The crisis ignited by COVID-19 has transformed the volume and composition of waste generation and requires a dynamic response from policy makers. This study selected Bangkok as a case study to semi-quantitatively examine the impact of the COVID-19 outbreak on consumer-generated food and plastic waste by examining changes in lifestyles and consumption behaviour through a face-to-face questionnaire survey. Travel bans and diminished economic activity due to COVID-19 have led to a dramatic reduction in waste from the business sector and in the total amount of municipal waste generated. However, the results of the survey showed that both food and plastic waste generated by households in Bangkok increased during COVID-19. The shift from eating out to online food delivery services led to an increase in plastic bags, hot-and-cold food bags, plastic food containers, and food waste. Reasons for the increase in household food waste during COVID-19 varied, with respondents citing excessive amounts of food and unappetising taste, followed by exceeding the expiration date and rotting/foul odours. These reasons may be the result of the inability to predict quantity and quality when ordering online, and inadequate food planning and management by consumers. To achieve more effective food and plastic waste management, home delivery services, consumer food planning and management, and the formation of a circular economy based on localised supply chains may be considered as important intervention points.

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.

Plastic pollution is a critical issue in rapidly developing cities. A nuanced understanding of consumer behavior related to single-use plastic (SUP) usage is therefore essential for effective interventions, in light of the global plastic treaty. This study conducts a survey of 1,492 participants across five Asian cities to analyze SUP consumption and disposal patterns amid the post-COVID “new normal”. Results reveal significant inter-city differences: Shanghai and Harbin demonstrate high overall SUP usage despite lower consumption of plastic shopping bags; Hanoi and Depok exhibit lower total consumption but distinct product preferences, such as elevated use of plastic shopping bags and party cups; and Phnom Penh recorded the highest consumption of plastic shopping bags, bottles, and straws. Plastic shopping bags were the most used item in all cities, ranging from 18 to 34 bags weekly, with no significant differences by urban versus rural areas, age, or gender. Conversely, urban areas showed higher usage of plastic take out containers, cutlery, coffee cups, and party cups. The COVID-19 pandemic has notably reshaped SUP consumption trends. Moreover, over half of SUPs were disposed of without proper separation. These findings underscore that reducing SUPs requires flexible, phased, and region-specific interventions to build a resilient circular economy.