Concentrations of 129I along a transect from the North Atlantic to the Baltic Sea
ABSTRACT Large amounts of iodine-129 were, and still are, released to the environment from nuclear facilities, in particular from two reprocessing facilities located at the east coast of the North Atlantic Ocean (Sellafield and La Hague). The main transport path of the releases from the two facilities is towards Northern Europe and further into the Arctic Ocean. Here we present data of 129I concentrations observed along a transect from the Baltic Sea to the North Atlantic in 1999. Concentration of 129I in surface water samples are several orders of magnitude higher than the natural background level, with the highest enrichment found in the Skagerrak basin. Three profiles taken in the Baltic Sea show an increase of 129I with depth. Preliminary inventory calculations suggest that the major source of 129I in the Baltic Sea is via marine input from the North Sea. So far concentrations of this isotope do not constitute a source of environmental hazard.
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ABSTRACT: Concentrations and species of iodine isotopes ((127)I and (129)I) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic (129)I in the Arctic Ocean and the Nordic Seas, concentrations of the isotope in the Atlantic Ocean are, however, still unknown. We here present first data on (129)I and (127)I, and their species (iodide and iodate) in surface water transect along the northeastern Atlantic between 30° and 50°N. The results show iodate as the predominant species in the analyzed marine waters for both (127)I and (129)I. Despite the rather constant ratios of (127)I(-)/(127)IO3(-), the (129)I(-)/(129)IO3(-) values reveal variations that apparently response to sources, environmental conditions and residence time. These findings provide a new tracer approach that will strongly enhance the application of anthropogenic (129)I in ocean environments and impact on climate at the ocean boundary layer.Scientific Reports 11/2013; 3:2685. · 5.08 Impact Factor
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ABSTRACT: The Bothnian Sea which is located between Finland and Sweden represents an important source of fresh water to the Baltic Sea. We here present new data on the radioactive isotope 129I species from water samples collected in December 2009 at different depths in the Bothnian Sea. Concentrations of 129I− (iodide) in the Bothnian Sea range from 14 × 108 to 32 × 108 atoms/L, while 129IO3− (iodate) concentrations are relatively low and fluctuating at 1 × 108 atoms/L. For nutrients data determined in the same samples as 129I, significant correlations could be found between 129I− and total P, NO3–N, SiO3–Si, but rather poor with NH4–N. The correlations suggest comparable source pathway of 129I− and nutrient parameters, while the source of NH4–N may be different. The small amounts and negligible change of 129IO3− indicate prevailing extensive reduction of iodate in the Baltic Sea.Journal of Radioanalytical and Nuclear Chemistry 02/2012; 295(2). · 1.42 Impact Factor
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ABSTRACT: A quantitative evaluation of the fate of (129)I, released from the European reprocessing plants of Sellafield (UK) and La Hague (France), has been made by means of a Lagrangian dispersion model. Transport of radionuclides to the Arctic Ocean has been determined. Thus, 5.1 and 16.6TBq of (129)I have been introduced in the Arctic from Sellafield and La Hague respectively from 1966 to 2012. These figures represent, respectively, 48% and 55% of the cumulative discharge to that time. Inventories in the North Atlantic, including shelf seas, are 4.4 and 13.8TBq coming from Sellafield and La Hague respectively. These figures are significantly different from previous estimations based on field data. The distribution of these inventories among several shelf seas and regions has been evaluated as well. Mean ages of tracers have been finally obtained, making use of the age-averaging hypothesis. It has been found that mean ages for Sellafield releases are about 3.5year larger than for La Hague releases. Copyright © 2014 Elsevier Ltd. All rights reserved.Marine Pollution Bulletin 12/2014; · 2.79 Impact Factor