[en] We present seasonal results of ¹²⁹I in fresh-water lakes located in central Sweden, an area over which the amount of fallout deposition from the Chernobyl accident varied significantly (2-120 kBq/m² for ¹³⁷Cs). ¹²⁹I concentrations in the lakes ranged from 2.1 to 15.0x10⁸ atoms per liter and did not show elevated concentration in lakes located in regions of high Chernobyl fallout. Apparently, the studied region is strongly influenced by ¹²⁹I releases from the reprocessing facilities through precipitation. Desorption or resuspension of ¹²⁹I from soils and sediments does not seem to be an active process to increase the concentration of ¹²⁹I in the lakes

[en] Short communication

[en] In this study, we present a chemical extraction procedure and an evaluation of storage and pH effects on the ¹²⁹I concentration in water samples from a variety of hydrospheric reservoirs. Our data suggest that storage of samples does not cause a significant change of ¹²⁹I concentration whereas acidification of samples causes increase of ¹²⁹I concentration. A compilation of other AMS published data and ours on ¹²⁹I in the hydrosphere shows a wide range of variability

[en] We present weekly ⁷Be (from 1972 to 1995), and weekly/seasonal ¹⁰Be (for 1994) data in surface air from ground level stations in Sweden with a coverage of most of the northern high latitudes (56 deg. - 68 deg. N). Our Be data are regionally representative and reveal seasonal variation and coupling with tropospheric air mass from middle-low latitudes. The Be data also suggests a few percent, and sometimes episodic, incursion of stratospheric air mass. Frequent precipitation depletes the Be isotopes in the air, but cyclone events contribute to enrichments. A strong coherence between the ⁷Be record and short-term (monthly-seasonal) change in solar activity is observed which introduces a new mechanism for driving the amplitude of seasonal variation

[en] We present in this study a ¹⁰Be profile from a deep-sea sediment section extending to 3.5 Ma. The ¹⁰Be concentration ranges at 2-14x10⁸ atoms/g and shows a clear decay trend. The flux of ¹⁰Be ranges at 1-5x10⁶ atoms/cm² y and averages at ∼##2.5x10⁶ atoms/cm² y. Enhancements in the ¹⁰Be record occur at the paleomagnetic reversals and excursions suggesting strong effect of changes in the geomagnetic field intensity. Indication of climatic-related variability is also observed from the generally higher ¹⁰Be values during interglacial compared to glacial periods

[en] 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

No abstract available

No abstract available

[en] Data are presented here on the anthropogenic ¹²⁹I inventory in regions that have been strongly affected by releases from European reprocessing facilities which, to the authors' knowledge, presently account for >90% of the global isotope source in the Earth's surface environment. The results show that >90% of the isotope inventory occurs in marine waters with the Nordic Seas and Eurasian basin of the Arctic Ocean containing most of the ¹²⁹I. Within the terrestrial environment of Europe, soils contain the largest part of the isotope inventory. However, the inventory of the terrestrial system did not provide clues on the most plausible atmospheric source of ¹²⁹I to Europe, thus supply from both gaseous and marine releases is proposed. The sum of the total inventory in both the marine and terrestrial environments did not match the estimated releases. This imbalance is likely to relate to unconstrained inventory estimates for marine basins (Irish Sea, English Channel and North Sea) close to the facilities, but also to the occurrence of ¹²⁹I in the biosphere, and possible overestimated releases from the nuclear reprocessing facilities. There is no doubt that the available data on ¹²⁹I distribution in the environment are far from representative and further research is urgently needed to construct a comprehensive picture

[en] The performance of a gas-filled magnet combined with a gas ionization detector for measurements of ³⁶Cl was systematically studied at the Uppsala tandem laboratory. Our tests were conducted at a terminal voltage of 4.6 MV using gas-foil stripping and a 37 MeV ³⁶Cl⁺⁷ ion beam. An optimal suppression of the interfering isobar ³⁶S in the stand-alone gas-filled magnet (2 mbar N₂ gas pressure) was found to be ≥300, and an additional ≥300 times reduction was achieved by the E _residual signal of the two-anode gas ionization detector. The overall suppression in the order of ≥10⁵ permits analysis of samples with a sulfur content of ≤5 ppm and ³⁶Cl/Cl ratios of ≥10^-15. We have successfully measured samples with ³⁶Cl/Cl ratios in the range of 10^-12-10^-15 demonstrating the use of a medium-sized tandem accelerator system (∼1 MeV/amu) for ³⁶Cl AMS