Amsterdam urban water system as entry point of river plastic pollution

Abstract

Accumulation of plastic litter in aquatic environments negatively impacts ecosystems and human livelihood. Urban areas are assumed to be the main source of plastic pollution in these environments because of high anthropogenic activity. Yet, the drivers of plastic emissions, abundance, and retention within these systems and subsequent transport to river systems are poorly understood. In this study, we demonstrate that urban water systems function as major contributors to river plastic pollution, and explore the potential driving factors contributing to the transport dynamics. Monthly visual counting of floating litter at six outlets of the Amsterdam water system results in an estimated 2.7 million items entering the closely connected IJ river annually, ranking it among the most polluting systems measured in the Netherlands and Europe. Subsequent analyses of environmental drivers (including rainfall, sunlight, wind speed, and tidal regimes) and litter flux showed very weak and insignificant correlations (r = $$-$$ - 0.19–0.16), implying additional investigation of potential drivers is required. High-frequency observations at various locations within the urban water system and advanced monitoring using novel technologies could be explored to harmonize and automate monitoring. Once litter type and abundance are well-defined with a clear origin, communication of the results with local communities and stakeholders could help co-develop solutions and stimulate behavioral change geared to reduce plastic pollution in urban environments.

Macroplastic fragmentation in rivers

“…It was also experimentally documented that microparticles formed via EPS and PS polymer fragmentation have smaller sizes than those released from PP and PET, with the largest formed from HDPE plastic (Boersma et al, 2023). Numerous riverine macroplastic waste items (e.g., cups, meat trays, plastic cutlery and straws, building insulation) are built from these fragmentation prone polymers (EPS, PS) (Plastic Europe 2021; Gonzalez-Fernandez et al, 2021;Tasseron et al, 2023). Gaining field-based information on their fragmentation rates seems to be especially important for our further understanding of the risks resulting from riverine macroplastic pollution.…”