History of heavy metal accumulation in the Svalbard area: Distribution, origin and transport pathways

Abstract

In this study temporal changes of Pb, Zn, Cd and Cu concentrations were studied in 19 dated sediment cores collected from Svalbard fjords and the Barents Sea. The main aim was to study spatial and historical variations in heavy metal concentrations, deposition rates and sources in the context of different metal transport pathways. Metal concentrations ranged from 5.7 to 45.8 mg kg^-1 for Pb, from 13.4 to 54.5 mg kg^-1 for Cu, from 0.01 to 0.90 mg kg^-1 for Cd and from 55.6 to 130.4 mg kg^-1 for Zn. Some fjords were unpolluted by heavy metals while in others a clear signal of metal enrichment was found (outer Kongsfjorden, Hornsund, Adventfjorden). Large-scale processes such as atmospheric and oceanic transport were found to be important drivers of heavy metal contaminant distribution. The significance of global drivers varied among the fjords, due to coupling with local processes. Outer fjord parts, the most impacted by oceanic transport, were characterized by the excess ²⁰⁶Pb/²⁰⁷Pb values of ∼1.17, while the inner basins were characterized by the excess ²⁰⁶Pb/²⁰⁷Pb of ∼1.14 suggesting possible different importance of Pb sources (marine currents and atmospheric transport).