Some areas of the world have high natural background levels of naturally occurring radionuclides (NOR) and/or rare earth elements (REE). With high background radiation risk, knowledge about, for example, uptake by crops is required in the process of assessing radiation doses to humans. In the Fen complex, in Norway, underlying bedrock has elevated levels of both NOR and REE. In Mining hill where these bedrocks surface and there are also legacy mines, soils also have high background levels. Most of Fen complex is, however, covered by thick Holocene deposits but some of its agricultural soils are situated near the areas of surfacing carbonatite bedrock and legacy mines. We assess whether there has been any influence on the levels in the agricultural soils within the Fen complex from the areas with high NOR and REE soil background. We also determine uptake from soils by cereals into grain or grain with hull, and present concentration ratios (CR) for NOR and REE in this high background area. In particular, the REE CRs are an important augmentation to existing sparse datasets. We furthermore assess whether uptake can be biased by any soil particles adhering to cereal grain or grain with hull. We investigate whether washing (or not washing) and use of different acids for dissolution may affect ICP-MS results on common elements. We also address soil mass in cereal samples using Scandium and Titanium as tracers for soil particles and assess the potential magnitude of bias CR.
Humans in arsenic-endemic and radiologically exposed settings may be co-exposed to inorganic arsenic and ionizing radiation, yet the combined effects of chronic low-dose-rate irradiation and environmentally relevant arsenic are poorly defined. In a single factorial experiment, male CBA and C57BL/6N mice were exposed to sodium arsenite in drinking water (0, 0.3 or 3 mg/L) and chronic γ irradiation (2.5 mGy/h, total 3 Gy), alone and combined. We measured blood genotoxicity (comet and micronucleus assays), characterised 21 circulating miRNAs, and sequenced liver and testis transcriptomes, analysing all endpoints in a factorial model (arsenite × irradiation × strain). Arsenite exposure was accompanied by an increase in oxidative DNA lesions in white blood cells along a slight reduction in single strand breaks. Micronucleus frequency in reticulocytes and erythrocytes was not affected by arsenite. Arsenite was identified as an oxidative rather than a chromosomal genotoxicant. The liver and testis transcriptomes shared a common DNA-repair and oxidative-stress response that diverged between the organs. Irradiation was the dominant stressor while the concurrent arsenite exposure was mainly non-additive or counteracting, but also additive effects were observed. Only two miRNAs responded to arsenite. Baseline strain differences were large but additive, with negligible strain×treatment interaction. Our study contributes new data, experimental design and analysis methods about the genotoxic and transcriptional landscape of multiple stressor exposures.
Understanding the neutron activation of modern urban materials following a nuclear detonation is important for effective emergency rescue and response planning, yet neutron-activation data for contemporary infrastructure remain limited. This study presents a dimensioning assessment of neutron-induced activation in electric vehicle (EV) battery systems, an increasingly common high-mass, high-metal component of modern cities. Using detailed Monte Carlo simulations, supported by controlled activation experiments with a thermalized neutron field, the activation products and resulting dose rates for three major battery chemistries (NMC-811, NCA, and LFP) arranged in a representative battery pack, were evaluated. Results show that EV batteries can generate substantial short-lived gamma activity immediately after neutron exposure, dominated by 28Al, 64Cu and 56Mn for nickel- and cobalt-bearing chemistries, while long-term activity is driven primarily by 60Co (NMC/NCA) and 32P (LFP). Dose rate estimations indicate that elevated fields may be present during the first hours post-detonation but decrease by several orders of magnitude within 24 h. Comparisons with activation of urban road materials reveal that 24Na generated in asphalt and sand substrates can equal or exceed battery-derived dose contributions. Overall, EV batteries constitute a relevant but transient localized radiological hazard in the immediate aftermath of a nuclear detonation, with significance highly dependent on battery chemistry and the timing of response operations. These findings support improved modelling of post-detonation environments and help contextualize EV batteries within broader urban activation scenarios.
The Arctic Ocean is undergoing rapid climate-driven change, making it increasingly important to quantify the circulation pathways and transit times of Atlantic Water entering and exiting the basin. Fram Strait, the primary gateway for Arctic–Atlantic exchange, provides a key location for assessing the evolving connectivity between the Arctic and the subpolar North Atlantic. Here, we combine the anthropogenic radionuclide tracer pair Iodine-129 (129I) and Uranium-236 (236U), with binary mixing and Transit Time Distribution (TTD) modelling to investigate the origin and transit history of surface Polar Water and mid-depth Atlantic Water sampled in Fram Strait between 2016–2021. Our results reveal significant interannual variability. Waters outflowing the Fram Strait in 2020 exhibited a higher degree of mixing and a stronger influence from Amerasian Basin sourced waters compared to 2016 and 2021. We further identify a distinct water parcel on the Greenland Shelf whose tracer signature indicates a long-path circulation originating from the Canada Basin. In contrast, waters sampled in 2021 exhibit generally longer transit times, consistent with either slower circulation or longer transport pathways. These results demonstrate substantial year-to-year variability in Arctic Ocean export through Fram Strait and highlight the need for sustained tracer observations to constrain changes in the circulation of the heat-bearing Atlantic Water layer and its role in Arctic–North Atlantic exchange.
The Norwegian government has maintained a plan of action on nuclear safety and security for over 25 years. The need for such a plan grew from extensive nuclear activities during the Cold War, both civil and military, that led eventually to significant amounts of radioactive waste (RW) and nuclear material being stored in unsafe conditions in Northwest Russia. As part of the program to implement the plan of action, the Norwegian Radiation and Nuclear Safety Authority has maintained a program of bilateral regulatory cooperation with corresponding authorities in countries of the former Soviet Union for over 25 years. This paper reviews the background to that regulatory program, identifies the main radiologically hazardous objects and the related regulatory challenges, and then documents how bilateral cooperation has contributed to the substantial progress made in risk reduction. The review then considers how bilateral work has contributed to and benefitted from sharing results and experience with international partners and draws conclusions and lessons for future work. The primary conclusion is that bilateral regulatory cooperation has supported reduction of radiation and nuclear risks at a range of complex legacy sites and facilities in countries of the former Soviet Union. Key to this process has been a clear strategy to help build and maintain an up-to-date, robust and independent regulatory process. Only with well-coordinated regulatory bodies with clear responsibilities and functions is it possible to address the diverse threats effectively. Among the most radiologically significant sites and facilities where risk has been significantly reduced or eliminated are the LEPSE spent fuel and RW storage vessel, the site for temporary storage for spent fuel and RW at Andreeva Bay, and the very large radio-isotope thermo-electric generators sources previously used in navigational devices all across the Russian arctic coastline. Noting the clear potential for transboundary impacts, this represents a substantial regional benefit. Following the full-scale invasion of Ukraine by the Russian Federation in February 2022, the bilateral cooperation activities with Russian authorities ceased. Using the successfully developed regulatory working methods and experience gained in Russia, substantial regulatory enhancement has also been achieved in countries of Central Asia and Ukraine, commencing in 2008 and 2014 respectively. Continuing such support in Ukraine, in the face of new regulatory challenges arising due to the full-scale Russian invasion, remains a high priority for the DSA within the Norwegian Nansen program.
