Radioactivity measurements and dose rate calculations using ERICA tool in the terrestrial environment of Greece

Abstract

In the present study, the radioactivity levels to which terrestrial non-human biota were exposed are examined. Organisms (grass and herbivore mammals) and abiotic components (soil) were collected during the period of 2010 to 2014 from grasslands where sheep and goats were free-range grazing. Natural background radionuclides ((226)Ra, (228)Ra, (228)Th) and artificial radionuclides ((137)Cs, (134)Cs, (131)I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site-specific data of the studied organisms were imported in ERICA Assessment Tool (version 1.2.0) in order to provide an insight of the radiological dose rates. The highest activity concentrations were detected in samples collected from Lesvos island and the lowest in samples collected from Attiki and Etoloakarnania prefectures. The highest contribution to the total dose rate was clearly derived from the internal exposure and is closely related to the exposure to alpha emitters of natural background ((226)Ra and (228)Th). The Fukushima-derived traces of (137)Cs, (134)Cs, and (131)I, along with the residual (137)Cs, resulted in quite low contribution to the total dose rate. The obtained results may strengthen the adaptation of software tools to a wider range of ecosystems and may be proved useful in further research regarding the possible impact of protracted low level ionizing radiation on non-human biota. This kind of studies may contribute to the effective incorporation of dosimetry tools in the development of integrated environmental and radiological impact assessment policies.

Radiological impact assessment in the terrestrial environment of Greece using innovative tools – Adaptation of ERICA Tool to actual measurements

“…The highest activity concentrations were detected in samples collected in Lesvos Island and the lowest in samples from Attiki and Etoloakarnania prefectures. The measured activity concentrations of naturally occurring radionuclides in soil ( 226 Ra, 228 Ra and 228 Th) exhibited some variations from region to region, which are generally correlated with the chemical composition of soils [4], however, they were in good agreement with measurements performed earlier in the country [8]. Traces of 137 Cs were detected in grass and mammals samples collected before and after the Fukushima-impact in Greece and it can be assumed that Fukushima-derived traces were added to the residual ones.…”

“…1). Natural background radionuclides ( 226 Ra, 228 Ra, 228 Th) and artificial radionuclides ( 137 Cs, 134 Cs, 131 I) were detected in the collected samples using gamma spectrometry [8]. The actual measured activity concentrations and site-specific data of the studied organisms were imported in ERICA Assessment Tool (Version 1.2.1, February 2016).…”

“…Traces of 134 Cs and 131 I were also detected in organisms but were not detectable in soil, indicating that the uptake by grass is attributed to the radioactive deposition on foliar surfaces. As the concentration of natural and artificial radionuclides in air are generally low compared to the activity concentration in soil and the duration of the exposure is limited, the ingestion process can be considered as the main pathway for the selected accumulation of the radionuclides to the critical organs of the organism (cesium in muscle, radium in bones, iodine in thyroid, etc) [6,8,9]. The Fukushimaderived traces ( 134 Cs and 131 I) were detectable in organisms for a finite period after Fukushima accident, dependent on their physical, ecological and biological half-lives [8,10].…”

“…Additionally, in 2011, traces of 137 Cs derived from the Fukushima Dai-Ichi nuclear power plant (N.P.P.) accident were also detected in environmental components [6][7][8] and were added to the residual ones. Traces of the Fukushima-derived 134 Cs and 131 I were also detected in the collected samples [9].…”

Radiological modeling in the environment

“…Calculating the radiological parameters used in non-human biota dose assessment tools using ERICA Tool and site-specific data. Radiation and Environmental Biophysics, 56(4), 443-451  Sotiropoulou M., Florou H., Manolopoulou M. (2016). Radioactivity measurements and dose rate calculations using ERICA Tool in the terrestrial environment of Greece.…”