Public Employment Services (PES) in Europe are authorities that attempt to match supply and demand on the labor market. Rising unemployment in times of crisis and demographic change are among the main challenges with which PES practitioners, as a direct interface between jobseekers and employers, have to deal. They have to support career adaptability of their clients as well as to enhance and transform their own individual and collective professional identities in order to cope successfully with the challenges of a changing labor market. As part of the research project EmployID, we are exploring how to facilitate the learning process of PES practitioners in their professional identity development. The aim of the project is to empower individual PES practitioners, their community and organizations, to engage in transformative practices, using a holistic tool suite combining e-coaching, reflection, MOOCs, networking, analytical and learning support tools. Key to successful professional identity transformation is continuous learning. Individuals may take on the role of facilitators for the learning of others as well as being facilitated by peers, technology and environment.
Background
Advanced/innovative materials are an undefined group of nano- and micro-particles encompassing diverse material compositions, structures and combinations. Due to their unique properties that enable specific functions during applications, there are concerns about unexpected hazards to humans and the environment.
In this study, we provide ecotoxicity data for 36 nano- and microparticles of various inorganic species (single constituents and complex compositions; materials releasing toxic ions and others), morphologies (spheroidal, cubic, flaky, elongated/fibrous) and sizes (10 nm–38 µm). By applying Raphidocelis subcapitata algae growth inhibition and Daphnia magna immobilisation tests according to OECD test guidelines 201 and 202, and extensive material characterisation, we aimed to identify indicators of concern. This would allow better predictions of the hazardous properties of these materials in the future.
Results
The chemical identity (toxic ion-releasing materials vs. other materials) and agglomeration behaviour, which is affected by size (nm vs. µm) and morphology (fibres vs. others), were obvious drivers of ecotoxicity on R. subcapitata. Differences in morphology had an impact on agglomeration behaviour. Fibres formed agglomerates of varying sizes with entrapped and attached algae. Small compact (e.g. spheroidal) particles attached to algae. A high coverage resulted in high ecotoxicity, while less toxic materials attached to a much lesser extent. No agglomeration of algae and particles was observed for particles with a µm size. Small toxic components of large hybrid materials did not affect ecotoxicity. For D. magna, despite uptake of all materials studied into the gut, the sole indication of toxicity was the release of toxic ions. This is in line with previous observations on nanomaterials. Based on the identified criteria, charts were developed to indicate the expected toxicity of advanced/innovative materials toward algae and daphnia.
Conclusion
Indicators for the toxicities of advanced materials differ for algae and daphnia. Thus, different materials give rise to concerns for the two aquatic organisms. For D. magna, only the toxic ion-releasing materials are relevant, but for R. subcapitata, more complex interactions between particular materials and cells must be considered.
Graphical Abstract
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