Environmental radioactivity in Caithness and Sutherland: Pt. 6

The main purpose of this work was to study the movement of airborne radionuclides through the environments in the north of Scotland. Sampling sites were established at five locations in 1980, and airborne particulate and rainwater samples taken monthly from 1980 until mid-1983 and then quarterly to the end of 1985. These measurements are compared with measurements taken at Lerwick and Milford Haven which are remote from nuclear installations. A strong seasonal variation was found in some of the airborne particulate data. The contributions for the values recorded near Dounreay are discussed, e.g. the contributions from the Dounreay stack discharge, nuclear weapons fallout. Evidence is found for the sea-land transfer of actinides. A model of the dispersion around Dounreay from the Dounreay stack is developed and validated. (author)