Temporal changes in gamma dose rates in the Esk Estuary, UK

Over the last 30 years there has been a reduction in the radioactive discharges from the UK's Sellafield site. Radionuclide activity concentrations in the environment around Sellafield have declined as a result. However, routine monitoring results from the nearby Esk Estuary show a less clear trend, with fluctuations in gamma dose rate measurements being reported from year to year. A comprehensive survey (n = 576) of gamma dose rates in the Esk Estuary was undertaken in 2007 and the data compared to a similar survey carried out in 1989. There was a highly statistically significant decrease in the external gamma dose rates within the Esk Estuary between 1989 and 2007. The measured total gamma dose rate range in 2007 was 0.064 - 0.235 μGy h-1with a mean of 0.123 μGy h-1. This equates to a maximum exposure of 0.200 μSv h-1. There was no evidence of large-scale sediment redistribution under current conditions. However, there was limited evidence to suggest that part of the reason for the reduction in measured dose rates was the burial of contaminated sediment deposits by uncontaminated sediments transported by tidal processes

Impact Assesment of ionising Radiation on Wildlife

This is the Impact Assessment of ionising Radiation on Wildlife document produced by the Environment Agency in 2001. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the Impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those ecosystems most likely to be impacted by the authorised discharges of radioactivity within England and Wales. The use of biomarker techniques is reviewed in the report, and their application to the study of exposure to multiple contaminants is discussed

A new version of the ERICA tool to facilitate impact assessments of radioactivity on wild plants and animals

A new version of the ERICA Tool (version 1.2) was released in November 2014; this constitutes the first major update of the Tool since release in 2007. The key features of the update are presented in this article. Of particular note are new transfer databases extracted from an international compilation of concentration ratios (CRwo-media) and the modification of ‘extrapolation’ approaches used to select transfer data in cases where information is not available. Bayesian updating approaches have been used in some cases to draw on relevant information that would otherwise have been excluded in the process of deriving CRwo-media statistics. All of these efforts have in turn led to the requirement to update Environmental Media Concentration Limits (EMCLs) used in Tier 1 assessments. Some of the significant changes with regard to EMCLs are highlighte

Field effects studies in the Chernobyl Exclusion Zone: lessons to be learnt

In the initial aftermath of the 1986 Chernobyl accident there were detrimental effects recorded on wildlife, including, mass mortality of pine trees close to the reactor, reduced pine seed production, reductions in soil invertebrate abundance and diversity and likely death of small mammals. More than 30 years after the Chernobyl accident there is no consensus on the longer-term impact of the chronic exposure to radiation on wildlife in what is now referred to as the Chernobyl Exclusion Zone. Reconciling this lack of consensus is one of the main challenges for radioecology. With the inclusion of environmental protection in, for instance, the recommendations of the International Commission on Radiological Protection (ICRP), we need to be able to incorporate knowledge of the potential effects of radiation on wildlife within the regulatory process (e.g. as a basis on which to define benchmark dose rates). In this paper, we use examples of reported effects on different wildlife groups inhabiting the Chernobyl Exclusion Zone (CEZ) as a framework to discuss potential reasons for the lack of consensus, consider important factors influencing dose rates organisms receive and make some recommendations on good practice