Half a century of mercury contamination in lake Vänern (Sweden)
2006 (English)In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 170, no 1-4, 285-300 p.Article in journal (Refereed) Published
Lake Vänern is Sweden's largest freshwater reservoir. It has been significantly affected by mercury contamination during the latter half of the 20th century. The aim of this study was to analyse the spatial and vertical mercury distribution, whereas 46 sediment cores were sampled in 2001 and analysed for total mercury. Several of these cores were dated presenting sediment accumulation rates varying from 6-8 mm yr-1 outside major rivers to ~2 mm yr-1 in the deeper areas. This was made using 137Cs, which was verified by 210Pb dating. Cluster analysis was used to identify five areas with similar accumulation and mercury concentration regimes. In areas far from shore, surface concentrations ranged from 0.1 to 0.5 ppm Hg, while the deeper layers in contaminated areas held concentrations up to 11 ppm Hg. In total, ~50 tonnes of mercury accumulated in the lake's sediment between ~1940-2001, almost 80% (or 37 tonnes) originate from before the mid 70's when the recovery period began, and at least 30 tonnes can be attributed to the former point source - a chlor-alkali industry. © Springer 2006.
Place, publisher, year, edition, pages
2006. Vol. 170, no 1-4, 285-300 p.
137Cs, Cluster analysis, Lake Vänern, Mercury accumulation, Sediment
IdentifiersURN: urn:nbn:se:liu:diva-50306DOI: 10.1007/s11270-006-3121-0OAI: oai:DiVA.org:liu-50306DiVA: diva2:271202