Sedimentology of plastics: state of the art and future directions

Plastic waste is now a ubiquitous sedimentary material, from the polar ice caps to the deep ocean. Determining the physical and chemical properties, transport pathways and accumulation sites of plastic particles is essential to characterize and mitigate the harmful effects of waste plastic on ecosystems and human health. This requires experimental, modelling and observational approaches across disciplines, including sedimentology, hydrology, chemistry, biology, materials science and many others. Plastic pollution is a deeply complex challenge, and this issue compiles how we may view solutions and understandings through a sedimentological lens. We cover a range of environments, from oceans to rivers and urban stormwater ponds, as well as global questions that consider plastic degradation amid climate change. In this preface, we outline key topics of the papers in this issue and the challenges and opportunities associated with each topic. The special issue illustrates the inherent value and strength of sedimentology as a tool to meaningfully advance our understanding of the transport, accumulation and degradation of plastic waste in the environment.This article is part of the Theo Murphy meeting issue 'Sedimentology of plastics: state of the art and future directions'.