Plastic trade and its plastic waste footprint of Lancang–Mekong River Basin countries: An analysis based on inter-country input-output tables

: One of the key issues around inter-government negotiation on Resolution on Ending Plastic Pollution , initiated by the United Nations Environment Program, is the divergence between producers and consumers in the plastic supply chain. Uncovering the international trade network of plastics is essential to design the extended producer responsibility (EPR) and environmental-burden sharing mechanism for promoting international cooperation in co-mitigating plastic pollution; however, regional-focused cases with robust datasets around the production, consumption, and waste management of cross-country plastic flows remain unexplored. In this work, the Lancang–Mekong River Basin (LMRB) countries, one of the hotspots for plastic waste leakage in the world, were chosen as the studied case to reveal the complex plastic flows from 1995 to 2020 by leveraging harmonized input-output datasets. We found that inter-LMRB transfers of plastic-containing goods increased by 67.5-fold and associated plastic waste increased by 48.2-fold, driven by expanding production and export in China, Thailand, and Vietnam. In contrast, Laos, Cambodia, and Myanmar became increasingly dependent on imported plastic-containing goods, with imported and consumed goods generating 94.9% and 65.7% of national plastic waste in Laos and Cambodia, respectively, in 2020. The mismanaged plastic waste footprint attributed to imported plastic-containing goods reached 5.16 kg/cap across the basin, dominated by packaging and electronic products, highlighting the demand of international cooperation on controlling environmental leakage from import-driven waste. This research reveals long-overlooked transboundary waste flows, providing a scientific basis for designing and implementing EPR models for controlling plastic pollution in the LMRB.