Plastic particles are everywhere in the environment and there is concern about the adverse effects they may have on organisms, and subsequently on ecosystems Much global attention has been directed towards so-called microplastics, ie plastic particles with dimensions in the millimeter to micrometer range Microplastics slowly degrade in the environment, by physical and chemical processes, into smaller and smaller entities, eventually reaching the nano-size domain Due to difficulties in sampling and characterisation, almost nothing is known about the amounts and behaviour of extremely small plastic particles with dimensions on the order of nanometers, ie nanoplastics Our project addresses this knowledge gap We will measure and model the chemical reactivity, biouptake, and bioaccumulation of nanoplastics and their adverse effects on aquatic organisms The results will provide fundamental information which enable robust risk assessment strategies to be developed that inform environmental policies