Radionuclide transfer to wildlife at a ‘Reference site’ in the Chernobyl Exclusion Zone and resultant radiation exposures

Abstract

This study addresses a significant data deficiency in the developing environmental protection framework of the International Commission on Radiological Protection, namely a lack of radionuclide transfer data for some of the Reference Animals and Plants (RAPs). It is also the first study that has sampled such a wide range of species (invertebrates, plants, amphibians and small mammals) from a single terrestrial site in the Chernobyl Exclusion Zone (CEZ). Samples were collected in 2014 from the 0.4 km sampling site, located 5 km west of the Chernobyl Nuclear Power complex. We report radionuclide (Cs, Sr,Am and Pu-isotopes) and stable element concentrations in wildlife and soil samples and use these to determine whole organism-soil concentration ratios and absorbed dose rates. Increasingly, stable element analyses are used to provide transfer parameters for radiological models. The study described here found that for both Cs and Sr the transfer of the stable element tended to be lower than that of the radionuclide; this is the first time that this has been demonstrated for Sr, though it is in agreement with limited evidence previously reported for Cs. Studies reporting radiation effects on wildlife in the CEZ generally relate observations to ambient dose rates determined using handheld dose meters. For the first time, we demonstrate that ambient dose rates may underestimate the actual dose rate for some organisms by more than an order of magnitude. When reporting effects studies from the CEZ, it has previously been suggested that the area has comparatively low natural background dose rates. However, on the basis of data reported here, dose rates to wildlife from natural background radionuclides within the CEZ are similar to those in many areas of Europe.

Towards solving a scientific controversy – The effects of ionising radiation on the environment

“…2500 t of Pb were dropped onto the burning reactor (National Report of Ukraine, 2011)). However, a study conducted on a terrestrial site in the Red Forest, found levels of Pb in soil typical for European soils (Beresford et al, 2019b), which agrees with Jagoe et al, (1998) who found no elevated Pb (or Hg) concentrations in freshwater ecosystems close to the Chernobyl NPP. Hence, based on current evidence, it seems unlikely that there is widespread non-radiological contamination in the CEZ because of the accident.…”

Genetic, epigenetic and microbiome characterisation of an earthworm species (Octolasion lacteum) along a radiation exposure gradient at Chernobyl

“…There could be a localised dose from 90 Sr to the gut surface, but within one order of magnitude of the estimated internal dose rate, although localised dose may be similar. The dominance of external exposure due to 137 Cs and the relative contributions of the different radionuclides to internal dose are in agreement with dose estimates based upon radionuclide activity concentrations measured in earthworms (Lumbricidae) and soil sampled from the Red Forest (CEZ) in 2014 (Beresford et al, 2019a).…”

The effect of chronic low-dose environmental radiation on organ mass of bank voles in the Chernobyl exclusion zone

“…Radiation data were right skewed, so the radiation measurements were log 10 -transformed to achieve normality. A recent study shows that approximately 70% of radiation dose of Chernobyl bank voles comes from external sources of Cs 137 and Sr 90 (Beresford et al 2020). However, IR also accumulates in plant tissue, which is eaten by animals and increase their exposure (Boraty nski et al 2016).…”

“…Long-lived radioactive compounds, such as cesium-137 (Cs 137 ) and strontium-90 (Sr 90 ) from Fukushima and Chernobyl, have spread far in landscape scale and due to their long half-life (approximately 30 years) the effects persist for decades (Askbrant et al 1996;IAEA 1996;Baba 2013). In Chernobyl area, many species gain most of their radiation burden externally and accumulation of Cs 137 and Sr 90 is species-specific (Beresford et al 2020). Due to its water solubility, Cs 137 has high mobility and enters the body through the diet and drinking water (Murakami et al 2015).…”