DEVELOPMENT OF AN APPROACH TO ESTIMATING MID-TERM TO LONG-TERM CRITICAL LOADS FOR RADIOCESIUM CONTAMINATION OF COW MILK IN WESTERN-EUROPE

This paper describes the application of the critical load methodology, developed to set emission targets for atmospheric pollutants, to radi oecology. The critical load can be redefined within radioecology as th e radionuclide deposition at which radionuclide activity concentration s in a specified food product will exceed the: maximum permitted level . An empirically based approach is described which provides estimates of critical load values for cow milk in the mid- to long-term after an accident when soil-to-plant transfer of radiocaesium is largely respo nsible for plant radiocaesium contamination. The areas identified as b eing most potentially vulnerable to radiocaesium deposition using this approach are those with extensive areas of organic soils such as west ern Scotland, parts of Ireland, The Netherlands and Denmark. The class ification of European soil types into soil groups with significantly d ifferent soil-to-plant transfer of radiocaesium, and the allocation of a transfer value to each soil group provide the greatest uncertaintie s within this approach. Potential problems and deficiencies affecting the estimation of parameter values are discussed. (C) 1998 Elsevier Sc ience B.V. All rights reserved.