Stock Photo - PRODUCTION - 23 September 2021, Hessen, Rüsselsheim: Microplastic particles have settled on a stainless steel membrane after filtration in the laboratory of the Institute of Environmental and Process Engineering at RheinMain University. The specific dangers posed by microplastics or the even smaller nanoplastics - that is currently still the subject of research. But it is already clear that particularly small particles can penetrate cells and trigger reactions there. These nanoparticles are found in cosmetics, for example. (to dpa ""Hessian scientists research microplastics"") Photo: Arne Dedert/dpa. - Rüsselsheim/Hessen/Germany