Even tiny amounts of toxins in rivers and lakes can endanger aquatic organisms. The public has become more aware of this environmental problem in recent years. Trace amounts of toxins found in our waterways are included in many of the things we use every day – dishwasher tablets, washing powder and shower gel – as well as pharmaceuticals, cosmetics, and pesticides. These substances are in household wastewater and are transported to wastewater treatment plants, where conventional techniques cannot completely remove or degrade them. The treated wastewater flows into our streams, taking the toxins with it. A group of researchers headed by the University of Tübingen’s Professor Rita Triebskorn has been investigating the effects of various wastewater treatments on the health of fish. The scientists, from the Institute of Evolution and Ecology (EvE), found that the type of wastewater treatment needs to be decided on a case by case basis, depending on the composition of toxins in the wastewater. Their study has been published in the journal Environmental Sciences Europe.