A study by the University of Tübingen first investigated, which pharmaceuticals cause a special environmental risk and which organisms are very sensitive to this substances. On that basis the researchers want to develop cell based methods for two active substances from the group of painkillers and the group of beta blockers. These substances which are very often found in surface waters cause harmful effects in laboratory test with aquatic organisms such as fish and water fleas. In field experiments, the researchers want to determine if their cell systems are suitable. They also want to investigate whether effects found in the laboratory occur under real environmental conditions as well. This so-called effect monitoring could help to identify environmental risks of pharmaceuticals after their approval and to derive need for action e.g. for wastewater treatment.