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Centennial records of lead contamination in northern Atlantic bivalves (Arctica islandica) Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R.
Centennial records of lead contamination in northern Atlantic bivalves (Arctica islandica) Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R.
In the study, we establish centennial records of anthropogenic lead pollution at different locations in the North Atlantic (Iceland, USA, and Europe) by means of lead deposited in shells of the long-lived bivalve Arctica islandica. Due to local oceanographic and geological conditions we conclude that the lead concentrations in the Icelandic shell reflect natural influxes of lead into Icelandic waters. In comparison, the lead profile of the US shell is clearly driven by anthropogenic lead emissions transported from the continent to the ocean by westerly surface winds. Lead concentrations in the European North Sea shell, in contrast, are dominantly driven by local lead sources resulting in a much less conspicuous 1970s gasoline lead peak. In conclusion, the lead profiles of the three shells are driven by different influxes of lead, and yet, all support the applicability of Pb/Ca analyses of A. islandica shells to reconstruct location specific anthropogenic lead pollution.
Afficher plus [+] Moins [-](Fig. 5.4) Profile of Lead/Calcium ratios of an Arctica islandica shell collected in the North Sea near Helgoland, Germany Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R
Lead/Calcium profiles in the common time window 1770-2010 of the three Arctica islandica shells Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R
In the study, we establish centennial records of anthropogenic lead pollution at different locations in the North Atlantic (Iceland, USA, and Europe) by means of lead deposited in shells of the long-lived bivalve Arctica islandica. Due to local oceanographic and geological conditions we conclude that the lead concentrations in the Icelandic shell reflect natural influxes of lead into Icelandic waters. In comparison, the lead profile of the US shell is clearly driven by anthropogenic lead emissions transported from the continent to the ocean by westerly surface winds. Lead concentrations in the European North Sea shell, in contrast, are dominantly driven by local lead sources resulting in a much less conspicuous 1970s gasoline lead peak. In conclusion, the lead profiles of the three shells are driven by different influxes of lead, and yet, all support the applicability of Pb/Ca analyses of A. islandica shells to reconstruct location specific anthropogenic lead pollution.
Afficher plus [+] Moins [-]Centennial records of lead contamination in northern Atlantic bivalves (Arctica islandica)
(Fig. 5.2) Profile of Lead/Calcium ratios of an Arctica islandica shell collected off the coast of Northeast Iceland Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R
(Fig. 5.3) Profile of Lead/Calcium ratios of an Arctica islandica shell collected off the coast of Virginia, USA Texte intégral
2012
Krause-Nehring, Jacqueline | Brey, Thomas | Thorrold, Simon R
History of bioavailable lead and iron in the Greater North Sea and Iceland during the last millennium – A bivalve sclerochronological reconstruction Texte intégral
2014
Holland, Hilmar A. | Schöne, Bernd R. | Marali, Soraya | Jochum, Klaus P.
We present the first annually resolved record of biologically available Pb and Fe in the Greater North Sea and Iceland during 1040–2004 AD based on shells of the long-lived marine bivalve Arctica islandica. The iron content in pre-industrial shells from the North Sea largely remained below the detection limit. Only since 1830, shell Fe levels rose gradually reflecting the combined effect of increased terrestrial runoff of iron-bearing sediments and eutrophication. Although the lead gasoline peak of the 20th century was well recorded by the shells, bivalves that lived during the medieval heyday of metallurgy showed four-fold higher shell Pb levels than modern specimens. Presumably, pre-industrial bivalves were offered larger proportions of resuspended (Pb-enriched) organics, whereas modern specimens receive fresh increased amounts of (Pb-depleted) phytoplankton. As expected, metal loads in the shells from Iceland were much lower. Our study confirms that bivalve shells provide a powerful tool for retrospective environmental biomonitoring.
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