Showing papers by "Norwegian Radiation Protection Authority published in 2016"

Ultraviolet exposure from indoor tanning devices: a systematic review.

Abstract: Summary Use of indoor tanning devices increases the risk of cutaneous melanoma and nonmelanoma skin cancer. Indoor tanning devices have become important sources of ultraviolet (UV) exposure, both UVB and UVA. This systematic review assessed UV measurements performed in indoor tanning devices related to irradiance level, wavelength distribution and similarities to natural sun. The study was performed in accordance with the MOOSE and PRISMA guidelines. We searched PubMed, Embase and Web of Science from inception to May 2015, and also examined the reference lists of the retrieved studies. Eighteen studies were included. Twelve studies examined the erythema-weighted UV irradiances of indoor tanning devices, 11 studies examined UVB and 13 studies studied UVA. Compliance with irradiance limits was reported in nine studies. Erythema-weighted irradiances were highest in the most recent studies. Most studies had mean values higher than from natural sun and with large variations between devices. All studies except two had mean unweighted UVB irradiances lower than from natural summer sun (at latitudes from 37°S to 35°N), while mean unweighted UVA irradiances were, with one exception, substantially higher than from natural sun. The high values of UVA exposure from modern tanning devices are alarming in light of the increased focus on UVA irradiance as a carcinogen, and as UVA exposure confers little protection against subsequent UV exposure.

Gamma radiation at a human relevant low dose rate is genotoxic in mice.

Abstract: Even today, 70 years after Hiroshima and accidents like in Chernobyl and Fukushima, we still have limited knowledge about the health effects of low dose rate (LDR) radiation. Despite their human relevance after occupational and accidental exposure, only few animal studies on the genotoxic effects of chronic LDR radiation have been performed. Selenium (Se) is involved in oxidative stress defence, protecting DNA and other biomolecules from reactive oxygen species (ROS). It is hypothesised that Se deficiency, as it occurs in several parts of the world, may aggravate harmful effects of ROS-inducing stressors such as ionising radiation. We performed a study in the newly established LDR-facility Figaro on the combined effects of Se deprivation and LDR γ exposure in DNA repair knockout mice (Ogg1−/−) and control animals (Ogg1+/−). Genotoxic effects were seen after continuous radiation (1.4 mGy/h) for 45 days. Chromosomal damage (micronucleus), phenotypic mutations (Pig-a gene mutation of RBCCD24−) and DNA lesions (single strand breaks/alkali labile sites) were significantly increased in blood cells of irradiated animals, covering three types of genotoxic activity. This study demonstrates that chronic LDR γ radiation is genotoxic in an exposure scenario realistic for humans, supporting the hypothesis that even LDR γ radiation may induce cancer.

Harvest-induced phenotypic selection in an island population of moose, Alces alces

Abstract: Empirical evidence strongly indicates that human exploitation has frequently led to rapid evolutionary changes in wild populations, yet the mechanisms involved are often poorly understood. Here, we applied a recently developed demographic framework for analyzing selection to data from a 20-year study of a wild population of moose, Alces alces. In this population, a genetic pedigree has been established all the way back to founders. We demonstrate harvest-induced directional selection for delayed birth dates in males and reduced body mass as calf in females. During the study period, birth date was delayed by 0.81 days per year for both sexes, whereas no significant changes occurred in calf body mass. Quantitative genetic analyses indicated that both traits harbored significant additive genetic variance. These results show that selective harvesting can induce strong selection that oppose natural selection. This may cause evolution of less favorable phenotypes that become maladaptive once harvesting ceases.

Individual and molecular level effects of produced water contaminants on nauplii and adult females of Calanus finmarchicus.

Abstract: In the Barents Sea region new petroleum fields are discovered yearly and extraction of petroleum products is expected to increase in the upcoming years. Despite enhanced technology and stricter governmental legislation, establishment of the petroleum industry in the Barents Sea may potentially introduce a new source of contamination to the area, as some discharges of produced water will be allowed. Whether the presence of produced water poses a risk to the Arctic marine life remains to be investigated. The aim of this study was to examine effects of exposure to several compounds found in produced water-a mixture of selected organic compounds (APW), radium-226 ((226)Ra), barium (Ba), and a scale inhibitor-on the copepod species Calanus finmarchicus. Experiments were performed using exposure concentrations at realistic levels based on those detected in the vicinity of known discharge points. The influence of lethal and sublethal effects on early life stages was determined and significantly lower survival in the APW exposure groups was found. In the Ba treatment the life stage development did not proceed to the same advanced stages as observed in the control (filtered sea water). The scale inhibitor and (226)Ra treatments showed no significant difference from control. In addition, adult females were exposed to APW, (226)Ra, and a mixture of the two. Both individual-level effects (egg production and feeding) and molecular-level effects (gene expression) were assessed. On the individual level endpoints, only treatments including APW produced an effect compared to control. However, on the molecular level the possibility that also (226)Ra induced toxicologically relevant effects cannot be ruled out.

Local populations facing long-term consequences of nuclear accidents: lessons learnt from Chernobyl and Fukushima

Abstract: After a large-scale nuclear accident, local populations face a high level of complexity, as their day-to-day life is seriously disrupted by the short and long term consequences of the event. Affected populations face numerous decisions related to their daily life and trade-offs in order to cope with a whole range of unfamiliar issues associated with the long-lasting radioactive contamination. This includes the choice to leave, stay or return in the contaminated zone. Feedback of the Chernobyl and Fukushima post-accident situations in Norway and Japan based on the results of the PREPARE European research project brings insights on the complexity of nuclear post-accident situations in modern democracies involving long-lasting contamination. The main goal of the project was to evaluate how and to what extent local populations can access reliable information to protect themselves and participate to collective decisions, as foreseen in the terms of the Aarhus Convention (1998) on public information & participation of the UNECE (United Economic Commission for Europe). After an accident, individuals and families, professionals, local communities, public authorities and experts have various response paths that are frequently conflicting. An analysis of the societal mechanisms was performed to identify the interactions of the different paths, the role of values in these social mechanisms as well as the impact of public policies on the resilience and social cohesion of local communities and on their capacity to build their own recovery strategies. It demonstrates the importance of a holistic approach that includes all the societal dimensions of the responses to post-accident situations. The capacity of local actors to build their response to the crisis depends on their capacity to build new forms of cooperation among themselves and with other actors and relevant networks.

Overview of the PREPARE WP3: management of contaminated goods in post-accidental situation – Synthesis of European stakeholders' panels

Abstract: Recommendations and requirements for the management of foodstuffs including drinking water and feedstuffs (but not other commodities) contaminated after a nuclear accident or a radiological event have been developed by international bodies such as Codex Alimentarius Commission or European Union as well as by individual countries. However, the experience from severe nuclear accidents (Chernobyl, Fukushima) and less serious radiological events, shows that the implementation of such systems (based on criteria expressed in activity concentration) seems to be not fully suitable to prevent several difficulties such as, for instance, stigmatization and even rejection attitudes from consumers or retailers (anticipating the fears of consumers). To further investigate the possible strategies and stakeholder expectations to deal with this sensitive issue, a study has been launched within the European research project PREPARE-WP3. The overall objective of this work, coordinated is to contribute to the development of strategies, guidance and tools for the management of the contaminated products, taking into account the views of producers, processing and retail industries and consumers. For this purpose, 10 stakeholder panels from different European countries have been set up. In addition, feedback experience from the management of contaminated goods following the Fukushima accident has been provided by Japanese stakeholders. This paper highlights the key topics tackled by the different European stakeholders’ panels.

Justification of CT for Individual Health Assessment of Asymptomatic Persons: A World Health Organization Consultation

Abstract: An international expert consultation was convened by the World Health Organization (WHO). The purpose of the meeting was to review the use of CT in examining asymptomatic people. This is often referred to as individual health assessment (IHA). IHA was identified as a global phenomenon unenthusiastically tolerated, and not actively promoted, structured, or regulated in most countries. This paper identifies the state of the art for IHA and some considerations in relation to its justification, in different regions of the world. The outcomes reached include the following: questions around terminology and culture of IHA practice; review of IHA in some countries, regions, and international bodies; dilemmas for participants in IHA; risk communication, education, and training for professions and public; the desirability of guidelines and clinical audit; social, ethical, public health, and resource considerations; and a framework for IHA and regulatory considerations. Three subcategories of examination for asymptomatic individuals were identified: formal screening programs; examinations for which the evidence base or risk profile is incomplete; and opportunistic examinations with little or no evidence or risk profile to suggest they have any merit. The latter challenges the justification principle of radiation protection. In addition, the issue of the costs, direct and indirect, associated with false positives and/or equivocal/incidental findings were highlighted. These and other considerations make it difficult to view some IHA as a bona fide medical activity. To allow it to be viewed as such requires that it be conducted within a robust clinical governance framework that includes regulatory dimensions.

Integration of marine food chain model POSEIDON in JRODOS and testing versus Fukushima data

Abstract: The marine box model POSEIDON-R was integrated into the JRODOS decision support system. The POSEIDON-R dynamic food web model was extended by a benthic food chain to describe the migration of radionuclides from contaminated bottom sediments to marine organisms. The model was validated using experimental data from the Fukushima accident. Simulated concentrations of 137 Cs in water, bottom sediments and marine organisms are in good agreement with measurements. An example of application of JRODOS was demonstrated for Acerinox incident (Spain, 1998).

Model analysis of worst place scenarios for nuclear accidents in the northern marine environment

Abstract: The North and Nordic Seas contains some of the world's most important fishery resources and is an area of significant traffic involving nuclear powered vessels and transports of nuclear and radioactive materials. Consumer awareness to even rumors of radioactive contamination imparts a special vulnerability to this region. The effective assignation of emergency resources, design of monitoring programs and provision of information regarding accidents relies upon an a-priori analysis of potential impacts. To this end, an adjoint sensitivity analysis regarding potential impacts on the most important regional fishery was conducted with a view towards development of a system capable of providing information regarding potential contaminant dispersal from any point within the North and Nordic Seas. Results indicate that the area is potentially vulnerable to releases of radioactive materials over a much wider area than has previously considered. An adjoint sensitivity analysis of the northern marine area was conducted.Potential impacts on the most important regional fishery were assessed.The fishery is vulnerable to releases of contaminants over a much wider area than previously considered.

Protection of the environment in existing exposure situations

Abstract: The International Commission on Radiological Protection (ICRP) described its approach to the protection of the environment and how it should be applied in Publication 124 The report expanded on the Commission's objectives for environmental protection, and how the Derived Consideration Reference Levels (DCRLs) apply within different exposure situations. DCRLs relate radiation effects to doses over and above their normal local background radiation levels, and consider different potential pathways of exposure for animals and plants. This paper will describe how the DCRLs may be used within existing exposure situations to better understand the potential impacts on animals and plants. In these circumstances, the Commission recommends that the aim be to reduce exposures to levels that are within the DCRL bands (or even below, depending upon the potential cost/benefits), but with full consideration of the radiological and non-radiological consequences of doing so. Using examples, this paper will demonstrate how this may be achieved in practice, bearing in mind the potential exposure of humans, animals and plants during and following any remediation attempted.

Distribution of artificial radioisotopes in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia

Abstract: The purpose of this study was to compare the distribution of the most significant medium and long-lived radioisotopes, i.e., 60Co, 137Cs, and 152Eu, in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia, to reveal natural patterns of their behavior and accumulation. Soil samples collected at different elevations and depths in a floodplain of the Yenisey River downstream from the KMCC (20–250 km) were subjected to granulometric analysis by dry screening and a modified Petelin method. Fractions <0.05 mm were collected by a pipette method. Radionuclide activity in the different soil layers and in their fractions was determined using a spectrometer equipped with an HPGe detector. Concentration of total C (Ctot) and C of carbonates (Ccarb) was determined using a CHN analyzer before and after elimination of carbonates, organic C (Corg) being calculated as the difference between the obtained values. Organic fractions were separated by saturation of the air-dry sample with 0.1 M NaOH and further precipitation of humic acid from filtrate by 1 M HCl at pH 1. The separation resulted in three fractions of the fulvic acids, humic acids, and the residue containing the denuded mineral phase and the refractory organic residue. The selected bulk samples and fractions were analyzed for radionuclide activity. Based on earlier results, the distribution of the pelite (<0.01 mm) and aleurite (0.01–0.1 mm) fractions in alluvium and soil samples have been analyzed to evaluate the grain-size contribution to radionuclide fixation. A positive correlation between radionuclide activity and the portion of pelite fraction was established for 60Co and 152Eu, while 137Cs accumulation was not related with this fraction. In organic matter (OM) extracts, more than 90 % of 137Cs, at proportions similar to those attributable to 238Th and 40K, were associated with the residue fraction, while 72 % of 152Eu and 46 % of 60Co were found in the mobile fraction of the low molecular fulvic acids. In successive layers of the soil vertical profile, approximately 94 % of the 152Eu variation may be explained by a linear model with Corg and Ccarb values as independent variables. Different associations of 137Cs, 60Co, and 152 Eu with particulate and organic fractions in river sediments and floodplain soils could be explained by the dominating discharge form (water soluble or particulate), affinity to organic substances of different mobility, sorption by minerals and their aggregates, and chemisorption.

Reconstruction of paediatric organ doses from axial CT scans performed in the 1990s – range of doses as input to uncertainty estimates

Abstract: To assess the range of doses in paediatric CT scans conducted in the 1990s in Norway as input to an international epidemiology study: the EPI-CT study, http://epi-ct.iarc.fr/ . National Cancer Institute dosimetry system for Computed Tomography (NCICT) program based on pre-calculated organ dose conversion coefficients was used to convert CT Dose Index to organ doses in paediatric CT in the 1990s. Protocols reported from local hospitals in a previous Norwegian CT survey were used as input, presuming these were used without optimization for paediatric patients. Large variations in doses between different scanner models and local scan parameter settings are demonstrated. Small children will receive a factor of 2–3 times higher doses compared with adults if the protocols are not optimized for them. For common CT examinations, the doses to the active bone marrow, breast tissue and brain may have exceeded 30 mGy, 60 mGy and 100 mGy respectively, for the youngest children in the 1990s. The doses children received from non-optimised CT examinations during the 1990s are of such magnitude that they may provide statistically significant effects in the EPI-CT study, but probably do not reflect current practice. • Some organ doses from paediatric CT in the 1990s may have exceeded 100 mGy. • Small children may have received doses 2–3 times higher compared with adults. • Different scanner models varied by a factor of 2–3 in dose to patients. • Different local scan parameter settings gave dose variations of a factor 2–3. • Modern CTs and age-adjusted protocols will give much lower paediatric doses.

ICRP Fukushima dialogue seminars: joint learning at many levels.

Abstract: The Norwegian Radiation Protection Authority and representatives from the CERAD Centre of Excellence participated at the majority of the International Commission on Radiological Protection dialogue seminars in Fukushima between 2011 and 2015. The open and sharing structure of the seminars contributed to an unprecedented understanding of the challenges faced by the general public affected by radioactive contamination due to an accident at a nuclear power plant. Most importantly by presentations from people in Fukushima, but also by presentations from lay people in Norway and Belarus who shared their experiences from the Chernobyl accident at several seminars. The seminars created new friendships and connections, which inter alia led to several exchange visits between affected people in Norway and Japan where worries and experiences could be shared in an open and reflective manner. The mix of actors (various experts, authorities, local populations) created joint learning across sectors and levels, represent...

Improved source term description in Eulerian models in ARGOS

Abstract: Atmospheric dispersion models can be formulated and implemented in two different ways, e.g. as Eulerian and Lagrangian models. These implementations have both advantages and disadvantages concerning numerical requirements and accuracy. A combination of both implementations – a hybrid approach is also possible and, we show some improvement to a pure approach, when using this method. In many practical cases of measured radioactive air concentrations, the source time and location is not known. Inverse modelling can be used to help identifying the source. Using a simplified footprint analysis, it is even possible to combine the information from several measurement stations to get an improved picture over possible sources from an atmospheric point of view.

Health check-ups of children living in a Belarus district contaminated after the Chernobyl accident

Abstract: The Chernobyl nuclear accident, which occurred on April 26th, 1986, resulted in widespread long-term contamination, mainly due to 137 Cs, of large territories where populations live. A project was initiated to assess the 137 Cs body burden and health status, not limited to radiation-induced pathologies, for all children living in a highly contaminated district in Belarus; the aim was to provide detailed information for parents worried about their children’s health, without the intention of quantifying the radiation-induced risk. In total, about 2500 children benefited from these check-ups, which included approximately 30 parameters and were repeated three times between 2005 and 2009. The internal 137 Cs burden was rather low; about 50% of children had less than 10 Bq kg -1 . The health indicators reported in this paper are the global health status, physical development, and frequencies of thyroid modifications and cardiac dysfunctions. The 137 Cs body burden or density deposition did not appear to be strongly associated with these health indicators; other parameters, such as quality of living conditions and rural or urban residence, appeared to be more important. The aim of the project was achieved, as the results provided a global overview of the health status and level of internal contamination of children living in a contaminated territory about 20 years after the accident.