Papers

61,005 results
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Article Tier 2

Effects of urbanisation and a wastewater treatment plant on microplastic densities along a subtropical river system

Researchers quantified microplastic pollution in sediments along a subtropical river system in southern Africa and examined how urbanization and wastewater treatment affect contamination levels. They found that microplastic densities were highest near urban areas and downstream of wastewater treatment plants. The study suggests that urban development and inadequate wastewater infrastructure are key drivers of freshwater microplastic pollution in the region.

2021 Environmental Science and Pollution Research 63 citations
Article Tier 2

Riverine Microplastics in South Africa: Unravelling Pollution Sources from Source to Sediment

Scientists found high levels of tiny plastic particles called microplastics in two South African rivers, with the worst pollution coming from industrial areas and farms. These microscopic plastic pieces can end up in drinking water and the food chain, potentially affecting human health. The study shows that different human activities create different types of plastic pollution, which means we need targeted solutions to clean up our water sources.

2026 Microplastics
Article Tier 2

Longitudinal patterns of microplastic concentration and bacterial assemblages in surface and benthic habitats of an urban river

This study measured microplastic concentrations and microbial communities in a river from source to mouth, finding that both plastic levels and unique plastisphere bacterial communities increased downstream of wastewater treatment plant outflows. The results identify wastewater discharge as a key driver of both microplastic loading and microbial community shifts in rivers.

2017 Freshwater Science 184 citations
Article Tier 2

Microplastic abundance, distribution, and diversity in water and sediments along a subtropical river system

Researchers investigated microplastic abundance in water and sediments along a subtropical river system in South Africa, finding widespread contamination with fibers as the dominant shape and polyethylene as the most common polymer type.

2023 Environmental Science and Pollution Research 39 citations
Article Tier 2

Water or sediment? Assessing seasonal microplastic accumulation from wastewater treatment works

Researchers assessed seasonal microplastic accumulation in two subtropical South African rivers relative to wastewater treatment works, finding that seasonal differences were more pronounced in sediment than in water and that elevated pollution loads were present even upstream of treatment facilities.

2023 H2Open Journal 14 citations
Article Tier 2

Microplastic occurrence and densities in small subtropical reservoirs of Southern Africa

Researchers measured microplastic levels across seasons in small reservoirs in southern Africa, finding that microplastic concentrations were higher during the dry season and in reservoirs near areas with greater human activity. The study establishes baseline data for a region where plastic pollution research is scarce and warns that contamination could worsen without targeted intervention.

2025 Discover Sustainability 6 citations
Article Tier 2

Profiling microplastics in a forgotten river system in Southern Africa

Researchers profiled microplastic distribution across the Nyl, Mogalakwena, and Limpopo Rivers in South Africa over multiple seasons. They found that seasons with reduced water flow had significantly higher microplastic concentrations in both water and sediment, while high-flow seasons produced a more evenly distributed but lower overall abundance. The study also detected microplastics in benthic macroinvertebrates throughout the river system, indicating the particles have become bioavailable in the food web.

2025 Environmental Monitoring and Assessment 5 citations
Article Tier 2

Evaluating the role of microplastics and wastewater in shaping Vibrio spp. and antibiotic resistance gene abundance in urban freshwaters

Researchers sampled water and microplastic biofilms from urban South African rivers and found that microplastics disproportionately enriched Vibrio spp. and tetracycline resistance genes relative to the surrounding water, suggesting microplastics selectively concentrate pathogens and antibiotic resistance genes.

2025 Scientific Reports
Article Tier 2

Microplastic is an Abundant and Distinct Microbial Habitat in an Urban River

Researchers demonstrated that microplastic surfaces in an urban river host a microbial community that is distinct from surrounding water and sediment communities, establishing microplastic as an abundant and ecologically distinct habitat for river microorganisms.

2014 Environmental Science & Technology 1428 citations
Article Tier 2

Microplastic in surface waters of urban rivers: concentration, sources, and associated bacterial assemblages

Researchers measured microplastic levels in the surface waters of the Chicago River and its urban tributaries, finding concentrations as high as 1.94 particles per cubic meter near wastewater outflows. They discovered that microplastic fibers and pellets were often colonized by bacterial communities distinct from those in the surrounding water. The study provides early evidence that urban rivers are significant conduits for microplastic pollution and that these particles may serve as rafts for microorganisms.

2016 Ecosphere 565 citations
Article Tier 2

Riverine microplastic and microbial community compositions: A field study in the Netherlands

Researchers collected microplastic samples from the Dutch section of the Rhine River and analyzed the microbial communities living on them. The study found an average of over 213,000 microplastic particles per cubic meter of water, with polyamide and PVC being the most common types. Larger microplastics hosted distinctly different bacterial communities compared to the surrounding water, including biofilm-forming species and potential pathogens, raising concerns about microplastics as vehicles for harmful microorganisms.

2021 Water Research 193 citations
Article Tier 2

Anthropogenic Litter in Urban Freshwater Ecosystems: Distribution and Microbial Interactions

Researchers quantified anthropogenic litter in urban rivers and streams and found that microplastics dominated by mass and particle count compared to macroplastic items. The study highlights urban freshwater systems as major conduits for plastic pollution moving toward marine environments and documents distinct microbial communities on plastic surfaces.

2014 PLoS ONE 287 citations
Article Tier 2

Seasonal occurrence of microplastics in sediment of two South African recreational reservoirs

Researchers tracked seasonal microplastic levels in sediments from two recreational reservoirs in South Africa, one near agricultural land and the other near populated areas. They found microplastics at all sites, with significantly higher concentrations near areas of greater human activity, particularly during the hot-dry season. The study highlights that even inland freshwater systems in regions with relatively low industrial presence are not immune to microplastic pollution.

2023 Water Biology and Security 28 citations
Article Tier 2

The Effect of Microplastics on Microbial Succession at Impaired and Unimpaired Sites in a Riverine System

Researchers compared microbial biofilm diversity on microplastic polymers and natural substrates at impaired and unimpaired riverine sites, examining how environmental nutrient loads, seasonality, and geography influence microbiome succession on plastic surfaces in freshwater ecosystems.

2024
Article Tier 2

Relative contributions of different local sources to riverborne microplastic in a mixed landuse area within a tropical catchment

Researchers quantified the relative contributions of different land-use sources to riverborne microplastics in a tropical catchment, providing data to help prioritize pollution reduction measures for protecting human and ecological health.

2022 Environmental Research 23 citations
Article Tier 2

Identifying Environmental Factors Influencing the Concentration, Fluxes and Spatial Distribution of Microplastic Pollution in an Urban River: A Case Study of the Klip River, South Africa

Environmental factors such as precipitation, temperature, and land cover were analyzed to identify which variables most strongly control microplastic concentrations in a study ecosystem. Pinpointing these drivers helps predict spatial and seasonal patterns of microplastic pollution for monitoring and management purposes.

2025 Water Air & Soil Pollution 1 citations
Article Tier 2

Microplastic Abundance and Sources in Surface Water Samples of the Vaal River, South Africa

Researchers surveyed microplastic contamination in the surface waters of the Vaal River in South Africa, finding microplastics present at every sampling site. The particles were predominantly fragments and fibers smaller than one millimeter, identified as polyethylene and polypropylene from secondary sources such as single-use plastics and textiles. The findings highlight growing concerns about microplastic pollution in South African freshwater systems and its potential effects on aquatic life.

2024 Bulletin of Environmental Contamination and Toxicology 18 citations
Article Tier 2

Plastic substrate and residual time of microplastics in the urban river shape the composition and structure of bacterial communities in plastisphere

Researchers conducted an in-site incubation experiment in an urban river using microplastics from three plastic product types (garbage bags, shopping bags, and plastic bottles), finding that both plastic substrate type and incubation time shaped the bacterial communities colonizing the plastisphere. Different plastic products harbored distinct microbial communities, with potential implications for the spread of plastic-associated microorganisms in urban freshwater.

2023 Journal of Environmental Management 22 citations
Article Tier 2

Impacts of baseflow and flooding on microplastic pollution in an effluent-dependent arid land river in the USA

Researchers studied microplastic pollution in an Arizona river whose entire water flow comes from wastewater treatment plant discharge, finding that the wastewater effluent was the primary source of microplastics. The study showed that flood events temporarily diluted microplastic concentrations but also spread contamination to floodplain soils.

2021 Environmental Science and Pollution Research 21 citations
Article Tier 2

Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa

Researchers at two Johannesburg wastewater treatment works found extremely high concentrations of microplastics — over 3,000 particles per liter of influent — with the treatment processes removing most but not all particles before discharge. The study fills a data gap for South Africa and confirms that wastewater plants in the region are both a sink and a residual source of microplastic pollution into receiving water bodies.

2023 Water Practice & Technology 6 citations
Article Tier 2

Wastewater discharges and polymer type modulate the riverine plastisphere and set the role of microplastics as vectors of pathogens and antibiotic resistance

Researchers investigated how wastewater treatment plant discharges and polymer type shape microbial communities on microplastics in a river environment. They found that microplastics harbored significantly higher microbial diversity than surrounding water, and that wastewater discharges led to a 2.3-fold increase in antibiotic resistance gene abundance on the plastic surfaces. Different polymer types, including polyethylene, polypropylene, and PET, each attracted distinct microbial communities with varying levels of pathogens and resistance genes.

2025 Journal of Water Process Engineering 1 citations
Article Tier 2

Microplastic particles in river sediments and water of southwestern Nigeria: insights on the occurrence, seasonal distribution, composition, and source apportionment

Researchers surveyed microplastic contamination in river water and sediments across southwestern Nigeria, providing some of the first baseline data for the region. They found microplastics at every sampling site, with fibers and fragments being the most common forms, and concentrations varying by season and location. The study points to urban runoff, agricultural activities, and inadequate waste management as the primary sources of this pollution.

2023 Environmental Science and Pollution Research 27 citations
Article Tier 2

Microplastics in Namibian river sediments – a first evaluation

Researchers conducted the first microplastic survey of river sediments across Namibia's major catchments, detecting microplastics in every sampled river system and finding the highest concentrations in the densely populated Iishana region of northern Namibia.

2022 Microplastics and Nanoplastics 29 citations
Article Tier 2

Comparative analysis of microplastic and microbial communities in varied aquatic environments: Disparities in occurrence, interconnections, and ecological implications

Comparative surveys of microplastics and associated microbial communities across river, reservoir, and bay environments in the Dongjiang watershed found that MP abundance and microbial community composition differed significantly by water type, with MP surfaces hosting distinct microbial assemblages.

2025 Journal of Hazardous Materials 3 citations