland was identified in the Arctic Monitoring and Assessment Programme (AMAP) as one of the Arctic areas which received the most global fallout from atmospheric nuclear weapons tests, due to relatively high precipitation rates compared with much of the Arctic and sub arctic. Cs-137 in the Icelandic terrestrial ecosystem almost entirely originates from the nuclear weapons tests carried out in the atmosphere until the early sixties. Fallout was greatest in mid nineteen sixties. Additional fallout from the accident at the Chernobyl Nuclear Power Plant was relatively small. The study gave preliminary information on the spatial variation in 137 Cs deposition in Iceland, especially in areas used for agriculture. The objectives of the study were (1) to measure the spatial variation of radiocaesium inventories in soils in Iceland and (2) to compare the results with different approaches to predicting 137 Cs contents in soil. This quantification is a necessary first step in an evaluation of vulnerability to radiocaesium deposition in Iceland. It is anticipated that Icelandic soils could be highly vulnerable to radiocaesium due to their volcanic nature and consequent lack of illitic minerals, as has been suggested by initial chemical studies on the properties of soils in the Nordic countries. (ln)