Field studies on the influence of environmental factors on I - 131 interception and weathering loss in grass.

A series of 131I tracer experiments have been conducted at two research stations in Norway, one coastal and one inland to study radioiodine transfer and dynamics in boreal, agricultural ecosystems. The hypothesis tested was that site specific and climatological factors, along with growth stage, would influence foliar uptake of 131I by grass and its subsequent loss. Results showed that the interception fraction varied widely, ranging from 0.007 to 0.83 over all experiments, and showing a strong positive correlation with biomass and stage of growth. The experimental results were compared to various models currently used to predict interception fractions and weathering loss. Results provided by interception models varied in the range of 0.5-2 times of the observed values. Regarding weathering loss, it was demonstrated that double exponential models provided a better fit with the experimental results than single exponential models. Normalising the data activity per unit area to remove bio-dilution effects, and assuming a constant single loss rate gave weathering half-times of 22.8 ± 38.3 and 10.2 ± 8.2 days for the inland and coastal site, respectively. Whilst stable iodine concentrations in grass and soil were significantly higher (by approximately a factor of 5 and 7 times for grass and soil respectively) at the coastal compared to the inland site, it was not possible to deconvolute the influence of this factor on the temporal behaviour of 131I. Nonetheless, stable iodine data allowed us to establish an upper bound on the soil to plant transfer of radioiodine via root uptake and to establish that the pathway was of minor importance in defining 131I activity concentrations in grass compared to direct contamination via interception. Climatological factors (precipitation, wind-speed and temperature) appeared to affect the dynamics of 131I in the system, however the decomposition of these collective influences into specific contributions from each factor remains unresolved and requires further study. The newly acquired data on the interception and weathering of radioiodine in boreal, agricultural ecosystems and the reparametrized models developed from this, substantially improve the toolbox available for Norwegian emergency preparedness in the event of a nuclear accident.

An updated strategic research agenda for the integration of radioecology in the european radiation protection research.

The ALLIANCE Strategic Research Agenda (SRA) for radioecology is a living document that defines a long-term vision (20 years) of the needs for, and implementation of, research in radioecology in Europe. The initial SRA, published in 2012, included consultation with a wide range of stakeholders (Hinton et al., 2013). This revised version is an update of the research strategy for identified research challenges, and includes a strategy to maintain and develop the associated required capacities for workforce (education and training) and research infrastructures and capabilities. Beyond radioecology, this SRA update constitutes a contribution to the implementation of a Joint Roadmap for radiation protection research in Europe (CONCERT, 2019a). This roadmap, established under the H2020 European Joint Programme CONCERT, provides a common and shared vision for radiation protection research, priority areas and strategic objectives for collaboration within a European radiation protection research programme to 2030 and beyond. Considering the advances made since the first SRA, this updated version presents research challenges and priorities including identified scientific issues that, when successfully resolved, have the potential to impact substantially and strengthen the system and/or practice of the overall radiation protection (game changers) in radioecology with regard to their integration into the global vision of European research in radiation protection. An additional aim of this paper is to encourage contribution from research communities, end users, decision makers and other stakeholders in the evaluation, further advancement and accomplishment of the identified priorities.

The impact of the Fukushima nuclear accident on marine biota: retrospective assessment of the first year and perspectives.

An international study under the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was performed to assess radiological impact of the nuclear accident at the Fukushima-Daiichi Nuclear Power Station (FDNPS) on the marine environment. This work constitutes the first international assessment of this type, drawing upon methodologies that incorporate the most up-to-date radioecological models and knowledge. To quantify the radiological impact on marine wildlife, a suite of state-of-the-art approaches to assess exposures to Fukushima derived radionuclides of marine biota, including predictive dynamic transfer modelling, was applied to a comprehensive dataset consisting of over 500 sediment, 6000 seawater and 5000 biota data points representative of the geographically relevant area during the first year after the accident. The dataset covers the period from May 2011 to August 2012. The method used to evaluate the ecological impact consists of comparing dose (rates) to which living species of interest are exposed during a defined period to critical effects values arising from the literature. The assessed doses follow a highly variable pattern and generally do not seem to indicate the potential for effects. A possible exception of a transient nature is the relatively contaminated area in the vicinity of the discharge point, where effects on sensitive endpoints in individual plants and animals might have occurred in the weeks directly following the accident. However, impacts on population integrity would have been unlikely due to the short duration and the limited space area of the initially high exposures. Our understanding of the biological impact of radiation on chronically exposed plants and animals continues to evolve, and still needs to be improved through future studies in the FDNPS marine environment.

On the application of an environmental radiological assessment system to an anthropomorphic surrogate.

Recent developments have seen the expansion of the system of radiological protection for humans to one including protection of the environment against detrimental effects of radiation exposure, although a fully developed framework for integration of human and ecological risk assessment for radionuclides is only at an early stage. In the context of integration, significant differences exist between assessment methodologies for humans and the environment in terms of transfer, exposure, and dosimetry. The aim of this elaboration was to explore possible implications of the simplifications made within the system of environmental radiological protection in terms of the efficacy and robustness of dose-rate predictions. A comparison was conducted between human radiological assessment and environmental radiological assessment for an anthropomorphic surrogate, the results for which, produced by both the environmental and human-oriented risk assessment systems, were critically compared and contrasted. The adopted approach split the calculations into several parts, these being 1) physical transfer in an ecosystem, 2) transfer to humans, 3) internal doses to humans, and 4) external doses to humans. The calculations were carried out using both a human radiological assessment and ecological risk assessment system for the same surrogate. The results of this comparison provided indications as to where the 2 systems are amenable to possible integration and where such integration may prove difficult. Initial stage transport models seem to be an obvious component amenable for integration, although complete integration is arguably unattainable as the differences between endpoints mean that the relevant outputs from the models will not be the same. For the transfer and dosimetry components of 2 typical methodologies, it seems that the efficacy of the environmental system is radionuclide-dependent, the predictions given by the environmental system for (90) Sr and (60) Co being unsatisfactory and those for (239) Pu and (210) Po being evidently poor. Integration in this context might take the form of exploring the biokinetic models developed for humans with regard to selected animals and radionuclides. External dose assessment for environmental and human systems provide results for the surrogate that correspond quite closely providing an indication that integration in this regard is perhaps unnecessary.

Multivariate classification of structural MRI data detects chronic low back pain.

Chronic low back pain (cLBP) has a tremendous personal and socioeconomic impact, yet the underlying pathology remains a mystery in the majority of cases. An objective measure of this condition, that augments self-report of pain, could have profound implications for diagnostic characterization and therapeutic development. Contemporary research indicates that cLBP is associated with abnormal brain structure and function. Multivariate analyses have shown potential to detect a number of neurological diseases based on structural neuroimaging. Therefore, we aimed to empirically evaluate such an approach in the detection of cLBP, with a goal to also explore the relevant neuroanatomy. We extracted brain gray matter (GM) density from magnetic resonance imaging scans of 47 patients with cLBP and 47 healthy controls. cLBP was classified with an accuracy of 76% by support vector machine analysis. Primary drivers of the classification included areas of the somatosensory, motor, and prefrontal cortices--all areas implicated in the pain experience. Differences in areas of the temporal lobe, including bordering the amygdala, medial orbital gyrus, cerebellum, and visual cortex, were also useful for the classification. Our findings suggest that cLBP is characterized by a pattern of GM changes that can have discriminative power and reflect relevant pathological brain morphology.

Review of research on impacts to biota of discharges of naturally occurring radionuclides in produced water to the marine environment.

Produced water has been described as the largest volume waste stream in the exploration and production process of oil and gas. It is accompanied by discharges of naturally occurring radionuclides raising concerns over the potential radiological impacts of produced water on marine biota. In the Northern European marine environment, radioactivity in produced water has received substantial attention owing to the OSPAR Radioactive Substances Strategy which aims at achieving 'concentrations in the environment near background values for naturally occurring radioactive substances'. This review provides an overview of published research on the impacts to biota from naturally occurring radionuclides discharged in produced water by the offshore oil and gas industry. In addition to summarising studies and data that deal directly with the issue of dose and effect, the review also considers studies related to the impact of added chemicals on the fate of discharged radionuclides. The review clearly illustrates that only a limited number of studies have investigated possible impacts on biota from naturally occurring radionuclides present in produced water. Hence, although these studies indicate that the risk to the environment from naturally occurring radionuclides discharged in produced water is negligible, the substantial uncertainties involved in the assessments of impact make it difficult to be conclusive. With regard to the complexity involved in the problem under consideration there is a pressing need to supplement existing data and acquire new knowledge. Finally, the present work identifies some knowledge gaps to indicate future research requirements.

Towards a physiology-based measure of pain: patterns of human brain activity distinguish painful from non-painful thermal stimulation.

Pain often exists in the absence of observable injury; therefore, the gold standard for pain assessment has long been self-report. Because the inability to verbally communicate can prevent effective pain management, research efforts have focused on the development of a tool that accurately assesses pain without depending on self-report. Those previous efforts have not proven successful at substituting self-report with a clinically valid, physiology-based measure of pain. Recent neuroimaging data suggest that functional magnetic resonance imaging (fMRI) and support vector machine (SVM) learning can be jointly used to accurately assess cognitive states. Therefore, we hypothesized that an SVM trained on fMRI data can assess pain in the absence of self-report. In fMRI experiments, 24 individuals were presented painful and nonpainful thermal stimuli. Using eight individuals, we trained a linear SVM to distinguish these stimuli using whole-brain patterns of activity. We assessed the performance of this trained SVM model by testing it on 16 individuals whose data were not used for training. The whole-brain SVM was 81% accurate at distinguishing painful from non-painful stimuli (p<0.0000001). Using distance from the SVM hyperplane as a confidence measure, accuracy was further increased to 84%, albeit at the expense of excluding 15% of the stimuli that were the most difficult to classify. Overall performance of the SVM was primarily affected by activity in pain-processing regions of the brain including the primary somatosensory cortex, secondary somatosensory cortex, insular cortex, primary motor cortex, and cingulate cortex. Region of interest (ROI) analyses revealed that whole-brain patterns of activity led to more accurate classification than localized activity from individual brain regions. Our findings demonstrate that fMRI with SVM learning can assess pain without requiring any communication from the person being tested. We outline tasks that should be completed to advance this approach toward use in clinical settings.

Whole-body to tissue concentration ratios for use in biota dose assessments for animals.

Environmental monitoring programs often measure contaminant concentrations in animal tissues consumed by humans (e.g., muscle). By comparison, demonstration of the protection of biota from the potential effects of radionuclides involves a comparison of whole-body doses to radiological dose benchmarks. Consequently, methods for deriving whole-body concentration ratios based on tissue-specific data are required to make best use of the available information. This paper provides a series of look-up tables with whole-body:tissue-specific concentration ratios for non-human biota. Focus was placed on relatively broad animal categories (including molluscs, crustaceans, freshwater fishes, marine fishes, amphibians, reptiles, birds and mammals) and commonly measured tissues (specifically, bone, muscle, liver and kidney). Depending upon organism, whole-body to tissue concentration ratios were derived for between 12 and 47 elements. The whole-body to tissue concentration ratios can be used to estimate whole-body concentrations from tissue-specific measurements. However, we recommend that any given whole-body to tissue concentration ratio should not be used if the value falls between 0.75 and 1.5. Instead, a value of one should be assumed.