In collaboration with the research teams of Prof. Manu Soto and Prof. Txema Becerril from the University of the Basque Country, we have just started a project on the impact of the application of sewage sludge on soil health. In this project, we pay special attention to the ecotoxicological consequences of such application, using different end-points from microbial, plant and animal species. The project is carried out in a site located in the Basque Country.