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A straightforward method for measuring the range of apparent density of microplastics
Abstract
Density of microplastics has been regarded as the primary property that affect the distribution and bioavailability of microplastics in the water column. For measuring the density of microplastis, we developed a simple and rapid method based on density gradient solutions. In this study, we tested four solvents to make the density gradient solutions, i.e., ethanol (0.8 g/cm3), ultrapure water (1.0 g/cm3), saturated NaI (1.8 g/cm3) and ZnCl2 (1.8 g/cm3). Density of microplastics was measured via observing the float or sink status in the density gradient solutions. We found that density gradient solutions made from ZnCl2 had a larger uncertainty in measuring density than that from NaI, most likely due to a higher surface tension of ZnCl2 solution. Solutions made from ethanol, ultrapure water, and NaI showed consistent density results with listed densities of commercial products, indicating that these density gradient solutions were suitable for measuring microplastics with a density range of 0.8-1.8 g/cm3.
... Although tracking the fate of detached plasticrusts in the field was beyond the scope of our monitorings, our floating tests at the lab found that high density plasticrusts (PEST: 1.3-1.4 g/cm 3 ; Li et al., 2018) sink whereas low density plasticrusts (PE: 0.9-1.0 g/cm 3 ; Li et al., 2018) float (Fig. S9). ...
... This conclusion is supported by a recent study which found that rocky intertidal snails collected from several locations on European coasts in 2007-2009 and 2019-2020 contained more high density microplastics (e.g., acrylic/ alkyd; 1.0-1.2 g/cm 3 , Li et al., 2018) than low density microplastics (e.g., PE; Ehlers et al., 2022) which supports the notion that polymer floatability influences the fate of detached plasticrusts. ...
Plasticrusts are a plastic form that consists of plastic encrusting intertidal rocks. To date, plasticrusts have been reported on Madeira Island (Atlantic Ocean), Giglio Island (Mediterranean Sea) and in Peru (Pacific Ocean) but information on plasticrust sources, generation, degeneration and fate is largely missing. To address these knowledge gaps, we combined plasticrust field surveys, experiments and monitorings along the Yamaguchi Prefecture (Honshu, Japan) coastline (Sea of Japan) with macro-, micro- and spectroscopic analyses in Koblenz, Germany. Our surveys detected polyethylene (PE) plasticrusts that derived from very common PE containers and polyester (PEST) plasticrusts that resulted from PEST-based paint. We also confirmed that plasticrust abundance, cover and distribution were positively related to wave exposure and tidal amplitude. Our experiments showed that plasticrusts are generated by cobbles scratching across plastic containers, plastic containers being dragged across cobbles during beach clean-ups, and waves abrading plastic containers on intertidal rocks. Our monitorings found that plasticrust abundance and cover decreased over time and the macro- and microscopic examinations indicated that detached plasticrusts contribute to microplastic pollution. The monitorings also suggested that hydrodynamics (wave occurrence, tidal height) and precipitation drive plasticrust degeneration. Finally, floating tests revealed that low density (PE) plasticrusts float whereas high density (PEST) plasticrusts sink suggesting that polymer type floatability influences the fate of plasticrusts. By tracking the entire lifespan of plasticrusts for the first time, our study contributes fundamental knowledge of plasticrust generation and degeneration in the rocky intertidal zone and identified plasticrusts as novel microplastic sources.
... The presence of a biofilm may alter the overall density of MPs, affecting their distribution in water, and thus, significantly influencing their fate in the aquatic environment (Li et al., 2018;Jalón-Rojas et al., 2022). In the case of PE, PP, and PVC, where the density of the pristine particles was below 1.2 g/cm 3 , ageing in freshwater and wastewater increased the particle density (Table 1). ...
... The density of biofilm ranges from 1.1 to 1.5 g/cm 3 (Long et al., 2015;Lagarde et al., 2016), and thus, the biofilm that develops on MPs can lead to an increase (in the case of low-density polymers) or a decrease (in the case of high-density polymers) in the density of aged MPs. The determined densities of the pristine MPs were consistent with the results of previous studies (Li et al., 2018;Shamskhany et al., 2021). ...
Microplastics found in the environment are often covered with a biofilm, which makes their analysis difficult. Therefore, the biofilm is usually removed before analysis, which may affect the microplastic particles or lead to their loss during the procedure. In this work, we used laser-based analytical techniques and evaluated their performance in detecting, characterizing, and classifying pristine and aged microplastics with a developed biofilm. Five types of microplastics from different polymers were selected (polyamide, polyethylene, polyethylene terephthalate, polypropylene, and polyvinyl chloride) and aged under controlled conditions in freshwater and wastewater. The development of biofilm and the changes in the properties of the microplastic were evaluated. The pristine and aged microplastics were characterized by standard methods (e.g., optical and scanning electron microscopy, and Raman spectroscopy), and then laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used. The results show that LIBS could identify different types of plastics regardless of the ageing and major biotic elements of the biofilm layer. LA-ICP-MS showed a high sensitivity to metals, which can be used as markers for various plastics. In addition, LA-ICP-MS can be employed in studies to monitor the adsorption and desorption (leaching) of metals during the ageing of microplastics. The use of these laser-based analytical techniques was found to be beneficial in the study of environmentally relevant microplastics.
... g/cm 3 ; PP: 0.8-0.9 g/cm 3 ; Li et al., 2018), as confirmed by our plastic fiber floating tests (Section 3.1, Fig. 1I). Yet, our plastic form bulk density measurements and plastic form floating tests showed that all plasticoncretes, plastimetals and plastisessiles (bulk density: 1.35-5.56 ...
Plastic forms, including plastiglomerate, pyroplastic, plasticrusts, anthropoquinas, plastistone and plastitar, were recorded worldwide. These plastic forms derive from geochemical or geophysical interactions such as heat-induced plastic fusion with rock in campfires, incomplete plastic combustion, water motion-driven plastic abrasion in the rocky intertidal zone, plastic deposition in hardened sediments and plastic bonding with tar. Thereby, these interactions can profoundly influence the fate of plastics in the environment. This study characterized three novel plastic forms (plasticoncrete, plastimetal and plastisessiles) discovered on Helgoland island (North Sea). Plasticoncrete consisted of common polyethylene (PE) and polypropylene (PP) fibers hardened in concrete. Plastimetal included PE fibers rusted with metal. Plastisessiles consisted of PE fibers attached to benthic substrates by sessile invertebrates (oysters and polychaetes). Plasticoncrete and plastimetal constitute the first plastic forms composed of two man-made materials. Plastisessiles show that plastic forms not only result from human- or environment-mediated interactions but also from biological interactions between invertebrates and plastic. All plastic forms (bulk density ≥ 1.4 g/cm3) sunk during floating tests and hardly changed their positions during a 13-day field experiment and 153- to 306-day field monitorings, confirming their local formation, limited mobility and longevity. Still, experimentally detached plastic fibers floated, confirming that the formation of these plastic forms influences the fate of plastic fibers in the environment. The experiment also showed that plasticoncrete got deposited in beach sand under wavy and windy conditions, indicating that coastal waves and onshore winds drive plasticoncrete deposition in coastal sediments. We also provide first records of plasticoncrete on Mallorca island (Mediterranean Sea) and plastimetal on Hikoshima island (Sea of Japan), respectively, which show that these plastic forms are no local phenomena. Thereby, our study contributes to the growing fundamental knowledge of plastic forms that is essential to understand the role and fate of these pollutants in coastal habitats worldwide.
... For pretreatment, 50gm dry sample from each of the samples was taken and subjected to density separation using ZnCl 2 solution [18]. ZnCl 2 has a density of 1.7 g/cm 3 and the density of plastics varies in a range between 0.8 and 1.4 g/cm 3 , specifically for polyethylene (0.92-0.97 g/cm 3 ), polypropylene (0.85-0.94 g/cm 3 ), polystyrene (0.05-1 g/cm 3 ) and others are also in the same range [19]. ...
Microplastics, due to their microscopic size, constitute a concern to aquatic species since they are easier to consume and the recent discovery of microplastic in human blood shows that these may also have undisclosed health effects on humans. This study provides microplastic characteristics and abundance of microplastics in the shore sediments of Narmada river flowing along Jabalpur City. The information about the presence of microplastics can be crucial in preventing further pollution and developing management interventions. Sediments samples were collected from 4 sites along a 50 km stretch of the river. Sample pretreatment was performed using ZnCl2 solution for density separation and H2O2 for oxidation of organic material. Microplastics examination was carried out using Fourier Transform Infrared Spectroscopy (FTIR). Microplastics in the 20-1000 μm size range were found to be more abundant (114-273 MP/Kg) than larger microplastics in the 1-5 mm size range (18-110 MP/Kg). This research presents the first accounts of microplastic pollution in the shore sediments of Narmada River and it emphasizes the need for more in-depth research into microplastic pollution in fresh water sources.
... All absorbance and fluorescencebased assays; DCFDA assay Change probe (e.g., MTS to MTT) or switch to a similar assay (e.g., LDH release instead of MTS); add control measurements to quantify amount of interference; add steps to remove particles after exposure period Filtrate only control 68 44 flotation on the air−water interface, 45,46 and sedimentation of the particles out of the suspension after homo-or heteroagglomeration. 47,48 Sedimentation can potentially be accelerated in the presence of test organisms by agglomeration during passage through the organism or by attachment to suspended cells (e.g., algae, bacteria). 40,49,50 For other types of exposure systems, the size of the particles can impact function of the exposure test method. ...
To fully understand the potential ecological and human health risks from nanoplastics and microplastics (NMPs) in the environment, it is critical to make accurate measurements. Similar to past research on the toxicology of engineered nanomaterials, a broad range of measurement artifacts and biases are possible when testing their potential toxicity. For example, antimicrobials and surfactants may be present in commercially available NMP dispersions, and these compounds may account for toxicity observed instead of being caused by exposure to the NMP particles. Therefore, control measurements are needed to assess potential artifacts, and revisions to the protocol may be needed to eliminate or reduce the artifacts. In this paper, we comprehensively review and suggest a next generation of control experiments to identify measurement artifacts and biases that can occur while performing NMP toxicity experiments. This review covers the broad range of potential NMP toxicological experiments, such as in vitro studies with a single cell type or complex 3-D tissue constructs, in vivo mammalian studies, and ecotoxicity experiments testing pelagic, sediment, and soil organisms. Incorporation of these control experiments can reduce the likelihood of false positive and false negative results and more accurately elucidate the potential ecological and human health risks of NMPs.
The ice-covered periods is a natural phenomenon where ice forms on the water surface of rivers in areas with high latitude and cold climate. Ice blocks the diffusion of pollutants, thus causing changes in water quality characteristics. This paper focuses on the Harbin section of the Songhua River in the cold region of northern China. The occurrence characteristics and pollution level of microplastics (MPs) are explored in both ice and water of urban inland rivers and estuaries during the ice-covered periods. The results identified the discharge of domestic sewage as the main source of MPs in urban inland rivers. The abundance of MPs in MaJiaGou average of 324.36 ± 261.45 item/L, the abundance of MPs in SongHua ice raverage of 65.02 ± 68.15 item/L, while in the water with different depths of SongHua, the MPs it ranged from 1.03 ± 0.66 item/L to 12.86 ± 9.35 item/L,average is 5.59 ± 7.57 item/L.The amount of MPs in ice is about 11 times that in water.Ice formation caused a decline in MPs prevalence within the aquatic environment primarily due to the inclusion of a relatively large proportion of MPs within the ice mass during freezing. Additionally, it restricted atmospheric MPs from entering the river waters, contributing to the decrease.The abundance of MPs in urban inland rivers gradually increased from south to north, while that in the mainstream of the Songhua River showed an increasing trend from east to west. Detected MPs were mainly fibrous and white in shape and color, respectively, with a particle size < 0.5 mm. The fragmentation of micro plastics in ice is greater than that in water. Polyethylene, polypropylene, and polyacrylonitrile,etc were the main types of polymers. The results of ecological risk assessment showed that the MPs pollution in the Harbin section of the Songhua River reached moderate and severe pollution levels during the ice-covered periods Its potential risk should receive more attention and control should be strengthened. The research results have important reference significance for providing basic information for river pollution control and ecological protection in cold regions, providing a new direction for future research. In the future, more attention should be directed to the transfer and toxic effects of environmental MPs.
Microplastics are plastic debris smaller than 5 mm in size. In recent decades, the issue of microplastics contamination in marine organisms from the marine environment has gained more attention. This study focuses on the occurrence of microplastics in the gastrointestinal tract (GIT) of the crescent perch (Terapon jarbua). Sixty-two crescent perch were collected from four locations in Malaysia: Sungai Besar and Kuala Selangor on the west coast of Peninsular Malaysia, Kuantan on the east coast of Peninsular Malaysia, and Mukah in East Malaysia. Microplastics were found in the GIT in 82% of the samples with a mean value ranging from 1.46 ± 0.60 to 2.25 ± 1.26 particles/ind. Microplastics contamination in samples from Mukah was significantly higher than in samples from Kuala Selangor. The increased number of ingested microplastics could be attributed to the higher levels of microplastics contamination present in the coastal waters of Mukah due to the anthropogenic activities taking place there. The extracted particles were predominantly fibres, followed by fragment, and film. The microplastics ingested by crescent perch were primarily blue and black. µ-FTIR tests showed that the most common polymers found in crescent perch were rayon, polyethylene terephthalate, and polyethylene. The findings from this study provide initial evidence that microplastic contamination is emerging as a threat to crescent perch and the Malaysian water ecosystem. Further investigations into microplastics contamination in fish in Malaysia are required, as microplastics exposure to fish can induce adverse effects on the species and the food web.
Microplastics (MPs) released from food packaging have attracted widespread attention. In this study, drip bags made from polyethylene (PE), polypropylene (PP), polyester (PET), and rayon selected from eight brands were employed to investigate MPs releasing. Fourier-transform infrared microspectroscopy (μ-FTIR), optical microscope and scanning electron microscope (SEM) were used to study the effects of brewing time and temperature on the release of MPs. The results showed that a single plastic coffee bag steeped at 95 ℃ for 5 min could release more than 10,000 MPs particles into a cup of coffee. Irregular blocks, long strips, and size range of 10-500 μm MPs were easier to be released, implying that consuming 3-4 cups of coffee will lead to an intake of 50 thousand MPs particles daily. Rayon was the primary type of released MPs, accounting for over 80% of the total amount of the released MPs. Our results are hoped to provide evaluation standards of material selection for processing coffee bags.
This is the first study that investigated the presence, distribution, and composition of microplastics, MPs (1-5 mm) on beaches in the Yasawa Islands, Fiji. A temporal assessment over three years on six beaches was undertaken to investigate different beach traits on MP abundance. Average MP concentration was 4.5 ± 11.1 MPs·m-2 with significantly higher concentrations were found on east-facing beaches than west (p < 0.001), and higher on the storm line compared to the high tide line (p < 0.001). No difference was found between tourist and local beaches (p = 0.21). These results demonstrate the role of current-driven ocean transport of plastic pollution in this part of The South Pacific. ATR FT-IR analysis showed that across all sites 34 % of MPs were polypropylene (PP), 33 % polystyrene (PS), 25 % polyethylene (PE), and 8 % other polymer types. Further studies are needed to assess the potential impacts of MPs on Fiji's coral reefs and marine life.
Microplastics have been considered a new type of pollutant in the marine environment and have attracted widespread attention worldwide in recent years. Plastic particles with particle size less than 5 mm are usually defined as microplastics. Because of their similar size to plankton, marine organisms easily ingest microplastics and can threaten higher organisms and even human health through the food chain. Most of the current studies have focused on the investigation of the abundance of microplastics in the environment. However, due to the limitations of analytical methods and instruments, the number of microplastics in the environment can easily lead to overestimation or underestimation. Microplastics in each environment have different detection techniques. To investigate the current status, hot spots, and research trends of microplastics detection techniques, this review analyzed the papers related to microplastics detection using bibliometric software CiteSpace and COOC. A total of 696 articles were analyzed, spanning 2012 to 2021. The contributions and cooperation of different countries and institutions in this field have been analyzed in detail. This topic has formed two main important networks of cooperation. International cooperation has been a common pattern in this topic. The various analytical methods of this topic were discussed through keyword and clustering analysis. Among them, fluorescent, FTIR and micro-Raman spectroscopy are commonly used optical techniques for the detection of microplastics. The identification of microplastics can also be achieved by the combination of other techniques such as mass spectrometry/thermal cracking gas chromatography. However, these techniques still have limitations and cannot be applied to all environmental samples. We provide a detailed analysis of the detection of microplastics in different environmental samples and list the challenges that need to be addressed in the future.
Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1-6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon.
Microplastic pollution is increasingly becoming a great environmental concern worldwide. Microplastics have been found in many marine organisms as a result of increasing plastic pollution within marine environments. However, the relationship between micoplastics in organisms and their living environment is still relatively poorly understood. In the present study, we investigated microplastic pollution in the water and the mussels (Mytilus edulis, Perna viridis) at 25 sites along the coastal waters of China. We also, for the first time, conducted an exposure experiment in parallel on the same site using M. edulis in the laboratory. A strong positive linear relationship was found between microplastic levels in the water and in the mussels. Fibers were the dominant microplastics. The sizes of microplastics in the mussels were smaller than those in the water. During exposure experiments, the abundance of microbeads was significantly higher than that of fibers, even though the nominal abundance of fibers was eight times that of microbeads. In general, our results supported positive and quantitative correlations of microplastics in mussels and in their surrounding waters and that mussels were more likely to ingest smaller microplastics. Laboratory exposure experiment is a good way to understand the relative impacts of microplastics ingested by marine organisms. However, significant differences in the results between exposure experiments and field investigations indicated that further efforts are needed to simulate the diverse environmentally relevant properties of microplastics.
Microplastic pollution is recognized as an emerging threat to aquatic ecosystems. One of the main environmental risks associated with microplastics is their bioavailability to marine organisms. Up to date, ingestion has been widely accepted as the sole way for the animals to uptake microplastics. Nevertheless, microplastics have also been found in some organs which are not involved in the process of ingestion. We hypothesize that the animal might uptake microplastics through adherence in addition to ingestion. To test this hypothesis, we collected mussels from the fishery farms, conducted exposure/clearance experiments and analyzed the accumulation of microplastics in specific organ of mussels. Our studies clearly showed the uptake of microplastic in multiple organs of mussels. In the field investigations, we found that the abundance of microplastic by weight but not by individual showed significant difference among organs, and the intestine contained the highest level of microplastics (9.2items/g). In the uptake and clearance experiment, the accumulation and retention of microfibers could also be observed in all tested organs of mussels including foot and mantle. Our results strongly suggest that adherence rather than ingestion led to the accumulation of microplastics in those organs which are not involved in ingestion process. To our best knowledge, it is the first time to propose that adherence is a novel way for animals to uptake microplastics beyond ingestion. This new finding makes us rethink about the bioavailability, accumulation and toxicity of microplastics to aquatic animals.
The incidence of microplastics in marine environments has been increasing over the past several decades. The objective of this study was to characterize the size and shape dependent effects of microplastic particles (spheres, fibers and fragments) on the adult daggerblade grass shrimp, Palaemonetes pugio. Grass shrimp were exposed to 11 sizes of plastic; spheres (30, 35, 59, 75, 83, 116, and 165 µm), fragments (34 and 93 µm), and fibers (34 and 93 µm) at a concentration of 20,00 particles/400 mL (= 50,000 particles/L) for three hours. Following exposure, grass shrimp were monitored for survival, ingested and ventilated microplastics, and residence time. Mortality ranged from 0-55%. Spheres and fragments under 50 microns were not acutely toxicity. Spheres and fragments greater than 50 microns had mortalities ranging from 5-40%. Mortality was significantly higher at 93 µm fibers than other sizes tested (p < 0.001). The shape of the particle had a significant influence on the number of particles ingested by the shrimp (p < 0.001). The residence time of particles in the gut ranged from 27-75 hours with an average at 43.0 ± 13.8 hours. Within the gills, the residence time ranged from 27-45 hours with an average of 36.9 ± 5.4 hours. Results from this study suggest that microplastic particles of various sizes and shapes can be ingested and ventilated by adult daggerblade grass shrimp, resulting in acute toxicity. This article is protected by copyright. All rights reserved.
The presence of microplastic (MP) in the aquatic environment is recognized as a global-scale pollution issue. Secondary MP particles result from an ongoing fragmentation process governed by various biotic and abiotic factors. For a reliable risk assessment of these MP particles, knowledge about interactions with biota is needed. However, extensive testing with standard organisms under reproducible laboratory conditions with well-characterized MP suspensions is not available yet. As MP in the environment represents a mixture of particles differing in properties (e.g., size, color, polymer type, surface characteristics), it is likely that only specific particle fractions pose a threat towards organisms. In order to assign hazardous effects to specific particle properties, these characteristics need to be analyzed. As shown by the testing of particles (e.g. nanoparticles), characteristics other than chemical properties are important for the emergence of toxicity in organisms, and parameters such as surface area or size distribution need consideration. Therefore, the use of “well-defined” particles for ecotoxicological testing (i.e., standard particles) facilitates the establishment of causal links between physical-chemical properties of MP particles and toxic effects in organisms. However, the benefits of well-defined particles under laboratory conditions are offset by the disadvantage of the unknown comparability with MP in the environment. Therefore, weathering effects caused by biological, chemical, physical or mechanical processes have to be considered. To date, the characterization of the progression of MP weathering based on powder and suspension characterization methods is in its infancy. The aim of this commentary is to illustrate the prerequisites for testing MP in the laboratory from 3 perspectives: (i) knowledge of particle properties; (ii) behavior of MP in test setups involving ecotoxicological test organisms; and (iii) accordingly, test conditions that may need adjustment. Only under those prerequisites will reliable hazard assessment of MP be feasible. Integr Environ Assess Manag 2017;13:500–504.
Microplastic is an umbrella term that covers many particle shapes, sizes, and polymer types, and as such the physical and chemical properties of environmental microplastics will differ from the primary microbeads commonly used for ecotoxicity testing. In the present article, we discuss the physical and chemical properties of microplastics that are potentially relevant to their ecotoxicity, including particle size, particle shape, crystallinity, surface chemistry, and polymer and additive composition. Overall, there is a need for a structured approach to the testing of different properties to identify which are the most relevant drivers of microplastic toxicity. In addition, the properties discussed will be influenced by and change depending on environmental conditions and degradation pathways. Future challenges include new technologies that will enter the plastic production cycle and the impact of these changes on the composition of environmental microplastics.
Integr Environ Assess Manag 2017;13:470–475.
Microplastics [MPs], now a ubiquitous pollutant in the oceans, pose a serious potential threat to marine ecology and has justifiably encouraged focused biological and ecological research attention. But, their generation, fate, fragmentation and their propensity to sorb/release persistent organic pollutants (POPs) are determined by the characteristics of the polymers that constitutes them. Yet, physico-chemical characteristics of the polymers making up the MPs have not received detailed attention in published work. This review assesses the relevance of selected characteristics of plastics that composes the microplastics, to their role as a pollutant with potentially serious ecological impacts. Fragmentation leading to secondary microplastics is also discussed underlining the likelihood of a surface-ablation mechanism that can lead to preferential formation of smaller sized MPs.
These test methods describe the determination of the specific gravity (relative density) and density of solid plastics in forms such as sheets, rods, tubes, or molded items. 1.2 Two test methods are described: 1.2.1 Test Method A—For testing solid plastics in water, and 1.2.2 Test Method B—For testing solid plastics in liquids other than water. 1.3 The values stated in SI units are to be regarded as the standard.
Marine microscopic plastic (microplastic) debris is a modern societal issue, illustrating the challenge of balancing the convenience of plastic in daily life with the prospect of causing ecological harm by careless disposal. Here we develop the concept of microplastic as a complex, dynamic mixture of polymers and additives, to which organic material and contaminants can successively bind to form an ‘ecocorona’, increasing the density and surface charge of particles and changing their bioavailability and toxicity. Chronic exposure to microplastic is rarely lethal, but can adversely affect individual animals, reducing feeding and depleting energy stores, with knock-on effects for fecundity and growth. We explore the extent to which ecological processes could be impacted, including altered behaviours, bioturbation and impacts on carbon flux to the deep ocean. We discuss how microplastic compares with other anthropogenic pollutants in terms of ecological risk, and consider the role of science and society in tackling this global issue in the future.