title: History of bioavailable lead and iron in the Greater North Sea and Iceland during the last millennium - a bivalve sclerochronological reconstruction.
abstract: 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.
authors.affiliation: Institute of Geosciences, University of Mainz, Johann-Joachim-Becher-Weg 21, 55128 Mainz, Germany.
authors.forename: Hilmar A
authors.initials: HA
authors.lastname: Holland
authors.affiliation: Institute of Geosciences, University of Mainz, Johann-Joachim-Becher-Weg 21, 55128 Mainz, Germany.
authors.forename: Bernd R
authors.initials: BR
authors.lastname: Schöne
authors.affiliation: Institute of Geosciences, University of Mainz, Johann-Joachim-Becher-Weg 21, 55128 Mainz, Germany.
authors.forename: Soraya
authors.initials: S
authors.lastname: Marali
authors.affiliation: Max Planck Institute for Chemistry, P.O. Box 3060, 55020 Mainz, Germany.
authors.forename: Klaus P
authors.initials: KP
authors.lastname: Jochum
mesh_terms: D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D004784:Environmental Monitoring / Q000379:methods; D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D049691:History, Medieval; D007055:Iceland; D007501:Iron / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D009659:North Sea; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000266:history*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D007854:Lead; D007501:Iron
keywords: Anthropogenic pollution; Eutrophication; Iron; Lead; Redox potential; Retrospective environmental biomonitoring