ABSTRACT
ABSTRACT: The behaviour and effects of xenobiotics in urban water systems are not well known. Xenobiotics include pharmaceuticals, fragrances and endocrine disruptors, and there are numerous ways they can enter the environment and the human food chain. Field investigations and modelling of the xenobiotics in urban areas are presented that demonstrate their mobility as well as their potential impacts on human health and ecosystems. Using indicators for anthropogenic impacts on water resources such as Bisphenol A and t-Nonylphenol (endocrine disruptors), Carbamacepine (antiepileptic drug), Galaxolide and Tonalide (fragrances), 34S-sulphate and 15N-nitrate (stable isotopes), and Gadolinium (rare earth element), investigations of the pathways and the behaviour of the substances in the environment have been carried out. In the city of Halle an der Saale in Germany, remarkably high concentrations of the indicators were found in rivers and in groundwater. Using 34S-sulphate and 15N-nitrate analyses, the movement of groundwater to surface water and various sources of nitrate have been investigated. Evidence for the degradation of xenobiotics was found. Based on the measurements, a water balance and mass flux rates were determined for rivers in the city. The calculation of mass loads shows increasing values of Galaxolide, Tonalide and Bisphenol A, Carbamacepine and t-Nonylphenol, is stable or decreases during passage through the city.
