The semi-closed nature of the Baltic Sea together with sporadic replenishment of its water body from the basins of Kattegat and Skagerak, and the North Sea made this region highly sensetive for marine pollution. Iodine-129 has been accumulate in the Baltic Sea at concentrations much higher than the pre-atomic era natural level which calls for a systematic study of distribution patterns in this water body. We report here data on surface and deep water distribution of the isotope in the Baltic Sea and Skagerrak-Kattegat basins. Two sediment cores from the Baltic Sea were also measured for their I-129 content in the aim of estimating temporal migration since the introduction of the anthropogenic input to the region. Trend of I-129 in the water of Skagerrak-Kattegat shows persistently high concentrations in both the surface and deep waters. A decreasing trend in I-129 concentration is observed away from the Kattegat basin and into the Baltic Sea whereas higher concentrations are found in the deep water compared to surface water of the Baltic Sea. A strong correlation between salinity and I-129 occurs in the water samples examined. Distribution of the isotope in sediment cores seems to agree well with the start of discharges from Sellafield (in early fifties) and La Hague facilities (in mid sixties). Inventory calculation indicate that at least 95% of the isotope supply to the Baltic Sea is from the North Sea marine water and minor part is from riverine inflow and the Chernobyl accident.
See more of Poster Session I
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)