The terrestrial distribution of artificial radioactivity in south-west Scotland

• Published in: The Science of the total environment 1992, Vol.111 (1), p.59-82
• Main Authors: McDonald, Paul, Cook, Gordon T., Baxter, Murdoch S., Thompson, James C.
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Pollution; Pollution sources. Measurement results; Soil and sediments pollution
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/0048-9697(92)90045-T

This investigation extends the data base on dispersion of Sellafield-derived radionuclides to the northern Solway coastal zone of south-west Scotland. Results of a 10 × 10 km grid soil survey indicate that the predominant source of 239+240Pu to the area has been weapons fallout, Chernobyl fallout having greatly modified 134Cs and 137Cs inventories. Inland transects reveal little evidence of airborne sea-to-land transfer of Sellafield-derived radionuclides, but riverine systems exhibit regions of significant on-land input from Sellafield via tidal inundation and deposition of particles. Sequential chemical leaching of soil and sediment samples suggests a change in chemical association of plutonium between marine and terrestrial systems. In radiological terms, airborne on-land transfer of Sellafield radionuclides is of negligible significance. Radionuclide inventories in Solway soils are generally well below the limiting values implied by the recommended generalised derived limits (GDL). In some tidally inundated riverbank areas, however, 137Cs, Puα and 241Am levels occasionally exceed 25% of the appropriate GDL values.