Analysis, assessment and mapping of chemical mixture risks/footprints in European river basins  

Hundreds of chemicals can be found in water resources and soils in Europe and all over the world. We combine and apply consistent target screening approaches on LC-HRMS and GC-HRMS on different scales together with mixture risk assessment approaches based on existing and predicted (no)effect concentrations to determine chemical footprints. Footprint assessments compare measurable pollution translated to Toxic Units or other mixture effect metrics compared to the safe operating space where no major impacts are expected. 

Major recent achievements were chemical footprint mapping of a consistent set of 600 organic micropollutants at more than 400 sites in 22 European river basins (Finckh et al., 2024), the characterisation of chemical mixture risk drivers in European freshwaters (Schor et al., 2025), the screening and assessment of European wastewater treatment plant effluents for organic micropollutants (Finckh et al., 2022a) and endocrine disruptors (Finckh et al., 2022b) as a basis for the development of a reference mixture for wastewater (Beckers et al., 2023) and European scale assessment of the potential of advanced wastewater treatment (Pistocchi et al., 2022). EXPO also contributes to the advancement of mixture risk assessment in the regulatory context (Backhaus et al., 2025).

We coordinate basin to continental scale wastewater assessment projects in Joint Danube Survey (JDS5) and the European Partnership on Risk Assessment of Chemicals (PARC).