Vertical Distribution Of Microplastics Research Articles

Vertical distribution of microplastics in an agricultural soil after long-term treatment with sewage sludge and mineral fertiliser

Sewage sludge applications release contaminants to agricultural soils, such as potentially toxic metals and microplastics (MPs). However, factors determining the subsequent mobility of MPs in long-term field conditions are poorly understood. This study aimed to understand the vertical distribution of MPs in soils amended with sewage sludge in comparison to conventional mineral fertiliser for 24 years. The depth-dependent MP mass and number concentrations, plastic types, sizes and shapes were compared with the distribution of organic carbon and metals to provide insights into potentially transport-limiting factors. Polyethylene, polypropylene and polystyrene mass concentrations were screened down to 90 cm depth via pyrolysis-gas chromatography/mass spectrometry. MP number concentrations, additional plastic types, sizes, and shapes were analysed down to 40 cm depth using micro-Fourier transform-infrared imaging. Across all depths, MP numbers were twice and mass concentrations 8 times higher when sewage sludge was applied, with a higher share of textile-related plastics, more fibres and on average larger particles than in soil receiving mineral fertiliser. Transport of MPs beyond the plough layer (0–20 cm) is often assumed negligible, but substantial MP numbers (42 %) and mass (52 %) were detected down to 70 cm in sewage sludge-amended soils. The initial mobilization of MPs was shape- and size-dependent, because the fractions of fragmental-shaped and relatively small MPs increased directly below the plough layer, but not at greater depths. The sharp decline of total MP concentrations between 20 and 40 cm depth resembled that of metals and organic matter suggesting similar transport limitations. We hypothesize that the effect of soil management, such as ploughing, on soil compactness and subsequent transport by bioturbation and via macropores drives vertical MP distribution over long time scales. Risk assessment in soils should therefore account for considerable MP displacement to avoid underestimating soil exposure.

The Vertical Distribution of Microplastics in the Water Column of Lake Ladoga

The Vertical Distribution of Microplastics in the Water Column of Lake Ladoga

Unveiling microplastic distribution and interactions in the benthic layer of the Yangtze River Estuary and East China Sea

Microplastics (MPs), recognized as an emerging global environmental concern, have been extensively detected worldwide, with specific attention directed towards the Yangtze River Estuary (YRE) and East China Sea (ECS) regions. Despite their critical research significance, there remains a knowledge gap concerning the distribution of MPs in the benthic layer within this area, particularly regarding interactions governing their occurrence. Here we illuminate the distribution of MPs within the benthic layer and unravel the intricate interplay between bottom water and sediment in the YRE and ECS. We find that MPs are notably more abundant in bottom water, ranging from 8 to 175 times higher than in surface water. These MPs predominantly consist of polyester fibers, exhibit a size range between 0.5 and 5.0 mm, and display distinct coloration. Co-occurrence network analysis and Principal Coordinate Analysis confirm a robust correlation between MPs in bottom water and sediment, signifying the pivotal role of bottom water in mediating the distribution and transportation of MPs within the benthic layer. Furthermore, a positive correlation between MPs in sediment and bottom water turbidity underscores the impact of surface sediment resuspension and upwelling on MPs distribution. This study clarifies the intricate interactions within the benthic layer and highlights the crucial role of bottom water as a mediator in the vertical distribution of MPs, advancing our understanding of the “source-to-sink” transport processes governing MPs within water-sediment systems.

Vertical distribution of microplastics in a river water column using an innovative sampling method.

Due to limitations of sampling methods, subsurface water is usually a less well-investigated compartment of the water column when scientists assess microplastic contamination. In this study, microplastic (MP) contamination was assessed in a freshwater river both in surface and subsurface using an innovative sampling method. Microplastic contamination in the lower part of the water column, i.e., near-bottom water and in sediments, was also studied. Three sampling campaigns were carried out during different weather conditions: stormy, rainy, and dry in order to observe their influence on the microplastics vertical distribution. No significant difference was observed between the abundance and types of MPs in surface and subsurface water. The proportion of polymer with theoretical density < 1 (polypropylene d = 0.9, polyethylene d = 0.91-0.95) and polystyrene (d = 0.1-1.06) in the surface and subsurface samples was 73.5%, and this proportion drops to 40.8% for the samples located in the near-bottom water and the sediments. Our results indicate that the MP concentration of the different compartments analyzed can be significantly influenced by rainfall during and prior to the sampling day. This study highlights that in shallow rivers, surface water sampling is representative of the water column MP contamination, but that sampling without taking environmental conditions into account may lead to erroneous estimation of MPs concentration and flux entering the marine environment.

Microplastics Distribution within Western Arctic Seawater and Sea Ice.

Microplastic pollution has emerged as a global environmental concern, exhibiting wide distribution within marine ecosystems, including the Arctic Ocean. Limited Arctic microplastic data exist from beached plastics, seabed sediments, floating plastics, and sea ice. However, no studies have examined microplastics in the sea ice of the Canadian Arctic Archipelago and Tallurutiup Imanga National Marine Conservation Area, and few have explored Arctic marginal seas' water column. The majority of the microplastic data originates from the Eurasian Arctic, with limited data available from other regions of the Arctic Ocean. This study presents data from two distinct campaigns in the Canadian Arctic Archipelago and Western Arctic marginal seas in 2019 and 2020. These campaigns involved sampling from different regions and matrices, making direct comparisons inappropriate. The study's primary objective is to provide insights into the spatial and vertical distribution of microplastics. The results reveal elevated microplastic concentrations within the upper 50 m of the water column and significant accumulation in the sea ice, providing evidence to support the designation of sea ice as a microplastic sink. Surface seawater exhibits a gradient of microplastic counts, decreasing from the Chukchi Sea towards the Beaufort Sea. Polyvinyl chloride polymer (~60%) dominated microplastic composition in both sea ice and seawater. This study highlights the need for further investigations in this region to enhance our understanding of microplastic sources, distribution, and transport.

Vertical distribution and weathering characteristic of microplastics in soil profile of different land use types

After deposition on the topsoil, microplastics (MPs) may be vertically migrated to deeper soil layers over time or eventually enter the groundwater system, leading to more widespread environmental and ecological issues. However, the vertical distribution of MPs in natural soils are not yet fully understood. In this study, we collected soil profiles (0–100 cm) from four different land use types on the west bank of Taihu Lake in China to investigate the vertical distribution and weathering characteristics of MPs. The average abundance of soil MPs followed the pattern of paddy field (490 ± 82 items/kg) > dryland (356 ± 55 items/kg) > tea garden (306 ± 32 items/kg) > woodland (171 ± 27 items/kg) in the 0–10 cm layer, and the abundance of MPs decreased linearly with soil depth (r = −0.89, p < 0.01). Compared to tea garden and woodland, MPs in dryland and paddy field have migrated to deeper soil layers (80–100 cm). The carbonyl index of polyethylene and polypropylene MPs increased significantly with soil depth (r = 0.96, p < 0.01), with values of 0.58 ± 0.30 and 0.54 ± 0.33, respectively. The significant negative correlation between MPs size and carbonyl index confirmed that small-sized MPs in deeper soil layers originated from the weathering and fragmentation of MPs in topsoil. The results of structural equation model showed that roots and soil aggregates may act as filters during the vertical migration of MPs. These findings contribute to a better understanding of the environmental fate of MPs in soil and the assessment of associated ecological risks.

Distribution and abundance of microplastics in the water column of Vembanad Lake–A Ramsar site in Kerala, India

The study focuses on the occurrence, abundance and characteristics of microplastics (MPs) in the subsurface and bottom waters of Vembanad Lake, a Ramsar site in the state of Kerala. Even though several studies elucidate the prevalence of microplastic pollution in the surface waters of aquatic ecosystems, a little is known about the vertical distribution of MPs in the water column. Vembanad Lake water is greatly affected by microplastic pollution compared to other Indian lakes as it receive discharges from six rivers; a number of sewage canals and run-off. Ubiquitous distribution of MPs was found in the lake with a mean abundance of 26.79 ± 3.74 items L−1 and 52.70 ± 5.43 items L−1 in subsurface and bottom waters respectively. Fibers, constitute more than half of the total MPs in both subsurface and bottom waters. The dominance of polyamide and polypropylene with most of the MPs being fibers indicate that they originate probably from fishing activities and laundry wastewater. The particles with in the size range 100–500 μm were in excess in the water samples. Further fragmentation, increasing the number of MPs in the lake water was envisaged from the SEM images of MPs showing cracks and crevices. These MPs along with adsorbed contaminants upon ingestion by the aquatic organisms become a threat to the food web of the lake. The local population which depends mainly on the fishes and mussels of the lake for their dietary needs would be greatly affected by the contamination of the lake with MPs. Further research on MPs contamination in edible biota would give more insights on the extent and risks of MPs pollution in the lake.

Evaluation of vertical distribution characteristics of microplastics under 20μm in lake and river waters in South Korea.

Following the alarming reports of microplastic pollution in the marine environment, increased attention has been given to microplastics in other environmental media. Despite the attention, there is limited research available on the depth-distribution of microplastics in freshwater. Specifically, in the case of water sources used for drinking or tap, the height of intake facilities varies, and it is highly likely that there is a correlation between the vertical distribution of microplastics and these water intake structures. Further, because the size of microplastics varies widely in the environment, the commonly used sampling devices are not suitable for selectively extracting microplastics without causing cross-contamination. Thus, we developed a suitable device for microplastics of size 5-20µm and studied microplastic distribution in freshwater at various depths by considering various types of microplastics and aqueous systems. Lake and river, two major water sources, were selected for the study of microplastics distribution in water system. The microplastic distribution characteristics in both water systems showed that polypropylene and polyethylene were the most abundant across all depths because of their production volume. Plastic types with higher density were found only at the lower layers, and polystyrene was found in the upper layers because of the environmental effects on its buoyancy caused pore diameter and surface area. The lake and river had higher microplastic distribution in the lower layer and upper layer, respectively. This was because the flow rate in river was higher than that of lake. The higher flow rate reduced the settling velocity in river. Thus, hydrodynamic stability influences the vertical distribution and concentrations of microplastics in the water systems. These results are expected to be used for understanding the behavioral characteristics of microplastics in water systems and to manage water sources.

Longitudinal and vertical distribution of microplastics in various pipe scales in an operating drinking water distribution system

Microplastics (MPs) are ingested by humans through the daily consumption of drinking water. Pipe scales are recognized as important sites of MPs occurrence in the drinking water distribution system (DWDS). Despite extensive research on drinking water, no study has been conducted to investigate the distribution of MPs in pipe scales within an operational DWDS. The underground placement of DWDSs brings challenges for sampling pipe scales. In this study, 5 tap water and 16 pipe scales samples were collected from a typical DWDS. The analysis of MPs abundance in these 21 samples filled the data gap in the distribution of MPs in both pipe scales and tap water along the DWDSs. MPs were detected in all water samples (1.74–20.88 MPs/L) and pipe scales samples (0.03–3.48 MPs/cm2). In tap water, MPs abundance increased abruptly in the stagnant-slow flow region and reached the maximum value (20.88 MPs/L), even surpassing the abundance in raw water (6.42 MPs/L). In the pipe scales, MPs abundance decreased from the upstream to downstream of DWDS and was associated with the heavy metal concentration. MPs smaller than 150 µm accounted for 91.6% of the tap water (21–971 µm) and pipe scales (20–2055 µm). The abundance of MPs showed a logarithmic increase as the size decreased. The proportion of MPs fibers in tap water was lower than that in pipe scales. A total of 35 MPs polymers were detected, with 34 polymers in pipe scales and 26 polymers in tap water. In terms of abundance, polyethylene terephthalate (50.0%) was the dominant polymer in pipe scales, while polyamide (70.3%) was the dominant polymer in tap water. Regarding detection rate, polyamide was detected in all 21 samples, followed by polyurethane in 19 samples. The distribution of MPs along the longitudinal direction of the DWDS was correlated with heavy metal. While the distribution of MPs in the vertical direction of large diameter pipe scales was dependent on their sizes, and densities. The greatest abundance, size and density of MPs were detected at the bottom 120-degree.

Abundance, spatial distribution, and physical characteristics of microplastics in stormwater detention ponds

Despite extensive research on microplastics (MP) in marine environments, little is known about MP abundance and transport in terrestrial systems. There is, therefore, still little understanding of the main mechanisms driving the substantial transport of MP across different environmental compartments. Storm events can transport MP beyond boundaries, such as from the land to groundwater or the ocean, as has already been discovered for organic carbon transport. Urban stormwater detention ponds are suitable environments to study the impact of stormwater on the environmental fate and transport of MP. Herein, we investigate the longitudinal and vertical distribution of MP within two detention ponds with different physical characteristics. Soil samples were collected at various locations and from multiple depths (surface and subsurface layers) for measuring MP concentrations using fluorescence microscopy. Our findings show that MP are retained more near the inlet of the ponds, and MP of larger sizes were found more abundantly near inlets than outlets. We also found that MP mass and sizes decrease from surface soil to subsurface soil. In the pond, where vegetation (grass root network) was more considerable, MP were found more evenly distributed along the depth. In terms of shape, the fragments were the most abundant MP shape.

Horizontal and vertical distribution of microplastics in Gehu Lake, China

Abstract Microplastics (MPs) widely exist in the aquatic environment. In this study, the horizontal and vertical distribution of MPs in different depths of Gehu Lake was analyzed. The study found that MPs were detected in water bodies at different depths. The Gehu Lake Basin's MP abundance throughout the entire lake region ranged from 1.40 to 5.53 n/L. Microplastic abundance in surface water (3.13 ± 0.32 n/L) was highest, and the average abundance of MPs in the middle water (2.28 ± 0.24 n/L) and bottom water (1.03 ± 0.14 n/L) was appreciably reduced (p &amp;lt; 0.05). The microplastics observed in water samples were analyzed, and it was found that the particle size of most of the obtained microplastic particles was between 100 and 500 microns, the main shape was fibrous MP, and the MP content of transparent color was highest, and the four most common MPs was polyethylene (PE), polystyrene, polyester (PES), and polypropylene (PP). In this article, we emphasize the importance of comprehending the specific distribution characteristics of MPs in Gehu Lake. It provides a data foundation for future monitoring of MPs present in Gehu Lake, provides scientific and technological support for the assessment and prevention of microplastic pollution in this area, and offers some assistance for future lake water quality regulation.

Pollution Characteristics of Microplastics in Sediments of Xiamen Bay Beach

Microplastics widely exist in various environmental media and have become a global environmental problem. To investigate the pollution characteristics, deposition patterns, and influencing factors of microplastics in the sediments of bay beach, five typical beaches were selected in Xiamen Bay. According to the tidal variation, 0-10 cm, 10-20 cm, and 20-30 cm sediment column samples were collected in layers at the high tide line, middle tide line, and low tide line at the same time, and the characteristics of the horizontal and vertical distribution of microplastics in the beach sediments were studied. The results showed that the abundance of microplastics in 45 sediment samples in Xiamen Bay beach ranged from 39 to 260 n·kg-1, with an average abundance of (114±26) n·kg-1. The shapes of microplastics were mainly fibers, fragments, granules, and foams, with fibers making up the largest proportion. The main components were polyethylene terephthalate (PET), cellophane, and polyethylene (PE). The colors of microplastics included transparent, yellow, blue, black, white, etc. The average abundance of microplastics showed a certain pattern depending on the beach location, intertidal zone, and sampling depth. Moreover, the abundance and distribution of microplastics on the beach were affected by various natural and human factors such as waves, tides, shoreline shape, the number of tourists, and the cleaning of marine floating debris. These results aid the understanding of the distribution characteristics and sources of microplastics in beach sediments, provide a basis for the transport of microplastics from land to sea, and provide data support for the collection of sea floating garbage and shoreline garbage.

Vertical distribution of microplastics in the sediment profiles of the Lake Taihu, eastern China

Microplastics are ubiquitous in the freshwater environment, while its abundance in the sediment profiles has received little attention. The vertical microplastic distribution in the sediment of the North (NTH) and Southwest (SWTH) of Lake Taihu was identified and characterized in this study. Microplastics could be detected at all depths (0–50 cm) at the two sites, with the total abundance of 8100 and 5300 particles kg−1 dry weight sediment at NTH and SWTH, respectively. This indicates that the microplastic storage in the sediment of the Lake Taihu may be underestimated, if only the surface sediment is considered. Microplastics composed of various polymer types were identified in the sediment of the two sites, including polyamide (PA), acrylic acid, polyethylene terephthalate and cellulose acetate, while high density polyethylene and polypropylene were only detected at NTH. The main type of polymers detected at NTH (42%) and SWTH (43%) were PA. The major shape of microplastics was fibers, with a ratio of 76% and 78%, respectively at the site NTH and SWTH. The colors of microplastics were mainly white (accounted for 42 and 43% at NTH and SWTH, respectively), which may be caused by the long-term decomposition of dyestuff in the syngenesis of sediment and/or probably the degradation during sample treatments. The textile industry and fishery activities may provide the source. In summary, our findings in the Lake Taihu provide better understanding of the microplastic pollution and tackle microplastics challenges.

Horizontal and vertical distribution of microplastics in dam reservoir after impoundment

In freshwater ecosystems, microplastics (MPs) are commonly found in reservoirs. However, limited information is available on the distribution of MPs in the reservoirs. In this study, we investigated the horizontal and vertical distribution characteristics of MPs in the Guanyingyan reservoir (the upper reaches of the Yangtze River, China) after impoundment and the influence of free-floating plant residues on the distribution of MPs. Results indicated that the MPs abundance in the horizontal distribution of the reservoir decreased significantly while the distance from the dam increased. The abundance of MPs in shoreline waters (average: 8.45 items L−1) was significantly higher than that in central waters (average: 4.80 items L−1). As for the vertical distribution, the percentages of fibers in the three water layers (surface, intermediate, and deep) have less variation when compared to other types of MPs. Besides, MPs who are less than 0.5 mm in size are the majority. With deeper underwater, there would be more MPs with particles smaller than 200 μm in size. At the same time, there would be fewer MPs with particles ranging from 200 to 500 μm in size. PS, PP, and PE are the main polymer types of surface water, while PVC, PE, and PET are the common type in deep water. In shoreline water, the dry weight of floating plant residues showed a positive correlation with microplastic abundance in different layers. As above said, this study confirmed that MPs in reservoirs after impoundment would tend to accumulate in the front section of the reservoir and the shoreline water. Besides, free-floating plant residues would accumulate in reservoirs, resulting in the sinking of MPs.

Spatial and vertical distribution of microplastics and their ecological risk in an Indian freshwater lake ecosystem

This study investigated the spatial and vertical distribution of microplastics (MPs) in the water and sediment samples collected from different locations in Kodaikanal Lake, a very popular tourist location. The lake provides water to placesdownstream. MPs are found in the surface water, surface sediment and core sediment, with their respective values of abundance being 24.42 ± 3.22 items/ l, 28.31 ± 5.29 items/ kg, and 25.91 ± 7.11 items/ kg. Spatially, abundance, colour, type and size of MPs vary in the samples of surface water and sediment. The highest levels of MPs are found in the lakes' outlet region. MPs detected are primarily fibres and fragments 3-5 mm in size with PE and PP being the predominant polymers. Seven sampling points were selected to investigate the vertical distribution of MPs. In the core sediment, the abundance and size of MPs decrease with depth. This probably indicates the presence of more MPs in the recent sediment. The core sediment is dominated by sand silt clay fractions, which facilitates potential downward infiltration of fine MPs. SEM images of MPs reveal that the degree of weathering increases with depth, and EDAX shows that smooth MP surface displays a lesser adhesion ability than the rough surface. Plastic wastes generated by tourism are the important source of MPs in the lake. The lake has high PHI values (>1000) due to MPs with high hazard score polymers (PS and PEU), whereas the PLI values (1.33) indicate low level of MP pollution representing a minor ecological risk. The MP level in Kodaikanal Lake is influenced by the lake's hydrology and the sources of pollution. Although the impacts of MP pollution on the health and functioning of the environment is uncertain, observing, understanding and halting of further MP contamination in the Kodaikanal Lakes is important.

Vertical distribution of microplastics in water bodies causes sublethal effects and changes in Daphnia magna swimming behaviour

Plastic debris has been found to be ubiquitous in many aquatic ecosystems and is constantly accumulating, not only because more and more plastic is being rapidly released into the environment, but also because its slow degradation means it persists in the water. Some more buoyant plastics accumulate in the water column, whereas other heavier types sink to the bottom. Consequently, the presence of microplastics can threaten organisms living in the water column as well as those found in the benthic zone. In this study, the filter feeder Daphnia has been found to ingest microplastics as the particle diameter (< 30 µm) is within their edible particle size range and they are unable to differentiate between particles of different natures. Four different treatments were considered: food only; only microplastic particles; 50% food and 50% microplastic particles; neither food nor microplastics. Sinking microplastics have been found to decrease Daphnia magna individuals’ swimming velocity during vertical or cruising swimming trajectories, therefore demonstrating the sublethal effects microplastics have on this organism. In addition, microplastics decreased their body growth and survival rates. In cases with the presence of only microplastics, the swimming trajectories of Daphnia indicated the most serious stress experienced as individuals reversed vertical or cruising swimming trajectories to hopping and sinking movements. Therefore, Daphnia individuals in freshwater systems polluted by microplastics might take on the role of ingesting them and later on transporting them to deeper layer water column. In this way microplastics that would remain in the water column for a long time due to their buoyancy, might accumulate at the bottom of the water column.

Trapping of Microplastics in Halocline and Turbidity Layers of the Semi-enclosed Baltic Sea

Microplastic pollution in semi-enclosed seas is gaining attention since microplastics are more likely to accumulate there. However, research on the vertical distribution of microplastics and impact factors is still limited. In this study, we focus on the Baltic Sea, which has distinguished salinity stratification, and we assume that the resulting strong density stratification (halocline) can influence the vertical distribution of microplastics in the water column. Therefore, we analyzed the vertical abundance distribution, the composition, and the sizes of microplastics (27.3–5,000.0 μm) in the Baltic Sea. The results showed that microplastics comprising fibers, fragments, and films occurred throughout the water column at an abundance of 1.1–27.7 items L−1. The abundance of microplastics (3.2–27.7 items L−1) at haloclines was significantly higher than those at other water depths except the near surfaces (p &amp;lt; 0.05), contributing 24.1–53.2% of the microplastics in the whole water column. Small microplastics (&amp;lt;100 μm) were more likely to accumulate in the water layers above halocline. Moreover, the current with high turbidity might be another carrier of microplastics in the near-bottom water layer due to its strong correlation with microplastics abundance. This study provides valuable evidence for the accumulation trend of microplastics in water columns and its influencing factors in the semi-enclosed marginal sea. Further research on the vertical distribution of microplastics under the control of multiple factors should be conducted in the future.

Direct radiative effects of airborne microplastics.

Microplastics are now recognized as widespread contaminants in the atmosphere, where, due to their small size and low density, they can be transported with winds around the Earth1-25. Atmospheric aerosols, such as mineral dust and other types of airborne particulate matter, influence Earth's climate by absorbing and scattering radiation (direct radiative effects) and their impacts are commonly quantified with the effective radiative forcing (ERF) metric26. However, the radiative effects of airborne microplastics and associated implications for global climate are unknown. Here we present calculations of the optical properties and direct radiative effects of airborne microplastics (excluding aerosol-cloud interactions). The ERF of airborne microplastics is computed to be 0.044±0.399milliwatts per square metre in the present-day atmosphere assuming a uniform surface concentration of 1microplastic particle per cubic metre and a vertical distribution up to 10 kilometres altitude. However, there are large uncertainties in the geographical and vertical distribution of microplastics. Assuming that they are confined to the boundary layer, shortwave effects dominate and the microplastic ERF is approximately -0.746±0.553milliwatts per square metre. Compared with the total ERF due to aerosol-radiation interactions27 (-0.71 to -0.14watts per square metre), the microplastic ERF is small. However, plastic production has increased rapidly over the past 70years28; without serious attempts to overhaul plastic production and waste-management practices, the abundance and ERF of airborne microplastics will continue to increase.

Microplastics in a salt-wedge estuary: Vertical structure and tidal dynamics

The abundance and distribution of microplastics in estuaries have been barely documented, and generally without accounting for the vertical structure in the water column. This study presents the very first data on the occurrence and distribution of microplastics in the Adour Estuary, SW France. The experimental data set was complemented by numerical simulations to gain understanding of the behaviour of suspended microplastics. Microplastics were found throughout the water column with a mean abundance of 1.13 part/m3. Films and fragments were the most abundant types of particles collected. Numerical simulations demonstrated that vertical distribution of microplastics in the water column is highly dependent on particle characteristics and on the local hydrodynamics. The main trend is that neutrally-buoyant microplastics are easily flushed out while heavier microplastics are prone to entrapment in the estuary, in particular under low discharge conditions. The present study suggest that estuaries could be a sink of microplastics.

Microplastics in sea ice and seawater beneath ice floes from the Arctic Ocean

Within the past decade, an alarm was raised about microplastics in the remote and seemingly pristine Arctic Ocean. To gain further insight about the issue, microplastic abundance, distribution and composition in sea ice cores (n = 25) and waters underlying ice floes (n = 22) were assessed in the Arctic Central Basin (ACB). Potential microplastics were visually isolated and subsequently analysed using Fourier Transform Infrared (FT-IR) Spectroscopy. Microplastic abundance in surface waters underlying ice floes (0–18 particles m−3) were orders of magnitude lower than microplastic concentrations in sea ice cores (2–17 particles L−1). No consistent pattern was apparent in the vertical distribution of microplastics within sea ice cores. Backward drift trajectories estimated that cores possibly originated from the Siberian shelves, western Arctic and central Arctic. Knowledge about microplastics in environmental compartments of the Arctic Ocean is important in assessing the potential threats posed by microplastics to polar organisms.