Anthropogenic lead concentrations and sources in Baltic Sea sediments based on lead isotopic composition

The Gulf of Gdansk is influenced by heavy metals of anthropogenic origin. In this study, temporal concentration changes of Pb, Zn, Cd, and Cu were studied in six, 50 cm long sediment cores. The main aim of the study was to concentrate on the history of Pb fluxes and Pb isotopic composition ((206)pb/(207)pb and Pb-208/Pb-206) to trace Pb sources. The lowest Pb concentrations (19 mu g g(-1)) were measured in sediments deposited circa 1860, while the highest Pb concentrations (63-147 mu g(-1)) were measured in sediments deposited between 1960s and 70s. Pre-industrial Pb fluxes were 7 Pb m(2) year(-1), while after WWII they reached 199 Pb m(2) year(-1). Highest Pb-206/Pb-207 ratios (similar to 1.22) were measured in the oldest sediment layers, and the lowest Pb-206/Pb-207 ratios (similar to 1.165) were measured in the sediments deposited in 1970s-90s. During the period of highest Pb contamination, the anthropogenic Pb fraction reached up to 93%. A general discussion of the Pb sources, emissions, and loads for Poland is included. (C) 2014 Elsevier Ltd. All rights reserved.