Predicting the radiation exposure of terrestrial wildlife in the Chernobyl exclusion zone: an international comparison of approaches

Abstract

There is now general acknowledgement that there is a requirement to demonstrate that species other than humans are protected from anthropogenic releases of radioactivity. A number of approaches have been developed for estimating the exposure of wildlife and some of these are being used to conduct regulatory assessments. There is a requirement to compare the outputs of such approaches against available data sets to ensure that they are robust and fit for purpose. In this paper we describe the application of seven approaches for predicting the whole-body ((90)Sr, (137)Cs, (241)Am and Pu isotope) activity concentrations and absorbed dose rates for a range of terrestrial species within the Chernobyl exclusion zone. Predictions are compared against available measurement data, including estimates of external dose rate recorded by thermoluminescent dosimeters attached to rodent species. Potential reasons for differences between predictions between the various approaches and the available data are explored.

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

“…); and k r , em is the effective loss rate of radionuclide "r" from mammal (day À1 ) incorporating both excretion rate and physical decay of the radionuclide. These types of models have been applied, albeit for a limited suite of radionuclides, within international inter-comparison exercises (Beresford et al, 2010) and indicate that the approach provides reasonable predictions of transfer to wild mammals in natural terrestrial environments. On a more negative note, these types of models require much greater parameterisation than the more commonly used CR approach and, in many cases, parameter values are simply unavailable.…”

“…This yields an IR value for bank vole of 1.14 d À1 . No direct empirical data in relation to fresh matter ingestion rates for common shrew are available in Nagy (2001), but by assuming a mass of 10 g for an adult shrew (Beresford et al, 2010) and by applying the allometric relationship as shown in Eq.…”

“…The dietary compositions of common shrew and bank voles have been considered in the recent aforementioned studies concerning transfer to wild-life (Beresford et al, 2010). The diet of bank vole was assumed, for the "Faster-lite" model applied within that inter-comparison, to comprise of grasses and herbs (60%), lichen and bryophytes (20%) and soil invertebrate (20%) and for common shrew of different types of insects and soil invertebrates.…”

The transfer of radionuclides to wildlife

“…Recent international evaluations of the available models have shown this to be the case (Vives i Batlle et al 2007Beresford et al 2008aBeresford et al , 2010aYankovich et al 2010a). There are many reasons for this including lack of empirical data for many radionuclide-organism combinations and the theoretical approaches used to derive transfer values when no data exist; use of national data sets; and the conservative nature of some of the parameter values selected to meet the purpose of specific tools (Beresford et al 2008aYankovich et al 2010a).…”

Modelling transfer to animals accounting for trans-generational factors

“…This simplified model was thereafter used to make predictions of activity concentrations in wild animals in terrestrial environment and appears to yield reasonable results in the sense that for most radionuclides and animals where predictions were made, results were not substantially different from those predicted using more conventional concentration ratio based approaches [2]. The model is represented in the form of an interaction matrix as shown in Figure 1.…”