Gjelsvik R.,Norwegian Radiation Protection Authority |
Steinnes E.,Norwegian University of Science and Technology
Journal of Environmental Radioactivity | Year: 2013
In order to follow the turnover of 137Cs in natural soils and estimate future trends in exposure of livestock, samples of natural surface soils were collected at 0-3cm depth at 464 sites in 1995 and 463 sites in 2005 covering the country. In both cases the geographical pattern observed was similar to the original distribution from 1986, but the decline of 137Cs activity in the surface soil was not the same everywhere. In 1995 the 137Cs reduction since 1986 was found to be considerably greater in coastal areas than farther inland. The main reason for this appears to be the much greater deposition of marine cations such as Mg2+ and Na+ in the coastal areas, replacing Cs ions fixed on soil particle surfaces. This cation exchange appeared to be particularly strong near the southern coast where deposition of NH4+ from transboundary air pollution is evident in addition to the marine cations. During 1995-2005 the 137Cs decline in the surface soil was more uniform over the country than in the preceding 10-year period but still significantly higher in coastal areas than inland. Differences in precipitation chemistry may have influenced the uptake of 137Cs in terrestrial food chains. © 2013 Elsevier Ltd. Source
Thorring H.,Norwegian Radiation Protection Authority
Health Physics | Year: 2012
The Chernobyl fallout is an enduring challenge to reindeer husbandry in Norway, and South Sámi reindeer herders in central and southern Norway are as contaminated by 137Cs as inhabitants close to Chernobyl. Therefore, Norwegian authorities continuously recommend to these reindeer herders the use of countermeasures to reduce their intake of 137Cs. In this study, the authors have applied data on contamination levels in reindeer, results of dietary surveys, and whole body monitoring data in low and high contaminated areas to estimate the effectiveness of countermeasures and resulting averted doses to the reindeer herders. In the most contaminated area, the various countermeasures applied reduced radiocesium ingestion doses during 1986-2009 by about 73%, to an integrated dose of about 17 mSv. However, to comply with the recommended 137Cs ingestion dose limit of 1 mSv y -1, the study indicates that reindeer herders in the most contaminated areas will need to carry on with their countermeasures for another 10-15 y. Furthermore, the study indicates that whole body monitoring is an important tool to assess individual doses and countermeasure effectiveness in long-term management of a contamination situation and that such monitoring may be required to reach long-term reference levels. Copyright © 2012 Health Physics Society. Source
Iosjpe M.,Norwegian Radiation Protection Authority
Journal of Marine Systems | Year: 2011
A sensitivity analysis has been carried out on the basis of the local and global sensitivity indexes for selected radionuclides (3H, 137Cs, 238Pu, 241Am and 244Cm) and main parameters describing the water-sediment interaction (sediment reworking rate, pore-water turnover rate, sediment distribution coefficient, suspended sediment load in water column, sedimentation rate, molecular diffusion coefficient, surface sediment thickness, porosity of bottom sediment and density of sediment material). Sensitivity analysis has been carried out using a compartment model for dose assessment to man and biota, which includes the processes of advection of radioactivity between compartments, sedimentation, diffusion of radioactivity through pore water in sediments, particle mixing, pore water mixing and a burial process of radioactivity in deep sediment layers.The sensitivity analysis indicates that for the conditions in the Norwegian Current (the Norwegian Sea) particle mixing dominates the transfer of radioactivity between the bottom water and surface sediment compartments. For the conditions in the Ob Bay (the Kara Sea), the sedimentation process has also been found to be significant.The calculated dynamics of the sensitivity indexes demonstrate clearly the complexities encountered when modeling water-sediment interactions. It is also shown that the results can be strongly dependent on the time of analysis. For example, given a specific change of parameters the radionuclide concentration will be either increased or decreased, depending on the temporal interval.Information provided by the sensitivity analysis can contribute to a better understanding of experimental data and might further improve the parameterization process. The obtained results show that water-sediment interactions can play a key role in the marine coastal environment, thus demonstrating the need to further deepen our understanding of them, as well as improve the models describing them. © 2011 Elsevier B.V. Source
Agency: Cordis | Branch: FP7 | Program: CSA-SA | Phase: Fission-2012-6.0.1 | Award Amount: 1.45M | Year: 2013
The health effects of exposures to fallout from Soviet nuclear weapons testing among the residents living nearby the Semipalatinsk nuclear test site in Kazakhstan are not well investigated. There are reports with contradicting results coming from the studies conducted on two independent cohorts: historical and new. Both use different control groups and dosimetric methods. The two cohorts have a high probability of including the same individuals. There is a need to investigate possibilities to merge them in order to avoid duplication of efforts and resources for future studies of the health effects in these populations. The main objectives of our feasibility study include: developing and testing mechanisms for identification of cohort members in the two cohorts; identification and testing of data linkage mechanisms; determination of the outcomes that can be studied (cancer and non-cancer diseases); setting up and testing procedures for follow-up; identification of case ascertainment mechanisms and sources, depending on the outcome; characterization and validation of dose assessment methods used in the two cohorts; investigation of the feasibility to collect data on confounding factors; assessing the availability of biological samples and their potential use in the future. The project will bring together scientists from Europe, Kazakhstan and Japan with the aim of developing a proposal for a future prospective full scale epidemiological study to address the dose-effect relationship for both cancer and non-cancer effects from low to moderate chronic doses, if the feasibility is demonstrated. To achieve the overall objective it is proposed to set-up a consortium that have considerable experience in epidemiological studies on populations residing around the Semipalatinsk nuclear test site and/or who have been extensively involved in the low dose risk research. The group will include European and international scientists with expertise in epidemiology, dosimetry, radiation biology and clinical medicine. At the end of the project, a detailed report based on the results of the work conducted will be developed, critically reviewed by the External Advisory Board and recommendations for future research needs will be made, if feasible. Other populations exposed to low to moderate dose radiation like in Fukushima or elsewhere can benefit from the outcomes of studying the unique Semipalatinsk cohort and the results will contribute to a better understanding and quantification of radiation risks for low to moderate chronic doses. The proposed project is in line with the Strategic Research Agenda of MELODI.
Agency: Cordis | Branch: FP7 | Program: CP-CSA | Phase: Fission-2013-3.1.1 | Award Amount: 10.26M | Year: 2013
Within the OPERRA project, it is proposed that the MELODI Association, as a well-advanced network, takes the lead in establishing the necessary structures able to manage the long-term European research programmes in radiation protection, also taking advantage of the valuable experience gathered through the DoReMi network of excellence. Whilst in fields adjacent to low-dose risk research (radioecology, nuclear emergency management) scientific issues would continue to be hosted by the sister associations, Alliance and NERIS, these associations are encouraged to join MELODI to establish an umbrella structure as equal partners. OPERRA will exploit the synergies of EURATOM and other EC programmes considering the most relevant joint program areas and mechanisms for funding joint activities. The project will also strengthen the links with national funding programs as well as the European education and training structures. Also, it will take steps towards a greater involvement of those new Member States who could benefit from increased participation in the radiation research programmes. Finally, OPERRA will take steps to further integrate the joint use of infrastructures in European countries, and to develop and facilitate an easier access to research infrastructures. The final objective of this project is to build up an umbrella coordination structure that has the capacity in a legal and logistical sense to administer future calls for research in radiation protection as a whole (including low-dose risk, radioecology, nuclear emergency management, and also research activities related to the medical uses of ionizing radiation) on behalf of the European Commission. OPERRA will prepare the organisation for a first competitive call by the end of 2013 for projects in low-dose risk research and a second competitive call in 2014 for broader projects in radiation protection research, subject to the approval of EC services, with the support of Go-between administrator operator and an external advisory entity.