| Summary: | The Arctic is recognized as an important focus for long-range transport of contaminants, such as mercury(Hg), from industrial regions at lower latitudes. in addition to large geographic gaps, there a re few long-term retrospective time trends in arctic research, besides the Greenland ice record, to assess the onset of atmospheric pollution as well as to establish the rates of change in the terrestrial environment. In a study of sediments from 21 lakes along a 150 km transect from the coast to the ice sheet margin in the Sondre Stromfjord (Kangerlussuaq) region, we p resent stratigraphic evidence for elevated Hg inputs to this ice-free region on Greenland's west coast. Nineteen study lakes showed Hg concentration enrichments (HgEFconc) in surface compared to deeper sediments, with a mean HgEFconc of 3. Higher HgEFconc are found in lakes closest to the ice margin. The existence of this Hg gradient is supported by pollution Hg inventories in three Pb-210-dated cores. While Pb-210 inventories and Ph pollution are higher at the coast, pollution Hg inventories are nearly 3-fold higher at the ice margin (570 mug m(-2)) than at the coast (210 mug m(-2)). These dated cores also indicate an onset of Hg pollution in the region beginning at least by the late 19th century but possibly as early as the 17th century.
|
|---|