We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Monitoring of microplastic concentrations in 132 Iowa lakes in relation to abiotic, biotic, and anthropogenic factors
Summary
Researchers surveyed microplastic concentrations in 132 lakes across Iowa, examining how biological, physical, and human factors influence plastic levels. Lakes near populated areas and with greater human activity showed higher microplastic concentrations, demonstrating that freshwater lakes are broadly contaminated by plastic pollution.
Global annual plastic production rate is approaching 400 million metric tons, with substantial amounts invading aquatic environments yearly. Numerous studies have been conducted monitoring marine environment plastic litter. An understanding of plastic litter's magnitude in freshwater ecosystems is lagging, particularly for microplastics (MP(s) 100 nm to 5 mm in length/diameter). Their ubiquitous presence and small sizes are concerning, since MP effects remain inadequately understood. Our objective was to document MP concentration in lake surface waters, and investigate how abiotic, biotic, and anthropogenic elements explain MP concentration variability among lakes. We sampled MPs in 132 Iowa lakes, collected throughout the water column using a Wisconsin net (63µm mesh size). A fully automated custom-built Bruker LUMOS-II Fourier-transform infrared (FTIR) spectro-microscope was employed to identify MPs. Average MP concentration across lakes was 5.2 particles/L, with dimensions averaging 139 µm in length and 77 µm in width. Predominant MP polymers collected were polyvinyl chloride (46% of all MPs), polyester (30%), and polyethylene (11%). Two variance partitioning analysis models were created to explore variability in MP concentration. The first classical model explained 7.5% of data variability based on: roads; developed medium, and high intensity land cover; sewage plants; and thermocline. The second model, based on Louvain Groups, explained 8.3% of data variability based on: lake area; maximum lake depth; zooplankton tow depth; Secchi depth; lake perimeter; lake shoreline development factor; evergreen forest cover; and thermocline. Roads and developed intensity cover were positively correlated with MP concentrations, alongside household visits standardized to the lake area. Maximum lake depth, zooplankton tow depth, Secchi depth and thermocline presence were negatively correlated with MP concentration. In nine instances, MP concentrations exceeded 50% of the modeled hazardous concentration affecting 5% of aquatic species.
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.
Variability of microplastic loading and retention in four inland lakes in Minnesota, USA
Researchers measured microplastic levels in four small lakes in Minnesota and found that watershed size and urban development were the biggest factors driving contamination. Surface water concentrations varied widely, and sediment levels did not directly correlate with what was found in the water above. The study highlights how local land use patterns influence where microplastics end up in freshwater ecosystems.
Global microplastic contamination in freshwater lakes: Spatial patterns, environmental drivers, and methodological challenges
This review systematically analyzed 84 studies covering more than 300 lakes worldwide to assess global microplastic contamination in freshwater lake systems. Surface water MP concentrations ranged from below 0.001 to over 200 MP/L, with fibers and fragments dominating, polyethylene and polypropylene most common, and highest levels found in shallow, lowland, and eutrophic systems near urbanized shorelines.
A comparative review of microplastics in lake systems from different countries and regions
Researchers reviewed microplastic contamination data from lake systems across multiple countries, finding that abundance, size, and polymer type varied widely by region and identifying land use, population density, and hydrological connectivity as key drivers of lake microplastic levels.
Microplastics in lakes: Distribution patterns and influencing factors
This review analyzed 84 studies across 64 lakes worldwide to understand where microplastics tend to concentrate in freshwater systems. Microplastic levels were highest near areas of heavy human activity and water inflows, and concentrations in lake sediments have been increasing over time, which matters because lakes are important sources of drinking water.