Effect-based monitoring of Danube river using mobile passive sampling approach

Surface waters are often polluted by complex mixtures of pollutants whose toxic properties are relatively difficult to describe. Effect-based monitoring with a battery of bioassays represents an efficient approach for toxicological profiling and identification of samples of major interest through providing data of the toxic potencies and mode of action of the extracted mixtures that cannot be evaluated by chemical analysis alone. In our work we used an “active” passive sampling system (APS) for temporally and spatially integrative sampling using silicone rubber and EMPORE disc based passive samplers, which efficiently preconcentrate a wide spectrum of polar and non-polar organic pollutants from the water column along a defined river stretch. This concept was employed during Joint Danube Survey 3 in summer 2013. Eight Danube river stretches were sampled to cover spatial distribution of the pollutants characterized through a set of bioassays investigating presence of contaminants with several non-specific and important specific toxic modes of action. Presence of contaminants with potentials for causing endocrine disruption (anti/estrogenic anti/androgenic), dioxin-like activities, potential to elicit adaptive stress responses associated with oxidative stress, p53-mediated apoptotic response and NF-κB-associated inflammatory response were characterized in samples from different river stretches. This wide range of assessed endpoints serves as a toxicological profiling tool to describe risks associated with fresh water pollutant mixtures. The obtained results also serve for spatial characterization of pollution gradients along the river and selecting hotspots for further studies. This research was supported by SOLUTIONS Project from the European Union Seventh Framework Programme (FP7-ENV-2013-two-stage Collaborative project) under grant agreement 603437