The growing problem of plastic waste has become a call to ASEAN member states to develop and implement national action plans. In this study, a mechanism for applying national action plans to address plastic waste was applied to plastic leakage monitoring. Focusing on Myanmar’s action plans, we developed a comprehensive methodology that focuses on maximizing monitoring to fill gaps in national action plan implementation. This study implemented waste management assessment using the Waste Flow Diagram (WFD) tool, which established the initial framework for monitoring plastic waste status in cities. This assessment was also supported by field surveys using a mobile application (app) for getting an overview of microplastics and consulting stakeholders. We processed the results through Geographic Information System (GIS) analysis to calculate the amount of plastic leaking into the open environment. From our first assessment, we found more than 5,000 tons of plastic waste had possibly leaked from 33 townships in Yangon and, judging from an accumulation survey, that most of the municipal solid waste handled in this city was subjected to open dumping practices. The challenges addressed here emphasize cultivation of different sectors of waste management stakeholders and engagement with informal sectors.

Disaster waste is defined as the waste generated as a result of natural disasters. Not only are meteorological disasters becoming more severe and frequent due to climate change, but urbanization and population growth in Asia are also increasing the damage caused by natural disasters. Once a natural disaster happens, a huge amount of waste is generated, so guidelines for disaster waste management should be prepared before disasters happen. In Southeast Asia, guidelines for disaster waste have been established by Indonesia’s national government and the Metropolitan Manila government in the Philippines, and have been developed at universities in Thailand. Each of these three sets of guidelines takes a different approach, so comparing them can provide suggestions for various points that are important to consider. This paper explores the three sets of guidelines for disaster waste management and attempts to formulate a typology from the perspectives of “motivations and mandates” for developing such guidelines and “entities responsible for the guidelines.” Such perspectives and typologies will be useful when assessing the status of disaster waste management in a country or region, or when considering specific policies for disaster waste management. In addition, academia has contributed to the development of these guidelines by utilizing their accumulated knowledge in waste management.

In recent years, large-scale natural disasters have occurred frequently in Asia and the Pacific, resulting in the generation of huge amounts of disaster waste. Failure to take appropriate measures could lead to serious problems such as deterioration of the living environment. The objective of this study is to identify important points of the organizational arrangements for disaster waste management adjusted to the actual and practical situation of each country or region, by reviewing case studies on support for establishing disaster waste management systems in six countries/regions: Japan, Bangkok (Thailand), Indonesia, Lautoka City (Fiji), Honiara (Solomon Islands) and Samoa. The results show that incorporating disaster waste management in normal-time waste management is important for improving community resilience, normal-time waste management skills, capacity and technology, and for maintaining motivation for DWM preparedness. The responsible government agencies often have a dual structure at the national and local government levels, so it is essential to strengthen cooperation between different institutions regardless of the organizational structure. Furthermore, it is effective for small and medium-sized countries or local governments to strengthen cooperation with local residents, and building social capital through disaster waste disposal can be an effective means of that.

This study aims to evaluate greenhouse gas (GHG) emissions from municipal solid waste disposal in Metropolitan Bangkok and its mitigation potential from the perspective of the waste sector. The evaluation was performed by comparing GHG emissions in three scenarios: business-as-usual (BAU). implementation of the Bangkok solid waste management plan, and adoption of the national GHG mitigation policy proposed for the waste sector in Thailand. Estimation of GHG emissions was carried out following Intergovernmental Panel on Climate Change (IPCC) methodology. In 2019, GHG emissions from solid waste management in Metropolitan Bangkok under BAU were determined to be 1,067.66 GgCO₂-eq and they are expected to rise to an estimated 1,258.81 GgCO₂-eq in 2032 in the BAU scenario. The implementation of solid waste management following Bangkok’s solid waste management plan would reduce the emissions to 863.01 GgCO₂-eq. Adoption of the national GHG mitigation policy in terms of increasing methane recovery from landfill disposal and increasing waste treatment through composting would yield total emissions of 633.01 GgCO₂-eq, a 49.7% reduction compared to the emissions in the BAU scenario in 2032.

This study aims to evaluate the life cycle CO₂ (LCCO₂) of different waste management practices from tambon municipalities (local administrative organizations) in Chiang Rai, Thailand. “Tambon Municipality A” (TM-A) refers to a tambon municipality that used open dumping for final disposal. Two others, TM-B and TM-C, used small-scale incineration. The difference between the latter two is the waste collection method prior to delivery to the incinerator. TM-B used a waste compaction truck which had a greater capacity than the pickup truck used in TM-C. Finally, TM-D used mechanical biological treatment (MBT) for waste treatment and disposal. A waste composition investigation was also conducted for use in estimating GHG emissions. In parallel, waste mass flows, fossil fuel consumption and electricity consumption in the waste management process were also investigated. The LCCO₂ results show that the tambon municipality that used open dumping had the greatest GHG emissions while the municipality using MBT showed negative GHG emissions. The GHG emissions offset from TM-D is from utilizing compost and refuse-derived fuel (RDF). These results could be used to support other municipalities, waste operators or stakeholders in selecting appropriate modes of waste management from the perspective of GHG emissions reduction to reach national carbon neutrality and net zero targets.

Ever-growing Southeast Asian cities are facing resilience and sustainability issues with regard to their rivers. While the impact of municipal solid waste disposed of in rivers (river waste) is highly discussed, the causes of river waste need more exposure. This paper aims to clarify the current understanding of the causes of river waste in Southeast Asian cities by undertaking a review of the literature on river waste and theories on waste disposal behavior. We analyze the causes of river waste in terms of its sources, as in the actors, and factors, as in reasons for behaviors. We elaborate on three types of causal factors: physical, psychological and governance. Our results show that most of the causes of river waste in Southeast Asian cities from the physical, psychological and governance perspectives intersect at issues related to informal settlements, which have inadequate MSW services, and a lack of risk perception as the most frequently reported causes, while other aspects are still rarely brought up in the literature.

In urban areas with a high degree of concrete urbanization, the urban heat island (UHI) effect has become an environmentally significant concern. Among UHI factors, the materials that cover the ground surface significantly affect temperature variation in urbanized areas. Several solutions have been implemented for mitigating the increase in ground surface temperatures, including the use of materials with self-cooling capabilities such as water-permeable (pervious) interlocking blocks, asphalt and concrete. In particular, surfacing with the pavements using water-permeable interlocking blocks and concrete supplemented with water-retaining materials has been employed to enhance the effective reduction of ground surface temperatures under hot summer climate conditions. The objective of this study is to evaluate the thermal performance of water-permeable surface pavers in car parking lots in Hanoi, Vietnam. Various water-permeable pavement structures were applied in the test areas for on-site testing. Pervious concrete (PC), which included recycled materials from construction waste, natural aggregates and fine lightweight aggregate from autoclaved aerated concrete (AAC), was utilized with variations in ground surface temperature monitored. Additionally, ground surfaces using both asphalt concrete and conventional concrete were tested for comparison. During the on-site monitoring conducted in the summer, all water-permeable pavements contributed to surface temperature reductions of over 5°C. Remarkably, the surface temperature of water-retaining PC using AAC was more than 10°C lower when the surface temperature of asphalt concrete reached nearly 60°C. This paper also reports results on the mechanical properties and permeability coefficients of water-permeable pavements.

Sri Lanka, facing economic challenges exacerbated by COVID-19, is grappling with significant issues including poverty, income inequality and environmental concerns, particularly poor solid waste management (SWM). Projections indicate a sharp increase in national waste generation, exceeding 10,000 tonnes per day by 2020. Waste collection rates vary between provinces, with higher rates in the most populous ones, Western and Eastern provinces. The research methodology includes a literature review and observations to ascertain the current state of SWM in Sri Lanka. International and national policies, influenced by global conventions, shape Sri Lanka’s waste management strategy, with a focus on circular-economy practices, biodegradable waste management, energy recovery and sustainable landfill practices. JICA has played a key role in supporting Sri Lanka’s SWM initiatives, including the Clean City Initiative (JCCI) and historical assistance dating back to 2000. Projects such as the Western Province Solid Waste Management Master Plan aim to address challenges, with JICA’s involvement extending to the promotion of composting policies supported by Japanese technology. Notable achievements include the introduction of mechanised composting facilities and the development of a waste management database system. Efforts also extend to strengthening plastic management capacity, as outlined in the National Action Plan for Plastic Waste Management 2021–2030. JICA’s ongoing support includes capacity building for the newly established Plastic Management Centre. Overall, these initiatives reflect a commitment to sustainable waste management, environmental protection and the pursuit of a cleaner and healthier future for Sri Lanka.

With increasing amounts of waste being generated in developing countries, landfill capacity shortages are becoming apparent. As a result, there are concerns that the number of open dumping sites managing waste poorly and disposing of waste inappropriately will increase. These sites are not generally government-authorized, and their gas emissions and leachates are not managed at all. Moreover, identifying the locations of open dumping sites is not simple. In this study, we calculated spectral reflectances and recorded spectral reflectance curves of waste, soil, vegetation and leachate from measurements with a portable spectral radiometer in central and southern Vietnam, at landfill sites in Hue and Nha Trang. Even though waste in landfill and dumping sites is heterogeneous, being mixtures of various materials including plastic, paper and food waste, we confirmed that the spectral reflectance curves of waste presented in this study have consistent regularity regardless of measurement point and field of measurement; the spectral reflectance of waste gradually increases from 10% to 40% as the wavelength goes from 350 nm to 850 nm. The results suggest that using satellite data to develop techniques for identifying locations of open dumping sites will be worthwhile and signify that reflectance curves of waste obtained by on-site measurements will be useful as ground-truth data. The study also revealed that spectral reflectance curves of waste are similar to those of soil as the next challenge in detecting the locations of open dumping sites via satellite data.

In the Asian region, rivers have been an undoubtedly strategic resource for human activities such as agriculture and transportation and as a water resource for everyday life. This has been true for the Citarum River of Indonesia for a long time. The river, however, has been endangered by pollution that harms its water quality to the extent that the river has been dubbed “the dirtiest river in the world” by the international media. Pollution sources include disposed plastic waste swept by runoff into the river. The Indonesian government has given serious attention to the issue, endorsing a presidential regulation in 2018 to tackle water pollution in the Citarum River. The “Citarum Harum” program is the vehicle for implementing this presidential regulation, involving multiple layers of government from the national to the village level. Aiming to clean-up and prevent pollution, including from different kinds of plastic waste that reach the river and eventually the ocean. This study has focused on observing the governance system of the Citarum Harum program, which includes plastic waste management and clean-up of the Citarum River, Indonesia by applying a collaborative governance framework (Emerson et al., 2022) to examine how the program has been implemented from a governance perspective. It offers policy and action recommendations to further enhance the sustained collaborative governance of Citarum River plastic waste management in the years to come.

By emphasizing the need for co-creative international cooperation, mutual learning and innovation between developed and emerging economies, this paper presents a case study on a city-to-city partnership between the cities of Da Nang, Viet Nam and Yokohama, Japan, focusing on development of collaborative actions on waste source segregation and recycling. It outlines a four-stage model for developing a circular economy; focusing on solid waste management and recycling policies along with economic development. It then discusses the case of Da Nang, which also faces typical challenges in transitional governance to develop waste management and recycling policies for a circular economy. At the same time, through the Yokohama case study, it highlights the motivations and drivers for promoting recycling as a policy that are in common with those of Da Nang. It discusses how the collaboration between Yokohama and Da Nang has encouraged a step-by-step improvement in overcoming challenges in transitional governance toward a circular economy. Lastly, it suggests a step-by-step approach for enhancing such cooperation through similar partnerships.

Microplastics, or fragments of plastic smaller than 5 millimeters in size, have received considerable attention in recent years. As these microscopic particles enter our oceans, water sources, and even the air we breathe, concerns about their impact on human health have increased, particularly in Asia, a region experiencing rapid industrialization and urbanization. This study provides an up-to-date review of the current state of knowledge regarding microplastic pollution, with a particular focus on the Southeast Asia (SEA) region. It encompasses an evaluation of microplastic origins, characteristics, removal efficiencies in wastewater treatment plants and potential impacts of microplastic pollution. The findings of this review reaffirm that microplastic pollution is a widespread issue in the region, with the Philippines and Vietnam having the most contaminated rivers. The prevalent microplastic shapes found in fresh water in SEA are fibers and fragments, with PP and PE being the most common polymer types. Moreover, blue and transparent microplastics are observed in nearly all the studies. Microplastic sizes exhibit variations due to different collection methods. Notably, there is a significant lack of studies concerning the impacts of microplastic pollution on humans and aquatic organisms. This study underscores the need for more comprehensive and proactive approaches to microplastic management. These include implementation of designated policies for microplastic management, adoption of standardized sampling methods and initiation of more extensive research endeavors aimed at addressing this form of pollution in freshwater environments.