The prevalence of microplastics on the earth and resulting increased imbalances in biogeochemical cycling
Abstract
The biogeochemical cycles are responsible for the constant transfer and transformation of matter and energy between the biosphere and the other active reservoirs of the planet. During the progress of a biogeochemical cycle, a series of molecular species (ecological “nutrients”) are constantly transferred and chemically altered. Plastic, a new material, has now begun to participate in the biogeochemical cycles. More than just participating, microplastics are interfering with the normal flow of these processes insofar as they can block the transfer of some elements and serve as a shortcut for others. These new materials can increase the bioavailability of pollutants and thus interfere with physiological activities. The results of this interference have not yet been fully evaluated, but in view of the universal presence of these particles in the most varied ecosystems of the planet, urgent measures must be taken to mitigate the negative effects of this invasion. The present review seeks to establish a global view of the distribution of microplastics around the planet and their impact on the main biogeochemical cycles, thus emphasizing the need for the development of adequate management and remediation strategies in the coming years.
Keywords
INTRODUCTION
Planet Earth can be considered a closed system, where all its constituent chemical elements are trapped by gravity and distributed in several pools among the existing global ecosystems[1]. However, in response to heat fluxes, the elements are constantly cycling between the different compartments[2]. The fluxes of chemical elements such as carbon, oxygen, nitrogen, phosphorus, etc., among different Earth reservoirs, compose the biogeochemical cycles[3], in which biological, geological, and chemical elements are all involved. These fluxes run through compartments present in the most varied spheres of our planet, including living to non-living, from air to land and sea, and from soils to biosphere; they can impact plant productivity as well as the speciation and resulting bioavailability of potentially toxic elements[4].
Biogeochemical cycles and compounds sustain the dynamics of the Earth. This equilibrium is based on the capacity of the elements to transit through extremely diverse pools. Microorganisms, being able to recycle carbon, nitrogen, phosphorus, sulfur, and other elements, thus play a key role in many biogeochemical cycles [Figure 1][5]. The metabolism of microbiota sustains the most important biogeochemical cycles on the planet, especially the production of oxygen, which allows aerobic life and consequent biological transference of carbon to biological reservoirs as biomass[6].
Throughout their existence, human beings have caused a series of disturbances in the natural balance of the planet. Following the industrialization of human society, various contaminants began to be discharged into the environment, generating direct impacts on ecosystem balance[7-9]. The global balance of carbon and other nutrients is increasingly affected by human activities[10] insofar as they accelerate or block the processes of transfer of elements between the different Earth compartments, as well as creating new transfer vectors and “shortcuts”. Keeping in mind the magnitude of microplastic particles in the marine environment, this may significantly modify the route and impacts of contaminants in the environment[11]. It is within this context that microplastic is discussed in the present article.
Traditional plastics are a group of synthetic polymers produced from hydrocarbons to which various chemicals are added to define the final properties of the product, such as elasticity, color, resistance to microbial growth, etc. During degradation, plastic is broken down into small particles, known as micro or nanoplastics (plastic particles ranging from 1 μm to 5 mm), that currently represent the most abundant and ubiquitous class of anthropogenic wastes in marine and freshwater ecosystems[12]. The sudden appearance of these wastes meant that the Earth was not prepared to deal with such complex compounds through its biogeochemical cycles. There are few groups of microorganisms able to rework, and thus recycle, the components of the plastic matrix, leading to its accumulation in many ecosystems.
The plastic matrix has an extremely versatile nature, being able to attract and sorb other contaminants, thus changing the trajectory of these potentially toxic compounds in the natural environment[13]. This may intensify their bioavailability and toxicity to other levels of the trophic chain[14,15]. Thus, only through the understanding of its nature and behavior in a global way will it be possible to effectively manage and attenuate the impact of plastic pollution[16]. Thus, this article presents the potential impacts already observed in the main biogeochemical cycles in order to allow the projection of the impacts on the chemical balances between the different geochemical compartments of the planet Earth.
MICROPLASTIC: A NEW BIOGEOCHEMICAL CYCLE?
Discovered during the 1930s and produced on a large scale from the 50-60s, plastics now play an important role in the daily lives of human beings. The properties of these man-made long-chain polymeric materials, such as strength and durability, together with flexibility, thermal and electrical insulation, corrosion resistance, and low cost, have made them important in the production of a wide diversity of items such as clothes, cosmetics, tools, paints, appliances and others[15,17]. Additionally, these same characteristics represent a threat to human beings in the medium and long term; the refractory nature of plastics offers great ecotoxicological potential. Because of improper management and disposal practices, plastic residues are found throughout the planet’s ecosystems. The action of environmental agents promotes deterioration, producing plastic fragments that are classified as microplastics when their size is < 5 mm[17]. They are ubiquitous in all global ecosystems[18] and their special characteristics allow transference even to remote sites[19].
Exposure to and bioaccumulation of these particles can impact human health[15] as they can adsorb toxic chemicals[20] and bioaccumulate in food and tissue[21,22]. Microplastics can also alter and negatively influence soil microbiomes[23,24] and impact physiological and resulting ecological processes[22,25].
The terrestrial environment represents the main source of plastic microparticles since this is where the processes of industrial production, utilization (consumption) and waste accumulation and treatment are concentrated[26-28]. Plastic microparticles are released from products that contain them, such as cosmetics and abrasives[29,30], from wastewater sludge[31,32] and many other sources. Such industrially produced microplastic (MP) particles are classified as “primary microplastics”[33]; they do not result from the breakdown of macroplastics.
During the lifetime of a larger plastic item, however, it faces a number of factors that contribute to its wear, resulting in the release of small particles, which can be classified as secondary microplastics, into the environment. One example is the release of plastic microfibers from fabrics during washing[34]. These may be transported by wind and water, from soils via surface runoff, and through rivers and canals[35,36]. They may accumulate in seas and oceans or in transitional locations. As they travel, they are continually subjected to deterioration by physical[37], chemical[38,39], and biological[40] degrading agents like UV, temperature, buffeting actions of wind, waves and currents, acids and biological enzymes. This class of plastic particles, resulting from the deterioration of primary MPs or breakdown of larger pieces, is called “secondary microplastics” [Figure 2].
MP accumulations obviously vary by the location, polymer nature and how far they are from the source. The dynamics of distribution and abundance, the factors that dictate MP distribution, and the transport fluxes that could affect the distribution are still unclear. It is important to understand the nature and distribution dynamics of MPs in global environment pools to allow us to project the ecotoxicological threats and devise and offer appropriate management strategies to minimize their impact in natural environments.
MICROPLASTIC DISTRIBUTION THROUGH THE GLOBAL POOLS AND POTENTIAL ECOSYSTEM TOXICITY
MPs have been recorded in diverse environmental compartments, from soils to aquatic systems[41,42]. The following is a summary of potential sources and flows through each compartment.
The terrestrial compartment
Effective sources of MPs for the terrestrial ecosystem include the transport industry, e.g., traffic and vehicle tire abrasion[43-45], cosmetics and cleaning products[23], clothing and textile washing[34,46], automobile and architectural paints[47], among others. Consequently, urban dust and its runoff, containing all the residues mentioned above, are important sources of microplastic contamination for the terrestrial environment[48,49].
Agricultural practices can also contribute through improper disposal of wrapping and bale twine, and sewage sludge applied to agricultural lands[50]. MPs can be transported vertically through the soil interstitial spaces to the deeper layers[51]. Along with mismanaged waste and littering, plastic accumulation within the terrestrial environment acts as a source for other ecosystem pools[52].
The aquatic compartments
After deposition on the soil surface, the plastic microparticle can be transported horizontally to aquatic ecosystems through surface runoff. It can also be a viable route to aquifers or groundwater systems[53,54]. It has been suggested that groundwater contamination by microplastics [Figure 3] is mainly linked to anthropogenic activities, such as agriculture, fishing, wastewater treatment, and family activities aboveground[55-57].
Figure 3. Microplastic particles found in Marica City Groundwater (Rio de Janeiro/Brazil) (Source: own material).
Due to the multitude of freshwater ecosystems with differing hydrology, chemistry, and biome, as well as their surrounding watershed and land-use patterns, MP pollution in aquatic freshwater ecosystems is very complex. In the same way as the atmosphere and other compartments, freshwater environments potentially work as both receivers and diffusers of plastic pollution[42,58]. For example, rivers may have significance in the transfer of plastic from land to the adjacent sea[52,59]. It has been projected that rivers and estuaries release 0.47-2.75 million tons of plastic into the sea annually[59]. On the other hand, significant concentrations of MPs have been recorded in ponds and lakes around the planet[60-62]. In contrast to the riverine sites, however, lakes and lagoons, being more confined and thus presenting minor water transport competence, tend to concentrate plastic in the sediment without further exportation to the surrounding sea and can thus more readily concentrate plastic over time[63].
MP pollution in the salty marine environment has received more attention than in other ecosystems. First, because MPs are frequently recorded in high levels in both the water column[64] and in the bottom sediments[65], where they can be available to the marine biota, and secondly, since seafood is a primary source of protein for a significant percentage of the world’s population[66], MP contamination in marine ecosystems represents a potential human health risk[15]. Sources of MPs for the oceans include terrestrial runoff[67], plastic industrial wastes[68], abandoned fishing nets[69] and many others. Anthropogenic activities on the coasts, including fishing, aquaculture[70] and tourism, also represent important sources of MPs for saltwater environments.
Marine waters have specific features, such as their physicochemical characteristics and extremely variable hydrodynamic flows[64,65,71], that impact the diffusion dynamic of MPs. In addition, the salt content of marine water may be expected to influence MP water column distribution (buoyancy and sinking properties), fate, diffusion dynamic in marine environments and, finally, the bioavailability of MPs to marine biota[72]. MPs are composed of a variety of polymers with varied molecular structures[73], resulting in properties that determine the action of saline water on the particles. For example, the transport of MPs through the water column is influenced by the settlement of organic particles from the surface to deeper layers (“marine snow”), enabling the contamination of deeper pelagic environments down to the benthic communities[74,75]. The sea bottom settlement stability of MPs can be impacted by deeper thermohaline currents[65], which may allow their return to the global plastic cycle.
It is thus accepted that the ocean environment is the depository of MP, with terrestrial and freshwater fluxes being important contributors to marine deposits[52]. Aquatic sites like oceans represent not just deposits of plastic microparticles, but effective sources of plastic back to the atmospheric pool via wind-driven sea spray and the bubble burst ejection[76]. Aquatic MPs hotspots may thus act not just as a final deposit of these pollutants but also as a source of MPs back to the atmospheric “pool” and further to terrestrial sites. Hence diffusion of plastic microparticles through several ecosystem compartments impacts the distribution of pollutant molecules through soil and water, just as carbon, oxygen, nitrogen, and other elements participate in their environmental and biogeochemical cycles[77].
The atmospheric compartment
Regardless of features such as shape, size and molecular structure, MPs generally present low density, small size, and high surface area, enabling easy spread through the air[78-80]. Daily human littering activities linked to inadequate management, unconfined litter storage, and release from landfill sites are also potential atmospheric MP sources; these have been shown to be deposited with precipitation even in remote sites such as the French Pyrenees[81] and the Alps[82,83]. MPs are indeed subject to long-range transference and atmospheric deposition[84] from urban areas to remote locations[81,85-87]. The atmospheric pool acts to link the processes, influencing the flux and retention of MPs in the environment [Figure 4][88].
THE DETERMINING FACTORS FOR MP DISTRIBUTION IN THE GLOBAL ENVIRONMENTAL COMPARTMENTS
The distribution of MPs is directly associated with their physical features. Their diffusion in the environment is directly linked to the mechanical transport associated with wind flows and water currents; it is coherent to suggest that the different shapes of MPs may influence their transport through the environment. For example, plastic films can vary in thickness and size and thus have a greater surface area for atmospheric entrainment than fragments of the same mass[76]. Thus, it has been shown that fibers and fragments are the dominant MP shapes in the atmosphere and seawater, beach sediments, and freshwater[89-91]. Comparison with MPs of aquatic and sedimentary environments[41,91] suggests that atmospheric MPs are much smaller. Finally, plastic particle size and shape are determinants of bioavailability and environmental fate[92,93]. Certain MP shapes or sizes may result in a greater impact on living organisms, with smaller, more angular particles passing more easily through membrane barriers than particles with smoother surfaces[73,94], also allowing the easier entrance of associated contaminants.
Not only shape and size but also MP composition impact particle dispersion in the environment. Different polymers have different densities[94], which affects their pathways through the environmental compartments. Less dense polymers are more common in aqueous and atmospheric compartments[84].
MPS, ENVIRONMENT, AND TOXICITY: THE INTERACTIONS
Plastics are polymers formed from resins. Polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polyethylene terephthalate (PET) make up approximately 90% of the total plastics in common use[95]. Chemical additives such as plasticizers, stabilizers, antioxidants, pigments, and flame retardants are commonly added to the formula to improve characteristics like resistance and flexibility[96,97]. The plastics industry uses small plastic pellets as feedstock. These are tiny plastic granules that are melted down and remodeled into the required shape; thus, they are an important raw material for many industries around the world. Nowadays, however, improper transport management and irregular disposal in the environment have resulted in worldwide pollution by these primary MPs.
With a highly variated composition, MPs can sorb a large group of contaminants. Various mechanisms are involved, such as physical adsorption, pore filling, surface complexation, and electrostatic attraction[98], as well as agents like UV radiation, microorganisms, humidity, and other environmental factors. Certain additives, such as pigments, can affect sorption capacity. Antunes et al.[99] suggested that black-colored MPs are more likely to contain polyurethane, which may contribute to higher sorption. Fisner et al.[100], on the other hand, reported that lighter-pigmented particles adsorbed lower molecular weight hydrocarbons, while darker particles contained higher-weight PAHs. Polymer density has also been suggested to influence pollutant sorption; higher-density MPs may carry lower concentrations of pollutants such as PAHs and PCB[101-103].
As explained previously, secondary MPs result from the degradation of the primary class, pellets, or larger manufactured plastic items, by physical and chemical environmental agents like UV, mechanical abrasion, and microbial action. These modifications can affect pollutant sorption capacity[100-106], and hence contaminant carrying ability. Naturally, during plastic aging and degradation in the environment, MP characteristics like porosity, density, and roughness will change[107]. After degradation, the smaller granulometry and corresponding higher surface/volume ratio increase pollutant sorption[108]. Chemical weathering and UV action modify the functional groups on the particle surface, transforming both polymer chain and additives chemistry by oxidation and chain scission of polymers[17]. This increases the ability to attract environmental pollutants, including hydrophobic and hydrophilic organic pollutants, endocrine disruptor compounds, and heavy metals[104,109]. The effect of MP degradation on the pollutant sorption capacity does not depend only on the size or degree of degradation. The information available in the literature is very controversial. Some authors support the idea that the adsorption capacity increases with aging[104,109], while others[106] reported that weathered or aged MP had lower pollutant sorbing capacity. In fact, the impact of MP degradation on contaminant sorption depends on several variables, including the type of polluting compounds and microplastic, and the stage of chemical modifications or resulting interactions over time.
Some types of polymer composition confer the ability to sorb hydrophobic pollutants[110]. In aqueous or solid ecosystems, MPs are always recorded as part of a mixture or diverse suite of chemical compounds[73], reinforcing their ability to attract organic chemicals and trace metals from the adjacent environment[97]. This occurs because hydrophobic chemicals are attracted to the neutral spots on the MP surface, while hydrophilic or charged compounds establish electrostatic bonds with the negative areas on the particle surface[110]. The nature of the plastic matrix thus has an important and versatile effect on the accumulation of pollutants.
Apart from the composition of the plastic polymer, the sorption of polluting molecules also depends on the physical and chemical nature of the environment, as discussed in the following paragraphs.
Organics content
The presence of organic matter can alter the in-situ sorption capacity and distribution of marine MPs[92,111,112]. When the level of organic compounds in the ecosystem is low, adsorption occurs as a result of the strong interactions between the forces on the surfaces of the MP particles. When the organic content is high, absorption prevails, as there is a larger volume for the molecules to settle[113,114].
pH
This environmental factor has attracted more attention with the advent of global warming. The marine environment has passed through an acidification course, which could increase the sorption process of certain aquatic contaminants. Although the pH of oceanic environments is severely buffered to around 8.0, coastal waters can be impacted by pH variations[115]. In the case of plastic microparticles, fluctuations in seawater pH can change the surface chemical stability of microplastics, stimulating or neutralizing the leaching rate of chemical compounds adhered to the surface. Thus, the PET that is usually classified as relatively safe for the environment could become a threat in different environmental conditions. For example, the attraction of the endocrine disruptor tylosin to PVC is stimulated after the plastic’s solubility increases at lower pH; the sorptive capacity of PS and PE for perfluorooctanesulfonic acid also increases Guo et al.[116]. Despite the existing evidence, broader and more detailed data are needed to project the real effects of pH on the sorption capacity of plastic microparticles.
Salinity
Salinity represents the main environmental characteristic that impacts the toxicity of chemicals on biota[117]. Additionally, it plays an important role in the contaminant adsorption dynamic of MPs. As an example, the adsorption of some pollutants onto MPs was investigated through a controlled assay, in which adsorption was stimulated by changing salinity, altering hydrophobic forces, and the salting-out process[118,119]. Results suggested that increasing salinity is one of the processes that decrease the adsorption of contaminants on microplastics, although the kinetics depends on the makeup of the plastic matrix.
The chemical patterns in the environment may be a key factor in the attraction of contaminants by MPs; these attractions do not exist only as a function of the physical or chemical characteristics of the polymers, but also of the properties of the surrounding medium. The influence of the age of the plastic and its composition on the attraction of a contaminant are a result of the functional groups existing on the surface of the plastic matrix; the polarity and chemical forces are due to differences in these functional groups affecting polarity or chemical forces such as hydrophobicity over time or across various types of pollutants[109,120].
THE INFLUENCE OF MICROPLASTIC PARTICLES ON MICROBIAL COMMUNITIES AND RESULTING IMPACTS ON BIOGEOCHEMICAL CYCLING
The potential impact of microplastic particles (MPs) on biogeochemical cycling and microbial communities has been the focus of much research because of their crucial role as drivers of biological and nutrient balance in various ecosystems[121-127].
Microorganisms play a crucial role in the trophic pyramid, allowing dead organic matter to be recycled through saprotrophy, resulting in the release and reuse of chemical elements, mainly C, N and P[128,129]. Thus, MPs influence the microbial oxidation-reduction reactions that represent a basic issue in environmental balance. Despite the lack of information regarding the impact of MPs on the environment, their importance on microbial communities can be discussed under a number of headings, as follows.
Bioinvasion
The MP surface offers unique microhabitats which allow the transportation and diffusion of allochthonous species, which can seriously impact communities in specific environments[130]. The invasion of exotic species is one of the most to local biodiversity and ecosystem functioning in local environments[131,132]. There are increasing records of invasive microorganisms, which can modify the functioning of entire ecosystems[133-138]. Invasive microorganisms can modify these geochemical paths through local disturbance of symbiotic patterns, pathogenicity, or imbalance of local decomposition processes. The transport by MPs of microbial cells and potential allochthonous species can thus upset the pre-established structure of an ecosystem, putting its particular biogeochemical processes at risk [Figure 5][139].
Ecotoxicity
MPs can attract, transport and release complex toxic compounds through the ecosystems, affecting local microbial community structure and abundance, potentially impacting biogeochemical cycles [Figure 5]. Some authors showed that the availability of polyethylene (PE) transformed the local microbial community by reducing its richness and raising the abundance of lignin-degrading and plastic-degrading species[140]. Several other researchers have revealed that MP toxicity can disturb the structure of microbial populations[24,80,141,142].
Changes of colonization substrate
The imbalance generated in biogeochemical cycles by MPs is mainly concentrated in their impact on the microbial population. In addition to carrying invasive species to other ecosystems or impacting the health of the microbiota through the bioavailability of pollutants, microplastics can also modify soils and underwater sediments by altering substrate characteristics, resulting in ecological succession/replacement [Figure 5]. According to[130], during the biofouling process, a “protective layer” forms on the surface of the microplastic, allowing the group of organisms dependent on the compounds leached into the plastic matrix to survive in other environments. Thus, the very pre-existence of a plastic substrate in the environment makes it open to bioinvasion from more MP-attached microorganisms, which may impact the biogeochemical processes promoted by the original microbiota.
The impact of MPs on microbial communities may be particularly significant in environments prone to plastics accumulation by urban surface runoff[143], in situations where waste management is poor[52] or fails due to overload of the sewage network[78], or in the vicinity of the wastewater treatment plant outfalls[144,145]. It is, therefore, to be expected that aquatic environments will be the most subject to MP pollution. Particularly ecosystems such as salt marshes and mangroves, usually located in geomorphologically protected areas, represent extremely sensitive environments since the hydrodynamics in these areas is usually restricted, with the tides as the main source of currents[71]. Additionally, these ecosystems present typically adapted flora, with aerial roots, for instance, that block hydrodynamic currents, resulting in the accumulation and decantation of fluctuant solids, organic matter (OM) and MPs[71]. On the other hand, these ecosystems represent highly active areas of OM remineralization and hence biogeochemical cycling, for which sediment bacteria are fundamental.
The diagenetic process starts with the decomposition of the most-labile OM compounds within the oxygenated surface water[146]. In low-oxygen areas, organic matter is usually degraded through fermentation, denitrification, sulfate-reduction, and methanotrophy[147]; these reactions are carried out by specific organisms with particular redox requirements.
MPs, mainly microfibers, have been shown to impact sediment quality and health by modifying the microbial community and its resulting biogeochemical activity[122,148]. For instance, microplastic fibers decrease bacterial enzymatic activity[149].
In terrestrial environments, carbon and nitrogen recycling is mainly conducted through transformation between vegetation and internal constituents of soil and occurs in the transition zone between the atmosphere and water environment. Abiotic features, such as soil properties and local climatology, as well as biological elements such as microbial communities, animals, and anthropogenic activities, affect the biogeochemical turnover of carbon and nitrogen in the Earth’s complex ecosystem[80,150]. The impacts on the main elements of the biogeochemical cycles are discussed in the following sections.
IMPACTS OF MPS ON THE MAIN BIOGEOCHEMICAL CYCLES
Carbon
The plastic matrix is composed of carbon chain polymers[151-154]. around 80% of MP composition is carbon[155] and the scale of plastic production and disposal each year has made it a new element in the carbon cycle[156]. The plastics industry is directly related to the release of greenhouse gases in all phases of the plastic life cycle, from production to transport and final waste disposal[151,157]. MP carbon is thus already present in the global soil compartment, although generally representing only a small fraction of total soil organic matter carbon[155]. This picture may, however, change in the future, since the organic carbon from microplastics is not easily bioavailable, unlike plant residues, and not subject to ready biodegradation[158]. MPs can negatively impact plant development in several ways; they can influence the physical and chemical structure of the soil itself, as well as the microorganisms that live in it[159]. For instance, in addition to disseminating pollutants in the surrounding environment, MPs can modify the density and cohesion of the soil sediment particles, influencing interstitial water flow and root penetration. Fundamental symbiotic relations between plants and microorganisms can also be impacted by MP bioavailability. Both positive[160-162] and mainly negative[163,164] impacts of MPs on plant development have been reported.
Eriksen et al.[165] reported that about 268,940 tons of plastic float at the surface of the sea; however, this figure will undoubtedly have increased, not least as a result of the COVID epidemic and a resulting rise in the use of personal protective equipment[166]. The accumulation of plastic in the surface layers of marine water, a compartment originally rich in organic matter resulting from microbial activity, further stimulates the abundance of microorganisms, in addition to making complex organic compounds bioavailable in the atmospheric/aquatic transition zone. This can result in decreasing penetration of solar rays to deeper layers, impacting primary productivity and resulting oxygen production, in addition to modifying the dynamics of gas exchange between atmospheric and marine compartments[167].
Dissolved organic carbon (DOC) is a significant component in the carbon cycle and is recognized as the main reduced carbon reservoir on Earth[168]. Several bacterial groups are able to transform MPs into dissolved carbon sources, which could be the source of the high levels of dissolved organic carbon recorded in ecosystems with significant MP concentrations[169].
The concentration of DOC released by plastic degradation increases in surface waters[170], potentially stimulating heterotrophic bacterial activity and the rework of Dissolved Organic Matter (DOM). This results in increases in bacterial respiration and oxygen consumption, directly affecting the biogeochemical balance of this stage of the carbon cycle. Additionally, “transitioning” or production of by-products of plastic degradation, available as electron donors, potentially stimulates the concentration of microbe-plastic aggregates, which are recognized to influence DOC cycling in the ocean[129]. MPs may influence the growth of carbon-cycling microorganisms in the ocean[171,172].
Still, the impact of MPs on the carbon balance in the marine environment is not limited to microscopic aspects. Recent research suggested the MPs assimilation by zooplankton as a booster of water deoxygenation, since, according to Kvale et al.[173], the fecal pellets resulting from this process potentially present lower density, promoting greater buoyancy of the eliminated fecal particle and reducing the marine snow flux. Thus, the higher concentrations of carbon in the surface strata water column, as particulate organic carbon, would reduce the ocean’s capacity to absorb carbon from the atmosphere[174-176].
Therefore, based on the above-cited data, it is reasonable to consider that the omnipresence of MPs on the Earth, especially in aquatic environments, will affect carbon cycling and the global productivity of the oceans. In addition, the complexity of the biogeochemical carbon cycle makes the projection of impacts in the various compartments of this cycle on the Earth difficult. More studies are needed for a global prediction of the effects of MPs on this specific biogeochemical cycle.
Nitrogen
This vital nutrient plays a fundamental role in energy and cell production, assuming several chemical forms during microbial metabolism. For instance, denitrification is of significant importance in controlling the levels of reactive nitrogen in coastal environments. Denitrification takes place in the lower oxygen levels where nitrate (NO3-) and nitrite (NO2-) function as the terminal electron acceptor in the oxidation of OM (Queiroz et al.[177]). Through denitrification, N is removed by converting NO3- and NO2- to gaseous N compounds. Nitrification can also take place in surface waters, transforming ammonium (NH4+) to NO2- and finally to NO3-. Usually, nitrification and denitrification reactions are critical for the balance of excess N in contaminated areas, as well as controlling productivity in N-limited environments[178]. However, the impact of MPs on the recycling of inorganic N has been scarcely addressed. Based on laboratory assays, Cluzard et al.[179] and Seeley et al.[180] suggested that PE bioavailability to microbiota raises ammonium levels and impacts N cycling, perhaps stimulating the eutrophication process. Both these studies affirmed that nitrogen biogeochemical processes in subaquatic sediments can be significantly impacted by various polymeric compounds that can act as organic carbon substrates for microbial strains. Notably, polyurethane foam (PUF) or polylactic acid (PLA) is able to stimulate nitrification and denitrification processes[180]. Additionally, the same authors recorded that the presence of PE significantly negatively affected the abundance and structure of the microbial communities, finally impacting the nitrification/denitrification balance. Li et al.[181] evaluated the influence of five types of MPs on activated sludge. MP presence resulted in a significant neutralization of the nitrification reactions. Based on such studies, the availability of MPs in the environment can be stated to disturb ecological structure, leading to a potential imbalance of biogeochemical processes linked to nitrogen cycling.
Phosphorus
There is still a lack of information on phosphorus geochemical cycling and potential MP impacts on phosphorus transformations in the environment. However, according to the scarce data available, MPs can disturb the biogeochemical balance by modifying the structure of microbial groups in the sediment and impacting enzymes and genes involved in phosphorus metabolism, which, in turn, would affect phosphorus nutrient cycling[182]. Liu et al.[121], in a laboratory assay, showed that the addition of MPs resulted in an increase in total and soluble P levels. However, additional phosphorus cycling assays are still necessary to define more clearly the impact of MPs on terrestrial and aquatic environments.
Calcium
Microorganisms, mainly cyanobacteria and heterotrophic bacteria, are responsible for the transformation of calcium salts in the cycling of rocks and stones[5]. Indeed, it is probable that phototrophic microorganisms were responsible for the formation of the first soils containing organic carbon through the degradation of silicate rocks[183]. Endolithic cyanobacteria have been demonstrated, usingSEM plus EDX, to redeposit previously solubilized gypsum around their cells within the rock[184], demonstrating a very short calcium cycle. There is also considerable literature on biomineralizing and calcifying bacteria (mainly heterotrophs) that dissolve calcium substrates[185,186] and that produce calcium carbonate crystals[187-190]. Although it has been determined that the level of Ca in seawater has decreased over time and that this is due to decreased carbonate weathering with increased sedimentation[191] there is no information on the interaction between microorganisms involved in the calcium geochemical cycle and MPs.
However, in a similar way to carbon, the calcium biogeochemical cycle does not occur only at the microbiological level, however. Biomineralization, for instance, the process responsible for the formation of the mollusk shell, represents a fundamental physiological mechanism for the survival of these animals. It consists of the use of dissolved ions to produce solid minerals[192], involving several biomolecules, especially proteins[193]. The resulting products of biomineralization include teeth and bones, the exoskeleton of coral, mollusk shells, and the skeletons of many other organisms. Biominerals are widely distributed in the environment, presenting several fundamental ecological functions. Until now, at least around 60 varied biominerals have been recorded, playing a varied range of roles, including tissue composition, embryonic and UV sheltering, predation protection, nutrition, reproduction, light or magnetic field resistance and mineral ions[194-196]. Calcium carbonate is the most abundant biomineral in the metazoan group skeleton[194,195,197,198].
Biomineralization is also extremely important for the formation of the mollusk shell. It has been suggested that, as feed filters, marine mollusks, especially bivalves, are impacted by MP exposure[14]. MPs have been recorded in several common commercial species such as mussels, scallops, oysters, and clams[199]. The negative influence of MPs on these organisms is varied[200]; the majority of published papers deal with bioavailability, absorption pathways, transference and transformation paths, and toxicological impacts[201]. Han et al.[202] indicated that MPs impact the biomineralization process by changing the appearance of biominerals and the expression of biomineralization-related genes. MPs may be incorporated into the shell structure, highlighting a new pathway by which MPs may accumulate in bivalves[203]. MPs can affect the production of calcite and aragonite crystals, which are key components in shell production[202,204-206]. Much remains to be studied regarding the impacts of MPs on biogeochemical cycles.
CONCLUSIONS AND FUTURES PERSPECTIVES
Throughout their evolution, humans have created a series of new chemicals with the aim of facilitating their survival on planet Earth. Only recently has the overpopulation of the planet begun to show that the old ways cannot continue. The development of sustainability-based plastic management concepts and measures is long overdue. This chronological lag has produced the critical challenge of creating and improving techniques to answer the problems of contamination of natural environments. In the case of microplastics, this is a challenging issue. The peculiar chemical composition and consequent toxicity of MPs not only protect them from the planet's purification mechanisms, but also make them effective carriers of a diverse range of pollutants. This facility becomes even more intense during the degradation of the plastic matrix, not only intensifying its ability to attract chemical pollutants, but also increasing its qualitative versatility in terms of attracting new compounds from the contaminated environment.
One of the most critical issues regarding the impact of microplastics in natural environments is their potential toxicity and direct impact on living organisms. Their influence on the cycling of elements, through the micro or macro level, in natural systems and exchanges between the different geochemical compartments affect the pre-established balance of the entire planet. It is not wrong to suggest that microplastic combines the negative effects of domestic sewage (an imbalance through the enrichment of nutrients, resulting in the eutrophication of aquatic ecosystems) and the toxicity of industrial waste (that directly affects the trophic chain).
So, the development of methods to manage and alleviate the problems of MPs in the environment is a race against time; these particles are already ubiquitous on the planet and are closely linked with the potential for the spread of other contaminants.
In this article, the abilities of plastic microparticles to take up and transport chemical pollutants are correlated with their basic properties, which can change when the particles are exposed to various environmental compartments. The similarities between the well-known biogeochemical cycles of the Earth and the recycling of microplastics are described. The simple characteristics of industrially produced plastics are described as a basis for encouraging the development and application of sustainable methods in the management of plastic manufacturing and for reducing the impact of microplastic pollution on the environment. The pollutant-carrying capacity of microplastics is dependent on the interaction between the plastic matrix and the environmental conditions; the evolution of microplastic management should therefore focus on creating more inert plastic matrices and less toxic inputs. This could result in their safe recycling in the environment, both chemically and biologically.
DECLARATIONS
AcknowledgmentsThe authors are also grateful to the Municipality of Maricá for infrastructure and administrative support.
Authors’ contributionsConception; development of the theory; discussion of results and contribution to the final manuscript: de Almeida MP
Conception; development of the theory; discussion of results and contribution to the final manuscript: Gaylarde CC, da Fonseca EM
Discussion of results and contribution to the final manuscript: Baptista Neto JA, Delgado JdF, Lima LdS, Neves CV, Pompermayer LLdO, Vieira K
Availability of data and materialsNot applicable.
Financial support and sponsorshipThis research was funded by Maricá Development Company - CODEMAR and by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
Conflicts of interestAll authors declared that there are no conflicts of interest.
Ethical approval and consent to participateNot applicable.
Consent for publicationAll authors give our consent for the publication of this article.
Copyright© The Author(s) 2023.
REFERENCES
2. Panagiotaras D, Koulougliotis D, Nikolopoulos D, Kalarakis AΝ, Yiannopoulos AC, Pikios K. Biogeochemical cycling of nutrients and thermodynamic aspects. J Thermodyn Catal 2015;6:2.
3. Raimi MO, Abiola I, Alima O, Omini DE. Exploring how human activities disturb the balance of biogeochemical cycles: evidence from the carbon, nitrogen and hydrologic cycles. Nitrogen Hydrologic Cycles 2021;2:23-44.
5. Gaylarde C, Baptista-Neto JA, Ogawa A, Kowalski M, Celikkol-Aydin S, Beech I. Epilithic and endolithic microorganisms and deterioration on stone church facades subject to urban pollution in a sub-tropical climate. Biofouling 2017;33:113-27.
6. Rousk J, Bengtson P. Microbial regulation of global biogeochemical cycles. Front Microbiol 2014;5:103.
7. De Souza PF, Vieira KS, Gaylarde CC, et al. Heavy metal and hydrocarbons bioaccumulation by two Bivalve’s species from Santos Bay, Brazil. Stud Neotrop Fauna Environ ;2022:1-9.
8. Aguiar VMDC, Baptista Neto JA, Monteiro da Fonseca E. Assessment of eutrophication through ecological indicators at the entrance of a tropical urbanized estuary. Revista da Gestão Costeira Integrada 2022;22:175-92.
9. Azevedo Netto A, Farias de Souza P, Da Silva Lima L, et al. Dinâmica de distribuição e fontes potenciais de hidrocarbonetos aromáticos policíclicos para sedimentos de superfície e bivalves de um estuário altamente antropizado. Revista Eletrônica Sistemas Gestão 2022:17.
10. Griggs D, Stafford-Smith M, Gaffney O, et al. Policy: sustainable development goals for people and planet. Nature 2013;495:305-7.
11. Wang J, Peng J, Tan Z, et al. Microplastics in the surface sediments from the Beijiang River littoral zone: composition, abundance, surface textures and interaction with heavy metals. Chemosphere 2017;171:248-58.
12. Khan QF, Anum S, Sakandar HA, et al. Occurrence of microplastic pollution in marine water. In: Hashmi MZ, editor. Microplastic pollution. Cham: Springer International Publishing; 2022. pp. 257-74.
13. da Fonseca EM, Gaylarde C, Baptista Neto JA, et al. Microbial interactions with particulate and floating pollutants in the oceans: a review. Micro MDPI 2022;2:257-76.
14. Vieira KS, Neto JAB, Crapez MAC, et al. Occurrence of microplastics and heavy metals accumulation in native oysters Crassostrea Gasar in the Paranaguá estuarine system, Brazil. Mar Poll Bull 2021;166:112225.
15. Neves CV, Gaylarde CC, Baptista Neto JA, et al. The transfer and resulting negative effects of nano- and micro-plastics through the aquatic trophic web - a discreet threat to human health. Water Biol Secur 2022;1:100080.
16. Neves C, Da Silva Perri B, Monteiro da Fonseca E. desafios do uso ambientalmente sustentável de plásticos: uma breve reflexão. Revista Eletrônica Sistemas Gestão 2022:17.
17. Zhang K, Hamidian AH, Tubić A, et al. Understanding plastic degradation and microplastic formation in the environment: a review. Environ Pollut 2021;274:116554.
18. Geyer R, Jambeck JR, Law KL. Production, use, and fate of all plastics ever made. Sci Adv 2017;3:e1700782.
19. Zhang S, Liu X, Hao X, Wang J, Zhang Y. Distribution of low-density microplastics in the mollisol farmlands of northeast China. Sci Total Environ 2020;708:135091.
20. Gaylarde CC, Neto JAB, da Fonseca EM. Paint fragments as polluting microplastics: a brief review. Mar Pollut Bull 2021;162:111847.
21. Ribeiro F, O’Brien JW, Galloway T, Thomas KV. Accumulation and fate of nano-and micro-plastics and associated contaminants in organisms. Trends Analyt Chem 2019;111:139-47.
22. He D, Luo Y, Lu S, Liu M, Song Y, Lei L. Microplastics in soils: analytical methods, pollution characteristics and ecological risks. TrAC Trends Analyt Chem 2018;109:163-72.
23. de Souza Machado AA, Lau CW, Till J, et al. Impacts of microplastics on the soil biophysical environment. Environ Sci Technol 2018;52:9656-65.
24. Fei Y, Huang S, Zhang H, et al. Response of soil enzyme activities and bacterial communities to the accumulation of microplastics in an acid cropped soil. Sci Total Environ 2020;707:135634.
25. Barnes DK, Galgani F, Thompson RC, Barlaz M. Accumulation and fragmentation of plastic debris in global environments. Philos Trans R Soc Lond B Biol Sci 2009;364:1985-98.
26. Wezel A, Caris I, Kools SA. Release of primary microplastics from consumer products to wastewater in the Netherlands. Environ Toxicol Chem 2016;35:1627-31.
27. He P, Chen L, Shao L, Zhang H, Lü F. Municipal solid waste (MSW) landfill: a source of microplastics? Water Res 2019;159:38-45.
28. Canopoli L, Coulon F, Wagland ST. Degradation of excavated polyethylene and polypropylene waste from landfill. Sci Total Environ 2020;698:134125.
29. Anderson AG, Grose J, Pahl S, Thompson RC, Wyles KJ. Microplastics in personal care products: exploring perceptions of environmentalists, beauticians and students. Mar Pollut Bull 2016;113:454-60.
30. Habib RZ, Salim Abdoon MM, Al Meqbaali RM, et al. Analysis of microbeads in cosmetic products in the United Arab Emirates. Environ Pollut 2020;258:113831.
31. Li J, Liu H, Paul Chen J. Microplastics in freshwater systems: a review on occurrence, environmental effects, and methods for microplastics detection. Water Res 2018;137:362-74.
32. Edo C, González-Pleiter M, Leganés F, Fernández-Piñas F, Rosal R. Fate of microplastics in wastewater treatment plants and their environmental dispersion with effluent and sludge. Environ Pollut 2020;259:113837.
33. Mitrano DM, Wohlleben W. Microplastic regulation should be more precise to incentivize both innovation and environmental safety. Nat Commun 2020;11:5324.
34. Gaylarde C, Baptista-Neto JA, da Fonseca EM. Plastic microfibre pollution: how important is clothes' laundering? Heliyon 2021;7:e07105.
35. Amrutha K, Warrier AK. The first report on the source-to-sink characterization of microplastic pollution from a riverine environment in tropical India. Sci Total Environ 2020;739:140377.
36. Hitchcock JN. Storm events as key moments of microplastic contamination in aquatic ecosystems. Sci Total Environ 2020;734:139436.
37. Ren SY, Sun Q, Ni HG, Wang J. A minimalist approach to quantify emission factor of microplastic by mechanical abrasion. Chemosphere 2020;245:125630.
38. Song YK, Hong SH, Jang M, Han GM, Jung SW, Shim WJ. Combined effects of UV exposure duration and mechanical abrasion on microplastic fragmentation by polymer type. Environ Sci Technol 2017;51:4368-76.
39. Cai L, Wang J, Peng J, Tan Z, Zhan Z, Tan X, Chen Q. Characteristic of microplastics in the atmospheric fallout from Dongguan city, China: preliminary research and first evidence. Environ Sci Pollut Res 2017;24:24928-35.
40. Auta HS, Emenike CU, Jayanthi B, Fauziah SH. Growth kinetics and biodeterioration of polypropylene microplastics by Bacillus sp. and Rhodococcus sp. isolated from mangrove sediment. Mar Pollut Bull 2018;127:15-21.
41. Auta HS, Emenike CU, Fauziah SH. Distribution and importance of microplastics in the marine environment: a review of the sources, fate, effects, and potential solutions. Environ Int 2017;102:165-76.
42. Li X, Chen L, Mei Q, et al. Microplastics in sewage sludge from the wastewater treatment plants in China. Water Res 2018;142:75-85.
43. Kole PJ, Löhr AJ, Van Belleghem FGAJ, Ragas AMJ. Wear and tear of tyres: a stealthy source of microplastics in the environment. Int J Environ Res Public Health 2017;14:1265.
44. Evangeliou N, Grythe H, Klimont Z, et al. Atmospheric transport is a major pathway of microplastics to remote regions. Nat Commun 2020;11:3381.
45. Zhang M, Yin H, Tan J, et al. A comprehensive review of tyre wear particles: Formation, measurements, properties, and influencing factors. Atmos Environ 2023;297:119597.
46. Wang C, Chen W, Zhao H, et al. Microplastic fiber release by laundry: a comparative study of hand-washing and machine-washing. ACS EST Water 2023;3:147-55.
47. An L, Liu Q, Deng Y, Wu W, Gao Y, Ling W. Sources of microplastic in the environment. In: He D, Luo Y, editors. Microplastics in terrestrial environments. Cham: Springer International Publishing; 2020. pp. 143-59.
48. Jartun M, Ottesen RT, Steinnes E, Volden T. Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps. Sci Total Environ 2008;396:147-63.
49. Cheung PK, Hung PL, Fok L. River Microplastic contamination and dynamics upon a rainfall event in Hong Kong, China. Environ Process 2019;6:253-64.
50. Corradini F, Meza P, Eguiluz R, Casado F, Huerta-Lwanga E, Geissen V. Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal. Sci Total Environ 2019;671:411-20.
51. Li S, Wang T, Guo J, et al. Polystyrene microplastics disturb the redox homeostasis, carbohydrate metabolism and phytohormone regulatory network in barley. J Hazard Mater 2021;415:125614.
52. Meng QJ, Ji Q, Zhang YG, Liu D, Grossnickle DM, Luo ZX. Mammalian evolution. An arboreal docodont from the Jurassic and mammaliaform ecological diversification. Science 2015;347:764-8.
53. Re V. Shedding light on the invisible: addressing the potential for groundwater contamination by plastic microfibers. Hydrogeol J 2019;27:2719-27.
54. O’Connor D, Pan S, Shen Z, et al. Microplastics undergo accelerated vertical migration in sand soil due to small size and wet-dry cycles. Environ Pollut 2019;249:527-34.
55. Raza M, Lee J. Factors affecting spatial pattern of groundwater hydrochemical variables and nitrate in agricultural region of Korea. Episodes 2019;42:135-48.
56. Alle PH, Garcia-Munoz P, Adouby K, Keller N, Robert D. Efficient photocatalytic mineralization of polymethylmethacrylate and polystyrene nanoplastics by TiO2/β-SiC alveolar foams. Environ Chem Lett 2021;19:1803-8.
57. Kumar M, Xiong X, He M, et al. Microplastics as pollutants in agricultural soils. Environ Pollut 2020;265:114980.
58. Eerkes-Medrano D, Thompson RC, Aldridge DC. Microplastics in freshwater systems: a review of the emerging threats, identification of knowledge gaps and prioritisation of research needs. Water Res 2015;75:63-82.
59. Schmidt C, Krauth T, Wagner S. Export of plastic debris by rivers into the sea. Environ Sci Technol 2017;51:12246-53.
60. Eriksen M, Mason S, Wilson S, et al. Microplastic pollution in the surface waters of the Laurentian Great Lakes. Mar Pollut Bull 2013;77:177-82.
61. Free CM, Jensen OP, Mason SA, Eriksen M, Williamson NJ, Boldgiv B. High-levels of microplastic pollution in a large, remote, mountain lake. Mar Pollut Bull 2014;85:156-63.
62. Alfonso MB, Scordo F, Seitz C, et al. First evidence of microplastics in nine lakes across Patagonia (South America). Sci Total Environ 2020;733:139385.
63. Horton AA, Dixon SJ. Microplastics: an introduction to environmental transport processes. WIREs Water 2018:5.
64. Choy CA, Robison BH, Gagne TO, et al. The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column. Sci Rep 2019;9:7843.
65. Kane IA, Clare MA, Miramontes E, et al. Seafloor microplastic hotspots controlled by deep-sea circulation. Science 2020;368:1140-5.
66. Food and Agriculture Organization of the United Nations. The state of world fisheries and aquaculture 2018: meeting the sustainable development goals. Available from: https://www.fao.org/3/i9540en/i9540en.pdf [Last accessed on 7 Apr 2023].
67. Campanale C, Galafassi S, Savino I, et al. Microplastics pollution in the terrestrial environments: poorly known diffuse sources and implications for plants. Sci Total Environ 2022;805:150431.
68. Stovall JK, Bratton SP. Microplastic pollution in surface waters of urban watersheds in central Texas, United States: a comparison of sites with and without treated wastewater effluent. Front Analyt Sci 2022:2.
69. Xue B, Zhang L, Li R, et al. Underestimated microplastic pollution derived from fishery activities and “hidden” in deep sediment. Environ Sci Technol 2020;54:2210-7.
70. Lusher A, Hollman P, Mendoza-Hill J. Microplastics in fisheries and aquaculture: status of knowledge on their occurrence and implications for aquatic organisms and food safety. Available from: https://oceanrep.geomar.de/id/eprint/49179/1/Microplastics%20in%20fisheries%20and%20aquaculture.pdf [Last accessed on 7 Apr 2023].
71. Almeida MPD, Gaylarde C, Pompermayer FC, et al. The complex dynamics of microplastic migration through different aquatic environments: subsidies for a better understanding of its environmental dispersion. Microplastics 2023;2:62-77.
72. Sharma S, Chatterjee S. Microplastic pollution, a threat to marine ecosystem and human health: a short review. Environ Sci Pollut Res Int 2017;24:21530-47.
73. Ochman CM, Brookson C, Bikker J, et al. Rethinking microplastics as a diverse contaminant suite. Environ Toxicol Chem 2019;38:703-11.
74. Porter A, Lyons BP, Galloway TS, Lewis C. Role of marine snows in microplastic fate and bioavailability. Environ Sci Technol 2018;52:7111-9.
75. Fonseca EM, Gaylarde C, Baptista Neto JA, Camacho Chab JC, Ortega-morales O. Microbial interactions with particulate and floating pollutants in the oceans: a review. Micro 2022;2:257-76.
76. Allen S, Allen D, Moss K, Le Roux G, Phoenix VR, Sonke JE. Examination of the ocean as a source for atmospheric microplastics. PLoS One 2020;15:e0232746.
77. Bank MS, Hansson SV. The plastic cycle: a novel and holistic paradigm for the anthropocene. Environ Sci Technol 2019;53:7177-9.
78. Dris R, Gasperi J, Tassin B. Sources and fate of microplastics in urban areas: a focus on paris megacity. In: Wagner M, Lambert S, editors. Freshwater Microplastics. Cham: Springer International Publishing; 2018. pp. 69-83.
79. Abbasi S, Keshavarzi B, Moore F, et al. Distribution and potential health impacts of microplastics and microrubbers in air and street dusts from Asaluyeh County, Iran. Environ Pollut 2019;244:153-64.
80. Wang X, Li C, Liu K, Zhu L, Song Z, Li D. Atmospheric microplastic over the South China Sea and East Indian Ocean: abundance, distribution and source. J Hazard Mater 2020;389:121846.
81. Allen S, Allen D, Phoenix VR, et al. Atmospheric transport and deposition of microplastics in a remote mountain catchment. Nat Geosci 2019;12:339-44.
82. Ambrosini R, Azzoni RS, Pittino F, Diolaiuti G, Franzetti A, Parolini M. First evidence of microplastic contamination in the supraglacial debris of an alpine glacier. Environ Pollut 2019;253:297-301.
83. Bergmann M, Mützel S, Primpke S, Tekman MB, Trachsel J, Gerdts G. White and wonderful? Sci Adv 2019;5:eaax1157.
84. Zhang Y, Kang S, Allen S, Allen D, Gao T, Sillanpää M. Atmospheric microplastics: a review on current status and perspectives. Earth-Science Reviews 2020;203:103118.
85. Dris R, Gasperi J, Saad M, Mirande C, Tassin B. Synthetic fibers in atmospheric fallout: A source of microplastics in the environment? Mar Pollut Bull 2016;104:290-3.
86. Peeken I, Primpke S, Beyer B, et al. Arctic sea ice is an important temporal sink and means of transport for microplastic. Nat Commun 2018;9:1505.
87. Roblin B, Ryan M, Vreugdenhil A, Aherne J. Ambient atmospheric deposition of anthropogenic microfibers and microplastics on the western periphery of Europe (Ireland). Environ Sci Technol 2020;54:11100-8.
88. Liu K, Wu T, Wang X, et al. Consistent transport of terrestrial microplastics to the ocean through atmosphere. Environ Sci Technol 2019;53:10612-9.
89. Isobe A, Uchida K, Tokai T, Iwasaki S. East Asian seas: a hot spot of pelagic microplastics. Mar Pollut Bull 2015;101:618-23.
90. Fu Z, Wang J. Current practices and future perspectives of microplastic pollution in freshwater ecosystems in China. Sci Total Environ 2019;691:697-712.
91. Hanvey JS, Lewis PJ, Lavers JL, Crosbie ND, Pozo K, Clarke BO. A review of analytical techniques for quantifying microplastics in sediments. Anal Methods 2017;9:1369-83.
92. Besseling E, Quik JTK, Sun M, Koelmans AA. Fate of nano- and microplastic in freshwater systems: a modeling study. Environ Pollut 2017;220:540-8.
93. Hüffer T, Praetorius A, Wagner S, von der Kammer F, Hofmann T. Microplastic exposure assessment in aquatic environments: learning from similarities and differences to engineered nanoparticles. Environ Sci Technol 2017;51:2499-507.
94. Hidalgo-Ruz V, Gutow L, Thompson RC, Thiel M. Microplastics in the marine environment: a review of the methods used for identification and quantification. Environ Sci Technol 2012;46:3060-75.
95. Andrady AL, Neal MA. Applications and societal benefits of plastics. Philos Trans R Soc Lond B Biol Sci 2009;364:1977-84.
96. Wei GL, Li DQ, Zhuo MN, et al. Organophosphorus flame retardants and plasticizers: sources, occurrence, toxicity and human exposure. Environ Pollut 2015;196:29-46.
97. Hermabessiere L, Dehaut A, Paul-Pont I, et al. Occurrence and effects of plastic additives on marine environments and organisms: a review. Chemosphere 2017;182:781-93.
98. Igalavithana AD, Mahagamage MGYL, Gajanayake P, et al. Microplastics and potentially toxic elements: potential human exposure pathways through agricultural lands and policy based countermeasures. Microplastics 2022;1:102-20.
99. Antunes J, Frias J, Micaelo A, Sobral P. Resin pellets from beaches of the Portuguese coast and adsorbed persistent organic pollutants. Estuar Coast Shelf Sci 2013;130:62-9.
100. Fisner M, Majer A, Taniguchi S, Bícego M, Turra A, Gorman D. Colour spectrum and resin-type determine the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets. Mar Pollut Bull 2017;122:323-30.
101. Mato Y, Isobe T, Takada H, Kanehiro H, Ohtake C, Kaminuma T. Plastic resin pellets as a transport medium for toxic chemicals in the marine environment. Environ Sci Technol 2001;35:318-24.
102. Karapanagioti HK, Klontza I. Testing phenanthrene distribution properties of virgin plastic pellets and plastic eroded pellets found on Lesvos island beaches (Greece). Mar Environ Res 2008;65:283-90.
103. Fries E, Zarfl C. Sorption of polycyclic aromatic hydrocarbons (PAHs) to low and high density polyethylene (PE). Environ Sci Pollut Res Int 2012;19:1296-304.
104. Hüffer T, Weniger AK, Hofmann T. Sorption of organic compounds by aged polystyrene microplastic particles. Environ Pollut 2018;236:218-25.
105. Llorca M, Schirinzi G, Martínez M, Barceló D, Farré M. Adsorption of perfluoroalkyl substances on microplastics under environmental conditions. Environ Pollut 2018;235:680-91.
106. Ma H, Pu S, Liu S, Bai Y, Mandal S, Xing B. Microplastics in aquatic environments: Toxicity to trigger ecological consequences. Environ Pollut 2020;261:114089.
107. Fotopoulou KN, Karapanagioti HK. Surface properties of beached plastic pellets. Mar Environ Res 2012;81:70-7.
108. Wang X, Huang W, Wei S, et al. Microplastics impair digestive performance but show little effects on antioxidant activity in mussels under low pH conditions. Environ Pollut 2020;258:113691.
109. Liu G, Zhu Z, Yang Y, Sun Y, Yu F, Ma J. Sorption behavior and mechanism of hydrophilic organic chemicals to virgin and aged microplastics in freshwater and seawater. Environ Pollut 2019;246:26-33.
110. Tourinho PS, Kočí V, Loureiro S, van Gestel CAM. Partitioning of chemical contaminants to microplastics: Sorption mechanisms, environmental distribution and effects on toxicity and bioaccumulation. Environ Pollut 2019;252:1246-56.
111. Koelmans AA, Meulman B, Meijer T, Jonker MT. Attenuation of polychlorinated biphenyl sorption to charcoal by humic acids. Environ Sci Technol 2009;43:736-42.
112. Lambert S, Sinclair CJ, Bradley EL, Boxall AB. Effects of environmental conditions on latex degradation in aquatic systems. Sci Total Environ 2013;447:225-34.
113. Luthy RG, Aiken GR, Brusseau ML, et al. Sequestration of hydrophobic organic contaminants by geosorbents. Environ Sci Technol 1997;31:3341-7.
114. Hartmann NB, Rist S, Bodin J, et al. Microplastics as vectors for environmental contaminants: exploring sorption, desorption, and transfer to biota. Integr Environ Assess Manag 2017;13:488-93.
115. Hofmann GE, Smith JE, Johnson KS, et al. High-frequency dynamics of ocean pH: a multi-ecosystem comparison. PLoS One 2011;6:e28983.
116. Guo X, Pang J, Chen S, Jia H. Sorption properties of tylosin on four different microplastics. Chemosphere 2018;209:240-5.
117. Hall LW Jr, Anderson RD. The influence of salinity on the toxicity of various classes of chemicals to aquatic biota. Crit Rev Toxicol 1995;25:281-346.
118. Sacks VP, Lohmann R. Development and use of polyethylene passive samplers to detect triclosans and alkylphenols in an urban estuary. Environ Sci Technol 2011;45:2270-7.
119. Lohmann R. Critical review of low-density polyethylene’s partitioning and diffusion coefficients for trace organic contaminants and implications for its use as a passive sampler. Environ Sci Technol 2012;46:606-18.
120. Hüffer T, Hofmann T. Sorption of non-polar organic compounds by micro-sized plastic particles in aqueous solution. Environ Pollut 2016;214:194-201.
121. Liu H, Yang X, Liu G, et al. Response of soil dissolved organic matter to microplastic addition in Chinese loess soil. Chemosphere 2017;185:907-17.
122. Huang Y, Zhao Y, Wang J, Zhang M, Jia W, Qin X. LDPE microplastic films alter microbial community composition and enzymatic activities in soil. Environ Pollut 2019;254:112983.
123. Zhang M, Zhao Y, Qin X, et al. Microplastics from mulching film is a distinct habitat for bacteria in farmland soil. Sci Total Environ 2019;688:470-8.
124. Sun Y, Duan C, Cao N, et al. Effects of microplastics on soil microbiome: the impacts of polymer type, shape, and concentration. Sci Total Environ 2022;806:150516.
125. Yu H, Fan P, Hou J, et al. Inhibitory effect of microplastics on soil extracellular enzymatic activities by changing soil properties and direct adsorption: an investigation at the aggregate-fraction level. Environ Pollut 2020;267:115544.
126. Zang H, Zhou J, Marshall MR, Chadwick DR, Wen Y, Jones DL. Microplastics in the agroecosystem: are they an emerging threat to the plant-soil system? Soil Biol Biochem 2020;148:107926.
127. Sun Y, Duan C, Cao N, Ding C, Huang Y, Wang J. Biodegradable and conventional microplastics exhibit distinct microbiome, functionality, and metabolome changes in soil. J Hazard Mater 2022;424:127282.
128. Zettler ER, Mincer TJ, Amaral-Zettler LA. Life in the “plastisphere”: microbial communities on plastic marine debris. Environ Sci Technol 2013;47:7137-46.
129. Rogers KL, Carreres-Calabuig JA, Gorokhova E, Posth NR. Micro-by-micro interactions: how microorganisms influence the fate of marine microplastics. Limnol Oceanogr Lett 2020;5:18-36.
130. Gaylarde CC, de Almeida MP, Neves CV, Neto JAB, da Fonseca EM. The Importance of biofilms on microplastic particles in their sinking behavior and the transfer of invasive organisms between ecosystems. Micro 2023;3:320-37.
131. der Putten WH, Klironomos JN, Wardle DA. Microbial ecology of biological invasions. ISME J 2007;1:28-37.
132. Amalfitano S, Coci M, Corno G, Luna GM. A microbial perspective on biological invasions in aquatic ecosystems. Hydrobiologia 2015;746:13-22.
133. Liebhold AM, Macdonald WL, Bergdahl D, Mastro VC. Invasion by exotic forest pests: a threat to forest ecosystems. For Sci 1995;41:a0001-z0001.
134. Gerlach J. Predator, prey and pathogen interactions in introduced snail populations. Anim Conserv 2001;4:203-9.
135. Jules ES, Kauffman MJ, Ritts WD, Carroll AL. Spread of an invasive pathogen over a variable landscape: a nonnative root rot on port Orford cedar. Ecology 2002;83:3167-81.
136. Niwa S, Iwano H, Asada S, Matsuura M, Goka K. A microsporidian pathogen isolated from a colony of the European bumblebee, bombus terrestris, and infectivity on Japanese bumble-bee. Jpn J Appl Entomol Zool 2004;48:60-4.
137. Waring KM, O’hara KL. Silvicultural strategies in forest ecosystems affected by introduced pests. For Ecol Manag 2005;209:27-41.
138. Bouaziz A, Houfani AA, Arab M, Baoune H. Microplastics as a carrier of antibiotic resistance genes: a revision of literature. Micro and nanoplastics in soil: threats to plant-based food. Cham: Springer International Publishing; 2023. pp. 147-61.
139. Shi J, Wang J, Lv J, et al. Microplastic additions alter soil organic matter stability and bacterial community under varying temperature in two contrasting soils. Sci Total Environ 2022;838:156471.
140. Rong L, Zhao L, Zhao L, et al. LDPE microplastics affect soil microbial communities and nitrogen cycling. Sci Total Environ 2021;773:145640.
141. Elbasiouny H, Mostafa AA, Zedan A, et al. Potential effect of biochar on soil properties, microbial activity and vicia faba properties affected by microplastics contamination. Agronomy 2023;13:149.
142. Gao W, Wei X, Wu, K. Research progress of microplastics in the environment. Plast Sci Technol 2021;49:111-6.
144. Mintenig SM, Int-Veen I, Löder MGJ, Primpke S, Gerdts G. Identification of microplastic in effluents of waste water treatment plants using focal plane array-based micro-Fourier-transform infrared imaging. Water Res 2017;108:365-72.
145. Raju S, Carbery M, Kuttykattil A, et al. Transport and fate of microplastics in wastewater treatment plants: implications to environmental health. Rev Environ Sci Biotechnol 2018;17:637-53.
146. Lipka M, Woelfel J, Gogina M, et al. Solute reservoirs reflect variability of early diagenetic processes in temperate brackish surface sediments. Front Mar Sci 2018;5:413.
147. Wurzbacher C, Fuchs A, Attermeyer K, et al. Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment. Microbiome 2017;5:41.
148. T. Microplastics increase soil pH and decrease microbial activities as a function of microplastic shape, polymer type, and exposure time. Fron Environ Sci 2021;9:1.
149. Liang Y, Lehmann A, Yang G, Leifheit EF, Rillig MC. Effects of microplastic fibers on soil aggregation and enzyme activities are organic matter dependent. Front Environ Sci 2021;9:650155.
150. Chen X, Chen X, Zhao Y, Zhou H, Xiong X, Wu C. Effects of microplastic biofilms on nutrient cycling in simulated freshwater systems. Sci Total Environ 2020;719:137276.
151. Center for International Environmental Law (CIEL). Plastic & climate, the hidden costs of a plastic planet. Available from: https://www.ciel.org/wp-content/uploads/2019/05/Plastic-and-Climate-FINAL-2019.pdf [Last accessed on 7 Apr 2023].
152. Ellen MacArthur Foundation. The new plastics economy: rethinking the future of plastics. Available from: https://www.ellenmacarthurfoundation.org/publications/the-new-plastics-economy-rethinking-the-future-of-plastics [Last accessed on 7 Apr 2023].
153. Ghaddar A, Bousso R. Rising use of plastics to drive oil demand to 2050: IEA. Available from: https://www.reuters.com/article/us-petrochemicals-iea-idUSKCN1ME2QD [Last accessed on 7 Apr 2023].
154. International Energy Agency. The future of petrochemicals towards a more sustainable chemical industry. Available from: https://www.iea.org/reports/the-future-of-petrochemicals [Last accessed on 7 Apr 2023].
155. Rillig MC. Microplastic disguising as soil carbon storage. Environ Sci Technol 2018;52:6079-80.
156. Geyer R, Jambeck JR, Law KL. Production, use, and fate of all plastics ever made. Sci Adv 2017;3:e1700782.
157. Benavides PT, Lee U, Zarè-mehrjerdi O. Life cycle greenhouse gas emissions and energy use of polylactic acid, bio-derived polyethylene, and fossil-derived polyethylene. J Clean Prod 2020;277:124010.
158. Rillig MC, Leifheit E, Lehmann J. Microplastic effects on carbon cycling processes in soils. PLoS Biol 2021;19:e3001130.
159. Rillig MC, Lehmann A, Ryo M, Bergmann J. Shaping up: toward considering the shape and form of pollutants. Environ Sci Technol 2019;53:7925-6.
160. de Souza Machado AA, Lau CW, Kloas W, et al. Microplastics can change soil properties and affect plant performance. Environ Sci Technol 2019;53:6044-52.
161. Lozano YM, Lehnert T, Linck LT, Lehmann A, Rillig MC. Microplastic shape, concentration and polymer type affect soil properties and plant biomass. BioRxiv 2020;27:202007.
162. Chen J, Wan N, Li K, et al. Molecular characteristics and biological effects of dissolved organic matter leached from microplastics during sludge hydrothermal treatment. J Hazard Mater 2023;448:130718.
163. Kleunen M, Brumer A, Gutbrod L, Zhang Z. A microplastic used as infill material in artificial sport turfs reduces plant growth. Plants People Planet 2020;2:157-66.
164. Zantis LJ, Borchi C, Vijver MG, Peijnenburg W, Di Lonardo S, Bosker T. Nano- and microplastics commonly cause adverse impacts on plants at environmentally relevant levels: a systematic review. Sci Total Environ 2023;867:161211.
165. Eriksen M, Lebreton LC, Carson HS, 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 2014;9:e111913.
166. Yang S, Cheng Y, Liu T, et al. Impact of waste of COVID-19 protective equipment on the environment, animals and human health: a review. Environ Chem Lett 2022;20:2951-70.
167. Okeke ES, Ezeorba TPC, Chen Y, Mao G, Feng W, Wu X. Ecotoxicological and health implications of microplastic-associated biofilms: a recent review and prospect for turning the hazards into benefits. Environ Sci Pollut Res Int 2022;29:70611-34.
168. Peter H, Ylla I, Gudasz C, Romaní AM, Sabater S, Tranvik LJ. Multifunctionality and diversity in bacterial biofilms. PLoS One 2011;6:23225.
169. Huang D, Tao J, Cheng M, et al. Microplastics and nanoplastics in the environment: macroscopic transport and effects on creatures. J Hazard Mater 2021;407:124399.
170. Galgani L, Loiselle SA. Plastic pollution impacts on marine carbon biogeochemistry. Environ Pollut 2021;268:115598.
171. Romera-Castillo C, Pinto M, Langer TM, Álvarez-Salgado XA, Herndl GJ. Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean. Nat Commun 2018;9:1430.
172. Galgani L, Loiselle S. Plastic accumulation in the sea surface microlayer: an experiment-based perspective for future studies. Geosciences 2019;9:66.
173. Kvale K, Prowe AEF, Chien CT, Landolfi A, Oschlies A. Zooplankton grazing of microplastic can accelerate global loss of ocean oxygen. Nat Commun 2021;12:2358.
174. Cole M, Lindeque PK, Fileman E, et al. Microplastics alter the properties and sinking rates of zooplankton faecal pellets. Environ Sci Technol 2016;50:3239-46.
175. Wieczorek AM, Croot PL, Lombard F, Sheahan JN, Doyle TK. Microplastic ingestion by gelatinous zooplankton may lower efficiency of the biological pump. Environ Sci Technol 2019;53:5387-95.
176. Shore EA, deMayo JA, Pespeni MH. Microplastics reduce net population growth and fecal pellet sinking rates for the marine copepod, Acartia tonsa. Environ Pollut 2021;284:117379.
177. Queiroz LM, Aun MV, Morita DM, Alem Sobrinho P. Biological nitrogen removal over nitritation/denitritation using phenol as carbon source. Braz J Chem Eng 2011;28:197-207.
179. Cluzard M, Kazmiruk TN, Kazmiruk VD, Bendell LI. Intertidal concentrations of microplastics and their influence on ammonium cycling as related to the shellfish industry. Arch Environ Contam Toxicol 2015;69:310-9.
180. Seeley ME, Song B, Passie R, Hale RC. Microplastics affect sedimentary microbial communities and nitrogen cycling. Nat Commun 2020;11:2372.
181. Li C, Busquets R, Campos LC. Assessment of microplastics in freshwater systems: a review. Sci Total Environ 2020;707:135578.
182. Chen Y, Liu X, Leng Y, Wang J. Defense responses in earthworms (Eisenia fetida) exposed to low-density polyethylene microplastics in soils. Ecotoxicol Environ Saf 2020;187:109788.
183. Mergelov N, Mueller CW, Prater I, et al. Alteration of rocks by endolithic organisms is one of the pathways for the beginning of soils on Earth. Sci Rep 2018;8:3367.
184. Gaylarde CC, de Almeida MP, Neves CV, Neto JAB, da Fonseca EM. The importance of biofilms on microplastic particles in their sinking behavior and the transfer of invasive organisms between ecosystems. Micro 2023;3:320-37.
185. Tan L, Ke X, Li Q, et al. The effects of biomineralization on the localised phase and microstructure evolutions of bacteria-based self-healing cementitious composites. Cem Concr Compos 2022;128:104421.
186. Pastore G, Weig AR, Vazquez E, Spohn M. Weathering of calcareous bedrocks is strongly affected by the activity of soil microorganisms. Geoderma 2022;405:115408.
187. Ercole C, Bozzelli P, Altieri F, Cacchio P, Del Gallo M. Calcium carbonate mineralization: involvement of extracellular polymeric materials isolated from calcifying bacteria. Microsc Microanal 2012;18:829-39.
188. Chen J, Liu B, Zhong M, Jing C, Guo B. Research status and development of microbial induced calcium carbonate mineralization technology. PLoS One 2022;17:0271761.
189. Gao X, Li J, Hu K, et al. Calcification of cell membranes: from ions to minerals. Chem Geol 2023;617:121266.
190. Shaheen N, Khushnood RA, Memon SA, Adnan F. Feasibility assessment of newly isolated calcifying bacterial strains in self-healing concrete. Constr Build Mater 2023;362:129662.
191. Fantle MS, Depaolo DJ. Variations in the marine Ca cycle over the past 20 million years. Earth Planet Sci Lett 2005;237:102-17.
192. Simkiss K, Wilbur KM. Biomineralization. Available from: https://www.elsevier.com/books/biomineralization/simkiss/978-0-08-092584-4 [Last accessed on 7 Apr 2023].
193. in mollusc shells and their functions in biomineralization. Phil Trans R Soc Lond B 1984;304:425-34.
194. Cusack M, Freer A. Biomineralization: elemental and organic influence in carbonate systems. Chem Rev 2008;108:4433-54.
195. Marin F, Luquet G, Marie B, Medakovic D. Molluscan shell proteins: primary structure, origin, and evolution. Elsevier; 2007. pp. 209-76.
196. Islam T, Peng C, Ali I. Morphological and cellular diversity of magnetotactic bacteria: a review. J Basic Microbiol 2018;58:378-89.
197. Lowenstam HA, Weiner S. On biomineralization. New York: Oxford University Press; 1989.
198. Marin F, Pokroy B, Luquet G, Layrolle P, De Groot K. Protein mapping of calcium carbonate biominerals by immunogold. Biomaterials 2007;28:2368-77.
199. Li J, Yang D, Li L, Jabeen K, Shi H. Microplastics in commercial bivalves from China. Environ Pollut 2015;207:190-5.
200. N, Jha A, Turner A. Impacts of microplastic fibres on the marine mussel, Mytilus galloprovinciallis. Chemosphere 2021;262:128290.
201. Tang Y, Zhou W, Sun S, et al. Immunotoxicity and neurotoxicity of bisphenol A and microplastics alone or in combination to a bivalve species, Tegillarca granosa. Environ Pollut 2020;265:115115.
202. Han Z, Jiang T, Xie L, Zhang R. Microplastics impact shell and pearl biomineralization of the pearl oyster Pinctada fucata. Environ Pollut 2022;293:118522.
203. Reichert J, Arnold AL, Hammer N, et al. Reef-building corals act as long-term sink for microplastic. Glob Chang Biol 2022;28:33-45.
204. Guzzetti E, Sureda A, Tejada S, Faggio C. Microplastic in marine organism: Environmental and toxicological effects. Environ Toxicol Pharmacol 2018;64:164-71.
205. Kolandhasamy P, Su L, Li J, Qu X, Jabeen K, Shi H. Adherence of microplastics to soft tissue of mussels: a novel way to uptake microplastics beyond ingestion. Sci Total Environ 2018;610-611:635-40.
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de Almeida, M. P.; Gaylarde, C. C.; Baptista Neto, J. A.; Delgado, J. F.; Lima, L. S.; Neves, C. V.; Pompermayer, L. L. O.; Vieira, K.; da Fonseca, E. M. The prevalence of microplastics on the earth and resulting increased imbalances in biogeochemical cycling. Water Emerg. Contam. Nanoplastics. 2023, 2, 7. http://dx.doi.org/10.20517/wecn.2022.20
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