0
Article Tier 2 Environmental Sources Sign in to save

Hydrological and hydraulic drivers of microplastics in a rural river sourced from the UK's largest opencast coal mine

Environmental Pollution 2025 7 citations

AI summary Read the abstract

Researchers measured microplastic concentrations in a remote headwater river in Wales draining the UK's largest opencast coal mine over two years. They found that small acrylic and polyester fibers dominated, with concentrations linked to rainfall-runoff patterns and dry weather periods indicating source-limited dilution effects. The study suggests that total suspended solids may serve as a useful proxy for estimating microplastic levels in similar river systems.

Study Type Environmental

Microplastics (MPs) are ubiquitous in river and freshwater ecosystems. However, the hydraulic and hydrological mechanisms that regulate the activation and emissions of MPs from both the land surface and subsurface into rivers are not well understood. This study aims to quantify the instream MP concentration and MP load in a remote headwater catchment river (Taff Bargoed, Wales, UK), which drains the UK's largest opencast coal mine (Ffos-y-fran), over a two-year period. Small fibers (< 1 mm) composed of acrylic and polyester dominated the MPs found in the Taff Bargoed, while less commonly observed MP fragments were mostly composed of polysulfone. River MP concentrations ranged from 0.27 to 28.87 MP/m³ (average: 14.60 ± 10.31 MP/m³), and MP load ranged one order of magnitude from 0.08 to 3.04 MP/s (average: 1.42 ± 0.81 MP/s). Statistically significant relationships were found between MP concentration, the number of dry weather hours and river discharge, which indicated rainfall-runoff induced, source limited, dilution effects on instream MP concentration. A negligible relationship between MP load and river discharge was observed, which suggests that MP load variability was independent of flow conditions, dry weather hours, and the MP concentration in the Taff Bargoed. Significant positive relationships between MP concentration and instream total suspended solids were also observed, indicating that this may provide a useful proxy for estimating MP variation in the Taff Bargoed. No longitudinal variation in MP concentration over a 2 km reach was observed, where differences in flow and drainage area were negligible, however, MP concentration increased by a factor of 2-4 downstream of an inflowing tributary, also sourced from the Ffos-y-fran coal mine. Overall, the results of this study provide evidence that mining activities can contribute MPs in rural and remote rivers, with their contribution being regulated by the hydraulic and hydrological processes in the catchment.

More Papers Like This

Article Tier 2

Freshwater and airborne textile fibre populations are dominated by ‘natural’, not microplastic, fibres

AI summary Read the abstract

Researchers monitoring fibre pollution in a UK river and its surrounding air over twelve months found that natural textile fibres (e.g., cotton, wool) dominated the samples, representing 93.8% of all fibres detected, while synthetic microplastic fibres were entirely absent from more than 80% of samples.

Article Tier 2

Microplastics in freshwater ecosystems - influence of river runoff on microplastic concentrations

AI summary Read the abstract

Researchers investigated the presence and characteristics of microplastic pollution in the subsurface waters of the Tollense River in Mecklenburg-Western Pomerania, Germany, examining how river runoff volumes and hydrodynamic conditions influence microplastic concentrations and transport. The study found that runoff events were a key driver of temporal variability in microplastic loads, highlighting the importance of hydrological dynamics in understanding microplastic export from freshwater catchments to the marine environment.

Article Tier 2

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

AI summary Read the abstract

Researchers surveyed microplastic contamination in sediments from the River Tame and its tributaries flowing through Birmingham, UK, finding microplastics in every sample at an average of 165 particles per 100 grams. The study identified urban density, wastewater treatment plant proximity, and river hydrodynamics as key drivers of microplastic accumulation hotspots in urban rivers.

Article Tier 2

Spatio-temporal distribution of microplastics in a Mediterranean river catchment: The importance of wastewater as an environmental pathway

AI summary Read the abstract

Microplastic concentrations were mapped across a Mediterranean river catchment in central Spain over multiple seasons, finding that wastewater treatment plant effluents were the dominant point source and that storm events transiently increased concentrations in downstream reaches by mobilizing accumulated particles from river beds and floodplains.

Article Tier 2

Source identification of microplastics in highly urbanized river environments and its implications for watershed management

AI summary Read the abstract

Researchers identified the sources and pathways of microplastics entering highly urbanized rivers in the Shenzhen Bay watershed. The study found that 61.6% of annual microplastic loads came from point sources, with textile washing fibers accounting for over 92% of those, while nonpoint source contributions dominated during periods of heavy rainfall.

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.

Email me about

Share this paper