Papers

61,005 results
|
Article Tier 2

The unknown fate of macroplastic in mountain rivers

Researchers developed a conceptual model of macroplastic transport pathways through mountain rivers to address the unknown fate of plastic items larger than 5 mm in these ecosystems, identifying key physical and hydrological processes that modulate how plastic moves from populated mountain valleys toward downstream environments.

2022 1 citations
Article Tier 2

The unknown fate of macroplastic in mountain rivers

Researchers proposed that mountain rivers may function as "microplastic factories" because their fast currents, shallow depths, and rocky beds physically break down larger plastic debris into smaller microplastic particles more rapidly than slow-moving lowland rivers. This conceptual model, supported by testable hypotheses, suggests mountain rivers in populated tourist areas are an underappreciated source of microplastic pollution flowing downstream to broader ecosystems.

2022 The Science of The Total Environment 47 citations
Article Tier 2

Spatial variability of microplastic pollution on surface of rivers in a mountain-plain transitional area: A case study in the Chin Ling-Wei River Plain, China

Researchers measured microplastic pollution in surface waters from mountain tributaries to the main stream in the Chin Ling-Wei River Plain in China. They found concentrations ranging from 2.3 to 21 items per liter, with higher levels in the main stream compared to tributaries, and 82% of particles being fragments and films. The study suggests that as rivers flow from mountains to more developed plains, microplastic pollution risk increases sharply due to more diverse land use and human activity.

2022 Ecotoxicology and Environmental Safety 59 citations
Article Tier 2

Homogenization of microplastics in alpine rivers: Analysis of microplastic abundance and characteristics in rivers of Qilian Mountain, China

Researchers investigated microplastic contamination in five alpine rivers in China's Qilian Mountains and found plastic particles present in all water samples. The microplastics showed similar characteristics across different rivers, suggesting a homogenization effect during transport. The findings demonstrate that microplastic pollution has reached even remote mountain river systems far from major population centers.

2023 Journal of Environmental Management 45 citations
Article Tier 2

Mountains of plastic: Mismanaged plastic waste along the Carpathian watercourses

Using high-resolution mapping data, researchers quantified mismanaged plastic waste along river networks in the Carpathian mountains, one of Europe's most biodiverse regions. The results reveal that rivers carry substantial plastic waste through mountain ecosystems where it can harm wildlife and persist for years.

2023
Article Tier 2

Riverine macroplastic gradient along watercourses: A global overview

Researchers conducted a global overview of macroplastic pollution gradients along river systems, from upper reaches to lower stretches. The study found that plastic concentrations generally increase downstream, driven by population density and urbanization, and highlighted that upper and middle river zones have been largely overlooked in previous research.

2022 Frontiers in Environmental Science 67 citations
Article Tier 2

Investigating the Occurrence of Riverine Microplastic Pollution in Western Himalayan region

Scientists found tiny plastic particles called microplastics in rivers throughout the western Himalayan mountains, even in remote areas far from cities. These microscopic plastic pieces are flowing downstream from high mountain areas toward lower regions where millions of people get their drinking water. This matters because microplastics can potentially harm human health when they get into our water supply, and this study shows that even pristine mountain areas aren't safe from plastic pollution.

2026
Article Tier 2

Microplastics and heavy metal contamination along a land-use gradient in a Himalayan foothill river: Prevalence and controlling factors

Researchers mapped microplastic and heavy metal contamination in a river flowing through India's Himalayan foothills, finding plastic particles at every sampling site. Concentrations were highest near industrial areas and human settlements, with polyethylene and polystyrene being the most common plastic types. The study shows how human activity drives plastic pollution even in relatively remote freshwater environments.

2024 Journal of Contaminant Hydrology 20 citations
Article Tier 2

Microplastic pollution in the Himalayas: Occurrence, distribution, accumulation and environmental impacts

This review documents microplastic contamination throughout the Himalayan region, from mountain glaciers and rivers to remote high-altitude locations. Microplastics reach these areas through wind, precipitation, tourism waste, and river transport, and can become trapped in glacial ice before being released during snowmelt. The findings show that even one of the most remote places on Earth is not free from microplastic pollution, with implications for the billions of people who depend on Himalayan rivers for drinking water.

2023 The Science of The Total Environment 110 citations
Article Tier 2

Riverine microplastics in the Mount Everest region affected by glacier meltwater

Researchers studied microplastic distribution in streams and sediments around Mount Everest, finding that pollution levels were two to four times higher during the non-monsoon season compared to the monsoon season. Particles were mostly fragments made of nylon and PET in the 10 to 30 micrometer size range. Streams fed by non-glacial sources had higher microplastic concentrations than glacier-fed streams, suggesting human activity and surface runoff are key drivers even in remote high-altitude areas.

2025 Journal of Hazardous Materials 6 citations
Article Tier 2

Abundance, Distribution and Drivers of Microplastic Contaminant in Urban River Environments

Researchers surveyed microplastic distribution in urban river environments and identified key drivers of accumulation hotspots, finding that land use, hydrology, and infrastructure factors concentrated microplastics at predictable locations that could inform targeted management interventions.

2018 Preprints.org 38 citations
Review Tier 2

A Comprehensive Review of MP Pollution in Global Rivers: Distribution Patterns and Fluvial Transport Dynamics

A global review of microplastic pollution in river sediments found the highest concentrations in Africa and Asia, with wastewater treatment plants, industrial discharges, and urban runoff as the primary sources, and rivers transporting an estimated 70–80% of land-based plastic waste to the oceans. This synthesis underscores that rivers are critical intervention points for reducing the flow of microplastics into marine ecosystems.

2026 Water Environment Research
Article Tier 2

Occurrence of microplastic pollution in rivers globally: Driving factors of distribution and ecological risk assessment

Researchers constructed a global dataset of microplastic pollution across 862 river water and 445 sediment samples, identifying population density, GDP, and plastic waste generation as key driving factors of riverine microplastic distribution and ecological risk.

2023 The Science of The Total Environment 43 citations
Article Tier 2

Field experiment on transport and deposition of plastic bottles along mountain river

Researchers conducted a field experiment tracking plastic bottles released in a mountain river to understand how macroplastic is transported and where it gets stranded. The bottles traveled significant distances but were often retained at bends, log jams, and shallow sections. Understanding transport and deposition patterns in mountain rivers helps identify optimal locations for plastic collection infrastructure.

2023
Article Tier 2

Insights into the in-situ degradation and fragmentation of macroplastics in a low-order riverine system

Researchers studied the in-situ degradation and fragmentation of larger plastic debris into microplastics within a low-order stream system. The study found that these small, often overlooked waterways are active sites where plastic materials break down, serving as important conduits for microplastic generation and transport to downstream coastal environments.

2025 Environmental Toxicology and Chemistry 5 citations
Article Tier 2

Assessment of the sources and inflow processes of microplastics in the river environments of Japan

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.

2018 Environmental Pollution 514 citations
Article Tier 2

Microplastics pollution in selected rivers from Southeast Asia

Researchers surveyed microplastic pollution in rivers across Southeast Asia, a region with high plastic waste discharge but limited monitoring data, documenting the distribution and characteristics of microplastics in these understudied waterways.

2022 APN Science Bulletin 28 citations
Article Tier 2

A multidimensional approach for microplastics monitoring in two major tropical river basins, Malaysia

Researchers conducted a multidimensional assessment of microplastic distribution in surface waters of two major Malaysian river basins, providing much-needed field data on microplastic emissions from Asian rivers known to be major contributors to ocean pollution.

2023 Environmental Research 43 citations
Article Tier 2

Microplastics Monitoring in Environmental Matrices of an Alpine River originating from Hindu Kush Mountain Range

Scientists found microplastics in an alpine river originating from the Hindu Kush mountain range in Pakistan, demonstrating that plastic pollution reaches remote high-altitude environments. Glaciers, rainfall, and downstream human activity all appeared to contribute microplastics to the river system.

2021 4 citations
Article Tier 2

Microplastic pollution in two remote rivers of Türkiye

Researchers documented microplastic pollution in two remote rivers of Turkey, finding that even waterways far from major urban centers contain significant microplastic contamination, highlighting the widespread reach of plastic pollution in freshwater ecosystems.

2023 Environmental Monitoring and Assessment 31 citations
Article Tier 2

Microplastics in tropical Andean rivers: A perspective from a highly populated Ecuadorian basin without wastewater treatment

Researchers measured microplastic concentrations in a highly populated Ecuadorian river basin that lacks wastewater treatment, finding contamination throughout the system and demonstrating that rivers in low-income tropical countries with poor infrastructure are major conduits for microplastics.

2020 Heliyon 66 citations
Article Tier 2

Assessing microplastics pollution in the atmosphere and riverine system in the Pyrenees

This study measured airborne microplastics deposited in the Pyrenees mountains — a remote area far from major urban sources — finding significant contamination in both air deposition and river sediments. The results confirm that microplastics are transported long distances by wind and deposited even in pristine mountain environments. Rivers then act as conduits that transport these atmospherically deposited microplastics toward the ocean.

2021 HAL (Le Centre pour la Communication Scientifique Directe) 1 citations
Article Tier 2

Microplastics pollution in the Brahmaputra River and the Indus River of the Indian Himalaya

Researchers sampled shoreline sediments of the Brahmaputra and Indus Rivers in the Indian Himalayas and found microplastics at all sites, with concentrations increasing downstream toward more populated areas, representing some of the first MP data for major Himalayan river systems.

2021 The Science of The Total Environment 195 citations
Article Tier 2

Assessing small-scale freshwater microplastics pollution, land-use, source-to-sink conduits, and pollution risks: Perspectives from Japanese rivers polluted with microplastics

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.

2021 The Science of The Total Environment 292 citations