A novel approach to characterizing plastic waste releases from land-based sources using material flow analysis: The case of Thailand

Similar to many countries around the world, Thailand is faced with a significant plastic waste (PW) crisis. In 2018, the country announced a new roadmap for PW management which includes an aim to ban PW imports by 2025 and achieve 100% PW recycling by 2027. This study adapts, modifies and applies a methodology developed by the Basel Convention (BC) in evaluating PW releases from land-based sources in Thailand for the year 2023. The BC methodology is improved by incorporating new flows not previously accounted for. STAN 2.7, the software for material flow analysis is used to validate the results. The outputs are comparable, with a variation below 10%. The study shows that Thailand generates 4.4 million tonnes of PW annually, 27% of which leaks into the environment from the country's waste management system (WMS). Waste collection activities contribute to significant (11%) PW leakages, whereas activities linked to waste transportation, sorting and recycling present the least of Thailand's PW leakages. Leakages from uncontrolled landfill sites (836,861 tonnes) and controlled landfill sites (163,861 tonnes) constitute 85% of the PW losses from the WMS prompting the need to improve infrastructure for the safe disposal of residual wastes in the country. These results buttress calls for Thailand's Local Administrative Organizations to fast-track a transition to economic circularity in the waste sector. Furthermore, the baseline data produced can be used in developing targeted management interventions. The methodology can be used to develop PW national inventories where resources to conduct in-depth field studies are limited.