Levels of heavy metals in the tidal Elbe and its estuary and the heavy metal input into the sea

Abstract

Surface water samples were collected during missions in 1977, 1978, 1980 and 1983 at different sampling stations along the tidal Elbe, from river km 632 downstream from Hamburg to the outer end of the estuary. Special care was taken to minimize contamination during sampling, handling and analysis. Within the tidal Elbe five distinct zones of substantial anthropogenic heavy metal pollution inputs can be detected. An attempt is made to define anthropogenic background levels, which are extremely low for the dissolved trace metals Cd and Pb; 35 and 65 ng/kg, respectively. The level of dissolved Cu is 2200 ng/kg. Total baseline levels of Cd, Pb and Cu are, respectively, 120, 2500 and 4200 ng/kg. In the five river zones affected by anthropogenic trace metal inputs, distinctly larger maximum levels can occur. They decrease to the backgroud values after mixing with the main water body. More elevated levels caused by re-suspension in the mixing zone with maximum turbidity can be assumed. Nickel and Co data are from one mission only. The order of magnitude of the trace metal input from the Elbe into the sea is evaluated.