SREL Reprint #2785

129I in Swedish rivers: distribution and sources

A. Kekli1, A. Aldahan1, M. Meili2, G. Possnert3, N. Buraglio4, and R. Stepanauskas5

1Department of Earth Sciences, Uppsala University, Uppsala SE-752 36, Sweden
2lnstitute of Applied Environmental Research, Stockholm University, Stockholm SE-106 91, Sweden
3Tandem Laboratory, Uppsala University, Uppsala SE-751 21, Sweden
4Bain and Company Italy, Via Crocefisso 10, Milano 1-20122, Italy
5Department of Limnology/Ecology, Lund University, Ecology Building, Lund SE-223 62, Sweden;
Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29803, USA

Abstract: We analyzed the concentration of 129I in the water of 26 rivers covering most of the runoff from Sweden, with the aim of assessing current contamination levels, distribution patterns and potential sources in freshwater systems of northern Europe. The results show relatively high values (up to 1.4 X 109 atoms I-1), steeply decreasing levels with increasing latitude and a positive correlation with Cl concentration and other chemical parameters. The 129I concentrations observed in south Sweden are probably the highest ever recorded in rivers without any direct discharge from a nuclear installation. The strong latitudinal dependence suggests a northward dilution and possibly depletion of the isotope and a transport from a source located to the south. The most plausible source of the 129I in the studied rivers is atmospheric fallout of 129I emitted either by atmospheric discharges from the nuclear reprocessing facilities at Sellafield (England) and La Hague (France) or by volatilization from seawater contaminated by the same sources. The question is now whether and at what rate the 129I concentration in Nordic watersheds will increase further if discharges from nuclear reprocessing continue.

Keywords: Radioactive isotopes; Iodine-129; Rivers; AMS; Sweden

SREL Reprint #2785

Kekli, A., A. Aldahan, M. Meili, G. Possnert, N. Buraglio, and R. Stepanauskas. 2003. 129I in Swedish rivers: distribution and sources. The Science of Total Environment 309:161-172.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).