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Historical pollution of seldom monitored trace elements in Sweden—Part B: Sediment analysis of silver, antimony, thallium and indium

2006; Royal Society of Chemistry; Volume: 8; Issue: 7 Linguagem: Inglês

10.1039/b601948j

1464-0333

Evastina Grahn, Stefan Karlsson, Ulrika Karlsson, Anders Düker,

Heavy metals in environment

Sediment cores from four boreal and remote lakes in a south to north transect in central Sweden were analysed for acid leachable silver, antimony, thallium and indium in the solid sediment phase and the corresponding porewater. Dating of the cores was made by their content of acid leachable lead and the 206Pb/207Pb ratio, in one lake also by 210Pb. The impact of diagenesis on element redistribution in the sediments was included and found to be minor except for thallium. The results show lowered concentrations towards the north and most intense accumulation after the Second World War, which is taken as evidence for atmospheric deposition being the primary source. Indium has declining concentrations in recent strata while silver and antimony increase. Thallium has lowered acid-leachable concentrations in recent strata. For all metals the impact of domestic industrialisation as well as the early industrialisation of central Europe is discernible. Only thallium appears to reach a geological background at depths that correspond to the late 18th century. For the other metals elevated levels are concluded.