Our work group focusses on emission, distribution and effect of contaminants in aquatic systems. Hereby sediments are of special importance for their property to accumulate contaminants over long time scales which is why they have been named “memory of lakes and rivers”.Most of our work regarding the emission and transport of contaminants that are bound to resuspended particles, centres around the Elbe River (Projekt Sed-Trans, Seitenstrukturen, DiPol, Klimzug-Nord) and mostly goes along with the development of conceptual models as a basis for an risk assessment. In an international perspective we tackled contamination problems in Africa and Asia (Morogoro: persticide application in Tansania, Riskcycle: Emissions of additives during e-waste-recycling in China).
In order to assess the effect of contaminants on organisms we apply a number of standardized ecotoxi- cological tests during which specific test organisms are exposed to environmental samples and moni- tored whether these samples lead to retardations in growth, reduction of fecundity, mobility, physiological activity etc. If an organism is negatively impacted by a water or sediment sample, this could indicate that this effect can also occur in the environment. By applying different test organisms in so-called biotest combinations, the different modes of action of contaminants, different exposure pathways, the effects of multiple stressors and the impact of not known or not chemically determined substances are examined (project “Sullied Sediments”).
In cooperation with the Technical Unversity Hamburg-Harburg, we developed an ecotoxicological classi-fication system for sediments, which allows a rapid evaluation and comparison of toxicity potentials in an area. The overall aim is to combine ecotoxicological data with chemical and biological data and come to an integrated assessment of environ-mental quality for a specific area. Internationally, these topics have been addressed by projects in Africa and Asia (projects “Morogoro” and “Riskcycle”).
For some “new” or “emerging” substances, such as rare earth elements and nano-titanium dioxide, relatively little is known about the impact that they may have on aquatic organisms. For that reason, we study the effects of these substances on test organisms under controlled laboratory conditions with the aim to gain more information on a potential risk that they may pose.