Microplastics in soils: identification, dynamics and transfer risks to other ecosystem compartments

One of the most prominent examples of pervasive pollution in the ‘Anthropocene’ era is that of the ubiquitous presence of plastics in the environment. As Earth’s largest plastics reservoir, soils form the bridge for microplastics (MP) transfer from sources of MP pollution to other ecosystem compartments (to atmosphere by wind erosion – to ground and surface water by leaching and run-off/erosion; to the terrestrial food chain through uptake by soil organisms and by plants), and fundamental knowledge on MP behaviour in soils is urgently needed for risk analysis and mitigation. In this project we will develop dedicated methodologies for the extraction and analysis of MP from soils, using a combination of original methods from soil organic matter research and novel techniques for microscopic visualization. We will also determine the location of the MP in the soil matrix, investigate the MP life time in soil through biological degradation experiments, and assess the risk of MP transfer from soil to groundwater, which is of great concern with respect to safeguarding drinkwater quality. Finally, we also have the ambition to visualize for the first time the tiniest plastics particles – nanoplastics – direcly in soil. This research will provide policy makers with the necessary knowledge to assess the risks associated with plastics pollution in soils, and may be the first step in including this in overall soil quality protection.