Doses to terrestrial biota in the vicinity of BNFL Sellafield, Cumbria, UK

Abstract

Source terms and corresponding radionuclide activity concentrations in biota for 134Cs, 137Cs, 238Pu, 239+240Pu and 241Am have been assessed for three semi-natural ecosystems in the vicinity of BNFL Sellafield, Cumbria, UK. Estimates of absorbed doses (mGy.d-1) have been calculated. Doses to key indicator species, Oniscus asellus (detritivorous invertebrate), Carabus violaceous (predatory invertebrate) and Apodemus sylvaticus (granivorous wood mouse) are discussed with reference to the 1 mGy.d-1 level, below which it is postulated that no observable effects on populations in a terrestrial ecosystem occur. Implications for the 'critical group' and 'reference model' approaches for a framework of radiological environmental protection are discussed. The need to assess the most highly exposed species is advanced. New research focused on the application of biomarker techniques as a mechanism for determining the interactions and effects of environmental contaminants on ecosystem structure and functioning is presented.