Microplastics in Asian rivers: Geographical distribution, most detected types, and inconsistency in methodologies.

Microplastics pose a significant environmental threat, with potential implications for toxic chemical release, aquatic life endangerment, and human food chain contamination. In Asia, rapid economic growth coupled with inadequate waste management has escalated plastic pollution in rivers, positioning them as focal points for environmental concern. Despite Asia's rivers being considered the most polluted with plastics globally, scholarly attention to microplastics in the region's freshwater environments is a recent development. This study undertakes a systematic review of 228 scholarly articles to map microplastic hotspots in Asian freshwater systems and synthesize current research trends within the continent. Findings reveal a concentration of research in China and Japan, primarily investigating riverine and surface waters through net-based sampling methods. Polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) emerge as the predominant microplastic types, frequently observed as fibers or fragments. However, the diversity of sampling methodologies and reporting metrics complicates data synthesis, underscoring the need for standardized analytical frameworks to facilitate comparative analysis. This paper delineates the distribution of microplastic hotspots and outlines the prevailing challenges and prospects in microplastic research within Asian freshwater contexts.

Material flow analysis of commercial fishing gears in Taiwan.

Marine debris is an international environmental issue, and the growing amount of abandoned, lost, or otherwise discarded fishing gear (ALDFG) is a particular concern. Despite Taiwan's substantial fishing industry, there is a lack of comprehensive understanding of fishing gear. This work conducted a static material flow analysis to estimate the flows and the stocks of fishing gear in Taiwan in 2020, based on government statistics and interviews with fishing gears producing companies, fishermen, and recycling companies. Our findings reveal that the inflow, outflow, and stock of the fishing gears are 8,846 t/a, 4,271 t/a, and 4,575 t/a, respectively. Only 36 % of end-of-life fishing gear is recycled, while the rest is incinerated or landfilled. Additionally, the stock comprises 27 % in use, 23 % in ports, and 50 % entering the ocean. These results underscore the need to increase recycling capacity, prevent loss in oceans, and promote repairs to extend the lifespan of fishing gear.

Evaluating the waste and CO2 reduction potential of packaging by reuse model in supermarkets in Taiwan.

Consumption of single-use packaging has been increasing globally and the waste produced causes negative impacts on both human and the environment. Retailers, such as supermarkets, developed quickly in recent years to provide for the modern lifestyle, using a lot of packaging in the process of distribution and sales. This research evaluates the packaging waste and CO2 reduction potential of 10 different products sold in supermarkets in Taiwan when adopting different reuse strategies of Reduce, Return and Refill. In the suggested reuse strategies, a total of 8 kilotons of packaging waste and 30 kilotons of packaging CO2 can be reduced, accounting for 50.8% and 59.8% reduction of the current situation, respectively. Retailers are suggested to provide different reuse strategies and experiential activities to increase consumers familiarity with new consumption methods. Significant impacts are made with a slight change in the small proportion investigated, which suggests considerable benefits if the scope is expanded.

Microplastics in rivers along an urban-rural gradient in an urban agglomeration: Correlation with land use, potential sources and pathways.

Microplastics are ubiquitous and affect all environments, including rivers. In recent years the number of studies about microplastics in rivers has strongly increased. But still many questions exist regarding sources, pathways, and the role of land use patterns. In this study the relationship between microplastics abundance and anthropogenic factors (population density, urbanization, land use types), as well as the potential role of storm sewers as pathways in tributaries of the Wu River in Taichung, central Taiwan, were studied. Two river catchments of the Dali River were studied in greater detail to investigate the influence of land use on microplastics abundance along an urban-rural gradient, and to observe the change of microplastics abundance in the transition from rural to urban areas. Samples were taken from 41 different locations in urban and rural areas using a manta net with a mesh size of 0.3 mm. Results show abundances ranging from 0 pcs/m³ in unpopulated rural areas up to 230 pcs/m³ in densely populated urban centers, and are positively correlated with population density. Remarkably, a sharp increase in microplastics abundance was observed at the transition from rural to urban areas, which coincides with the appearance of storm sewers. Land use analysis revealed that microplastics abundance positively correlates with the size of industrial, residential and traffic areas in the catchment areas, and negatively correlates with the size of forest areas. Source areas for microplastics in the studied rivers are likely residential and commercial areas. Furthermore, the results of this study show that correlations between microplastics abundances and population density or land use patterns along urban-rural gradients are not trivial. Strength of correlations can depend on local factors or how well urban-rural gradients are developed. Absence of correlations need to be considered carefully, as existing correlations might be masked by the above-mentioned factors.

Quantification of food packaging generation and material loss from major retailers in Taipei, Taiwan.

Packaging accounts for the largest demand for global plastic consumption and around 60% is for food and beverage packaging. The amount of packaging is increasing rapidly due to the expansion of retailer industries, especially in supermarkets and convenience stores. Plastic recycling strategies for food packaging in retailer industries need to be developed, but the current consumption and recycling status is not clear. To address this knowledge gap, this study quantifies the food packaging generation from major supermarket and convenience store chains in Taipei, Taiwan. We focus on the composition, recycling habit, and the recycling status to evaluate the packaging recyclability and major pathways for material losses. Based on our field survey and analysis, the total amount of plastic packaging generation was 21846.04 tons in 2020 with 64.99% of it being recycled. We defined the recycling rates as the continued product of Recyclable Content Ratio of the packaging itself, Sorting Accuracy Ratio of consumers, and Re-granulated Ratio in the final treatment facilities. These three ratios for major food categories were also presented to identify the hotspots of material losses. Our results suggest that to promote plastic food packaging recycling, identifying the limitations in different stages and designing corresponding strategies is crucial.

An optimum treatment for waste electronic home appliance in remote area: The case of Kinmen, Taiwan.

An optimum treatment system for the waste electronic home appliance in remote area by local pre-processing and outsourcing post-processing is proposed. The cost reduction potential of the proposed treatment system is presented for main four types of electronic home appliances by the case study of Kinmen, Taiwan. Implementation of local pre-processing in Kinmen, Taiwan can provide 42, 54, 32, and 41 TWD unit cost reduction for television, washing machine, refrigerator, and air conditioner, respectively, comparing to the current treatment system. The different treatment characteristics according to the type of the appliances are the major factors for the applicability and cost reduction potential of the local pre-processing system. The application of this system to other cases is presented by sensitivity analysis with relative labor cost and transportation distance as the parameters. The results and the analysis process can be applied to the domestic systems with regions without recycling facilities, and also the international systems under the extended producer responsibility concept to take back the products for recycling.