A case study in the Chernobyl zone Part I: Predicting radionuclide transfer to wildlife

Abstract

Abstract.A number of frameworks have been proposed to assess the protection of wildlife from ionising radiations. In this paper we compare the predictions of transfer parameters recommended by one of these frameworks (FASSET) with observed whole-body 90 Sr and 137 Cs activity concentrations in a range of mammal and invertebrate species sampled within the Chernobyl exclusion zone. Predicted activity concentrations are generally within the observed ranges and mean predictions for reference organisms are similar to, or circa one order of magnitude higher than, the observed means. However, some predictions are more than one order of magnitude lower than observed values. No data were available for animals to test predictions for the other radionuclides released by the Chernobyl accident. In a separate paper the outputs of this assessment will be used to estimate doses to reference organisms and compare these to observed radiation induced effects reported within the Chernobyl zone.

A case study in the Chernobyl zone Part 2: Predicting radiation induced effects in biota

“…However, few, if any, studies have considered radiation effects in large wild mammals inhabiting the exclusion zone. From reported measurements of 90 Sr and 137 Cs activity concentrations in large herbivorous and carnivorous mammals sampled throughout the exclusion zone (1988-2000) [6], mean absorbed dose rates from internal exposure of 2.3 and 9.2 µGy h -1 respectively can be estimated; maximum estimates are 10 and 95 µGy h -1 respectively.…”

“…For plants, only external dose rates to meristem (grass) or bud (shrubs and trees) are estimated. Concentration ratios (CR) to enable the prediction of the activity concentrations in biota from soil activity concentrations are recommended when measurements of activity concentrations in biota are not available [6,7]. To conduct this assessment, prototype software incorporating the FASSET CR and DCC values was used.…”

“…Where soil activity concentrations were lacking, these were predicted from spatially variable deposition [6]. If activity concentrations in biota were not available these were estimated using recommended CR values (for semi-natural pasture/heathland ecosystems) [7] and measured or estimated soil activity concentrations.…”

“…One such site is the Chernobyl exclusion zone for which a considerable amount of data are available for a wide range of biota across a gradient of exposure rates [5]. In a separate paper we applied the methodology of the FASSET environmental impact assessment framework [3] to estimate the whole-body radiocaesium and 90 Sr concentrations of wild animals within the Chernobyl exclusion zone and compared these to available data for mammal and invertebrate species [6]. Predicted activity concentrations were generally within the observed ranges and mean predictions for reference organisms were similar to, or circa one order of magnitude higher than, observed means.…”