Regional Insights on the Usage of Single-Use Plastics and Their Disposal in Five Asian Cities

Single-use plastics (SUPs) are deeply embedded in everyday consumption in rapidly developing Asian cities, yet their widespread use contributes to marine debris, microplastic pollution, and health risks. This study aimed to inform evidence-based policymaking to mitigate marine plastic pollution in the ASEAN+3 region. Stratified random sampling surveys (n = 1492) were conducted both face to face and online across five representative cities between September 2022 and February 2023. We quantified and compared the consumption and disposal patterns across nine SUP categories, assessed demographic influences, evaluated the impact of COVID-19, and derived insights for targeted policy interventions. Non-parametric tests were used to evaluate the differences. The results reveal significant inter-city variation: Shanghai and Harbin reported high overall SUP use despite a lower consumption of plastic shopping bags; Hanoi and Depok showed lower overall use but distinct preferences for plastic shopping bags and party cups; and Phnom Penh had the highest consumption of plastic shopping bags, bottles, and straws. Plastic shopping bags were the most used item in all cities (18–34 bags per week), with no significant differences between urban and rural areas, ages, or genders. In contrast, urban residents reported a higher use of plastic takeout containers, cutlery, coffee cups, and party cups. The COVID-19 pandemic notably reshaped SUP consumption patterns. Additionally, over half of SUPs were disposed of without proper separation. These findings underscore the need for flexible, phased, and context-specific interventions to support a resilient circular economy.