Micropollutants (e.g. drugs, detergents, solvents, and many others) in lakes and rivers are an important environmental and public health concern. Using Lake Geneva as a model system, this project will focus on three central issues: Understanding the risks associated with antibiotic resistance, improving ecotoxicological risk assessment tools for micropollutant mixtures acting on the complex species assemblages in the lake, and assessing the impact of high pollutant concentrations on the composition and activity of microbes in lake sediments.
The largest freshwater reservoir in Western Europe, Lake Geneva exemplifies several key challenges for sustainable freshwater management during the next century. Increasing population will heighten drinking water demands and pressure on waste-water treatment. The project is organized in three subprojects: Antibiotic resistance: The increase of antibiotic resistance in pathogens is a worldwide phenomenon and a grave public health issue. Little is known about the effect of antibiotics and resistant bacteria released into the wastewater stream and natural aquatic ecosystems or the possibility of spreading antibiotic resistance within natural populations. Here we want to study this issue along the path from hotspots (e.g. hospital sewage) through wastewater treatment plants to the lake.Ecotoxicological effects of compound mixtures: Micropollutants occur in complex mixtures and affect complex natural assemblages of aquatic species in a lake. This subproject aims to assess the aquatic risk of the several micropollutants detected in Lake Geneva. Risk assessment approaches combine information on exposure to chemicals with information on the effects of these chemicals. We will base our developments on the most recent method proposed for effect evaluation, i.e. the species sensitivity distribution (SSD), a statistical function describing the variation in toxicity of a certain compound among a set of species.Metal and antibiotics in the sediment: effects and risks: A third sub-project will investigate heavy metals and bacterial antibiotic resistance in sediment: how does heavy metal contamination shape microbial communities, what is the role of sediment as a reservoir of antibiotic resistance and heavy metals, and what are associated risks?
The project aims to advance our understanding of the problems outlined above using microbiological, molecular, and chemical methods together with modeling approaches. With this information we aim to provide the groundwork for improved management and risk awareness associated with one of our most important natural resources, the lakes.