Parametric improvement for the ingestion dose module of the European ARGOS and RODOS decision support systems

The European decision support systems ARGOS and RODOS rely on the ECOSYS model for prognoses of ingestion doses. ECOSYS needs an update of various parameter values to provide reliable estimates. This paper reports on some results of a Nordic initiative to derive parameter values that are specific to Nordic conditions, as well as to improve generic parameter values in ECOSYS, taking into account the host of useful measurement data accumulated since ECOSYS was created

EJP-CONCERT. D9.15 - An evaluation of process-based models and their application in food chain assessments

EJP-CONCERT Work Package 9, Deliverable 9.15

CONFIDENCE overview of improvements in radioecological human food chain models and future needs

Radioecological models used to make predictions of the radionuclide activity concentrations in human foodstuffs must be sufficiently robust and fit for purpose with uncertainties reduced where practicable. The CONFIDENCE project had a work package with the objective to improve the capabilities of radioecological models and this paper presents the key findings of this work. Recommendations for future radioecological studies/model developments are made based on the findings of the work conducted and consultations with end-users

Characterisation of background dose-rates for marine environments

Environmental risk assessment methodologies often require background dose-rates for wild flora and fauna to be derived in a robust and transparent way. To facilitate this task, information can be organised around reference organisms (ROs), entities that can be used as representatives of the broader ecosystem. In this study, generic datasets have been collated on levels of naturally occurring radionuclides in sediments, seawater and ROs for marine ecosystems. In some cases, data gap filling methods have been required owing to a paucity of information. Once full datasets have been acquired, dose conversion coefficients (DCCs) can be applied and dose-rate calculations can be performed probabilistically allowing the variability in the underlying datasets to be accounted for. Unweighted absorbed dose-rates for marine reference organisms lie between 0.02–1.2 µGy h-1, whereas weighted dose-rates fall in the range 0.08 µGy h-1 to 8.8 µGy h-1. Except for the special case of sea anemones/corals, the most important nuclides for the total dose-rates are 210Po and 226Ra for heterotrophic ROs (i.e. all vertebrate and invertebrate animals), whereas 226Ra and 228Th contribute most for autotrophic ROs (i.e. macroalgae, phytoplankton and aquatic plants). In addition, 40K has a considerable impact on unweighted dose-rates for all ROs. Non-parametric statistical tests have been applied to show whether there are differences between activity concentrations data for ROs and ICRP-defined Reference Animals and Plants (RAPs)

Effects of chemical climate on soil depth distribution and plant uptake of radiocaesium in forest ecosystems

The aim of the present work was to study the impact of chemical climate (i.e. the chemical composition of precipitation) on radioactive caesium in soil and plants. This was done through field studies and a laboratory experiment. Three types of precipitation regimes were considered in both cases, representing a natural range found in Norway: Acidic precipitation (southernmost part of the country); precipitation rich in marine cations (coastal areas); and low concentrations of sea salts (inland areas). Results indicate that acid rain increases the mobility and the plant availability of radioactive caesium