We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Widespread microplastic pollution in Indiana, USA, rivers
Summary
Researchers surveyed nine Indiana river watersheds and found microplastics in every single one, regardless of whether the surrounding land was urban, agricultural, or forested. Plastic fibers dominated across all sites, suggesting they arrive mainly via atmospheric deposition rather than runoff, which means even remote waterways are exposed. The findings indicate that rivers have a distinct microplastic profile compared to large lakes, and that flowing water ecosystems are pervasively contaminated throughout the midwestern United States.
Abstract Microplastics (i.e., plastic particles <5 mm in size) are aquatic contaminants of emerging concern but are poorly quantified in flowing waters of the midwestern USA. Microplastics enter streams and rivers through a variety of pathways (e.g., wastewater effluent, breakdown of larger plastic debris, atmospheric deposition) and can potentially harm aquatic organisms through both direct consumption and indirect contamination from sorbed toxins. In this study, we quantified microplastic concentrations and types (i.e., beads, fibers, films, foams, fragments) in nine Indiana watersheds representing a gradient of dominant land use (i.e., agricultural, urban, and forested). We predicted that microplastic concentration would be higher in watersheds with higher percentages of urban and agricultural land use than in forested watersheds. Our results revealed measurable quantities of microplastics in samples from all watersheds, but microplastic concentration did not vary significantly with land use or longitudinally within watersheds. Fibers were the dominant form of microplastic at all sites, suggesting that fibers may be transported primarily through atmospheric deposition rather than via direct runoff from the surrounding landscape. We conclude that rivers have a different microplastic “signature” than large lakes, likely due to retention characteristics of flowing water ecosystems, unique microplastic sources, and a shorter legacy of microplastic pollution.
Sign in to start a discussion.
More Papers Like This
Microplastics in 132 Iowa lakes and variability in relation to abiotic, biotic, and anthropogenic factors
Researchers surveyed microplastic concentrations across 132 lakes in Iowa, finding that microplastics were nearly ubiquitous even in rural, minimally developed lakes — though concentrations were higher in lakes near urban areas, agricultural land, and higher human population density. Fiber-type microplastics were most common, consistent with patterns seen globally. The broad survey across diverse lake types provides compelling evidence that microplastic contamination of freshwater lakes is widespread across the American Midwest, not limited to industrial or highly urbanized regions.
Microplastic Prevalence in 4 Oregon Rivers Along a Rural to Urban Gradient Applying a Cost-Effective Validation Technique
Microplastics were found in all samples from four Oregon rivers spanning rural to urban settings, and microfiber abundance was correlated with human population within 5 km of sampling sites. The study demonstrates that even remote rural rivers carry measurable plastic pollution, underscoring the pervasive reach of microplastic contamination in freshwater systems.
Microplastic distribution and their abundance along rivers are determined by land uses and sediment granulometry
Researchers studied two river watersheds and found that microplastics were widespread in both water and sediment, with concentrations in water rising alongside increased urban land use. Interestingly, microplastics trapped in sediment were more influenced by the grain size of the riverbed than by human activity. The findings suggest that both human factors and natural river characteristics work together to shape where microplastics end up in freshwater systems.
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.
Microplastic pollution differences in freshwater river according to stream order: Insights from spatial distribution, annual load, and ecological assessment
Researchers compared microplastic pollution levels in a freshwater river across different land-use zones, finding higher concentrations near urban and agricultural areas than in forested regions. Fiber-type microplastics were predominant across all sampling locations.