Road-related macrolitter input to mountain river: the case of the Kamienica Gorczańska stream in Polish Carpathians

Roads are identified by many researchers as important source of waste emissions into the environment [1][2]. Previous works on this topic have analysed spatial distribution of roadside dumping sites as well as composition and amounts of waste they contain [3][4][5]. Recent work has hypothesized that in the case of populated mountain regions, where roads are preferentially located within relatively flat valley bottoms, roads can be an important source of macrolitter to the fluvial system [6]. In this study, we investigate the scale of this phenomenon in the Kamienica Gorczańska catchment in the Polish Carpathians. During fieldwork conducted in 2023, we determined the amount and composition of macrolitter within 103 plots located along various types of roads in the floodplain area of the studied stream. We have distinguished two types roadside macrolitter emission: dispersed and point one. Within plots representing dispersed emission (74) 1759 macrolitter items were reported, including 845 (48.04%) plastic items. Furthermore glass litter had the largest share in the total weight of the colleted waste (56.3%). Moreover, we found that point sources of macrolitter emission (e.g., illegal dumping sites) are most often located along roads surrounded by forests within a distance of up to 100 m from the nearest buildings. Our results highlight the importance of road systems in delivering household waste to the fluvial systems of mountain rivers, suggesting that roadside areas should be more adequately addressed in future waste management strategies.

Keywords: road system, macroplastic, mountain stream, household waste, waste management, Kamienica Gorczańska stream

The study was completed within the scope of the Research Project 2020/39/D/ST10/01935 financed by the National Science Center of Poland