Mapping mismanaged plastic waste in Indonesia: subdistrict-level analysis through material flow from sources to the environment

While Indonesia is a major contributor to global plastic pollution, national-level data obscures critical local hotspots where mismanagement is most severe. This study presents the comprehensive subdistrict level analysis of plastic waste flows across Indonesia to identify these hotspots and quantify their mismanagement pathways. Using a Material Flow Analysis (MFA) framework combined with Geographic Information Systems (GIS), we analyzed data from the Indonesia National Waste Management Information System (SIPSN), sampling and other governmental sources to model the fate of plastic waste. We estimate that 9.20 ± 1.52 million tonnes (Mt) of plastic waste are generated annually. This study focuses specifically on mismanaged plastic waste (MPW) that can potentially enter the environment and leak to waterways. While open burning is the largest single pathway (5.15 ± 0.68 Mt), this analysis concentrates on the 1.16 million tonnes that potentially leak into the environment. This includes 0.64 ± 0.11 Mt disposed directly into rivers and drains and 0.52 ± 0.09 Mt disposed illegally onto land. The analysis also reveals the critical role of the informal sector, which recovers four times more plastic than formal facilities (12% vs. 3%).