Rivers acts as a pathway for mismanaged waste to reach the sea. Results of the monitoring in the Fiumicino canal (Tiber river-Italy), estimated that 85.4 (± 9.4) litter items get into the sea each hour, with approximately 30% of which were already fragmented. Within the Medsealitter project, a surface density at the river mouth of approximately 1,270 litter items >2.5 cm and 190 litter items >20 cm per km2 was extrapolated. The percentage of the materials found is the following: Artificial polymer materials 82%; Cloth/Textiles 1%; Metal 3%; Paper/Cardboard 8%; Processed/worked wood 1%; Rubber 5%. Study reference: "Down to the river: amount, composition, and economic sector of litter entering the marine compartment, through the Tiber river in the Western Mediterranean Sea." (DOI: 10.1007/s12210-018-0747-y). Rendiconti Lincei. Scienze Fisiche e Naturali