HEAVY-METAL CHRONOLOGIES IN SELECTED COASTAL WETLANDS FROM NORTHERN EUROPE

Sediment cores were collected from five coastal wetlands in England, t he Netherlands, and Poland, and samples analysed for heavy metal conce ntrations. Depth profiles of metal concentrations were converted to ti me-based profiles, using vertical accretion rates obtained from Cs-137 dating. Chronologies of metal concentrations from the two cores (high and low marsh) at each site showed good agreement, indicating that se diment profiles represent historical inputs of metals. Sediment metal concentrations showed that some of the areas are highly polluted, with peak sediment concentrations up to five times greater than in the old est sediment samples (1890s to 1900s). Chronologies indicated differen t pollution histories for the five areas. Local hydrology appeared to be important in affecting metal accumulation. Metal concentrations hav e recently decreased in the cores from St. Annaland Marsh (the Netherl ands) and Stiffkey Marsh (UK), Levels of metals from the Oder River re mained high throughout the upper part of the cores. (C) 1998 Elsevier Science Ltd. All rights reserved.