We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microplastics in the sediments of small-scale Japanese rivers: Abundance and distribution, characterization, sources-to-sink, and ecological risks
AI summary Read the abstract
Researchers characterized microplastic pollution in sediments of four small-scale Japanese rivers, finding widespread contamination and identifying polymer types and potential sources, highlighting that even small river systems serve as microplastic transport pathways.
Microplastic pollution in small-scale river sediments remains mostly unknown. This study explored microplastics in the sediments of four small-scale Japanese rivers in Yamaguchi Prefecture: the Awano, Ayaragi, Asa, and Majime. Sediment samples (n = 23) were collected from the selected stations. Density separation and wet peroxidation methods were applied to extract microplastics. Polymers were detected through attenuated total reflectance-Fourier transform infrared spectroscopy. Microplastic abundance indicated relatively moderate values in the small-scale Japanese rivers compared to other rivers around the world. Large microplastics (1-5 mm) in size, fragments in shape, and high-density particles of diverse polymers dominated. Polyvinyl chloride, polyethylene, and polypropylene were the major polymers. The polymers-polyvinyl chloride, polymethylmethacrylate, polyurethane, fluorinated ethylene propylene, and polybutylene in sediments were distinct from those detected in surface water, as were the predominance of large-size (1-5 mm) and fragment-shape microplastics. In contrast to surface water, sediments preserved both common and distinctive microplastics. Thus, the riverine sediment compartment acted as microplastic sink. Scanning electron microscopic (SEM) analysis suggested the presence of weathered microplastics in sediments. Energy dispersive X-ray spectroscopic analysis (EDX) revealed metal contaminants on the microplastic surfaces, indicating synergistic hazard potentials in the riverine ecosystems. Ecological risk assessment results suggested low to very high risks of microplastic pollution for the rivers. The higher abundances of microplastics and highly toxic polymers contributed to the elevated ecological risks. Polyvinyl chloride, acrylonitrile butadiene styrene, polyurethane, and polymethylmethacrylate were the detected highly toxic polymers. The urban and residential areas affected stations ranked high to very high ecological risks. The sites posing very high ecological risks were regarded as pollution hotspots. Overall, this study developed new insights into microplastic pollution in the small-scale rivers and ecological risks for riverine environments, as well as providing a baseline for more comprehensive risk assessments and developing pollution control and management strategies.
More Papers Like This
Assessing small-scale freshwater microplastics pollution, land-use, source-to-sink conduits, and pollution risks: Perspectives from Japanese rivers polluted with microplastics
AI summary Read the abstract
Researchers assessed microplastic pollution in four small-scale Japanese rivers flowing into the Sea of Japan and Seto Inland Sea. The study found that these small rivers were more heavily polluted than many larger rivers worldwide, with polyethylene, polypropylene, and polyester fibers dominating, suggesting that small-scale rivers are significant but often overlooked conduits transporting land-based microplastics to marine environments.
Assessment of the sources and inflow processes of microplastics in the river environments of Japan
AI summary Read the abstract
Researchers mapped microplastic concentrations across 29 Japanese rivers and found plastic particles present at 31 of 36 sampling sites. The concentrations were strongly linked to urbanization and population density, confirming that human activities in river basins are a major driver of freshwater microplastic pollution. The findings demonstrate that significant plastic fragmentation occurs before debris reaches the ocean, making rivers an important area for pollution monitoring.
Assessment, characterization, and quantification of microplastics from river sediments
AI summary Read the abstract
Researchers assessed microplastic contamination in sediments from 14 sites along the Kaveri River in South India, characterizing particle types, sizes, and polymer compositions to quantify the extent of microplastic pollution in this freshwater system.
Occurrence, distribution, and possible sources of microplastics in the surface river water in the Arakawa River watershed
AI summary Read the abstract
Researchers investigated the occurrence, distribution, and potential sources of microplastics in surface river water along the Arakawa River watershed running through the Tokyo Metropolitan area, contributing to data on microplastic contamination in populated urban freshwater systems.
Environmental monitoring of riverine plastic contamination in Asia
AI summary Read the abstract
Researchers compared microplastic concentrations and polymer compositions in rivers across multiple Asian countries as part of coordinated monitoring projects, finding that Asian rivers carry diverse plastic types and vary widely in contamination levels. The results provide empirical data supporting the key role of Asian rivers in transporting plastic waste to the world's oceans.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.