Spatial distribution of microplastics in the fluvial sediments of a transboundary river – A case study of the Tisza River in Central Europe

The geographical environment fundamentally influences the transport and deposition of sediments, including microplastics. In addition, socioeconomic differences inherent in transboundary catchments result various waste management strategies among different countries influencing input microplastics into rivers. catchment Tisza River Central Europe is shared by five with economic statuses wastewater treatment practices. aim this research to study spatial changes microplastic debris along its main tributaries. mean number particles sediments was 3177 ± 1970 items/kg, while 3808 1605 items/kg were counted Most fibres, indicating dominance municipal input; especially case upstream sub-catchments, where there are low degrees management. highest amount found most-upstream section, a households connected plants. Thus, it hypothesized that suburban areas high population densities improper co-exist may contribute direct river systems development local contamination hotspots. concentration measured at furthest downstream resulting from decreased flow velocity related impoundment dam. efficiency trapping depositionary forms varies river, suggesting factors complexity process. higher observed tributaries compared stream reflect importance sources source-to-sink relations for routes through fluvial system; these processes do not always progressive increases. • Country-scale source sink areas. highly contaminated Tributaries large amounts river. Microplastic form. Impoundment increases content sediments.