Modelling the effects of ionising radiation on a vole population from the Chernobyl Red forest in an ecological context

Abstract

HighlightsMigration is effective in compensating for vole deaths at high levels of radiation exposure.Long term effects simulated include a small historic dose component.Adaptation can account for low dose radio-hypersensitivity and increased radio-resistance.Current radiation dose assessment benchmarks are protective for the modelled vole population.

Towards an ecological modelling approach for assessing ionizing radiation impact on wildlife populations

“…The information described in previous sections was synthesized into a model for voles inhabiting the Chernobyl Red Forest area at the time of the Chernobyl reactor accident in 1986. Full details are available in our previous publication [9], so the results are only summarized here. The model considers an inner contaminated region, an intermediate partly contaminated region and a non-contaminated outer region labelled i = 1-3.…”

“…Animal mobility is determined by migration fluxes proportional to population density. The following governing equations are cited from our previous publication [9]:…”

“…The derivation of the equations and associated parameter values cited here are given in detail in our previous publication [9]. The model was run with a realistic time-dependent dose profile for small mammals in the region, represented by the equation DR (t) = 144e − 1.1t 365 + 7.20 × 10 −3 e − 0.05t 365 (Gy d −1 ) [54].…”

“…Our main question was whether dose rate criteria established for the protection of wildlife based on effects on individuals (such as the ICRP DCRLs) are applicable to extrapolate conclusions on protection at the level of a population. This was addressed using a specific case study (a population of voles from the Chernobyl Red Forest [9]) and reviews of the available effect data for wildlife populations. Model outputs were compared with thresholds for effects at the level of individuals in experimentally controlled exposures (such as those provided within the FREDERICA database-www.frederica-online.org) to test whether existing benchmarks for wildlife population exposure are appropriate for the scenario considered, as well as to gain insight into whether the assessment approaches that are being routinely applied could include evaluations of how populations may grow and be affected by the presence of a contaminant.…”

“…Model outputs were compared with thresholds for effects at the level of individuals in experimentally controlled exposures (such as those provided within the FREDERICA database-www.frederica-online.org) to test whether existing benchmarks for wildlife population exposure are appropriate for the scenario considered, as well as to gain insight into whether the assessment approaches that are being routinely applied could include evaluations of how populations may grow and be affected by the presence of a contaminant. In addition to deriving conclusions from the aforesaid case study [9,10], we give a further sensitivity analysis of the model developed with respect to the key reproduction rate and migration parameters, and an extension of the method to cover the effects of radionuclides in combination with chemicals is proposed. We also present suggestions for further work related to IAEA's guidance on radiological environmental impact assessment, based on lessons learned from the MODARIA programme.…”