• Concentration ratios (CRwo-media) are used in most radioecological models to predict radionuclide activity concentrations in wildlife from those in environmental media. 
  • This simplistic approach amalgamates the various factors influencing transfer within a single generic value and, as a result, comparisons of model predictions with site-specific measurements can vary by orders of magnitude. 
  • To improve model predictions, the development of ‘condition-specific’ CRwo-media values has been proposed (e.g. for a specific habitat or wildlife sub-category). 
  • The underlying datasets for most CRwo-media value databases, such as the wildlife transfer database developed within the IAEA EMRAS II programme, include summarised data.
  • This presents challenges for the calculation and subsequent statistical evaluation of condition-specific CRwo-media values.
  •  A further complication is the common use of arithmetic summary statistics to summarise data in source references, even though CRwo-media values generally tend towards a lognormal distribution and should be summarised using geometric statistics. 
  • Wood et al. proposed a statistically-defensible and robust method for reconstructing underlying datasets to calculate condition-specific CRwo-media values from summarised data and deriving appropriate summary statistics.
  • To enable others to be able to conduct similar analyses of summarised data sets the authors have made the SPREADSHEET with macro's available.
  • Ensure you read and follw the intructions on the README sheet.

Reference details

 Wood M.D., Beresford N.A., Howard B.J. and Copplestone D. Evaluating summarised radionuclide concentration ratio datasets for wildlife (Submitted to Journal of Environmental Radioactivity, May 2013).

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