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Abstract

Today the world is going through the “Plastic Age.” Nowadays, it is difficult to find a commonly used convenient item that is nonplastic. Plastic production and consumption, thus, increased exponentially and plastic emerged as one of the major concerns for waste management. Recent studies confirmed a faster rate of plastic degradation than previously believed under various conditions (e.g. saltwater, UV, soil interaction) that microplastic has become a new type of health-hazardous pollution source. Much research has been conducted since the discovery of the “Pacific Garbage Patch,” and the scope has expanded from marine to soil, groundwater, air, and food chain. This article underwent a substantial amount of literature review to verify the degree of microplastic pollution progression in major pillars of the environment (aqueous, terrestrial, airborne, bio-organism, and human). Multiple kinds of literature indicated a high possibility of vigorous interaction among the pillars that microplastic is not stationary at the point of contamination but travels across the nation (transboundary) and medium (transmedium). Thus, only the waste reduction policy (i.e. production and consumption reduction) would be effective through a single national or local effort, while pollution and contamination management require more of a collective, if not global, approach. For these characteristics, this article proposes two most urgently required actions to combat microplastic pollution: (a) global acknowledgement of microplastic as transboundary and transmedium pollution source that require international collective action and (b) standardization of microplastic related research including basic definition and experimental specification to secure global comparativeness among data analysis. Without resolving these two issues, it could be very difficult to obtain an accurate global status mapping of microplastic pollution to design effective and efficient global microplastic pollution management policies.

Keywords

Microplastic pollution soil marine air food chain groundwater

Introduction

Since the commercialization of plastic materials to replace animal-derived materials such as elephants’ ivory or tortoiseshell in 1862,¹ plastic penetrated every corner of modern life. Owing to its cheap and easy mass production capability than conventional materials (e.g. paper, glass, and metals), plastic products have created a “single-use culture.” Fueled by the post-World War modern fast-moving lifestyle, it now is impossible to spend a day without using plastic of some kind. The outbreak of COVID-19 further expanded the use of plastic to “sanitation and safety.”² The world now faces a new type of daily “safety measure” waste (i.e. personal protective equipment, test kits, vaccine syringes, and single-use cutlery) in addition to the conventional high volume of plastic waste traded for its convenience, low-cost, durability, unbreakable, heat resistance, and lightweight.

Due to the traditional belief around the “durability” of plastics, the major issues focused on how to secure enough landfill space to address rapidly increasing plastic wastes and how to capture illegally dumped plastic products in the early years. The agenda, however, got stirred with the discovery of the “Pacific Garbage Patch,” also known as the Pacific Trash Vortex, in 1997 by Charles Moore on his sailing way back to California from Hawaii.³ Unlike traditionally imagined plastic trash floating on the ocean surface or sunk in deep-sea sediments, the Garbage Patch revealed a “cloudy soupy zone in the middle of the Pacific Ocean” made of tiny bits of plastics, now termed microplastic.⁴ As microplastic pollution gained research interest among academia, the scope of studies assessing the spread and impacts of microplastic also expanded from marine environment to fresh-to-groundwater, terrestrial habitats, and air. Reinforced by enhanced public awareness and international pressure, it also took less than a decade for many governments to adopt a microplastic reduction policy stance.²

The research, however, lacked time to fully ripe in depth that the state of global knowledge on microplastic is rather fragmentary and sparse than interdisciplinary and comprehensive.⁵ Although any research is meaningful for its own purpose, it would be even better if each puzzle piece can collectively contribute toward a global knowledge map on microplastic. This paper, thus, attempts to review the nature of microplastic pollution progress observed and analyzed in various environmental fields (marine, soil, groundwater, air, and food chain) to deduce possible policy implications to best support research advancement in this newly emerged environmental challenge of this “Plastic Age.”

Invasion of microplastic pollution in the ecosystem

Marine environment

The most common types of plastics found in marine environments are polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC).^6,7 There are two main processes, through which microplastics reach the marine environment. First, large plastics naturally degrade into microplastics in the marine environment, and second, the microplastics flow into seawater through rivers and other water cycles from the land.^6,8 The major source of large plastics in the marine environment is the fishery industry: fishing nets contributes approximately 640 thousand tons (10% of total marine wastes).⁹ These fishing nets undergo biodegradation, photodegradation, or hydrolysis into microplastic less than 5 mm.^6,10,11

Yet, beach waste is the largest contributor to marine microplastic pollution through plastic degradation.¹² This is because the low water temperature of saltwater slows the degradation process that the microplastic formation rate is lower in the far deep ocean. Contrarily, beach sand temperature rise up to 40 °C creating a faster photodegradation for plastic bottles dumped on the shore rather than floating in the Pacific Ocean.^6,12,13 Microplastics that reach the ocean floor from land usually are comprised of the wash-off of personal products, fabric from laundry, and particles from vehicle tires.¹⁴ This finding matches the analysis result on marine microplastics collected from Playa Grande Beach, Canary Islands of Spain in 2020 to have comprised of PP and PE in the form of microplastic fragments, pellets, fiber and films.^13,15 As the gravity of marine plastic pollution was only revealed in 1997 with Pacific Garbage Patch, the history of marine microplastic pollution research is not very long. Old observation records on plastics of a few millimeters in size both on the ocean surface and inside of many saltwater fishes on the East Coast of the United States and the Southern part of the United Kingdom went unnoticed for almost 30 years.^16–18 It was Thompson's article published in Science in 2004 that first introduced the term, “microplastic,”¹⁹ and triggered much research efforts in related fields.

Promisingly, the scope of marine microplastic research has been expanded to marine ecological microorganisms and food chains. Animals exposed to microplastic-concentrated water has been found to produce unhealthy egg and sperms, which resulted in 41% fewer larvae than the animals in clean water.⁸ The Pacific Krill (Euphasea Pacifica) was observed to ingest its staple algae, as well as PE beads, ground to about the same size range with no evident foraging bias.²⁰ This infers a possibility of microplastic invasion into the food chain as krill, whether it is ingested via algae or plastic beads, is favored diet by predators and seagulls nearby. Some researchers further introduced the concept of “secondary nanoplastics” resulting from the biodegradation of microplastic through digestion and food chain accumulation.¹⁴ Yet, many laboratory experiments and related research efforts still lean heavily toward “how much” and “what kind” of microplastic has polluted the marine environment. Thus, there currently is insufficient research on the effects of microplastic formation in marine environments that understanding on the possible consequences on marine ecology and human health is yet too low to be translated into effective policy.

Soil

Since the introduction of microplastic soil contamination²¹ related studies expanded both in scope and volume.^22–27 The United Nations Environment Program (UNEP) further recognized the need to verify the consequences of microplastic pollution in the soil environment on World Environment Day.²⁸ Insofar, researchers focused on the hazardous effects of microplastics in soil and terrestrial ecosystems,^29–31 with emphasis on its rapid spreading rate in soil environments.^21,29,31,32 Recent studies worryingly indicated the possibility of 4 to 23 times higher microplastic concentration on land than in the ocean²⁴ due to many entry points such as microfibers from clothing, plastic beads from personal care products, biosolids,^33–37 reclamation sites in urban and industrial centers,³² lake water flooding, road waste and illegal waste dumping,³⁸ tire wear,^39–41 atmospheric particles,⁴² and fertilizers.^24,31

Yet, there is a growing consensus that the agricultural ecosystem is the major pathway for microplastic in terrestrial environment^43,44; the largest concerns involve wastewater irrigation and mulching used in agricultural activities.^45–48 The application of PE plastics in agricultural processes in 1938 revolutionized commercial crop productivity^49,50 but resulted in heavy microplastic soil pollution (approximately 10% of all agricultural soil).⁵¹ The situation was exacerbated when the usage of sewage sludge as agricultural fertilizer became a standard management process. Studies estimate approximately 63,000 to 430,000 tons and 44,000 to 300,000 tons of microplastics have been discharged annually in Europe and North America, respectively.^31,32 Accounting for the vast physical coverage, the agricultural soil is also described as microplastic-contaminated large reservoirs in which airborne particles drop,⁴² mostly likely in form of precipitation.^25,38,52

Microplastic soil pollution has been found to alter the physical properties of soil, reduce soil fertility, and destroy resident microbial communities. Altogether, the contamination impairs soil quality and nutritional circulation^53–56 to infertile the crops,⁵⁷ damages the reproductive growth of plants,⁵⁸ and exhibits plant ecotoxicity and genetic toxicity.⁵⁹ It has been shown that macro and microplastic residues in soil have a negative effect on wheat (Tricum aestivum) growth.⁵⁸ In addition, the germination rate decreased when exposed to microplastics using Cress seeds, indicating that microplastics can physically block the pores of the seeds and interfere with moisture absorption, delaying germination.⁵⁷ Intracellular absorption of nanoplastics (20 and 40 nm) in tobacco BY-2 plant cell culture was confirmed by fluorescent microplastic images.⁶⁰ In addition, evidence of attachment, absorption, accumulation, and migration of microplastics within edible plant lettuce was observed using fluorescent markers.⁶¹ As such, there is still not much information on microplastic accumulation by plants in the soil, and research on quantifying microplastics in more plant species is needed.⁶²

In addition, microplastics ingested by earthworms were found to travel through the food chain, which may pose a potential threat to terrestrial predators and even humans.⁶³ Despite the seriousness of microplastic pollution hazard posed to soil biodiversity, ecosystem function, and food security, there currently is limited knowledge on the environmental impact of microplastics on actual soil, or how microplastic-polluted soil impedes nutritional circulation.

Groundwater

Groundwater is another important water resource as it accounts for 97% of accessible freshwater^64,65 that deserves an increase in quality management efforts. Yet, microplastic pollution research on groundwater only began in 2017 as groundwater traditionally was considered as impenetrable.⁶⁶ The first study subjected karst areas, the most vulnerable to aquifer pollution, to verify the existence of microplastic contamination in groundwater.⁶⁶ Since then, the experiments focused on the microplastic pollution progress investigation (e.g. concentration, polymer type, shape, and color) by the surrounding environment and geology of the aquifer.⁶⁷ Among various inflow pathways of microplastics into the aquifer, ranging from sinkholes, groundwater wells (pumping), seawater infiltration, and vertical transport by soil organisms or rainfall,^44,56,68 surface water is known to be the critical passage.^69,70 Although research on this important carrier, surface water, took its course a decade prior to groundwater in 2007, it still is in the early stage.^71–73 The findings deduced four major cases through which microplastic enters surface water: discharged residuals from unsuccessful decomposition or filtration during the wastewater treatment processes, run-offs, flooding and tidal inflows.^24,74,75

To understand the transport and retention of microplastics in the hyporheic zone (i.e. groundwater-surface water interaction zone), studies adopted colloidal transport model analysis under various environmental conditions (e.g. chlorine concentration, ion strength, and microplastic particle size change).^76–81 Research has also been expanded to develop a new upgraded microplastic transport model tailored for groundwater passage investigation from the conventional colloidal model.^76,82 The analysis results reported increasing average microplastic concentration in deeper layers of sediments with decreasing particle size.⁸³ As PP and PE are the dominant microplastic polymers collected from surface water, followed by PS, PET, PA, PCV, and PU, the two are the most common types detected also in groundwater.^80,84 The difference is observed from shape: while the majority takes fiber form in surface water, most are decomposed into fragments under 50 µm in groundwater.^65,67 Such difference satisfies research conclusions that surface water contributes the most to the microplastic pollution in groundwater and the geological environment surrounding groundwater acts as a natural filter against large pollutants.

Accounting that the major uses of groundwater are agricultural and drinking purposes, microplastic contamination poses a serious threat to human health, possibly worse than food. Furthermore, there is a growing concern about the effects of microplastic pollution on smaller organisms (microorganisms, troglofauna, and stygofauna) inhabiting in groundwater environment.^85–87 Yet, research on microplastic pollution in groundwater is limited to the verification of causes and subjects rather than the aftereffects or remedies to contamination.^88,89 Furthermore, much of the currently conducted microplastic transport modeling experiments are bounded within the laboratory that their actual application is still questionable. In this light, microplastic pollution-related research on groundwater environments can be categorized as being in its primitive stage and possess much room for expansion and development.

Air

Interest in research on microplastic atmospheric pollution increased when the first signs were detected in Grand Paris in 2015.⁹⁰ Since this identification, primary research efforts acknowledged the possible causal relation between airborne microplastic fallout and urban wastewater/freshwater microplastic contamination.^42,90,91 Another strand of comparative studies in remote areas with almost no anthropogenic activities (such as the Pyrenees, a nature-preserved mountain in France) further suggested the likelihood of microplastic atmospheric transport in a similar pattern with particulate matters.^42,52,92,93 Specifically, the meteorological factors and cloud formation process (atmospheric currents) are found to be the most vital conditions that determine the length and time of microplastic atmospheric transport.^94–96 The atmospheric microplastic fallout concentration is observed to be higher on rainy days and Winter seasons compared to Summer and Spring.^{42,90,91,94,97}

Their low density and very small size allow long buoyant time,^42,98 and there seems to be free interchange occurring between airborne, terrestrial, and aqueous microplastic. Strong wind and spray emission releases significant amounts of microplastics formed either through degradation in seawater or various economic activities on land into the atmosphere,^{42,90,99–101} while the airborne falls into vast land or oceans under appropriate climate conditions (e.g. precipitation).¹⁰² Although the exact interaction between extreme weather conditions (e.g. hurricanes, typhoons, cyclones, and monsoons) and airborne microplastics has yet to be identified, dust storms have been identified to play a key role in atmospheric microplastic transportation.¹⁰³ Erosion of synthetic materials (e.g. tires, fibers, building materials) is found to be the major source of airborne microplastic,^42,90,100 followed by building materials, waste incineration, fertilizers made of sludge, abrasive powders, and 3D printing.^104–106 Accordingly, fragments, films, and fibers^97,106–110 made of PE, PP, PS, and PET are the most common shapes and types of microplastic found in the atmosphere.^106,108

Recently, the research scope of microplastic pollution in the air has expanded to include the impacts of airborne microplastics on human health and the environment.^{108,110–113} A number of studies suggest a higher risk from indoor microplastic contamination than outdoor as is the case with many other typical air pollutants’ health risks.^{42,108,112,113} This is because pollutants typically require a certain inhalation concentration to exert health-hazardous reactions such as interstitial lung diseases.¹¹² Although such findings are still too broad to understand the movement and consequences of airborne microplastics, one thing clear is that microplastic air pollution is transboundary, transmittable to other mediums, and health hazardous. The world, thus, requires more collaborative research in the field to deduce policy recommendations for global cooperation. In this light, standardizing key experiment definitions, protocols, and specifications is an urgent task, especially in aspects regarding air pollution.

Food

Food research began when nonpollen particulates spotted in honey and sugar were identified as microfibers and fragments,¹¹⁴ which raised the possibility of microplastic existence in nature as much as being inserted during the food manufacturing process. In 2014, microplastic was detected in local beer sold in Germany,¹¹⁵ which triggered related research together with the findings that ocean creatures have been exposed to marine plastic waste for years. It was found that floating marine plastic waste is ingested by planktonic organisms and eventually travel across the food chain from trophic level to higher level.^6,116,117 Other research revealed that microplastic can reach marine mammals both directly from surrounding particles and indirectly through contaminated prey,¹¹⁸ which may result in decreased body defenses through cell damage.¹¹⁹ As microplastic ingestion by copepod and Euphausiacea (krill) were verified,^19,120–125 experiments on bivalves raised for human consumption were conducted to understand how close microplastic pollution has approached human's everyday lives.¹²⁵ Food items from which microplastic wastes are detected include: bivalves and various fishes,¹²⁶ salt,¹²⁷ dry fishes,¹²⁸ mussels,¹²⁹ tap water and beer,¹³⁰ and milk.¹³¹

Since the identification of microplastics from salt through a case study in China,¹²⁷ micro-Fourier Transform Infrared Spectroscopy (μ-FT-IR) analysis has been adopted to distinguish the type of plastic present in food and beverage. Supported by technical advancement, the related research scope has been expanded to verify that plastic residuals penetration into food occurs throughout the entire food preparation period: mulching film used in agriculture is absorbed by wheat,⁵⁸ microplastic present in groundwater is transferred to drinking water,¹³² microplastic exist in various drink packed in plastics bottles,¹³³ plastic tea bags released microplastic in hot water,¹³⁴ raw meat absorb microplastic from pressed PS used in packaging,¹³⁵ and microplastic was released from various plastic containers, plates, cutlery, and cups under various conditions.^136,137 Other researchers raised further concerns about the possibility of microplastic turning poisonous once ingested internally (adhesive to other chemicals and cohesive to metals or bacteria).^{121,138–141}

So far, microplastic-related research on food has expanded much in both quantity and subjects. Yet, the research scope and purpose are still limited to existence verification in items that are commonly consumed by people, either directly ingested food or plastics used in food packaging and cutlery.^135,142,143 The aftereffects of the microplastic present in these eatable conditions are still unknown as much as the process or degree of absorption once these microplastics successfully reach the human body (Table 1).

Table 1.

Literature review on microplastic pollution in research fields (marine, soil, groundwater, air and food).

Location	Sampling	Polymer types	Size	Shape	Color	Concentration (abundance)	Reference
Marine
Maine Bay, USA	Sea surface	Rayon and PE	5–282 mm	Fiber	Black (62%), blue (15%), red (13%), and colorless	0.60 ± 0.25 n/m³	¹⁴
Great Barrier Reef Marine Park, Australia	Sea surface	PE, PP, PS, and EVA	0.4–82.6 mm	Pellet	White, colorless, and blue	4.96 ± 0.27 n/m³	¹⁴⁴
The North Atlantic	Sea surface	PE, PS, and PP	1–100 mm	N/A	N/A	1.6 ± 0.5 n/m³	¹⁴⁵
Daebu Island, South Korea	Beach	PP, PE, PS, EVA, and PUF	0.3–5 mm	N/A	N/A	Summer: 272,349 (±357,535) n/m³ and winter: 10,318 (±6247) n/m³	¹⁴⁶
Soil
Franconia, Germany	Farmland	PE, PP, and PS	1–5 mm	Film, fragment and fiber	N/A	0.34 ± 0.36 n/kg⁻¹	¹⁴⁷
Shanghai, China	Farmland	PP, PE, and PES	1.91 ± 0.13 mm	Fiber, fragment and film	N/A	78.0 ± 12.9 n/kg⁻¹	¹⁴⁸
Mellipilla, Chile	Agricultural	N/A	20 mm (width) 0.97 mm (length)	Fiber	N/A	600–10,400 n/kg⁻¹	¹⁴⁹
Shanghai, China	Paddy	PE, PP, and PVC	0.02–1 mm (domain)	Fiber, fragment and film	N/A	10.3 ± 2.2 n/kg⁻¹	¹⁵⁰
Groundwater
Illinois, USA	Karst aquifer	PE	<1.5 mm	Fibers	Blue and/or colorless (65%), red (15%), and gray (13%)	15.2 n/L (max)	⁶⁶
Victoria, Australia	Alluvial aquifer	PE, PS, PP, PVC, PET, PC, PMMA, and PA	18–491 µm	Fragments and fibers	N/A	38 ± 8 n/L	⁶⁷
Tamil Nadu, India	Wells & borewells	Nylon (PA, 35%), PE (55%), and PET (10%)	0.11–12.5 mm (mean: 0.6 ± 1.4 mm) and <1 mm (34% domain)	Fibers, foam, pellets, films, and fragments	Colorless (53%), white (30%), blue (10%), gray (5%), and yellow (2%)	4.2 n/L (median) and 10.1 n/L (max)	¹⁵¹
Krakow, Poland	Deep well (untreated potable water)	N/A	0–0.045 mm	Fragments	Blue and green	N/A	¹⁵²
Air
Greater Paris, France	Urban outdoor atmospheric fallout	N/A	100–5000 µm	Fibers and fragments	N/A	30–100 n/100 m³	⁹⁰
Asaluyeh County, Iran	Outdoor	N/A	100–1000 µm	Fiber, spherules, fragment and film	White-transparent: >70% blue–green	0.3–1.1 n/m⁻³	¹⁵³
Central London	Outdoor	PAN, PES, PA, PP, PVC, PE, PET, PE, PUR, and PPR	75–100 µm	Fragments, films, granules and foam	N/A	59 ± 32 n/m²/d (mean)	¹⁵⁴
South Korea	Indoor/outdoor	PE, PP, PA, PES, AR, and PS	Indoor: 20.1–6801.2 µm and outdoor: 20.3–4497.4 µm	Fibers, fragments, and film	N/A	Indoor: 0.49–6.64 (3.02 ± 1.77) n/m³ and outdoor: 0.45–5.16 (1.96 ± 1.65) n/m³	¹⁵⁵
Food
North Sea, Germany/Brittany, France	Bivalves (Mytilus edulis and Crassostrea gigas)	N/A	5–10 mm/11–15 mm	N/A	Red and blue	0.36 ± 0.07 n/g (Mytilus eduli) and 0.47 ± 0.16 n/g (Crassostrea gigas)	¹²⁵
China	Table salt (sea salt, lake salt, and rock/well salt)	PET, PE, and cellophane	45 μm–4.3 mm	Fiber and fragment	Black, red, blue, and white	550–681 n/kg (sea salts), 43–364 n/kg (lake salts), 7–204 n/kg (rock/well salts)	¹²⁷
Spain	Table salt (sea salt and rock/well salt)	PET, PP, and PE	30 μm–3.5 mm	Fiber	Black, red, blue, and white	50–280 n/kg (sea salt), 115–185 n/kg (well/rock salt)	¹⁵⁶
Mexico City, Mexico	Beer, soft drinks, energy drinks, and cold tea	PA, PEA, and ABS	0.1–3 mm	Fiber and fragment	Blue, red, brown, black, and green	ND–28 ± 5.29 n/L (beer), ND–7 ± 3.21 n/L (soft drinks), ND–6 ± 1.53 n/L (energy drinks), and 1 ± 0.57–6 ± 2 n/L (cold tea)	¹³³

N/A: not available/reported; ND: not detected; PA: polyamide; PE: polyethylene; PES: polyester; PP: polypropylene; PS: polystyrene; PVC: polyvinyl chloride.

Source: Author tabulated.

Microplastic pollution as global agenda

Transboundary and transmedium characteristics of microplastic pollution

As elaborated in the previous section, microplastic pollution is not a point-specific phenomena that remain at the point of origin until managed, but more of a transboundary, transmedium like conventional particulate matter air pollution or dichloro–diphenyl–trichloroethane (DDT) pollution.^106,157 Recent analytical results that reported 28% of marine microplastic pollution originated from road vehicle movements (tire wearing) further emphasized the need to understand the relationship between air circulation and the transportation of airborne microplastics.^158,159 Thus, there now is a growing concern calling for a comprehensive study on the dynamic interaction and transport among different environment mediums and locations to identify microplastic pollution cruising through the ecosystems¹⁵⁶ possibly taking different forms.

While the sea spray process and air bubble bursting on the ocean surface contribute to atmospheric microplastic pollution,^106,160,161 airborne microplastics also are deposited in terrestrial or aquatic environments that may end up in the human body through food chain accumulation^104,106 (Figure 1). Microplastic pollution from precipitation can spread over long distances through atmospheric transport, which can also spread microplastic pollution to remote uninhabited areas.^92,162 Soil and water basins act as a sink for microplastic¹⁴ receiving airborne microplastic fallouts and more generated from various anthropogenic activities. Microplastics, thereon, invade hidden pillars of the ecosystem like the food chain and groundwater.^22,38,162 Raindrops falling from the atmosphere are recharged into aquifers through soil or stream bed sediments (hyporheic zone).^56,163 In addition, in areas where tidal motion is active, microplastic enter the aquifer through seawater infiltration.¹⁶⁴

Figure 1.

Microplastic transport and circulation throughout environmental pillars.

The natural adaptation patterns have also been observed, which, in turn, confirm the prolonged effects of microplastic pollution: marine microorganisms are now utilizing plastic parts floating on marine surfaces as a new type of habitat¹¹ as the portion of plastic waste surface coverage increased exponentially for them to persist on traditional ways. Several marine ecologists have further experimented on the consequences of microplastic ingestion by marine animals and reported that the survival instincts of perch larvae exposed to microplastic pollution were weakened.¹⁶⁵ The observed microplastic concentration from Southern Bluefin tuna in Tasmania revealed that microplastic accumulates along the marine food chain in a similar manner to the famous mercury poisoning.¹⁴⁴ A study on the effects of microplastic-contaminated sewage sludges and mulching also revealed different onion growth patterns depending on the type of microplastic exposed.¹⁶⁶ It has also been found that plastics on surface soil can be integrated into the deep soil by the latent activity of earthworms,²¹ which indicated the possibility of debris plastics and microplastics combined in the surface soil can be transported into deeper layers by the activity of soil organisms such as collembolans, insects, and plants.^{44,54,167–169} Lwanga et al.⁶³ reported that the highest microplastic concentration was observed in chicken feces, especially in chicken sandbags (a popular food ingredient in many countries), in the nutritional migration study on microplastic in house garden soil, earthworms, and chicken excrement.

Prerequisite to address microplastic pollution together

Despite the growing number of literature addressing various aspects of microplastic pollution, it is still difficult to “stand on the shoulders of giants (Isaac Newton)” due to the absence of standard operating protocols for microplastic analysis.¹⁵⁷ Researchers across the world are adopting different terminology, size, meaning and apparatus that a direct comparison and contrast among the results is limited. One prime example of a currently lacking global consensus or standard is the absence of a global definition/classification of microplastic. While the most frequently cited definition goes “microplastics are plastics that are <5 mm in length,” as proposed by Zhu et al.,¹⁶⁹ there is no clear lower boundary that many researchers indicate only the lower limit of the sampling method or processing apparatus. This variation results in incomparable or incompatible data collection, which consequently poses risks to global knowledge sharing for complete microplastic pollution mapping. Another example is the inconsistency in an itemized subject definition of microplastic: while rubber, some fibers, and paint particles are not considered as plastic by many polymer chemists,¹⁷⁰ others name abrasion of vehicle tires (19% natural rubber and 24% synthetic plastic rubber polymer) as major contributors to microplastic pollution. This inconsistency may cause confusion in data collection with different total numbers undermining analysis results reliability.

Additionally, there still are many missing puzzle pieces in each environment medium for a comprehensive microplastic pollution mapping. In marine microplastic pollution, for example, it is very likely for microplastics to sink below and endanger deep sea or marine ecosystems beyond the surface water as density increases by adhering to marine microorganisms or others.^6,8,10 Despite a growing consensus, there are not many studies addressing the deep ocean floor or its potential consequences on marine ecosystems. Airborne microplastics are transported a long distance through air circulation system and are deposited on the terrestrial or aquatic environment under appropriate meteorological conditions such as rainfall and snowfall.^{92,94,161,171,172} Yet, the effects of extreme weather events (e.g. cyclone, hurricane, and monsoon) and climate change on microplastic pollution have yet been scrutinized. Similarly, despite the occurrence of microplastic in soil being ingested¹⁷³ or transferred to other soil organisms,³² the possible toxic side effects of microplastics on living organisms, including human health, have yet to be fully explored. As demonstrated, the research in groundwater contamination is in such an early stage to discuss the loopholes.

The most urgently required step, however, is to achieve global consensus to treat microplastic pollution as another kind of transboundary and transmedium pollutant that calls for a global approach. The absence of the exact term, “microplastic pollution,” on the global agenda (such as the Sustainable Development Goals of the United Nations or the Intergovernmental Oceanographic Commission of UNESCO) impedes cooperative international efforts including the collection and exchange of related data and knowledge.¹⁷⁴ It is also important to realize there is no reason for microplastic pollution to be less severe in developing or less-developed countries than in developed regions. Accounting for the effects of environmental policy in general terms, it is a logical deduction to expect a worse scenario under relatively fewer sensitive governments (i.e. heavier use of plastics for cost reduction). Yet not much research has been conducted in these regions for low interest. This is another reason to push microplastic pollution on the global agenda for collective efforts: such global attention will pressurize international organizations and local governments to monitor microplastic pollution circulation in these regions, thus, contributing toward global microplastic generation and circulation reduction.

Conclusion

The discovery of the “Pacific Garbage Patch” in 1997 changed the entire view on plastic pollution and the world realized the presence of microplastics in our daily lives. Nothing comes for free, and convenience demands payment of some sort. The world enjoyed the Plastic Age of convenience and now faces the Climate Change Age and the Pollution Management Age. Microplastic pollution is one of the items that require global efforts to Reduce (initial generation), Stop (transboundary and transmedium transport), Recover (damages done), and Shift (toward a sustainable living style). The world needs more information to design these international collaborative actions into policies and regulations. The first step for this is to acknowledge transboundary and transmedium characteristics of microplastic pollution and to stipulate the term in global actions. Global acknowledgment will trigger the standardization of research protocols, scopes, and experimental specifications to enable more concrete and comparative research in related fields. Once research data and volume reach a threshold, the research interest will naturally expand to developing and less-developed countries, beyond currently interested governments, for global status mapping of microplastic pollution. Microplastic pollution, in short, calls for more comprehensive and comparative scientific data and analysis interpretation to be translated into effective and efficient policy drivers, another cornerstone toward a Sustainable Development Age to avoid future environmental crises.

Footnotes

Author contributions

HK designed most of the research analysis input, and HSR, JM, NAK, CY, JHY, and ML wrote the manuscript. HK review and editing. HK resources, project administration, and funding acquisition. ML, HSR, JM, NAK, CY, and JHY edited the manuscript. All authors have read and agreed to the published version of the manuscript.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

This research was funded by the Korea Environment Industry & Technology Institute (KEITI) through the Measurement and Risk Assessment Program for the Management of Microplastics Program, funded by the Korea Ministry of Environment (MOE) (Grant No. 2020003110010); Korea Ministry of Environment, with the strategic EcoSSSoil Project (Grant No. 2019002820004); and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No. 2019R1I1A2A01057002 and 2019R1A61A03033167).

ORCID iDs

Minha Lee

Heejung Kim

Jinah Moon

Naing Aung Khant

Author biographies

Minha Lee received her PhD from Korea University in 2021. She is a post-Doc researcher at the Kangwon National University conducting researches on emerging environmental issues like water security, microplastic pollution, and climate change.

Heejung Kim is an associate professor in the Department of Geology at Kangwon National University, focusing on groundwater resources and environment.

Han-Sun Ryu is a Ph.D candidate in the Department of Geology at Kangwon National University, Korea. She mainly researched on hydrochemistry in karst area, the relationship between earthquake and groundwater, and the change in groundwater level in deep geothermal wells.

Jinah Moon is a PhD candidate in the Department of Geology at the Kangwon National University. Her current research interest is in geomicrobiology and environment.

Naing Aung Khant is a PhD candidate in Department of Geology at Kangwon National University. His research mainly focuses on microplastic pollution in the environments and environmental geology.

Chaerim Yu is a Master candidate in the Department of Geology at Kangwon National University, Korea. Her current reasearch interest is in geomicrobiology.

Ji-Hee Yu is a Master candidate in Department of Geology at Kangwon National University, Korea. Her current research interest is in geological heritage.

References

Science Museum. The age of plastic: from parkesine to pollution. https://www.sciencemuseum.org.uk/objects-and-stories/chemistry/age-plastic-parkesine-pollution (2019, accessed 14 May, 2022).

Lee

Kim

COVID-19 pandemic and microplastic pollution. Nanomaterials 2022; 12: 51.

National Geographic Society. School educational encyclopedic entry on “Great Pacific Garbage Patch”. 2022. https://www.nationalgeographic.org/encyclopedia/great-pacific-garbage-patch (accessed 14 May 2022).

International Union for Conservation of Nature (IUCN) Issues Briefs. Marine plastic pollution review. https://www.iucn.org/resources/issues-briefs/marine-plastic-pollution (2021, accessed 14 May 2022).

Welden

Lusher

Microplastics: From origin to impacts. In Plastic waste and recycling. Cambridge, MA: Academic Press, 2020, pp.223–249.

Andrady

. Microplastics in the marine environment. Mar Pollut Bull 2011; 62: 1596–1605.

Barboza

Gimenez

. Microplastics in the marine environment: current trends and future perspectives. Mar Pollut Bull 2015; 97: 5–12.

Cressey

. The plastic ocean: scientists know that there is a colossal amount of plastic in the oceans. But they don’t know where it all is, what it looks like or what damage it does. Nature 2016; 536: 263–265.

Macfadyen

Huntington

Cappell

. Abandoned, lost or otherwise discarded fishing gear. Report, Courtesy of the National Oceanic and Atmospheric Administration, USA, January 2009.

10.

Eriksen

Lebreton

Carson

, et al. Plastic pollution in the world's oceans: more than 5 trillion plastic pieces weighing over 250,000 tons afloat at sea. PLoS ONE. December 10, 2014. DOI: 10.1371/journal.pone.0111913.

11.

Rogers

Carreres-Calabuig

Gorokhova

, et al. Micro-by-micro interactions: how microorganisms influence the fate of marine microplastics. Limnol Oceanogr Lett 2020; 5: 18–36.

12.

Pedrotti

Petit

Elineau

, et al. Changes in the floating plastic pollution of the Mediterranean Sea in relation to the distance to land. PLOS ONE. August 24, 2016. DOI: 10.1371/journal.pone.0161581.

13.

Pelamatti

Fonseca-Ponce

Rios-Mendoza

, et al. Seasonal variation in the abundance of marine plastic debris in Banderas Bay, Mexico. Mar Pollut Bull 2019; 145: 604–610.

14.

Lindeque

Cole

Coppock

, et al. Are we underestimating microplastic abundance in the marine environment? A comparison of microplastic capture with nets of different mesh-size. Environ Pollut 2020; 265: 114721.

15.

Napper

Thompson

. Plastic debris in the marine environment: history and future challenges. Global Chall 2020; 4: 1900081.

16.

Carpenter

Anderson

Harvey

, et al. Polystyrene spherules in coastal waters. Science 1972; 178: 749–750.

17.

Carpenter

Smith

. Plastics on the sargasso sea surface. Science 1972; 175: 1240–1241.

18.

Morris

Hamilton

. Polystyrene spherules in the Bristol channel. Mar Pollut Bull 1974; 5: 26–27.

19.

Thompson

Olsen

Mitchell

, et al.

Lost at sea: where is all the plastic?

Science 2004; 304: 838–838.

20.

Andrady

. Fate of plastics debris in the marine environment. In: Arthur C, Baker J and Bamford H (eds.), NOAA marine debris program, WA, USA, 9–11 Sept 2008, pp.78. US: NOAA.

21.

Rillig

. Microplastic in terrestrial ecosystems and the soil? Environ Sci Technol 2012; 46: 6453–6454.

22.

Rillig

Ingraffia

de Souza Machado

. Microplastic incorporation into soil in agroecosystems. Front Plant Sci 2017; 8: 8–11.

23.

Chae

. Current research trends on plastic pollution and ecological impacts on the soil ecosystem: a review. Environ Pollut 2018; 240: 387–395.

24.

Horton

Walton

Spurgeon

, et al. Microplastics in freshwater and terrestrial environments: evaluating the current understanding to identify the knowledge gaps and future research priorities. Sci Total Environ 2017; 586: 127–141.

25.

Hurley

Nizzetto

. Fate and occurrence of micro(nano)plastics in soils: knowledge gaps and possible risks. Curr Opin Environ Sci Health 2018; 1: 6–11.

26.

Mai

Bao

Wong

, et al. Microplastic contamination in aquatic environments: an emerging matter of environmental urgency. In: Zeng

E. Y.

(ed) Microplastics in the terrestrial environment. Amsterdam: Elsevier, 2018, pp.365–378.

27.

Huerta Lwanga

Eldridge

, et al. An overview of microplastic and nanoplastic pollution in agroecosystems. Sci Total Environ 2018; 627: 1377–1388.

28.

UNEP. Plastic planet: how tiny plastic particles are polluting our soil. https://www.unenvironment.org/news-and-stories/story/plastic-planet-how-tinyplasticparticles-are-polluting-our-soil (2018, accessed 28 May 2022).

29.

Liu

Yan

. ‘White revolution’ to ‘white pollution’ agricultural plastic film mulch in China. Environ Res Lett. 2014; 9: 091001.

30.

Rochman

Kross

Armstrong

, et al. Scientific evidence supports a ban on microbeads. Environ Sci Technol 2015; 49: 10759–10761.

31.

Nizzetto

Futter

Langaas

. Are agricultural soils dumps for microplastics of urban origin? Environ Sci Technol. 2016; 50: 10777–10779.

32.

Nizzetto

Bussi

Futter

, et al. A theoretical assessment of microplastic transport in river catchments and their retention by soils and river sediments. Environ Sci Process Impacts 2016; 18: 1050–1059.

33.

Carr

Liu

Tesoro

. Transport and fate of microplastic particles in wastewater treatment plants. Water Res. 2016; 91: 174–182.

34.

Mason

Garneau

Sutton

, et al. Microplastic pollution is widely detected in US municipal wastewater treatment plant effluent. Environ Pollut 2016; 218: 1045–1054.

35.

McCormick

Hoellein

London

, et al. Microplastic in surface waters of urban rivers: concentration, sources, and associated bacterial assemblages. Ecosphere 2016; 7. DOI: 10.1002/ecs2.1556.

36.

Talvitie

Mikola

Setälä

, et al. How well is microliter purified from wastewater? – a detailed study on the stepwise removal of microliter in a tertiary level wastewater treatment plant. Water Res 2017; 2017: 164–172.

37.

Ziajahromi

Neale

Rintoul

, et al. Wastewater treatment plants as a pathway for microplastics: development of a new approach to sample wastewater-based microplastics. Water Res 2017; 112: 93–99.

38.

Blasing

Amelung

. Plastics in soil: analytical methods and possible sources. Sci Total Environ 2018; 612: 422–435.

39.

Dubaish

Liebezeit

. Suspended microplastics and black carbon particles in the jade system, southern north sea. Water Air Soil Pollut 2013; 224: 1352.

40.

Foitzik

Unrau

Gauterin

, et al. Investigation of ultra fine particulate matter emission of rubber tires. Wear 2018; 394: 87–95.

41.

Wagner

Hüffer

Klöckner

, et al. Tire wear particles in the aquatic environment – a review on generation, analysis, occurrence, fate and effects. Water Res 2018; 139: 83–100.

42.

Dris

Gasperi

Saad

, et al. Synthetic fibers in atmospheric fallout: a source of microplastics in the environment? Mar Pollut Bull 2016; 104: 290–293.

43.

Nizzetto

. Do microplastics spill on to farm soils? Nature 2016; 537: 88.

44.

Rillig

Ziersch

Hempel

. Microplastic transport in soil by earthworms. Sci Rep 2017; 7: 1362.

45.

Kasirajan

Ngouajio

. Polyethylene and biodegradable mulches for agricultural applications: a review. Agron Sustain Dev 2012; 32: 501–529.

46.

Moore-Kucera

Lee

, et al. Effects of biodegradable mulch on soil quality. Appl Soil Ecol 2014; 79: 59–69.

47.

Farmer

Zhang

Jin

, et al. Long-term effect of plastic film mulching and fertilization on bacterial communities in a brown soil revealed by high through-put sequencing. Arch Agron Soil Sci. 2017; 63: 230–241.

48.

Sintim

Flury

. Is biodegradable plastic mulch the solution to agriculture's plastic problem? Environ Sci Technol 2017; 51: 1068–1069.

49.

William

. Plastic mulches for the production of vegetable crops. Hort Technol 1993; 3: 35–39.

50.

Steinmetz

Wollmann

Schaefer

, et al. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation? Sci Total Environ 2016; 550: 690–705.

51.

Ramos

Berenstein

Hughes

, et al. Polyethylene film incorporation into the horticultural soil of small periurban production units in Argentina. Sci Total Environ 2015; 523: 74–81.

52.

Bergmann

Mutzel

Primpke

, et al. White and wonderful? Microplastics prevail in snow from the Alps to the Arctic. Sci Adv 2019; 5: 57.

53.

Awet

Kohl

Meier

, et al. Effects of polystyrene nanoparticles on the microbiota and functional diversity of enzymes in soil. Environ Sci Eur 2018; 30: 11.

54.

Machado

AA dS

Lau

Till

, et al. Impacts of microplastics on the soil biophysical environment. Environ Sci Technol 2018; 52: 9656–9665.

55.

Zhu

Fang

Zhu

, et al. Exposure to nanoplastics disturbs the gut microbiome in the soil oligochaete Enchytraeus crypticus. Environ Pollut 2018; 239: 408–415.

56.

Wan

Xue

, et al. Effects of plastic contamination on water evaporation and desiccation cracking in soil. Sci Total Environ 2019; 654: 576–582.

57.

Bosker

Bouwman

Brun

, et al. Microplastics accumulate on pores in seed capsule and delay germination and root growth of the terrestrial vascular plant Lepidium sativum. Chemosphere 2019; 226: 774–781.

58.

Yang

Pelaez

, et al. Macro- and micro-plastics in soil-plant system: effects of plastic mulch film residues on wheat (Triticum aestivum) growth. Sci Total Environ 2018; 645: 1048–1056.

59.

Jiang

Chen

Liao

, et al. Ecotoxicity and genotoxicity of polystyrene microplastics on higher plant Vicia faba. Environ Pollut 2019; 250: 831–838.

60.

Bandmann

Müller

Köhler

, et al. Uptake of fluorescent nano beads into BY2-cells involves clathrin-dependent and clathrin-independent endocytosis. FEBS Lett 2012; 586: 3626–3632.

61.

Zhou

Yin

, et al. Uptake and accumulation of microplastics in an edible plant. Chin Sci Bull 2019; 64: 928–934.

62.

Ebere

Wirnkor

Ngozi

. Uptake of microplastics by plant: a reason to worry or to be happy? World Sci News 2019; 131: 256–267.

63.

Huerta Lwanga

Mendoza Vega

Ku Quej

, et al. Field evidence for transfer of plastic debris along a terrestrial food chain. Sci Rep 2017; 7: 14071.

64.

European Commission. Directive 2006/118/EC of the European Parliament and of the … - eur-lex. 2006. https://eur-lex.europa.eu/legal content/EN/LSU/?uri=celex%3A32006L0118 (accessed 16 July 2022).

65.

Shi

Dong

Shi

, et al. Groundwater antibiotics and microplastics in a drinking-water source area, northern China: occurrence, spatial distribution, risk assessment, and correlation. Environ Res 2022; 210: 112855.

66.

Panno

Kelly

Scott

, et al. Microplastic contamination in karst groundwater systems. Groundwater 2019; 57: 189–196.

67.

Samandra

Johnston

Jaeger

, et al. Microplastic contamination of an unconfined groundwater aquifer in Victoria, Australia. Sci Total Environ 2022; 802: 149727.

68.

Viaroli

Lancia

. Microplastics contamination of groundwater: current evidence and future perspectives: a review. Sci Total Environ 2022; 824: 153851.

69.

Padervand

Lichtfouse

Robert

, et al. Removal of microplastics from the environment: a review. Environ Chem Lett 2020; 18: 807–828.

70.

Walker

. (Micro)plastics and the UN sustainable development goals. Curr Opin Green Sustain Chem 2021; 30: 100497.

71.

Shruti

Jonathan

Rodriguez-Espinosa

, et al. Microplastics in freshwater sediments of atoyac river basin, Puebla city, Mexico. Sci Total Environ 2019; 654: 154–163.

72.

Liu

Zhang

Cai

, et al. Occurrence and characteristics of microplastics in the haihe river: an investigation of a seagoing river flowing through a megacity in northern China. Environ Pollut 2020; 262: 114261.

73.

Yin

Wen

, et al. Comparison of the abundance of microplastics between rural and urban areas: a case study from East Dongting lake. Chemosphere 2020; 244: 125486.

74.

Simon

van Alst

Vollertsen

. Quantification of microplastic mass and removal rates at wastewater treatment plants applying focal plane array (fpa)-based fourier transform infrared (FT-IR) imaging. Water Res 2018; 142: 9.

75.

Barchiesi

Chiavola

Di Marcantonio

, et al. Presence and fate of microplastics in the water sources: focus on the role of wastewater and drinking water treatment plants. J Water Proc Eng 2021; 40: 101787.

76.

Bradford

Leij

. Modeling the transport and retention of polydispersed colloidal suspensions in porous media. Chem Eng Sci 2018; 192: 972–980.

77.

Dong

Qiu

Zhang

, et al. Size-dependent transport and retention of micron-sized plastic spheres in natural sand saturated with seawater. Water Res 2018; 143: 518–526.

78.

Jin

Jiang

Tang

, et al. Density effects on nanoparticle transport in the hyporheic zone. Adv Water Res 2018; 121: 406–418.

79.

Chu

, et al. Transport of microplastic particles in saturated porous media. Water 2019; 11: 2474.

80.

Song

Cai

. Focus topics on microplastics in soil: analytical methods, occurrence, transport, and ecological risks. Environ Pollut 2020; 257: 113570.

81.

Rong

, et al. Bacteria have different effects on the transport behaviors of positively and negatively charged microplastics in porous media. J Hazard Mater 2021; 415: 125550.

82.

Ryu

H-S

Moon

Kim

, et al. Modeling and parametric simulation of microplastic transport in groundwater environments. Appl Sci 2021; 11: 7189.

83.

Niu

, et al. New insights into the vertical distribution and microbial degradation of microplastics in urban river sediments. Water Res 2021; 188: 116449.

84.

Plastics Europe. Plastics - the facts 2020. Brussels: Plastics Europe, December 2020. https://plasticseurope.org/knowledge-hub/plastics-the-facts-2020/ (2022, accessed 10 June 2022).

85.

Momot

Synzynys

Kozmin

, et al. Pollution of ground sources of drinking water with technogenic tritium. In: Hlavinek P, Bonacci O, Marsalek J and Mahrikova I (eds) Dangerous pollutants (xenobiotics) in urban water cycle. NATO Science for Peace and Security Series. Dordrecht: Springer, 2008, pp.331–340. DOI: 10.1007/978-1-4020-6795-2_31.

86.

Huang

Chen

Zheng

, et al. Microplastic pollution in soils and groundwater: characteristics, analytical methods and impacts. Chem Eng J 2021; 425: 131870.

87.

Oladoja

Unuabonah

. The pathways of microplastics contamination in raw and drinking water. J Water Proc Eng 2021; 41: 102073.

88.

Jones

, et al. Behavior of microplastics and plastic film residues in the soil environment: a critical review. Sci Total Environ 2020; 703: 134722.

89.

Chia

Lee

J-Y

Kim

, et al. Microplastic pollution in soil and groundwater: a review. Environ Chem Lett 2021; 19: 4211–4224.

90.

Dris

Gasperi

Rocher

, et al. Microplastic contamination in an urban area: a case study in greater Paris. Environ Chem 2015; 12: 592–599.

91.

Dris

Gasperi

Mirande

, et al. A first overview of textile fibers, including microplastics, in indoor and outdoor environments. Environ Pollut 2017; 221: 453–458.

92.

Allen

Phoenix

, et al. Atmospheric transport and deposition of microplastics in a remote mountain catchment. Nat Geosci 2019; 12: 339–344.

93.

Allen

Baladima

, et al. Evidence of free tropospheric and long-range transport of microplastic at pic du midi observatory. Nat Commun 2021; 12: 1–10.

94.

Ferrero

Scibetta

Markuszewski

, et al. Airborne and marine microplastics from an oceanographic survey at the baltic sea: an emerging role of air-sea interaction? Sci Total Environ 2022; 824: 153–709.

95.

Takahashi

Hayasaka

. Air–sea interactions among oceanic low-level cloud, sea surface temperature, and atmospheric circulation on an intraseasonal time scale in the summertime north pacific based on satellite data analysis. J Clim 2020; 33: 9195–9212.

96.

Gouin

Roche

Lohmann

, et al. Thermodynamic approach for assessing the environmental exposure of chemicals absorbed to microplastic. Environ Sci Technol 2011; 45: 1466–1472.

97.

Xumiao

Prata

Alves

, et al. Airborne microplastics and fibers in indoor residential environments in Aveiro, Portugal. Environ Adv 2021; 6: 100–134.

98.

Cai

Wang

Peng

, et al. Characteristic of microplastics in the atmospheric fallout from Dongguan City, China: preliminary research and first evidence. Environ Sci Pollut Res 2017; 24: 24928–24935.

99.

Wright

Kelly

. Plastic and human health: a micro issue? Environ Sci Technol 2017; 51: 6634–6647.

100.

Klein

Fischer

. Microplastic abundance in atmospheric deposition within the metropolitan area of Hamburg, Germany. Sci Total Environ 2019; 685: 96–103.

101.

Allen

Moss

, et al. Examination of the ocean as a source for atmospheric microplastics. PLoS One 2020; 15: e0232746.

102.

Liu

Wang

Fang

, et al. Source and potential risk assessment of suspended atmospheric microplastics in Shanghai. Sci Total Environ 2019; 675: 462–471.

103.

Abbasi

Rezaei

Ahmadi

, et al. Atmospheric transport of microplastics during a dust storm. Chemosphere 2022; 292: 133–456.

104.

Catarino

Macchia

Sanderson

, et al. Low levels of microplastics (MP) in wild mussels indicate that MP ingestion by humans is minimal compared to exposure via household fibers fallout during a meal. Environ Pollut 2018; 237: 675–684.

105.

Hatinoğlu

Sanin

. Sewage sludge as a source of microplastics in the environment: a review of occurrence and fate during sludge treatment. J Environ Manag 2021; 295: 113–028.

106.

Munyaneza

Jia

Qaraah

, et al. A review of atmospheric microplastics pollution: in-depth sighting of sources, analytical methods, physiognomies, transport and risks. Sci Total Environ 2022; 153–339.

107.

Chen

Yang

, et al. An overview of analytical methods for detecting microplastics in the atmosphere. TrAC, Trends Anal Chem 2020; 130: 115–981.

108.

Chen

Feng

Wang

, et al. Mini-review of microplastics in the atmosphere and their risks to humans. Sci Total Environ 2020; 703: 135–504.

109.

Zhang

Kang

Allen

, et al. Atmospheric microplastics: a review on current status and perspectives. Earth Sci Rev 2020; 203: 103–118.

110.

Sridharan

Kumar

Singh

, et al. Microplastics as an emerging source of particulate air pollution: a critical review. J Hazard Mater 2021; 418: 126–245.

111.

Prata

. Airborne microplastics: consequences to human health? Environ Pollut 2018; 234: 115–126.

112.

Amato-Lourenço

dos Santos Galvão

de Weger

, et al. An emerging class of air pollutants: potential effects of microplastics to respiratory human health? Sci Total Environ 2020; 749: 141–676.

113.

Torres-Agullo

Karanasiou

Moreno

, et al. Overview on the occurrence of microplastics in air and implications from the use of face masks during the COVID-19 pandemic. Sci Total Environ 2022; 800: 149–555.

114.

Liebezeit

. Non-pollen particulates in honey and sugar. Food Addit Contam A 2013; 30: 2136–2140.

115.

Liebezeit

. Synthetic particles as contaminants in German beers. Food Addit Contam A 2014; 31: 1574–1578.

116.

Laist

. Overview of the biological effects of lost and discarded plastic debris in the marine environment. Mar Pollut Bull 1987; 18: 319–326.

117.

Setälä

Fleming-Lehtinen

Lehtiniemi

. Ingestion and transfer of microplastics in the planktonic food web. Environ Pollut 2014; 185: 77–83.

118.

Nelms

Galloway

Godley

, et al. Investigating microplastic trophic transfer in marine top predators. Environ Pollut 2018; 238: 999–1007.

119.

Wang

, et al.

Microplastic accumulation via trophic transfer: can a predatory crab counter the adverse effects of microplastics by body defence?

Sci Total Environ 2021; 754: 142099.

120.

Hart

. Particle captures and the method of suspension feeding by echinoderm larvae. Biol Bull 1991; 180: 12–27.

121.

Graham

Thompson

. Deposit- and suspension-feeding sea cucumbers (echinodermata) ingest plastic fragments. J Exp Mar Biol Ecol 2009; 368: 22–29.

122.

Murray

Cowie

. Plastic contamination in the decapod crustacean nephrops norvegicus (linnaeus, 1758). Mar Pollut Bull 2011; 62: 1207–1217.

123.

Cole

Lindeque

Fileman

, et al. Microplastic ingestion by Zooplankton. Environ Sci Technol 2013; 47: 6646–6655.

124.

Lee

K-W

Shim

Kwon

, et al. Size-dependent effects of micro polystyrene particles in the marine copepod tigriopus japonicus. Environ Sci Technol 2013; 47: 11278–11283.

125.

Van Cauwenberghe

Janssen

. Microplastics in bivalves cultured for human consumption. Environ Pollut 2014; 193: 65–70.

126.

Rochman

Tahir

Williams

, et al. Anthropogenic debris in seafood: plastic debris and fibers from textiles in fish and bivalves sold for human consumption. Sci Rep. September 24, 2015. DOI: 10.1038/srep14340.

127.

Yang

Shi

, et al. Microplastic pollution in table salts from China. Environ Sci Technol 2015; 49: 13622–13627.

128.

Karami

Golieskardi

, et al. Microplastics in eviscerated flesh and excised organs of dried fish. Sci Rep. Epub ahead of print 2017. DOI: 10.1038/s41598-017-05828-6.

129.

Green

Reynolds

, et al. Microplastics in mussels sampled from coastal waters and supermarkets in the United Kingdom. Environ Pollut 2018; 241: 35–44.

130.

Kosuth

Mason

Wattenberg

. Anthropogenic contamination of tap water, beer, and Sea Salt. PLoS One. April 11, 2018. DOI: 10.1371/journal.pone.0194970.

131.

Da Costa Filho

Andrey

Eriksen

, et al. Detection and characterization of small-sized microplastics (≥ 5 µm) in milk products. Sci Rep. December 15, 2021. DOI: 10.1038/s41598-021-03458-7.

132.

Mintenig

Löder

MGJ

Primpke

, et al. Low numbers of microplastics detected in drinking water from ground water sources. Sci Total Environ 2019; 648: 631–635.

133.

Shruti

Pérez-Guevara

Elizalde-Martínez

, et al. First study of its kind on the microplastic contamination of soft drinks, cold tea and energy drinks - future research and environmental considerations. Sci Total Environ 2020; 726: 138580.

134.

Hernandez

Larsson

, et al. Plastic teabags release billions of microparticles and nanoparticles into tea. Environ Sci Technol 2019; 53: 12300–12310.

135.

Kedzierski

Lechat

Sire

, et al. Microplastic contamination of packaged meat: occurrence and associated risks. Food Packag Shelf Life 2020; 24: 100489.

136.

Fadare

Wan

Guo

L-H

, et al.

Microplastics from consumer plastic food containers: are we consuming it?

Chemosphere 2020; 253: 126787.

137.

Hee

Weston

Suratman

. The effect of storage conditions and washing on microplastic release from food and drink containers. Food Packag Shelf Life 2022; 32: 100826.

138.

Mato

Isobe

Takada

, et al. Plastic resin pellets as a transport medium for toxic chemicals in the marine environment. Environ Sci Technol 2001; 35: 318–324.

139.

Teuten

Saquing

Knappe

, et al. Transport and release of chemicals from plastics to the environment and to wildlife. Philos Trans R Soc B 2009; 364: 2027–2045.

140.

Rochman

Hentschel

Teh

. Long-term sorption of metals is similar among plastic types: Implications for plastic debris in aquatic environments. PLoS One. January 15, 2014. DOI: 10.1371/journal.pone.0085433.

141.

McCormick

Hoellein

Mason

, et al. Microplastic is an abundant and distinct microbial habitat in an urban river. Environ Sci Technol 2014; 48: 11863–11871.

142.

Schymanski

Goldbeck

Humpf

H-U

, et al. Analysis of microplastics in water by micro-raman spectroscopy: release of plastic particles from different packaging into mineral water. Water Res 2018; 129: 154–162.

143.

Oßmann

Sarau

Holtmannspötter

, et al. Small-sized microplastics and pigmented particles in bottled mineral water. Water Res 2018; 141: 307–316.

144.

Reisser

Shaw

Wilcox

, et al. Marine plastic pollution in waters around Australia: characteristics, concentrations, and pathways. PLoS One. November 27, 2013. DOI: 10.1371/journal.pone.0080466.

145.

Everaert

De Rijcke

Lonneville

, et al. Risks of floating microplastic in the global ocean. Environ Pollut 2020; 267: 115499.

146.

Seung-Kyu

In-Sung

. Seasonal distribution characteristics of microplastics in the sand beach of the Daebu Island, Gyeonggi-do. J Environ Anal, Health Toxicol 2015; 18: 221–231.

147.

Piehl

Leibner

Löer

MGJ

, et al. Identification and quantification of macro- and microplastics on an agricultural farmland. Sci Rep 2018; 8: 17950.

148.

Liu

Song

, et al. Microplastic and meso-plastic pollution in farmland soils in suburbs of Shanghai, China. Environ Pollut 2018; 242: 855–862.

149.

Corradini

Meza

Eguiluz

, et al. Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal. Sci Total Environ 2019; 671: 411–420.

150.

Zhou

, et al. Microplastic pollution in rice-fish co-culture system: a report of three farmland stations in Shanghai, China. Sci Total Environ 2019; 652: 1209–1218.

151.

Selvam

Jesuraja

Venkatramanan

, et al. Hazardous microplastic characteristics and its role as a vector of heavy metal in groundwater and surface water of coastal south India. J Hazard Mater 2021; 402: 123786.

152.

Połeć

Aleksander-Kwaterczak

Wątor

, et al. The occurrence of microplastics in freshwater systems – preliminary results from krakow (Poland). Geol Geophys Environ 2018; 44: 91.

153.

Abbasi

Keshavarzi

Moore

, et al. Distribution and potential health impacts of microplastics and micro-rubbers in air and street dusts from Asaluyeh county, Iran. Environ Pollut 2019; 244: 153–164.

154.

Wright

Ulke

Font

, et al. Atmospheric microplastic deposition in an urban environment and an evaluation of transport. Environ Int 2020; 136: 105–411.

155.

Choi

Lee

Kim

, et al. Comparison of microplastic characteristics in the indoor and outdoor air of urban areas of South Korea. Water Air Soil Pollut 2022; 233: 1–10.

156.

Iñiguez

Conesa

Fullana

. Microplastics in Spanish table salt. Sci Rep. August 17, 2017. DOI: 10.1038/s41598-017-09128-x.

157.

Enyoh

Verla

, et al. Airborne microplastics: a review study on method for analysis, occurrence, movement and risks. Environ Monit Assess 2019; 191: 1–17.

158.

Panko

Chu

Kreider

, et al. Measurement of airborne concentrations of tire and road wear particles in urban and rural areas of France, Japan, and the United States. Atmos Environ 2013; 72: 192–199.

159.

Kooi

Besseling

Kroeze

, et al. Modeling the fate and transport of plastic debris in freshwaters. Rev Guidance 2018; 125–152.

160.

Lewis

, et al. Sea salt aerosol production: mechanisms, methods, measurements, and models. In Geophysical Monograph Series. Washington, DC: American Geophysical Union, Volume 152, 2004.

161.

Trainic

Flores

Pinkas

, et al. Airborne microplastic particles detected in the remote marine atmosphere. Commun Earth Environ 2020; 1: –9.

162.

Van der Does

Knippertz

Zschenderlein

, et al. The mysterious long-range transport of giant mineral dust particles. Sci Adv December 12, 2018; 4(12). DOI: 10.1126/sciadv.aau2768.

163.

Frei

Piehl

Gilfedder

, et al. Occurence of microplastics in the hyporheic zone of rivers. Sci Rep October 24, 2019. DOI: 10.1038/s41598-019-51741-5.

164.

Zhang

Rong

, et al. Transport and deposition of plastic particles in porous media during seawater intrusion and groundwater-seawater displacement processes. Sci Total Environ 2021; 781: 146752.

165.

Lönnstedt

Eklöv

. Environmentally relevant concentrations of microplastic particles influence larval fish ecology. Science 2016; 352: 1213–1216.

166.

de Souza Machado

Lau

Kloas

, et al. Microplastics can change soil properties and affect plant performance. Environ Sci Technol 2019; 53: 6044−6052.

167.

Maaß

Daphi

Lehmann

, et al. Transport of microplastics by two collembolan species. Environ Pollut 2017; 225: 456–459.

168.

Rillig

Ingraffia

Machado

. Microplastic incorporation into soil in agroecosystems. Front Plant Sci 2017b; 8: 1805.

169.

Zhu

Xiang

, et al. Trophic predator-prey relationships promote transport of microplastics compared with the single hypoaspis aculeifer and folsomia candida. Environ Pollut 2018; 235: 150–154.

170.

Lusher

McHugh

Thompson

. Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English channel. Mar Pollut Bull 2013; 67: 94–99.

171.

Perry

. Atmospheric transport and dispersion of air pollutants associated with vehicular emissions. In: Watson

Bates

Kennedy

(eds) Air pollution, the automobile, and public health. Washington DC: National Academies Press (US), 1988, pp. 77–98.

172.

Evangeliou

Grythe

Klimont

, et al. Atmospheric transport is a major pathway of microplastics to remote regions. Nat Commun 2020; 11: 1–11.

173.

Peng

, et al. Influence of graphene oxide on the transport and deposition behaviors of colloids in saturated porous media. Environ Pollut 2017; 225: 141–149.

174.

Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO). UNESCO and the Ocean Decade Community rally at 2022 UN Ocean Conference to advocate for science-driven ocean action. https://ioc.unesco.org/ (2022, accessed 25 July 2022).

Review on invasion of microplastic in our ecosystem and implications

Abstract

Keywords

Introduction

Invasion of microplastic pollution in the ecosystem

Marine environment

Soil

Groundwater

Air

Food

Microplastic pollution as global agenda

Transboundary and transmedium characteristics of microplastic pollution

Prerequisite to address microplastic pollution together

Conclusion

Footnotes

Author contributions

Declaration of conflicting interests

Funding

ORCID iDs

Author biographies

References