Estimating the exposure of small mammals at three sites within the Chernobyl exclusion zone – a test application of the ERICA Tool

Abstract

Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trade marks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. AbstractAn essential step in the development of any modelling tool is the validation of its predictions. This paper describes a study conducted within the Chernobyl exclusion zone to acquire data to conduct an independent test of the predictions of the ERICATool which is designed for use in assessments of radiological risk to the environment. Small mammals were repeatedly trapped at three woodland sites between early July and mid-August 2005. Thermoluminescent dosimeters mounted on collars were fitted to Apodemus flavicollis, Clethrionomys glareolus and Microtus spp. to provide measurements of external dose rate. A total of 85 TLDs were recovered. All animals from which TLDs were recovered were live-monitored to determine 90 Sr and 137 Cs whole-body activity concentrations. A limited number of animals were also analysed to determine 239,240 Pu activity concentrations. Measurements of whole-body activity concentrations and dose rates recorded by the TLDs were compared to predictions of the ERICA-Tool. The predicted 90 Sr and 137 Cs mean activity concentrations were within an order of magnitude of the observed data means. Whilst there was some variation between sites in the agreement between measurements and predictions this was consistent with what would be expected from the differences in soil types at the sites. Given the uncertainties of conducting a study such as this the agreement observed between the TLD results and the predicted external dose rates gives confidence to the predictions of the ERICA-Tool.

Radiation Ecology Issues Associated With Murine Rodents and Shrews in the Chernobyl Exclusion Zone

“…Table 9 shows that the contribution of the incorporated The absorbed dose calculations performed in this study were consistent with the values obtained in the concurrent study (Beresford et al 2008) but only for the doses from the external sources (Table 10). The assessment of the total absorbed dose from the external and internal sources appeared to be 1.5 -2 times lower in the present study which might have been associated with an a priori conservative approach of the ERICA Tool software package.…”

“…In the NSHP Forestry the study was conducted during 35 days in the summer of 2005 under a joint project on dose rate assessments for small mammals (Beresford et al 2008). Cs T ag values were found to be 20 -60% lower in small individuals (Table 4).…”

“…Such studies were performed in the ChEZ, but more or less detailed descriptions of the dose rate calculations and/or assessments methods were only provided in a small number of publications (Taskaev et al 1990;Chesser et al 2000;Baryakhtar et al 2003;Ryabokon et al 2005;Beresford et al 2008). In most papers, the authors limited themselves by only stating the dose rate values.…”

“…The baseline for this study was obtained in 2005 under another research project that was also focused on dose rates assessments but using thermoluminescent dosimetry (TLD) and the ERICA Tool software package (Beresford et al 2008). …”

Frequency Distributions of 90sr and 137cs Concentrations in an Ecosystem of the “Red Forest” Area in the Chernobyl Exclusion Zone

“…This problem is applicable not only to land contamination assessments, but to the assessment of contamination in animals and plants as well. Biota samples taken from relatively small areas are known to have a wide range of concentrations of radionuclides (Beresford et al 2008;Bondarkov et al 2003;Chesser et al 2000;Gashchak et al 2008;Jackson et al 2005;Jagoe et al 2002;Mietelski et al 2010;Oleksyk et al 2002). In this connection the determination A normal distribution of concentration values is implicit in the use of arithmetic group averages as a representative value for the assessment of exposure risk.…”