1 Introduction

The presence of microplastics (MPs) in ecosystems, including aquatic and terrestrial ecosystems, has addressed enormous environmental problems. It is alongside the production of plastics that increased, reaching up to 460 million metric tonnes in 2019 (Chen et al., 2021). 98% of the output was disposed of as plastic waste, which comes from 40% packaging, 12% consumer goods, and 11% textiles (Liang et al., 2021). Recently, it has been reported that only 9% of plastic waste is recycled, with 40% of it as residue. Other plastics waste is 19% incinerated, 50% disposed in landfills, and 22% evaded in waste management systems. In addition, it has been identified that 6.1 million metric tonnes of plastic waste is transferred into aquatic ecosystems (Zhang, Wu, et al., 2023). However, a large amount of it exists in ecosystems.

Plastics are categorized into three groups based on their size determined as macroplastics (MaPs) with more than 25 mm particles in size, microplastics (MPs) ranging from 5 to 25 mm particles in size, and nanoplastics (NPs) with less than 100 nm particles in size. As tiny particles, MPs are widespread, ubiquitous, remarkably durable, and highly robust particles once they are released into aquatic and terrestrial ecosystems. Several MPs have been found in marine ecosystems, such as MPs distributed in the surface and sediment of the Ergene River, Turkey (Akdogan et al., 2023), in the freshwater lake of Coimbatore, India (Ephsy & Raja, 2023), in the tropical northwestern pacific ocean and Indonesian seas (Yuan, Corvianawatie, et al., 2023), in coastal wetland, China (Zhang, Sun, et al., 2023), in freshwater stream in the Gulf St Vincent, South Australia (Leterme et al., 2023) and terrestrial ecosystem such as MPs abundance in Central Asian desert near Kazakhstan and Uzbekistan (Wang, Lai, et al., 2021), in grassland Qinghai-Tibet plateau (Feng et al., 2021), in neotropical rainforest, savanna, pine plantations, and pasture soils of Oaxaca, Mexico (Álvarez-Lopeztello et al., 2021), in urban, and agricultural soils of Yeoju City, Korea (Choi et al., 2021).

MP pollution in ecosystems is closest to their distribution and abundance, which interferes with physical and chemical properties in the terrestrial ecosystem and their accumulation in aquatic ecosystems that threaten aquatic organisms. MPs can be easily fed and ingested by marine organisms. As a result, tissues, organs, and intestinal tracts are potentially affected. MPs may serve as substrates for deleterious organism groups, such as antibiotic-resistant genes and microbial community structures. Previously, study evidence that MPs changed the microbial community structures in China during the winter season (Yu et al., 2023), delayed germination and root growth of Lepidium sativum (Bosker et al., 2019), led to metabolic disorders in H. diversicolor (Métais et al., 2023), damaged to gill, gut, and liver of zebrafish due to the accumulation (Li, Nie, et al., 2023b), affected growth and digestive enzyme ability of sea cucumbers Apostichopus japonicus (Zhang, Liu, & Zhang, 2023). In addition, MPs have absorptive properties on their surface that can facilitate other contaminants and pathogens attached, including bisphenol A (BPA), dichloro-diphenyl-trichloroethane (DDTs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and pathogenic microorganism (Gkoutselis et al., 2021). Accumulation MPs entailed by these contaminants in aquatic organisms are potentially involved in the food web and indirectly tend to influence human health.

Aside from MP's impact on organisms and human health, MPs are responsible for contributing to global climate change. MPs interfere with carbon sequestration during the biological process of the organism. The gas exchange and circulation of carbon and nitrogen are affected by the abundance of MPs in terrestrial and aquatic ecosystems. The percentage of greenhouse gas (GHG) emissions tends to be higher. The presence of MPs in soils interacted with nitrogen and carbon cycles, including increasing N2O emission by up to 37.5% (Li et al., 2022) and CO2 emission by up to 92% (Zhang et al., 2022). These GHGs were significantly promoted in 7-30 days by 5μm of MPs after biological interaction with microbes in the ecosystems (Zhang et al., 2022). Therefore, the presence of MPs is a crucial issue for terrestrial and aquatic ecosystems, including its related impact on GHG emissions.

It is noteworthy that there has been a tremendous amount of scholarly research in recent years focused on the topic of MPs abundance in ecosystems. However, previous reviews of this topic have only primarily concentrated on MPs abundance in mangroves with particular reference to Asia (Talukdar et al., 2023), MPs in sediments and their influential factors (Yuan, Gan, et al., 2023), MPs in the seagrass ecosystems (Li, Zhu, et al., 2023a), MPs distribution and effect on lakes (Pan et al., 2023) and MPs transfer in aquatic ecosystem (Ma et al., 2023). According to the best of the author's knowledge, as far as MPs abundance in ecosystems is concerned, there has yet to be a comprehensive review of MPs abundance in terrestrial and aquatic ecosystems as well as their correlation with climate change and impact on human health presented. This review presents a brief of the footprint studies related to MPs abundance in terrestrial and aquatic ecosystems and their relation to climate change and impact on human health to attain a great degree of understanding into the topic of MPs abundance in ecosystems. The description of types and sources of MPs was first discussed. The impacts of MPs on terrestrial and aquatic ecosystems, including human health, are also highlighted. According to the critical analysis of the transport of MPs in both ecosystems and the crucial nexus of MPs with climate change, this review affirms that it will contribute to a better understanding of MPs' abundance in ecosystems, the forthcoming MPs investigation, and minimizing the ecological impact of MPs abundance, human health as well as their relation to GHG.

2 Types and Sources of MPs

MPs are grouped as primary or secondary based on how they form. Primary MPs are plastics with a diameter of less than 5mm made for specialized uses and then introduced into the environment, either directly or indirectly (de Sá et al., 2018; Syberg et al., 2015). Fragments, threads, granules, and spheres are examples of primary MP particles (de Sá et al., 2018). They are often found in cosmetic formulations as microbeads and utilized in air-blasting mediums to remove impurities and varnish from machines and vessel bodies. Their application in the medical field as drug carriers is also becoming more common (Cole et al., 2011; Syberg et al., 2015).

Secondary MPs are generated through the chemical, mechanical, or biological decomposition of existing larger plastics in the environs (Boyle & Örmeci, 2020; de Sá et al., 2018). Ultraviolet light is the leading cause of the decomposition of MPs in the terrestrial ecosystem; oxidative deterioration from sunlight causes the plastic to lose its tensile qualities by increasing charged particle action within the polymer chain, causing it to become fragile and finally fracture (Boyle & Örmeci, 2020; New et al., 2023). Temperature variations and weathering are additional factors that promote plastic decomposition, resulting in comparatively operative plastic fracturing on land. MPs are typically degraded by sediment attrition and wave tides in the maritime environment, particularly during rain and stormy circumstances (Newet al., 2018).

MPs make the most outstanding contribution to the environment through using personal care and cosmetic items (Möhlenkamp et al., 2018). Microbeads frequently substitute natural and organic ingredients like grains, oats, and nuts in cosmetic products, exfoliates, and toothpaste (Issac & Kandasubramanian, 2021). Adding microbeads can stabilize mixtures, regulate gel strength, and moisturize or nourish the skin. Typically, each product has a variable average weight content of MPs; for example, toothpaste typically has 0.25% by weight of microbeads, whereas face cleansers include roughly 2.3%, 2.55% in a facial scrub, and 1.75% in a body wash (Sukanya et al., 2020). Microbead-containing items are rinsed down the sewer and collected with domestic effluent to the wastewater treatment plant (Heloisa & Amira, 2017). Several research findings have found that wastewater treatment plants are typically poor at retaining MPs, resulting in MPs escaping into the freshwater environments and eventually ending up in the ocean (Anderson, Park, & Palace, 2016). Researchers and the public have recently been aware of microbeads in cosmeceuticals, as they are now considered a substantial contaminant that threatens the marine ecosystem. Initiatives to restrict the involvement of microbeads in beauty products have made some advances, with regulations established in some nations to phase them out (Anderson, Grose, et al., 2016). In 2015, a group of European countries, including the Netherlands, Luxembourg, and Sweden, made a unified declaration to their Ministers urging a ban on MPs in beauty goods (Anderson, Park, & Palace, 2016).

Coastal vacations, fishing activities, and aquaculture are other MP sources that can directly reach the marine environment, putting aquatic species at peril. Plastics are usually tossed along shores and beaches after leisure and amusement due to human behavior. Conversely, plastic litter visible on coastlines can be attributed to the objects being transported in-shore by waves or winds due to their small size and lightweight (Cole et al., 2011; Issac & Kandasubramanian, 2021). Most components used in fisheries and aquacultures, such as strings, fish traps, and nets, are constructed from plastics. Although these products are not designed to be microscopic, they can discharge MPs into the water habitats following degradation and decomposition (Kurniawan et al., 2021). Discharged MPs typically have high buoyancy forces, allowing them to float and transport at varying depths in the water bodies. This incident is worrisome since MPs can entangle marine life and potentially be consumed by higher-level creatures in the food chain (Cole et al., 2011; Issac & Kandasubramanian, 2021). Based on a Norwegian fisheries study, abandoned fishing accessories grew by 3500 tonnes in nine years. Therefore, it is predictable and expected that fish feeds contain significant MPs. According to a recent investigation, several Malaysian fish feed brands involved more than 300 MP particles. Moreover, fish supplements also contribute to MPs in the marine ecosystem, as there is an association between MPs and antimicrobial medications. As a result, fishing and aquaculture are significant producers of MPs in water bodies, posing a substantial risk to the marine habitat and public health (Ding et al., 2021).

Laundering is a significant source of primary MPs in the natural habitat. Consequently, it is critical to comprehend how the garment-washing process contributes to this environmental hazard (De Falco et al., 2019). Artificial fibers in apparel increased by 48 million tons from 1950 to 2010; this increased output of textiles has resulted in a higher percentage of microfibers entering the ecosystem (Carney Almroth et al., 2018). This scenario contributes significantly to the growing global MP contamination problem due to their tiny dimensions and large specific surface area, amplifying their negative environmental consequences (Gaylarde et al., 2021). The mechanical and chemical disturbances that textiles encounter throughout the laundering procedure cause microfibers to escape from the threads. The discharged microfibers could conceivably slip through WWTPs due to their microscopic size and end up in the oceans. Microfibers have been found in the effluent of treatment plants in Europe and Australia, even if they have more extraordinary performance or sophisticated treatment methods, implying that WWTPs can operate as a conduit for MP release (De Falco et al., 2018). In a prior study, each kilogram of laundry can emit approximately 120000 fibers into the environment. Microfibers obtained after laundering could be influenced by garment aging based on use and time, with the older clothing releasing more fibers than the newer one. Therefore, specialists must explore innovative textile compositions and effective purifiers in washing machines to minimize the MP issue (Carney Almroth et al., 2018).

Agriculture is also one reason for global MP pollution in water bodies, as the application of plastic sheets for agricultural mulching grows worldwide to accommodate food security for the burgeoning population. Mulching, or coating the soil with plastic films to enhance the microenvironment for crop development, has ushered in a transformation by improving harvest and permitting farming in areas with scarce water and poor environmental settings. Plastic can preserve soil moisture content and warmth while avoiding soil degradation and grass growth, both of which can induce plant productivity. Besides, they also encourage fruit ripeness and freshness while reducing water, pesticide, and fertilizer consumption, making them essential to long-term agricultural sustainability. Low-density polyethylene is typically used as mulch due to its high perforation protection, tensile strength, extended lifespan, and water resistance (Serrano-Ruiz et al., 2021). In 2016, the world demand for agricultural plastic sheets peaked at 4 million tonnes, with a 5.6% annual growth rate expected until 2030. Plastic mulching is employed on around 20000 km2 of agricultural acreage globally, with China accounting for 90% of the total. Mulches exacerbate MP pollution since retrieving all mulch wreckage necessitates a large workforce for a long time (Huang et al., 2020). As a result, most of the mulches are frequently left in cultivated soils and broken down into smaller pieces, either deliberately or inadvertently (Huang et al., 2020; Serrano-Ruiz et al., 2021). This scenario has resulted in MPs being abundant in agricultural soils, which transferred into aquatic ecosystems because variables such as MPs' low density and tiny size made them easily conveyed by water and wind (Ding et al., 2021).

Tyre wear and tear (TWT) also releases MPs into the atmosphere and water bodies. Each individual is predicted to emit approximately 2465 grams per year to the ecosystem, with 8% of the released MPs ending up in the oceans and 5% retained in the air as particulate matter. Atmospheric MPs have lowered global air quality that increased public health stress and resulted in 3,000,000 fatalities in 2012. The quantity and dimension of TWT particulates being discharged and distributed are affected by several parameters: road surface, weather, velocity, tire aging, and material. The interaction between the tire and the pavement promotes friction and heat, leading to abrasive wear. The friction causes a high number of tire particulates. At the same time, heat provides hot patches on the tire's exterior, causing the high volatility element to vaporize, generating tiny particles (Kole et al., 2017). Small TWTs are often discharged into the atmosphere and are susceptible to air dispersion.

In contrast, larger ones accumulate on the roadways and then are carried away by precipitation into soil, streams, and rivers (Tamis et al., 2021). TWT currently can be found in all parts of the ecosystem and can invade our food supply chain, necessitating additional analysis to determine hazards to public health (Kole et al., 2017; Tamis et al., 2021). Therefore, stakeholders and authorities must raise their consciousness to tackle this issue by reducing information asymmetry and innovative solutions (Kole et al., 2017).

3 Impacts of MPs on Terrestrial Ecosystem

It is imperative to identify that MP contamination is not a one-size-fits-all problem, as MPs originate in a dizzying array of chemical compositions, durability, and surface qualities (Rillig et al., 2019). Different polymer compositions, types, concentrations, and sizes of MPs can affect the ecological environment. Tables 1 and 2 summarizes the fallouts of MP dimensions or types on soil systems and flora. MPs are classified as physical impurities in the soil. They can degrade soil compaction by decreasing the root penetration barrier and enhancing soil recirculation, contributing to increased root development. Another function of MPs, especially plastic films, is that they generate routes for water circulation, improving water vaporization and soil dehydration, with hypothetically severe repercussions for plant production rates. For instance, Rillig et al. (2019) described that different types of MPs impact plant growth and development differently. Some MPs showed a positive impact on plant growth, while some showed a negative impact on plant growth. They also concluded that the impact of MPs on plants varies according to plant species. In another study, Tang (2023) observed that MPs negatively impacted plant growth. They observed that MPs caused a blockage in seed and root pores, resulting in minimizing the water and nutrient uptake.

Table 1 Average concentration of MPs in different regions
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Table 2 Possible impacts of MPs type to terrestrial setting (Rillig et al., 2019)
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The modifications of soil stability by MPs can result in changes in soil microbial diversity, even if such adjustments, along with their repercussions, are difficult to ascertain. However, these changes may directly influence root symbiotic and plant life.

MPs also affect soil accumulation by forming soil aggregates, which contribute to soil quality and soil organisms' habitation structure. Aggregates commonly consist of carbon components to prevent rapid disintegration, resulting in a high C/N ratio and causing microbial inactivation (Rillig & Lehmann, 2020). Aside from that, MP presence can interfere with photosynthesis and transport metals as non-desirable contaminants, a crucial plant process for producing chlorophyll and absorbing sunlight to convert carbon dioxide into food. According to several studies, the toxicity and exposure of MPs lowered the chlorophyll concentration of thale cress and maize, resulting in lower net photosynthetic capacity (Colzi et al., 2022; Khatiwada et al., 2023). The decreased photosynthetic activity negatively impacts the plant's developmental process (Tang 2023). Additionally, MP exposure stimulates the antioxidant response mechanism to excrete disproportionate reactive oxygen species (ROS), providing adverse conditions for crop yields. ROS have a greater propensity to proliferate in plant roots than in other areas of the plant, inflicting more damage to roots (Chen et al., 2022). It indicated that plants produce more ROS to overcome this stress when they are under induced stress (Tang 2023).

Although MPs are prevalent, there are limited studies and research on MPs in terrestrial wildlife, with most of the studies focusing on soil organisms (Huerta Lwanga et al., 2016). MPs threaten soil creatures, like earthworms and springtails, which are fundamental to keeping soil health and ecological stability. Wang et al. (2022) presented that MPs adversely affected the soil fauna and their ecological functions. They speculated MPs altered the gut microbiota and cellular response of soil fauna, especially earthworms and nematodes. Various parameters influenced the toxicity of MPs, such as dimensions, shape, color, unit weight, chemical nature, and degradation level. MP toxic effects are highly dependent on their molecular structure. Most additives involved in MPs are held together by weak bonds, causing leakage into the environment over time and hazardous to species (Dissanayake et al., 2022). MPs with a diminutive dimension have the potential to cling to the outside surface of soil organisms, causing injury to the surface. According to earthworm studies, two days of MP exposure develop blisters and lacerations on their outer membrane, as well as genetic and reproductive mechanisms damage due to changes in the interpretation thresholds of stress signal transduction. Besides, introducing MPs to soil fauna can lower their reproductive rate by reducing generative cells and modifying genetic cells, but this field of knowledge is currently finite. MP consumption by soil creatures can obstruct nutrient absorption and cause severe metabolic problems. More critically, metabolism illnesses are associated with movement patterns and reproductive capabilities (Wang et al., 2022).

4 Impacts of MPs on Aquatic Ecosystem

Oceans and streams act as the primary sinks for the MP deposition, resulting in a disproportionately unfavorable impact on macrophytes. The consequences of MPs on aquatic plants can be divided into three categories: adsorption, absorption, and toxicity, but the determinants for toxicity are presently undefined (Mateos-Cárdenas et al., 2021). Aquatic plants are affected by nutrient uptake as MPs can cause mechanical obstruction via MP adsorption (De Silva et al., 2021). The introduction of MPs in the water bodies can be uptake by freshwater algal species, limiting root development and cellular uptake. Marine plankton is susceptible to MPs, as exposure to MPs can effectively adapt the molecular structure of extracellular polymeric compounds of plankton to deal with environmental pressure. It has been discovered that the production of nutrient polymeric compounds aids in MPs' aggregation and surface functionalization, altering their densities and migration. Besides, MPs can potentially disrupt algal photosynthesis by adhering to the exposed vascular tissue surface, reducing light absorption efficiency (Ge et al., 2021). In addition, the appearance of MPs can delay seed germination rate by obstructing the openings of seed capsules, preventing the seeds from adequately obtaining nutrition from the environment, and hindering the expansion of their roots or shoots (Mateos-Cárdenas et al., 2021).

The first occurrences of plastics in the stomachs of aquatic organisms were reported in the early 1950s due to increased plastic manufacture, with the incidence becoming more widespread in the 1970s (Vázquez & Rahman, 2021). Different aquatic species respond to MPs in various ways. MP impression is felt across the food chain in aquatic ecosystems, impacting development and proliferation while lowering life expectancies. Research shows that marine creatures prefer prey smaller than MPs, yet some consume MPs more than their prey species due to MP appearance and characteristics being similar to their diet (Usman et al., 2020). Ingestion is likely to be the primary method of MP introduction for most marine species. Ingestion of MP particles has been documented in over 690 maritime species from various taxonomic levels. This scenario requires immediate attention to control the severity of ecosystem impacts (Kumar et al., 2020). In addition, their existence can be vectors to transport other contaminants, such as metals, toxic chemicals, and persistent pollutants. Fish are an essential aquatic species in our ecosystem because they contribute significantly to material transportation and energy transfer. Their health is directly tied to the sustainability of the marine's anatomy and physiology. As a result, undertaking a study into the ecological impacts of MPs on fish is necessary. Usually, MPs can clog the gastrointestinal tract of aquatic organisms, preventing them from growing and maturing. The accumulation of MPs can lead to a feeling of fullness, resulting in a decrease in consuming capability and a reduction in energy stores in the body. The magnitude of blockage is proportional to the quantity of MPs' exposure to the creatures. Besides, MPs can disrupt their reproductive system by lowering egg cells and sperm formation, hindering aquatic life's reproductive capabilities. The occurrence can lead to the downfall of specific marine species, resulting in an imbalance in the food chain, hunger, and death in aquatic life. After consumption, MPs cause immunological and genetic damage since they can cause oxidative stress, which triggers a cascade of inter-reactions, resulting in immunotoxicity and teratogenic effects (Ning et al., 2021).

Aside from that, bivalves are a widespread species that researchers are studying because of their high filtering capabilities to purify water contaminants; therefore, they have a higher tendency to ingest MPs through filtration activities (Green et al., 2017). Researchers have found that exposure to a high concentration of MPs can interfere with the rate of respiration, immunology, reproductive capability, and purification process of bivalves (Green et al., 2017; Sendra et al., 2021). The limiting filtration mechanism can lower food absorption, reducing the energy available for development and other life activities like adenosine triphosphate and byssus thread production, which are required for bivalves to attach to solid surfaces. Besides that, MPs can pose genotoxicity by causing DNA intersection breakage, nuclear abnormalities, and subcellular organelles damage. These variations could generate ROS and oxidative stress, which the bivalves' antioxidant defense mechanisms cannot regulate and combat (Zhang, Man, et al., 2020). The reproductive health of bivalves is also impacted by MPs' exposure since the majority of energy demands are utilized to maintain the internal mechanism of an individual. In this scenario, bivalves may automatically minimize the energy they devote to reproduction processes, failing to regulate protein gene coding that is implicated in the reproduction system (Zhang, Yan, & Wang, 2020). In bivalves exposed to MPs, there is a reduction in the overall number of oocytes retrieved by stripping, oocyte size, and sperm kinetic energy (Sendra et al., 2021). According to studies, exposed bivalves will have a 23% drop in sperm mobility, which could reduce their capacity to fertilize oocytes because more sperm is required for fertilization accomplishment (Sussarellu et al., 2016). The process by which germ cells develop, differentiate, and mature is also altered, which reduces the likelihood of proliferation (Sendra et al., 2021).

Decapods, such as lobsters, shrimps, and crabs, have also been examined in recent studies since they are frequently caught or raised as a food source and constitute an essential component of the diet of those living along the coast. Decapods are usually captured under heavy human pressure, where higher concentrations of toxins have accumulated in those areas and pose health risks to people who consume them. Decapods can thus be employed as indicator species of water quality and model creatures to assess the poisonousness of several toxins (D'Costa, 2022). The accumulation of MPs in Decapods can affect how well their organs operate and how active their metabolism is, which can lower their survival rates (D'Costa, 2022; Gray & Weinstein, 2017). The osmoregulation mechanism and the excretory system are damaged by MPs blocking the gills of decapods. The organisms cannot function properly because of this condition, which also lowers the effectiveness of their oxygen exchange. Antioxidant concentrations have been observed to rise in Decapods exposed to MPs. Still, high levels of oxidative stress can outweigh the antioxidant defenses and cause severe cell damage, modifying the roles of organ functioning (D'Costa, 2022). Visual proof of the harmful consequences of MPs would come from behavioral changes in species exposed to them. Hermit crab startle reaction was found to be considerably reduced by MPs' exposure, which may have an impact on the crabs' capacity to elude predators. As a result, MPs may impact the creature's predating, breeding, fighting, and even moving, leaving the animal in a weaker condition (Nanninga et al., 2020). Table 3 indicates the ramifications of MPs on different categories of marine animals.

Table 3 Potential impacts of different MP polymers on aquatic life
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The three major concern of Microplastics on aquatic sytem is water contamination, bioaccumulation and Habitat alteration (Kumar et al., 2020). Microplastics infiltrate aquatic and marine systems via urban runoff, industrial emissions, and the fragmentation of larger plastic objects (Werbowski et al., 2021). These substances can remain in bodies of water for long periods, which poses a danger to aquatic creatures. Microplastics can be misidentified for food by tiny aquatic animals such as algae, seafood, and invertebrates because of their small size and similar appearance. Particles such as these collect in the tissues of organisms for an extended amount of time, increasing concentration as they move up the food chain (Kumar et al., 2020). Species that hunt and feed on other organisms at greater elevations in the food chain are more likely to come into contact with microplastics, which can intensify the detrimental impacts that they may have. Microplastics can attract and carry dangerous contaminants such as pesticides and heavy metals (Tang et al., 2021). It indicated that MPs can spread contamination in aquatic environments. Additionally, MPs can accumulate in sediments, which can have an impact on benthic species and disturb the processes of nutrient cycling (Wang, Zhang, et al., 2023).

5 Transport of MPs and Crucial Nexus of Climate Change

MP distributions are divided into vertical and horizontal, as presented in Fig. 1. MP vertical dispersal in aquatic settings depends on aggregation, homo-aggregation, and hetero-aggregation. Aggregation occurs when MPs engage and cluster together in the water column before sinking to the ocean floor or sediments. According to the Derjaguin−Landau−Verwey−Overbeek (DLVO) theory that is frequently employed to evaluate the fortunes of nanoparticles in water bodies, however, it is challenging to form homo-aggregates in aquatic, resulting in limited resources for homo-aggregation. Algal species, polymer composition, and morphology all have a role in MP hetero-aggregation (Wang, Bolan, et al., 2021). For instance, (Cheng & Wang, 2022) found that the microalgal species Scenedesmus abundans was highly capable (84%) of removal efficacy of multiple MPs in aquatic ecosystems. MP hetero-aggregation can also occur due to biofilm development and solids adherence; both are controlled by water variables such as temperature, nutrition concentrations, and suspended particles, causing them to increase density (Ding et al., 2021). The position of MPs is highly dependent on their densities, as previously mentioned (Li et al., 2020). Based on a Korean study at the coastline, PE and PP are usually discovered in the upper part of the ocean due to their lower densities, while PVC and PET are conveyed via vertical mixing in the water column (Song et al., 2018).

Fig. 1
figure 1

Detailed MP transport mechanism (Li et al., 2020)

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MP horizontal distributions are determined by environmental circumstances and bio-associated dispersal aspects shaped by hydrological conditions. MPs in local streams can migrate horizontally into the ocean and even to the arctic regions by wind and wave currents (Auta et al., 2017). Meanwhile, for the bio-associated distribution, MPs are consumed by or attached to the exterior of aquatics, and they may fall off during activities or ingestion. Conspicuously, parameters governed this distribution, including marine species, MPs geometry, and appearance. Different marine organisms have varying capabilities to deliver MPs, with filter-feeding fish having a higher capacity than other fish species. Other than that, marine creatures prefer MPs that are spherical in shape and black in color, which could be because their appearance is similar to that of their food (Ding et al., 2021). It indicated that MP color is the main factor for ingestion by marine organisms (Yuan et al., 2022). MPs can easily migrate from their origins to other regions or even countries in both distributions, resulting in high concentrations of MPs being observed in the water bodies. Table 1 indicates the dispersion of MPs from different locations to the ocean.

On the other side, a hitherto unrecognized problem of MPs has just surfaced in this rising awareness, which is the unavoidable commitment of MPs to global warming and climate change. The high abundance of oceanic MPs has resulted in a harmful impact on the carbon-fixing cycle. Initially, aquatic flora and fauna served as biological carbon filters, absorbing atmospheric carbon and transferring it to the ocean floor to inhibit it from returning to the atmosphere. MPs' existence tends to decrease phytoplankton's capabilities to restore carbon through photosynthesis; as indicated in the previous section, MPs can hinder their light absorptivity by attaching to the tissue surface (Shen et al., 2020). Furthermore, radiation and heat from the sun induce MPs to emit methane into the atmosphere, a potent greenhouse gas that inhibits heat escaping from the earth. This situation causes a rise in the local temperature while simultaneously contributing to a faster rate of climate change, creating a negative loop. Increasing temperature enhances the decomposition of MPs to emit methane gas, thereby perpetuating the circle (Kumar et al., 2020). Sea turtles are marine organisms vulnerable to becoming victims of climate change and aquatic plastic waste. Temperature fluctuations along subtropical and tropical coastlines can affect turtle genetic makeup throughout their embryonic period. According to turtle research, the sex proportion is shifted toward females with increased temperature, posing a threat to the population. With the evidence in Queensland, Australia, more than 99% of juvenile and sub-adult turtles are females, which is an issue that could lead to low reproduction and wildlife extinction (Ford et al., 2022). Notwithstanding the scarcity of proof on the climatic implications of plastics-related greenhouse gas productions, the current findings indicate severe climate changes. Thus, global emissions approaches and guidelines must be devised and executed to solve the problem entirely (Shen et al., 2020).

While reducing microplastic pollution can have numerous beneficial environmental effects, its direct impact on mitigating climate change may be restricted. The reduction of microplastic pollution can positively impact the overall environmental well-being, which is essential for addressing the issue of climate change. Here are a few crucial factors to take into account. MPs, which are plastic particles smaller than 5mm, directly impact the climate. They can be found in different ecosystems. Although they do not directly emit greenhouse gases or contribute to climate change like CO2 or methane, their existence can harm ecosystems and species crucial for carbon sequestration, such as mangroves, forests, and phytoplankton (Wang, Jiao, et al., 2023). Indirectly impacting these ecosystems adversely affects the planet's capacity to regulate climate.

MPs have the potential to cause harm to marine life, terrestrial creatures, and human health when they are introduced into the food chain. It is imperative to minimize microplastic pollution to safeguard marine ecosystems, which are vital for carbon sequestration and nutrient cycling (Sridharan et al., 2021). Robust ecosystems have more excellent resistance to the effects of climate change.

6 Impacts on Human Health

One of the significant concerns about MP contamination is whether it poses a threat to ecological systems and public health (Khan et al., 2023). Therefore, obtaining information on the prevalence of MPs' exposure to the surroundings is essential in assessing the relationship between MPs to the environment and human health. The negative impacts of MPs on organisms can be categorized into two types: physical and chemical effects. The former concerns MP particle size, geometry, and quantity, whereas the latter concerns harmful chemical compounds associated with MPs (Campanale et al., 2020). Humans are generally exposed to or come into contact with MPs through ingesting, inhaling, and directly contacting because of their existence in food, drinks, and air, as well as consumer items such as personal care accessories, household products, and food packaging (Rahman et al., 2021). According to research, children intake about 500 MP particles per day, and adults can amass approximately 50000 MP particles throughout their lifespan based on the investigated dietary and air sources for MP consumption (Mohamed Nor et al., 2021). MPs can travel past the intestine and into the circulatory system, providing MPs the opportunity to assess other body parts (Campanale et al., 2020).

Individual exposure to MPs can be considered unavoidable given the extensive seafood intake around the world. The human excretory system can remove MPs from the body, with feces likely clearing more than 90% of ingested MPs (Smith et al., 2018). MPs accumulate in our body and reduce clearance rate due to dimensions, geometry, polymer type, and additional chemical compounds of MPs (Pironti et al., 2021). The structural composition of the toxic chemical, dosage parameters, and individual sensitivity determine the intensity of negative consequences from hazardous chemical exposures. MPs with particular properties can pass through living cell membranes and enter the circulatory system, accumulating in subsequent organs and affecting immune function and cell wellness (Smith et al., 2018). Over time, the build-up of MPs in our bodies can cause persistent discomfort, inflammation, cell proliferation, and inflammatory cell deterioration. The most prevalent disease infected by those who consume more MPs than healthy people is inflammatory bowel disease, which is the chronic inflammation of the gastrointestinal tract caused by MPs being obstructed and lodged in the gut system, preventing the system from functioning normally (Bhuyan, 2022). As a vector of other contaminants, MPs may lead to the absorption of different pollutants to expose human health.

Obesity is also another health issue linked to MP exposure. The global percentage of obese people has risen dramatically in the last 50 years, which is consistent and aligned with the utilization of plastic. Based on WHO, 39% of adults globally are overweight, and 13% are obese. Obesity and overweight have been related to various factors, including high-calorie consumption, insufficient exercise, and an unhealthy lifestyle, but environmental pollutants are also thought to be involved. The researchers believe that obesogens such as MPs are linked to the worldwide obesity epidemic. Obesogens are substances that cause an increase in the accumulation of white adipose tissue resulting from exposure. MPs have been reported to impact adipocyte development or transformation after a build-up in the liver and kidney, as well as changes in energy balance and cholesterol profile. These findings highlight substantial ramifications for MP exposure in early life, metabolic changes, and overweight individuals (Kannan & Vimalkumar, 2021).

In practically all situations, the additives are not chemically attached to the plastic polymer; only certain flame retardants interact with the particles and become one of the molecular chains' components. Most plastic additives are classified as human-hazardous, with a high risk of polluting soil, air, and waterways. They are utilized to improve the quality of plastics, such as waterproofing, structural rigidity, non-degradability, and electrical resistance (Campanale et al., 2020).

Microplastic significantly impacts humans via different mechanisms like ingestion pathways, toxicological concerns, inflammatory responses, and microbiome disruption (Blackburn & Green, 2022). Humans can come into contact with microplastics by consuming contaminated water and food and breathing in particles that are suspended in the air. Microplastics have been detected in seafood, salt, and drinking water, which has raised concerns regarding the potential for direct consumption and related health hazards (Sharma et al., 2023).

MPs can attract and accumulate persistent organic pollutants, or POPs, and additives as they move through the environment, resulting in the concentration of harmful substances on their surfaces (Okeke et al., 2022). Upon ingestion by humans, these pollutants have the potential to permeate into bodily tissues, leading to potential disruptions in the endocrine system, reproductive abnormalities, and the development of cancerous effects in a short amount of time (Chen et al., 2020). Breathing in microplastics and coming into contact with plastic-related goods on the skin might cause the respiratory and immunity systems to react with inflammation. Prolonged contact with airborne microplastics, particularly in metropolitan areas with elevated pollution levels, may exacerbate respiratory disorders and allergic reactions (Blackburn & Green, 2022). Recent studies indicate that microplastics in the gastrointestinal system can modify the gut microbiota composition in humans, impacting metabolic processes, immunological function, and general health (Sharma et al., 2023). These alterations in microorganisms could lead to inflammatory diseases and metabolic problems. The additives can cause health issues when individuals are exposed to them in large doses, as summarized in Table 4.

Table 4 Different additives that found in plastic types and their effects
Full size table

7 Future Perspectives

Several perspectives have been highlighted regarding MPs abundance in ecosystems, for instance, their abundance in terrestrial and aquatic ecosystems. Mostly, MPs are characterized based on their size, shape, type of polymer, sample, place, density, and color. However, there are not yet standard characteristics and tracks that showed their abundance in certain periods. The standard characteristics are required to provide valid confirmation regarding their abundance in ecosystems. In addition, there are not yet certain characteristics either chemical or physical for MPs abundance in terrestrial and aquatic ecosystems. These characteristics are required to be further analyzed to characterize and track their abundance in certain periods in both ecosystems.

It has been notable that MPs can be vectors for other contaminants correlating to the ecotoxicology effect. Therefore, ecotoxicological evaluation is required to be attention since MPs can be vectors for other contaminants and may increase their toxicity level. Their interaction with other contaminants including their hydrophilicity or hydrophobicity properties is still questionable as well as the existence of other additives during the plastic production process. Their presence in terrestrial and aquatic ecosystems has the potential to affect microorganisms and organisms of their various size, shapes, types of polymer, samples, place, density, and color. However, there is no exact toxicity level that interferes with microorganisms’ and organisms’ lives. Therefore, MPs ecotoxicity including their interaction with other contaminants in both ecosystems is desired to be discovered. In addition, their presence in both ecosystems is a possible consequence of human health through the consumption of terrestrial and aquatic food products. In line with the previous section that mentioned MPs leading obesogens in human life, MPs need to be evaluated further regarding their accumulation in white adipose tissue. In addition, there is still a critical gap in research regarding the effect of MPs on human health.

The transport of MPs into terrestrial and aquatic food products for humans is uncertain. The complex mechanism that leads to exposure risk of MPs on tissue, organs, and system organs remains to be poorly undetermined. MPs behavior that has different sizes, shapes, types of polymer, samples, places, densities, and colors makes it possible to have different mechanisms and pathways to be derived It is also reasonable that MPs have different translocations in a different medium, for instance, soil in the terrestrial ecosystem and water in an aquatic ecosystem. Uncertainty of MPs fraction travel and consumption that can be moving across to both ecosystems as well as tissue and organs in the human body are required to be determined. Therefore, evaluation of transport, translocation, and pathways is recommended in future studies to understand the mechanism of MPs entering food products for human consumption.

There are some othe crucial point like Here are few crucial points that emphasize these elements: The mechanisms by which microplastics are transported within and between ecosystems are not completely comprehended. Although we know some transport processes including ocean currents, atmospheric deposition, and riverine transport, we still need to study how these mechanisms interact with different forms of microplastics (such as fibers and pieces) and environmental circumstances (such water flow and wind patterns).

Upon being introduced into the atmosphere, microplastics that have can experience a range of physical, chemical, and biological changes that impact their destiny and actions. These processes encompass aggregation, sedimentation, biofilm development, and ingestion by organisms. The behavior of microplastics is influenced by various environmental parameters, including temperature, pH, salinity, and organic matter content. However, the precise impact of these factors on microplastics in diverse ecosystems is still not well understood.

Ongoing research is investigating the consequences of microplastics on ecosystems and creatures, including their impact on biodiversity, food webs, and ecosystem services. To comprehend the various ways in which different species interact with microplastics, such as ingestion, adhesion, and bioaccumulation, and to understand the resulting impacts on ecosystem health and functioning, it is necessary to conduct interdisciplinary research that encompasses biology, ecology, chemistry, and environmental science.

Although there is increasing evidence of the detrimental impact of microplastics on marine and freshwater creatures, the complete scope of ecological risks in many habitats, such as terrestrial, freshwater, marine, and atmospheric, remains uncertain. Furthermore, the combined impacts of microplastics with other contaminants including pesticides and heavy metals) and environmental pressures like climate change and habitat loss are subjects of concern that necessitate additional research.

It is essential to develop dependable techniques for monitoring and detecting microplastics in various environmental components (such as water, sediment, air, and biota) to accurately evaluate their distribution, quantity, and effects. To enhance our comprehension of microplastic dynamics across ecosystems, it is imperative to establish standardized sample protocols, employ advanced analytical techniques such as spectroscopy, microscopy, and chemical analysis, and conduct biomarker studies.

By combining field measurements with various modeling techniques such as numerical modeling, fate and transport modeling, and ecological modeling, it is possible to simulate and forecast the behavior, fate, and effects of microplastics in different environmental conditions. Nevertheless, the process of improving these models necessitates a greater amount of observational data and validation research is conducted in various ecosystems.

8 Conclusion

The present study demonstrates the occurrences of MPs in soil and aquatic ecosystems and elucidates their adverse impacts on these environments. Additionally, the study identifies the significant sources of MPs in these environments. Moreover, climatic variables such as temperature and weather conditions have been found to enhance the plastic degradation process, leading to more efficient plastic fracturing on land. Furthermore, the study discusses the detrimental effects of various types of MPs, including fragments, fibers, films, and biodegradables, on plant growth, along with soil edaphic factors. Similarly, several fish species, bivalves, and decapods in aquatic ecosystems are highly adversely affected by various MP polymers such as HDPE, PE, PET, PS, and PVC. These polymers not only significantly alter the growth and development of these organisms but also induce behavioral changes.

Moreover, the study examines the vertical and horizontal distribution patterns of MPs in the environment. The vertical distribution patterns of MPs depend on two types of aggregations: homo and hetero-aggregation, which are controlled by several water variables such as temperature, nutrient concentrations, and suspended particles, leading to increased density. Additionally, the density of aggregated MPs is a primary factor determining their location in the aquatic environment. Furthermore, the study reveals that marine organisms prefer MPs that are spherical in shape and black in color, possibly due to their resemblance to their natural food sources. Additionally, the presence of MPs tends to decrease the capability of phytoplankton to sequester carbon through photosynthesis, thereby significantly altering global carbon cycles.

Moreover, the heat induced by the sun leads to methane emissions due to the degradation of MPs, contributing to the emission of greenhouse gases (GHGs) in the atmosphere and increasing the earth's temperature. Moreover, the study discusses the negative consequences of MPs on human health, including reproductive disorders, coronary heart disease, breast cancer, and hormone imbalance associated with MP exposure. Further assessments of ecotoxicological evaluations, combined with evaluations of other contaminants, are needed. Additionally, the ecotoxicological effects of MP abundance in ecosystems regarding obesogens and their accumulation in specific tissues need further confirmation. The transport, behavior, and interactions of MPs with different mechanisms relating to their size, shape, type of polymer, sample location, density, and color remain uncertain. Future studies should focus on analyzing the complex mechanisms regarding their pathways into food products for human consumption.