Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem

J Guillén,N.A Beresford,A Baeza,M Izquierdo,M.D Wood,A Salas,A Muñoz-Serrano,J.M Corrales-Vázquez,J.G Muñoz-Muñoz

doi:10.1016/j.jenvrad.2017.06.024

Abstract

A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CRwo, were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CRwo values estimated from these data are compared to those reported in international compilations and databases.

Highlights

Radiological protection of the environment has evolved from an anthropogenic perspective (‘if man is adequately protected, so is the environment’) (ICRP, 1997; 1991) to recommendations that the environment is assessed in its own right (ICRP, 2008a)
Heavy metal concentrations in the soils were below screening reference levels for negligible risks to the population according to national procedures in the EU for agricultural soils (BOE, 2010; Toth et al, 2016)
The databases used to derive transfer parameters for commonly used assessment approaches have some short-comings: a) there is a lack of CRwo data for many Reference Animals and Plants (RAPs)-element combination; and b) there is geographical and climate bias, since data are mostly from temperate and artic ecosystems

Summary

Introduction

Radiological protection of the environment has evolved from an anthropogenic perspective (‘if man is adequately protected, so is the environment’) (ICRP, 1997; 1991) to recommendations that the environment is assessed in its own right (ICRP, 2008a). Various models are available to quantify exposure (usually as dose rate) of animals and plants (wildlife). Most of these models use a quasi-equilibrium approach to estimate the activity concentration in organisms and their internal dose rate (e.g. the ERICA Tool (Brown et al, 2008, 2016); RESRAD-BIOTA (USDoE, 2002) and R&D128/ SP1a (Copplestone et al, 2001, 2003)). Concentration ratios, CRwo, are often used in such models (Beresford et al, 2008a) to predict activity concentrations in wildlife assuming that there is equilibrium between the whole organism (RAP) and the appropriate medium (i.e. usually soil in the case of terrestrial ecosystems). Data reported in ICRP (2009) were derived from the online database described by (Copplestone et al, 2013)

Objectives

Methods

Results

Conclusion