Annals of ICRP 2009 №39(6), Elsevier, 2009. - 111 p.The Commission has based its approach to environmental protection on the use of a set of Reference Animals and Plants (RAPs) as the basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants in an internally consistent manner. The results of this approach have, to date, resulted in the derivation of a set of dose conversion factors for the RAPs. These dose conversion factors allow dose rates to be calculated when the concentrations of radionuclides within the RAPs and the surrounding media have been established. The resultant dose rates can then be compared with evaluations of the effects of dose rates on the different RAP types using the derived consideration reference levels outlined previously in Publication 108 (ICRP, 2008). Each derived consideration reference level constitutes a band of dose rates for each RAP within which there is likely to be some chance of deleterious effects occurring in individuals of that type of animal or plant. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making. Within this report of the ICRP, a number of methods that have traditionally been used to model environmental radionuclide transfer to organisms are described, and a method for deriving internal body activity concentrations in RAPs has been identified that uses empirically based concentration ratios (CRs) to relate activity concentrations in the organism to those in its environment. Equilibrium CRs are commonly used to model such transfers, and they currently offer the most comprehensive data coverage. This report describes the formulation of a database that has allowed the collation of data on whole-body CRs and, where applicable, data entry in relation to activity concentrations in organisms and habitat media independently. For use with the RAPs, emphasis has been placed on collating data from field studies, although data from laboratory experiments have also been included for some RAPs. The database is structured in terms of generic wildlife groups, but the data have also been attributed to the RAPs where possible. In this way, CRs specifically for RAPs were extracted and, in cases where transfer data were lacking, a data-gap-filling methodology (e.g. adopting values from taxonomically-related organisms) was used to derive suitable surrogate values. The full set of rules that have been applied for filling gaps in RAP-specific CRs is described. Statistical summaries of the data sets are provided and CR values for 39 elements and 12 RAP combinations have been reported. The data coverage, reliance on derived values, and applicability of the CR approach for each of the RAPs is discussed. The results are, as to be expected, somewhat variable. It is recognised that for radionuclides emitting relatively short-range radiations (such as alpha particles and low-energy beta radiations), and for organisms above a certain size and complexity, doses to radiosensitive tissues are likely to dictate the resultant radiation effect compared with the more commonly modelled whole body exposure. However, few studies have been published on the internal distributions of radionuclides for many of the RAPs, and there is a lack of data on transfer for the various RAP life stages. Suggested approaches for deriving surrogate transfer data for life stages are therefore outlined. Finally, some consideration is given to approaches where RAPs and their life stages could be measured for the elements of interest under more rigorously controlled conditions to help fill the current data gaps.Contents executive summary glossary introduction overview of approaches used to model transfer of radionuclides in the environment concentration ratios Alternative approaches used in quantifying radionuclide transfer Selection of approach to provide baseline transfer parameters for the Icrp reference Animals and Plants Derivation of concentration ratios for reference animals and plants collation of data Categorisation of Reference Animals and Plants Data manipulation and derivation of concentration ratios Concentration ratios for reference animals and plants applicability of concentration ratios for Reference Animals and Plants Concentration ratio values for terrestrial Reference Animals and Plants and their applicability Concentration ratio values for freshwater Reference Animals and Plants and their applicability Concentration ratio values for marine Reference Animals and Plants and their applicability Transfer factor data for different life stages of development for Reference Animals and Plants Distributions of radionuclides within the tissues of Reference Animals and Plants Addressing the data gaps in the Reference Animal and Plant concentration ratio values References Annex a. Detailed statistical information on concentration ratios for reference animals and plants aNnex b. Derived concentration ratios annex c. Selected data for reference flatfish
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