Department Environmental Toxicology

The guidelines of the WHO list only four substances produced by cyanobacteria. This is a small fraction of all the metabolites that can have ecotoxicological effects.

This can indirectly affect the survival of fish populations and may be one of the reasons for the fish decline we are currently observing in Switzerland.

Work is currently underway in Montreal at the UN Biodiversity Conference (COP 15) to negotiate a framework agreement to preserve biodiversity. In addition to pesticides, nutrients and plastic waste, certain other chemicals ought to be restricted in their production and use, or replaced by less problematic substances, according to a recommendation by a group of scientists, including an environmental toxicologist from Eawag.

Together with the Canton of St. Gallen, Eawag has been investigating the impact of the expansion of the wastewater treatment plant at Flawil to include a stage for the removal of micropollutants on water quality in the River Glatt. Initial results now show a very positive picture.

Scientists from Eawag, along with researchers from the former Eawag spin-off aQuatox-Solutions and the National Institute of Biology in Slovenia, have won almost 800,000 Swiss francs in the second phase of a contest run by the British Centre for the Replacement of Animals in Research.

The smallest of all plastic particles have remained largely unexplored until now, because they could not be detected in the environment. Now researchers at Eawag show: Nanoplastics stick to slimy biofilms, which can for example be found on stones in streams or rivers. When freshwater snails feed on the slime, the nanoplastics are taken up.

As part of a new national research programme that aims to replace animal experiments in research, the National Science Foundation is supporting a project at Eawag. This opens up new possibilities for determining the toxicity of chemical substances based solely on tests with cultured cells and computer models. Animal experiments could thus be replaced.

Ozonation is an established treatment process to remove micropollutants from wastewater. However, since unstable toxic reaction products can be formed in the process, biological post-treatment is necessary. Results from the Ecotox Centre and Eawag show how well different post-treatment methods reduce ecotoxicological effects. The combination of ozonation and activated carbon proved to be the most effective.

Eawag researchers are using computer algorithms to predict the toxicity of chemicals to fish. Machine learning can help set priorities for experiments and, in the longer term, enable a tremendous reduction of animal testing.

Eawag researchers have won a competition organised by Britain’s National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3R). The prize money is awarded for use in research to develop technologies to replace animal testing.

With around 200 pictures and texts, the new Water Timeline takes you through 200 years of the eventful history of Swiss water protection. It aims to show how shifts towards more sustainable management of natural resources can be shaped. 

Microplastics, owing to their chemical properties, can carry micropollutants into a fish’s digestive system where they are subsequently released through the action of its gastric and intestinal fluids. Scientists of EPFL and Eawag, working in association with other research institutes, have studied this process by looking specifically at progesterone – often pointed to as an endocrine disrupter.

The "gene scissors" CRISPR/Cas9 can be used to precisely modify genes in order to study their function in an organism. A researcher at Eawag has now succeeded for the first time in establishing the gene scissors for a fish cell line of rainbow trout. This means that, as of now, genetically modified cell lines can be produced. These allow alternatives to ecotoxicological tests on living animals.

Toxic substances in the environment can harm the nervous system of fish embryos. Now, researchers at Eawag have developed a computer model that helps to better understand how the damage occurs.

The OECD gives the green light to the fish cell line assay developed at Eawag. This paves the way for companies and authorities around the world to determine the environmental toxicology of chemicals without having to resort to animal testing.

Ecotoxicological tests need to be extremely accurate – which often poses challenges in research and practice. Eawag has now developed a computer model that enables even more accurate testing at high throughput; the model is simple, widely applicable and saves resources.