This report is a first step to address the environmental and human health risks associated with plastic litter and microplastics in the marine environment, from a biological, physical and chemical perspective. It provides a state-of-the-art overview of risks and exposure pathways due to plastics and microplastics, including particles in the nano size range, and an overview of existing or planned initiatives to identify synergies and avoid overlap. It critically examines current methods of risk assessment and makes some recommendations for improving risk assessment methods, including the potential for developing a risk assessment framework that can capture the complexity of the exposure pathways identified. Finally, it provides guidance to GESAMP on its future work programme with respect to assessing the risks from plastics and microplastics and to addressing some of the related concerns of the United Nations Environmental Assembly (UNEA)
