Global assessment of fibrous microplastic pollution: Sources, environmental distribution, and ecological impacts

Abstract

Microplastic pollution is an emerging global concern, with fibrous microplastics (FMPs) representing a dominant class that poses a particular danger due to their persistence and high aspect ratios. FMPs originate from both industrial and consumer activities, with wastewater treatment plants acting as a major transmission pathway. Despite extensive research on microplastics, a morphology‐focused understanding of FMP sources, transport pathways, environmental fate, and biological impacts has remained limited. The present study integrates a systematic literature synthesis with a bibliometric analysis using VOSviewer to identify global research hotspots and trends on FMPs. Bibliometric analysis shows that 80% of publications have been led by China, the United States, and European countries in the past 5 years. Thematic clustering reveals textiles, polyester fibers, and wastewater systems as dominant research nodes. Global studies reported a 6.3‐fold increase in the production of synthetic microfibers between 1980 and 2015, with the laundering of textiles projected to release over 22 million tonnes of microplastic fibers between 2015 and 2050. Across both industrial and municipal wastewater treatment systems, FMPs consistently emerge as the dominant morphology, accounting for 50%–92% of detected microplastics in treated effluents. This review also identifies a conserved tri‐modal impact pattern of FMP exposure, mechanical disruption, oxidative inflammatory activation, and chemical vectoring, highlighting fiber morphology as a critical determinant of ecological and physiological vulnerability across biodiversity. In conclusion, this comprehensive review aims to contribute to the existing scholarship of FMPs and urges the development of strategies, sustainable textile innovations, and targeted research on FMPs and advanced removal technologies to limit their environmental footprint.

Plain Language Summary

Microplastic pollution is a growing global problem because tiny particles can easily spread through water, soil, and air. Among these particles, the fibrous class of microplastics is dangerous due to their small size, persistence, and difficulty of removing them once they are released into the environment. The present study reviewed the sources of fibrous microplastics (FMPs), how they move through different environmental matrices, and their environmental fate. We also collected evidence showing that FMPs can adversely affect a wide range of organisms, causing cellular damage and other toxic effects. Our findings show that FMPs are common in wastewater and are not always fully removed by existing treatment systems. We conclude that strengthening in‐house industrial treatment systems, standardizing monitoring frameworks, improving fiber capture technologies, and integrating source control measures such as textile design optimization and filtration innovations are essential to reduce their environmental release.

Abbreviations

ATR‐FTIR

attenuated total reflectance–Fourier transform infrared spectroscopy

FMP

fibrous microplastic

MBR

membrane bioreactor

MF

microfiber

MP

microplastic

PES

polyester

PET

polyethylene terephthalate

PP

polypropylene

PPE

personal protective equipment

Py‐GC/MS

pyrolysis–gas chromatography/mass spectrometry

TLS

total link strength

WoS

Web of Science

WWTP

wastewater treatment plant

1. INTRODUCTION

Plastic pollution is now widespread in natural environments, posing a significant global environmental issue (Eerkes‐Medrano et al., 2015). Its widespread use, pervasive presence, mobility, and potential harmful effects have raised serious global concerns (Hartmann et al., 2019). Since the 1950s, plastic production has rapidly increased, reaching 330 million tonnes in 2016 and 368 million tonnes in 2019 (Ivleva, 2021), and is expected to double in 20 years (Lebreton & Andrady, 2019). Microplastics (MPs) have drawn the attention of environmentalists, researchers, and scientists since their massive presence in the oceans was recognized in 2004 (Acharya et al., 2021). The term “microplastic” (MP) was first used by Thompson in his studies (Thompson et al., 2004).

Microplastics are defined as insoluble (ISO, 2020) plastic particles composed of synthetic polymers and appearing in various shapes and colors with maximum dimension of 5 mm, according to the American National Oceanic and Atmospheric Administration (NOAA, 2023), the European Commission (EC, 2023), and the European Chemical Agency (ECHA, 2018), and the lowest dimension of 0.1 µm (ECHA, 2020). Microplastics comprise various polymer types, including high‐density polyethylene, low‐density polyethylene, polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride, polystyrene, and polyurethane, as shown in Table 1 (Ivleva, 2021). Furthermore, MPs include paint particles or surface coatings, as well as tire wear particles, which contain 40–60% synthetic polymers such as styrene–butadiene rubber (Hartmann et al., 2019).

TABLE 1.

Common fiber‐forming polymers and their sources.

Polymer	Abbreviation	Density (g/cm3)	Source
Polyethylene	PE	0.89–0.96	Fishing lines, nets, ropes, food packaging bags, plastic bottles, and tableware
Polypropylene	PP	0.83–0.92	Clothing, blankets, packaging materials, conveying pipes, medical non‐woven fabrics and filter cloths
Polystyrene	PS	1.04–1.1	Foam lunch boxes, transparent film
Polyester	PES	1.24–2.3	Textile fibers in domestic washing wastewater, clothing, and textile production
Polyamide	PA (Nylon)	1.02–1.16	Textiles, clothing, fishing gear
Polyethylene terephthalate	PET	0.96–1.45	Textiles, synthetic clothing
Polyacrylonitrile	PAN	1.14–1.15	Sweaters, gloves, and carpets
Polyurethane	PU/PUR	1.2	Medical equipment supplies
Acrylic fiber	Acrylic	1.49	Synthetic clothing
Rayon (regenerated cellulose fibers)		1.53	Clothing
Cellulose acetate (cellulose derived plastic)		1.3	Cigarette filter

Note: Density: Based on Sun et al. (2019), Simon et al. (2018), Duis and Coors (2016), Hidalgo‐Ruz et al. (2012), and Schott et al. (2010).

Source: Based on Z. Hu et al. (2024); Talukdar et al. (2024); Li et al. (2023); and Mishra et al. (2019).

Microplastics are generally classified into primary and secondary MPs based on their generation pathways. Primary MPs are intentionally, commercially manufactured to be of microscopic sizes, and secondary MPs are unintentionally generated from fragmentation of larger plastic material through physical, chemical, and biological degradation (J. Song et al., 2024). Microplastics exist in a variety of shapes, such as beads, pellets, fragments, films, and fibers (Zhang, Lykaki, et al., 2021). Among these forms of MPs, the fibrous form is predominant in both marine (Browne et al., 2011; Gago et al., 2018) and freshwater ecosystems (Acharya et al., 2021; Q. Liu et al., 2023; Nan et al., 2020; Panno et al., 2019). However, the conventional distinction between primary and secondary MPs is not always straightforward for fibrous microplastics (FMPs). Synthetic textile fibers are intentionally manufactured but are unintentionally released into the environment during production, use, and laundering, illustrating the need to classify MPs according to their environmental generation pathways rather than manufacturing intent (J. Song et al., 2024). According to the European Chemical Agency (ECHA, 2020), FMPs are synthetic fiber‐like plastic particles characterized by a maximum length of 15 mm and a length‐to‐diameter ratio >3 (Zhang, Lykaki, et al., 2021). Owing to their distinctive morphology, dimensions, release pathways, and widespread occurrence in air, soil, rivers, lakes, and oceans, FMPs represent a unique category of MPs. It is important to distinguish between the terms “fibers,” “microfibers” (MFs), and “FMPs,” which are frequently used interchangeably in the literature despite referring to different material classes. Fibers typically have a diameter of <5 mm, though their lengths can extend beyond 5 mm (Chan et al., 2024). Based on the origin, fibers could be natural (e.g., cotton and wool), regenerated or semi‐synthetic (e.g., rayon and viscose), or synthetic (e.g., polyester [PES], nylon, and acrylic) (Figure 1). Consequently, not all fibers are MPs. Fibers derived from petrochemicals and classed as synthetic fibers are considered MPs (ISO, 2012).

FIGURE 1.

An overview of textile fibers originating from different sources. Modified from ISO (2012).

Similarly, the term “microfiber” refers to a thread‐like structure defined primarily by its dimensions and morphology rather than its composition. MFs may be natural, semi‐synthetic, or synthetic thread‐like structures and are generally characterized by a high length‐to‐diameter ratio (>100) and lengths ranging from 1 µm to 5 mm (Leela et al., 2024; J. Liu et al., 2022) with a linear density ranging between 0.3 dtex and 1 dtex (Figure 2) (J. Liu et al., 2022). The interchangeable use of FMPs and MFs has created ambiguity in the literature (Gaylarde et al., 2021; Haque et al., 2024). For instance, Haque et al. (2024) used the term “microfiber” to refer to synthetic FMPs, whereas Rathinamoorthy and Raja Balasaraswathi (2023) used the same term to describe 100% natural cotton fibers in their research. Therefore, while all FMPs can be considered microfibers, not all microfibers are FMPs. FMPs detected in the environment primarily originate from synthetic textiles, domestic laundering, and wastewater treatment plants (WWTPs), and this is widely agreed upon in the literature (Browne et al., 2011; Talukdar et al., 2024). Furthermore, recent studies have reported that FMPs are more frequently detected than other MP types in both water and sediment samples, suggesting there is a disproportionately higher rate of discharge from urban sources, particularly WWTPs, which process textiles (Murphy et al., 2016; Tarte et al., 2025). FMPs are considered emerging and ubiquitous contaminants across aquatic, terrestrial, and atmospheric systems. A study by Qu et al. (2018) presented a strong relationship between MPs found in mussels, which are bioindicators of marine pollution and their living water. The results found that microfibers were the dominant type because of their relatively smaller size and can be easily captured by macroinvertebrates (Qu et al., 2018).

FIGURE 2.

Illustration of synthetic microfibers when compared to common textile fibers and human hair. Modified from Chan et al. (2024).

Previous reviews have primarily focused on the sources, occurrence, fate, and analysis of a wide range of MPs in sludge, water, and sediment; however, a few have been optimized specifically for the study of FMPs. Given that FMPs are now recognized as the most prevalent class of MPs entering the environment, it is urgent to comprehensively understand their sources and the pathways through which FMPs enter and persist in the environment. It is also equally important to understand their implications for biota. Addressing this issue requires an in‐depth understanding of this dominant class of MPs to develop better monitoring and management strategies aimed at effectively eliminating contamination. Therefore, this review aims to combine systematic literature analysis with a bibliometric mapping using VOSviewer to uncover research trends and gaps in FMPs research. It attempts to synthesize current evidence on (i) their dominant sources of FMPs across environmental compartments (ii) their transport and fate in terrestrial, aquatic, and atmospheric ecosystems, and (iii) their ecological, toxicological, and human health impacts.

2. DATA SOURCE AND METHODOLOGY

The data for this study was retrieved from the Web of Science (WoS) Core Collection on December 18, 2025, using the search string “TS = (MP*) AND TS = (microfiber* or microfiber* or fiber* or fiber*)” to catch all relevant variations of the keywords. Considering the rapid growth in MP research, the search was restricted to the period from 2011 to 2025, resulting in an initial dataset of 5207 unique articles. Because the initial search retrieved numerous studies in which fibers were reported as one of several MP morphologies rather than the primary focus of the study, the bibliometric dataset was refined using the keyword “textile” to improve the specificity of the dataset toward studies focusing on textile‐associated FMPs, which represent the dominant source of FMPs. This refinement reduced the dataset to 584 articles (Figure 3).

FIGURE 3.

Preferred reporting items for systematic reviews and meta‐analyses (PRISMA)‐style flowchart summarizing the identification, screening, and selection of studies for bibliometric analysis and qualitative synthesis of fibrous microplastic research.

The refined dataset was subsequently screened using relevant WoS categories, including Environmental Sciences, Ecology, Marine Freshwater Biology, Engineering Environmental, Material Science Textiles, Toxicology, Public Environmental Occupational Health, Green Sustainable Science Technology, Multidisciplinary Sciences, Polymer Sciences, Environmental Studies, Fisheries, Zoology, and Water Resources. This step further removed unrelated subject areas such as MP deformation or energy fuels or food science technology or education, educational research or nanoscience nanotechnology or optics. This screening yielded a total of 504 publications for bibliometric analysis.

These selected records were exported in plain text format with complete records and cited references and analyzed using VOSviewer to assess publication output, country contribution, keyword co‐occurrence network analysis, and bibliographic coupling relationships. For qualitative synthesis, the full text of the 504 publications was further assessed for relevance to the objective of this review. Publications were included if FMPs constituted the primary focus of the study and the article contributed information on one or more of the following: sources, occurrence, transport pathways, environmental fate, ecological impacts, toxicological effects, human health impacts, or mitigation strategies. Publications focusing primarily on analytical method development, engineering applications, material development, or natural microfibers without direct relevance to environmental FMP contamination were excluded. Based on these eligibility criteria, 343 publications were selected for detailed qualitative review.

3. RESULTS OF BIBLIOMETRIC ANALYSIS

3.1. Publication outputs

The annual number of articles on FMPs is given in Figure 4. The earliest article indexed in WoS was in 2011, and the total number of publications increased slightly until 2018. After 2018, a drastic increase was observed, and the annual number of articles was almost doubled compared with the previous year. There has been an increase in studies, especially in the last 5 years. During the last 5 years, 399 articles were published, corresponding to 79% of total publications analyzed. The trajectory of FMP research can be traced back to Browne et al. (2011), the first study to report widespread fiber contamination across global shorelines and to implicate sewage discharge, particularly from laundering processes, as a dominant source. Subsequent studies built upon this foundational insight to explore their transport, removal, and ecological impacts, although research on MPs started in 2004. Since then, the number of publications on FMPs has continued to increase, making it a rapidly growing area of MP research.

FIGURE 4.

Annual distribution of publications on fibrous microplastics (FMPs) from 2011 to 2025, showing the temporal growth of research output over the study period.

The overlay visualization based on average publication year (Figure 5) further reveals an evolution in research themes. Earlier studies were mainly focused on the occurrence, identification, and environmental distribution of FMPs, particularly in marine environments and textile‐related sources. In contrast, more recent studies are characterized by the emergence of keywords such as “atmospheric deposition,” “atmosphere,” “indoor air,” “risk assessment,” “biodegradation,” “MP fibers,” and “domestic laundry.” This shift suggests that research has progressed beyond documenting the occurrence of FMPs to understanding their transport pathways, source attribution, risk assessment, biodegradation, and mitigation strategies.

FIGURE 5.

Overlay visualization of keyword co‐occurrence. Counting method: full counting. Minimum number of occurrences of a keyword: 5. Of the 1418 author keywords, 63 meet the threshold. Colors represent the average publication year of keywords, showing temporal evolution of research theme in fibrous microplastic research.

3.2. Country or regions

The number of papers issued by a country in a research field represents the research activity of that country in that field. Figure 6, generated using the WoS analysis tool, illustrates the geographical distribution of research on FMP from 2011 to 2025, highlighting the top 25 countries and regions. The largest share of publications is held by People's Republic of China (19.24%), followed by the United States (11.3%), England (10.11%), Italy (8.7%), and India (8.5%). These leading contributors indicate that both developed and emerging research economies are playing an important role in advancing scientific knowledge on FMP pollution. Continued research is particularly essential in emerging economies, where wastewater treatment facilities often lack advanced treatment technologies, making them more vulnerable to FMP pollution.

FIGURE 6.

Mapping of countries and regions publishing in the field of emerging fibrous microplastic pollution from the year 2011 to 2025.

3.3. Keyword co‐occurrence analysis

A keyword co‐occurrence analysis was performed using VOSviewer to identify the thematic foci of the literature. The dataset contained a total of 1418 author keywords, of which 63 keywords met the inclusion criteria of having a minimum of 5 occurrences. For each of these 63 terms, VOSviewer calculated the total link strength (TLS), representing the cumulative intensity of co‐occurrence relationships with other keywords in the network. These values served as the basis for constructing the co‐occurrence map and interpreting thematic linkages.

The resulting network visualization (Figure 7) displays several densely connected clusters that reflect major research themes within the field of MP pollution. The keyword “MPs” dominates the network with 168 occurrences and the highest (TLS = 338), indicating its centrality. Closely related high‐frequency terms such as “microfibers” (65 occurrences, TLS = 132), “textiles” (27 occurrences, TLS = 79), “pollution” (28 occurrences, TLS = 60), “PES” (30 occurrences, TLS = 90), “MP fibers” (17 occurrences, TLS = 23), and “wastewater” (23 occurrences, TLS = 67) form the core of the network. Their strong internal connectivity suggests that research on fiber‐based MPs, textile‐derived emissions, and wastewater pathways constitutes a major and interconnected research domain.

FIGURE 7.

Network visualization of co‐occurrence of terms based on keywords. Counting method: full counting. Minimum number of occurrences of a keyword: 5. Of the 1418 author keywords, 63 meet the threshold. For each of the 63 keywords, the total strength of the co‐occurrence links with others was calculated. Method: association strength. Weights: Occurrences.

Furthermore, the other map was generated in VOSviewer, which is a density visualization of keyword co‐occurrence related to MP pollution (Figure 8). The color intensity assesses the concentration of related studies and the prominence of thematic areas within the keyword co‐occurrence network. In this visualization, yellow represents the central theme, which revolves around MPs, microfibers, plastic pollution, and textiles, which suggests a strong emphasis on the environmental impacts of FMP contamination. Keywords like PES, laundry, PET, and wastewater highlight the growing concern over synthetic fiber pollution.

FIGURE 8.

Density visualization of Co‐occurrence of terms based on keywords. Counting method: full counting. Minimum number of occurrences of a keyword: 5. Of the 1418 author keywords, 63 meet the threshold. For each of the 63 keywords, the total strength of the co‐occurrence links with other keywords was calculated. Method: association strength. Weights: Occurrences.

3.4. Bibliographic coupling

The bibliographic coupling analysis (Figure 9) revealed an interconnected global research landscape, with clear clustering among countries that rely on similar scientific bases. China, the United States, England, Germany, Italy, and Canada exhibit the strongest bibliographic coupling strength. These countries form the largest nodes and occupy central positions in the network due to their high publication output. Their strong coupling indicates substantial overlap in the references they cite, indicating a strong intellectual alignment.

FIGURE 9.

Bibliographic coupling network of countries to identify intellectual proximity among countries in microplastic research.

Asian countries such as India, Japan, South Korea, Vietnam, and Thailand formed another tight cluster, indicating convergence in research on emerging MP issues, particularly those related to textile sources and wastewater pathways. A separate cluster centered around China linked countries such as Malaysia, Pakistan, Bangladesh, Saudi Arabia, and Russia, suggesting a shared reliance on foundational studies related to fiber‐based MPs and pollution sources.

4. ANTHROPOGENIC EMISSION PATHWAYS OF FMPS

Identifying the precise origin of synthetic microfibers in the environment is challenging; however, analyzing their composition in regional samples can help to identify significant contributors and suggest specific mitigation strategies. The most common and widely dispersed MP polymers found in environmental samples include PET, PES, PA, PE, PP, polyacrylonitrile, nylon, etc., as given in Table 1 (Li et al., 2023; Yadav et al., 2023), originating from various textiles such as clothing, tires, fishing nets, cigarette butts, floor mats, ties, and laces (Mishra et al., 2019). Furthermore, cellulose acetate is also commonly found, which is primarily used as a raw material for cigarette filters (Li et al., 2023). While various sources contribute to MP generation, synthetic textiles are recognized as a significant contributor to FMP pollution in the environment, as shown in Figure 10 (Browne, 2015; Leela et al., 2024). Synthetic materials such as PES and nylon account for approximately 60% of textile items (Carr, 2017), with PET as the primary polymer used in fiber manufacturing (Haque et al., 2024).

FIGURE 10.

Schematic illustration of the major sources of fibrous microplastics (FMPs) releasing fibers into the aquatic environment. PPE, personal protective equipment.

Globally, the production of synthetic microfibers has surged over sixfold, increasing from 10 million metric tonnes in 1980 to 63 million metric tonnes by 2015 (Piribauer & Bartl, 2019). The worldwide demand for fiber production has increased significantly, rising from 8.4 kg per person in 1975 to 14.3 kg per person in 2021; however, <0.6% of pre‐consumer or post‐consumer textiles are recycled and are estimated to reach 34% from 2020 to 2030 if current industry practices continue (Chan et al., 2024).

4.1. Textile manufacturing systems

The textile sector in India, Bangladesh, and China plays a critical role in their increasing economic development by fostering technology exchange between nations. However, this growth comes at an environmental cost, as the textile industry generates significant waste in the form of sludge, fibers, and chemically polluted water. The discharge of polluted textile effluents into natural ecosystems degrades the quality of water, soil, and air, posing a severe threat to environmental health. Textile industries are particularly accountable for the emission of microfibers, which are a major contributor to environmental pollution (Surana et al., 2024).

Textile products account for more than one‐third of the FMPs found in surface waters (Militký et al., 2024). The production of textiles and their initial washings are the main causes of their discharge into the environment (Militký et al., 2024). According to a study, around 35% of MPs detected in the ocean originated from textile‐derived microfibers present in wastewater (Prata, 2018). The textile sector consumes large volumes of water for production, dyeing, and finishing, generating large volumes of wastewater at the end of the production process. Some textile facilities operate on‐site WWTPs to pre‐treat their effluents before transferring them to municipal wastewater systems (Magalhães et al., 2024). Samples taken from a waterbody where wastewaters were released by a textile industrial park in China showed a concentration of 54,100 MFs/L (Zhou et al., 2020). This ascertains the increasing contribution of textile mills as a major source of microfiber pollution in nearby water bodies.

The data compiled from textile‐dominated treatment facilities (Table 2) reveal wide variation in MP concentrations across influent and effluent streams because of differences in wastewater treatment designs, industrial operations, or textile processing type or protocol employed for MP analysis. Influent concentrations ranged from as low as 0.344 items L^{− 1} in upstream textile facilities (Rasheed & Tshomo, 2024) to as high as 4452 items L^{− 1} in mixed synthetic and natural textile industries (Akyildiz et al., 2022). Corresponding effluent concentrations also varied substantially, between 16.3 ± 1.2 items L^{− 1} (Xu et al., 2018) and 2404 items L^{− 1} (Akyildiz et al., 2022). From the table, it is also evident that despite the variability, fibers are the predominant MP morphology, accounting for 40%–100% of total particles. Also, size distribution data show that most MPs are below 1 mm, with a significant proportion under 100 µm (Haque et al., 2024), suggesting their potential to pass through conventional filtration systems and persist in treated effluents. Although the average reported removal efficiency of on‐site textile WWTPs approaches ∼75%, the broad variability (23%–95%) indicates that current treatment systems are not consistently optimized for fiber capture, particularly for smaller and flexible microfibers. Xu et al. (2018) highlighted a study of a textile industry WWTP with a daily treatment capacity of 30,000 tonnes, which revealed an average microfiber abundance of 334.1 (±24.3) items/L in the influent, which was reduced to 16.3 (±1.2) items/liter in the final effluent, a decrease of 95%. Despite this reduction, the WWTP discharged approximately 4.89 × 10⁸ microfibers (including MP and non‐MP fibers) into the receiving water daily. These findings emphasize that even with high removal efficiency, the significant volume of treated wastewater can result in substantial fiber pollution.

TABLE 2.

Abundance of microplastics in textile industry wastewater.

Sampling collection site	Microplastic concentration in the industrial influent	Microplastic concentration in industry effluent	Removal efficiency of on‐site WWTP	Major type of microplastic	Dominant polymer	Microplastic size reported	References
Textile Industry Dominated Treatment Plant	161.33 ± 74.95 items/L	16.86 ± 6.24 items/L	89.6%	Fibers	PES, PE, PET, and PP	500–1000 µm	Işik et al. (2024)
Textile Industry (Cord/Greige Fabric/Dipped Fabric)	0.344–0.349 items/L (Upstream)	0.246–0.252 items/L (downstream)	–	Fragments and Fibers	–	–	Rasheed and Tshomo (2024)
Textile Industry (Woven, knit and denim)	615.45 items/L	212.72 items/L	23.52% (woven) to 82.19% (denim)	Fibers (40%)	–	0–100 µm (38.2%), 100–500 µm (37.5%), 500–1000 µm (9.5%)	Haque et al. (2024)
Synthetic and Natural Textile Producing Industry	893–4452 items/L	310–2404 items/L	38%–65%	Fibers	PE, PP, PA, viscose/rayon	<1000 µm	Akyildiz et al. (2022)
Textile Processing Mill	–	361.6 ± 24.5 items/L	–	Fibers (92%)	PES	<1000 µm (92%)	Chan et al. (2021)
Textile Dyeing and Printing	–	537.5 items/L	85%	Fibers (80%–100%)	–	100–300 µm	Zhou et al. (2020)
Surface Water of the Textile Industrial Area	–	71.0 items/L	–	Fibers	PES (65.7%)	1–1000 µm	Deng et al. (2020)
Textile Dyeing	334.1 ± 24.3 items/L	16.3 ± 1.2 items/L	95%	Fibers (80%–100%)	Rayon (38%), PES (25%), natural fibers	1–1000 µm	Xu et al. (2018)

Abbreviations: HDPE, high‐density polyethylene; PA, polyamide; PAN, polyacrylonitrile; PE, polyethylene; PES, polyester; PET, polyethylene terephthalate; PP, polypropylene; PP, polypropylene; PS, polystyrene; PVC, polyvinyl chloride; WWTP, wastewater treatment plant.

Studies conducted close to textile manufacturing zones identified PET transparent fibers as major MP compositions primarily within 100–500 µm size (Xu et al., 2022). The highest concentrations of MPs were recorded in areas close to textile manufacturing zones, which were attributed to discharges from textile industries (Xu et al., 2022). Similarly, Deng et al. (2020) reported MP contamination in both water and sediment samples collected from a textile industrial area in Shaoxing City, China, with concentrations ranging from 2.1 to 71.0 items/L in surface water and 16.7 to 1323.3 items/kg (dry weight) in sediments. In both studies, fibrous morphologies were the most prevalent form, with colored fibers under 1 mm in diameter dominating the samples and closely associated with textile production activities. The dominance of fibrous morphologies largely composed of PES, PE, PP, and rayon aligns with the materials commonly used in textile production and finishing processes. Overall, the persistence of FMPs in textile effluents indicates that current wastewater treatment technologies are insufficient to fully eliminate FMPs, particularly those in the sub‐100 µm range. It highlights the need for morphology‐informed treatment strategies and standardized reporting frameworks.

4.2. Domestic laundry as a diffuse amplifier

If textile production generates fibers, domestic laundering mobilizes them at scale. Synthetic microfibers are primarily released into the environment during textile production, usage, washing, and disposal (Henry et al., 2019). The most common pathways for MP fiber release into the environment are domestic textile laundering (Chan et al., 2021; Deng et al., 2020), and it is recognized as a major source of microfiber pollution in the aquatic environment (Grillo et al., 2023; F. Wang et al., 2020). Recent estimations have assessed that synthetic clothes contribute by about 35% to the global release of primary MPs to the world oceans, thus becoming the main source of MPs (De Falco et al., 2019), and based on domestic laundry sites, over 22 million tonnes of MP fibers were released to the ocean between 2015 and 2050 (Ellen MacArthur Foundation, 2017). C. Wang et al. (2024), through an empirical model, estimated that laundry releases approximately 5.69 million tons of MP fibers annually, with machine washing responsible for 93.7% of emissions and hand washing contributing the remaining 6.3%. These differences are supported by experimental studies demonstrating that machine washing generates higher synthetic fiber release than hand washing due to greater mechanical agitation, friction, and shear forces exerted on textile fabrics (C. Wang et al., 2023). For example, a comparative study reported that machine washing released an average of 23,723 FMPs per garment compared with 1853 FMPs per garment during hand washing (C. Wang et al., 2023). The higher emissions from washing machines are attributed to continuous abrasion, tumbling, and mechanical stress that promote fiber detachment. In contrast, washing temperature, washing duration, and water volume showed no significant effect on FMP release, whereas detergent use, prolonged soaking, and washboard‐assisted hand washing increased FMP shedding (C. Wang et al., 2023).

Garments and household textiles with loose fabric structures, such as fleece blankets, sweaters, and towels, shed fibers throughout their lifecycle (Napper & Thompsson, 2016). Fiber release is pronounced during laundering, where mechanical agitation and chemical actions cause significant release of FMPs into wastewater. Research estimates domestic laundering in the USA and Canada emits approximately 533 million microfibers annually, with a single fleece jacket shedding around 2000 fibers per wash (Vassilenko et al., 2021). Regular laundering of 5–6 kg of synthetic clothes can release up to 6.5 million fibers (Mishra et al., 2020). Several factors influence the release of fibers from textiles during laundering. For example, detergents can promote fiber shedding by mobilizing fibers from textile surfaces and increasing fiber detachment during washing (C. Wang et al., 2023). In addition, tumble drying has been reported to release synthetic microfibers approximately 3.5 times greater than washing from PES fleece textiles (Pirc et al., 2016). Furthermore, yarn twist, fabric density, and fiber composition affect fiber shedding; thicker clothing releases more fibers (De Falco et al., 2019). Browne et al. (2011) identified sewage from garment washing as a major source of FMPs, with forensic analysis of PES and acrylic fibers, which are frequently used in clothes, matching those identified in sewage‐affected habitats and sewage effluent. Laboratory tests revealed that a single wash can release over 1900 fibers (Browne et al., 2011), highlighting that the fibers largely derived from the garment shedding during laundering are a major contributor to FMP pollution in marine environments.

4.3. Maritime and fisheries systems

Fishing activities represent a structurally distinct source of FMPs. Modern fishing gears (ropes, nets, and lines) are primarily made of synthetic materials like polyamide and polyolefin (Fernández Severini et al., 2019), which are frequently worn down and fragmented into MPs by repeated abrasion, hydraulic tension, and drum friction (Parker‐Jurd et al., 2020). It is estimated that approximately 640,000 tons of fishing gear are lost in the ocean every year (Bessa et al., 2018). Regional studies further demonstrate the scale of this problem. For example, an estimated 3968 tons of PP, PET, and nylon fibers are introduced into Portugal's Mondego estuary each month (Bessa et al., 2018). Fisheries continue to act as a source of FMP emissions within coastal systems.

Across geographically distinct regions, fibers consistently dominate the MP pollution associated with fishing activities. In the Southern Ocean, synthetic fishing gear has been identified as a major contributor to fiber dispersal (Woodall et al., 2015). Similarly, research stations and vessels in Antarctica have been recognized as localized point sources of MP contamination (Leistenschneider et al., 2021). In the Yangtze Estuary, MP concentrations reached 4137 particles/m³, of which approximately 80% were classified as fibers (S. Zhao et al., 2014). These fibers were primarily attributed to sewage discharge, degradation of ropes, and fishing activities. Likewise, aquaculture systems further exhibited morphology‐specific dominance, with fishponds showing a higher abundance of PE MPs in the size range of 200–500 µm, largely resulting from the mechanical breakdown of fishing gear (F. Wang et al., 2020). Overall, the dominance of fibers across marine environments suggests that fishing gear acts as a major source of FMP pollution.

4.4. Personal protective equipment

Personal protective equipment (PPE) such as face masks, gloves, and face shields contribute significantly to PPE litter. Among these, surgical masks are the most used, and these are primarily made of fiber‐based materials, including an inner layer (fiber material or non‐woven fabric), a middle layer (meltblown fabric), an outer layer (non‐woven fabric), and ear loops (fiber) (Li et al., 2023). Face masks contribute significantly to PPE litter, with over 10 million face masks estimated to enter the environment each month due to improper disposal practices (Adyel, 2020; M. T. Khan et al., 2023). These disposable surgical masks can break into billions of microfiber particles (Shen et al., 2021), resulting in masks being found on coastlines and waterways, thus posing direct threats to marine life (Aragaw, 2020). It has been seen that millions of PPE end up in the environment. A study by Saliu et al. (2021) found that a single mask subjected to 180 h of agitation and ultraviolet exposure in a simulated saltwater release as many as 173,000 fibers per day. Another study by Martínez Silva and Nanny (2020) found concentrations up to 102.4 fibers/kg in the shoreline sediments of Magdalena River, Huila, Colombia, with approximately 75% of PP and PE, besides synthetic nonwoven materials.

Similarly, surgical gloves, now widely used, have impacted manufacturing industries due to their reliance on synthetic raw materials like nitrile, vinyl, and polyethylene. Their improper disposal further aggravates environmental challenges (De‐la‐Torre & Aragaw, 2021). Face shields, comprising components like PP headbands and polycarbonate or PET visors, have become a critical PPE item (Singh et al., 2021). Although less commonly used by the public, bouffant caps, primarily made of PP are integral to World Health Organization precautionary guidelines during the pandemic (Leela et al., 2024).

4.5. Municipal WWTPS

Municipal WWTPs act as a major emission pathway for the release of MPs into aquatic ecosystems (Ziajahromi et al., 2016). Although WWTPs were not originally designed to remove MPs, they receive huge loads originating from interconnected industrial and consumer activities. These include microfibers shed from clothing during the laundry process (Napper & Thompson, 2016), as well as microbeads, fragments, pellets, and foam, which mainly originate from consumer products like facial cleansers, scrubs, cosmetics, sunscreen, nail polish, hair dye, eyeshadow, shower gels, and toothpaste (Magalhães et al., 2024; Magni et al., 2019). Fibers and microbeads are the dominant types of MPs found in the WWTPs (Figure 11).

FIGURE 11.

Relative abundance (%) of microplastic morphologies in wastewater effluents, highlighting the predominance of fibrous microplastics (FMPs) across published studies.

Microplastics are frequently detected in both the influent and effluent streams of WWTPs. For example, influent concentrations in the Netherlands varied from 68 to 910 MP/L (Leslie et al., 2017), while values of 260–320 MP/L were recorded in France (Dris et al., 2015) and 93–133 MP/L in the United States (Michielssen et al., 2016). In India, influent concentrations as high as 4800 MPP/L were recorded (Roy et al., 2025). These data confirm that municipal WWTPs receive considerable MP load, placing significant pressure on the treatment structure.

Despite high global removal efficiency reported (Table 3), treated effluents still contain residual MPs. Talvitie et al. (2015) reported average concentrations of 4.9 (±1.4) fibers and 8.6 (±2.5) particles per liter in treated effluent, with the fiber concentration in the effluent approximately 25 times greater compared to the receiving waters. Similarly, downstream rivers often contain higher MP concentrations than upstream locations, indicating that WWTPs are an important point source of MP pollution in urban water bodies (McCormick et al., 2014). Reported removal efficiencies in WWTPs vary considerably from 11% to 99.9% across studies. However, these values cannot be directly compared because the studies differ substantially in their sampling and analytical approach. As summarized in Table 3, the mesh sizes used for cascade filtration range from 10 µm (Mintenig et al., 2017) to 5000 µm (Ainali et al., 2024; Lares et al., 2018; Van Do et al., 2022), while the final filtration thresholds vary between 0.2 and 25 µm. These methodological differences strongly influence the size, range, and quantity of MP detected, particularly fibrous particles. Studies using smaller mesh sizes and lower detection thresholds are more likely to capture fine fibers that may pass through treatment systems, whereas larger mesh sizes may underestimate fiber abundance and consequently report higher removal efficiencies.

TABLE 3.

Removal efficiency of microplastics from wastewater treatment plants across different countries.

Country	Influent MPP/L	Effluent MPP/L	Cascade filtration mesh size	Final filtration sieve size (µm)	Detection method	Removal efficiency	Morphology of MPs	References
Sweden	15	8.25	–	300	Visual observation & FT‐IR spectroscopy	99.9%	Fibers and fragments	Magnusson and Norén (2014)
United States		0.004–0.195	125	–	Visual observation	–	Fibers (59%), fragments (33%), films (5%), foams (2%) and pellets (1%)	Mason et al. (2016)
United States	1	8.8 × 10− 4	400, 180, 45, 20	–	FTIR	99.9%	Fragments	Carr et al. (2016)
Scotland	15.7	0.25	65	11	Visual observation and FTIR	98.41%	Fragments (67.3%), fibers (18.5%), beads (3%), film (9.9%) and foam (1.3%)	Murphy et al. (2016)
Netherlands	68–910	51–81	–	0.7	Visual microscope, FTIR	11%–94%	Fibers	Leslie et al. (2017)
Germany	–	0.08–7.52	10	0.2	FTIR	–	Transparent Fibers	Mintenig et al. (2017)
Australia	–	0.48	500, 190,100,25		FTIR	–		Ziajahromi et al. (2017)
Finland	0.5–2.0	0.3– 0.03	300, 100, 20	–	Stereomicroscope, FTIR spectroscopy	40%–98.5%	Fibers (91%), beads (9%)	Talvitie et al. (2017)
Finland	57.6	1.0	5000, 250	1.5	FTIR/Raman	98.3%	Fiber (92%),	Lares et al. (2018)
Italy	2.5 ± 0.3	0.4 ± 0.1	5000, 2000 and 63	8	Stereomicroscope, μ‐FTIR	84%	Fiber (80%),	Magni et al. (2019)
China	79.9 (±9.3)	28.4 (±7.0)	47	0.8	Micro‐Raman spectroscopy	64.4%	Fibers (33.5%–56.7%), fragment (30.4%–45.6%)	X. Liu, Yuan, et al. (2019)
China	18–890	6–26	13	0.45	Stereomicroscope and micro‐Raman spectroscopy	35%–98%	Film	F. Wang et al. (2020)
China	0.70–8.72	0.07–0.78	500, 200, 100, 25	0.45	Optical microscope, FTIR	89.2%—93.6%	Fibers	Zhang, Liu, et al. (2021)
Vietnam	183–443	138–340	5000	–	Stereomicroscope, FTIR	21.8%–25.3% 25.4%	Fibers (34.8%–41.1%), fragment (20.5%–32.7%)	Van Do et al. (2022)
Iran	180	5.3	106	0.45 µm	SEM, micro‐Raman, ICP	99.06%	Fibers	Oveisy et al. (2022)
Turkey	–	20	47	25	Fluorescence microscope, ATR‐FTIR	–	Fibers (49.5%), fragment (34.3%), film (16.2%)	Akdemir and Gedik (2023)
Indonesia	17.1 (±5.65)	1.41 (±0.01)	300, 100	1.2	Stereomicroscope	91.29%	Fibers (68%–70.17%), fragments (23.68%–26.24%), films (0.71%–2.9%), microbeads (0.4%–1.4%), foams (1.4%–2.8%)	Setiadewi et al. (2023)
Greece	–	5.68 ± 3.10	4000, 2000, 1000, 500, 125	1.6	Stereomicroscopy, Py−GC/MS	–	Fibers (50%–78 %), fragments (8%–41%), films (7%–36%), pellets (0%–4%)	Ainali et al. (2024)
India	4800	355	105,75, 50, 25	0.45	FTIR and Raman spectroscopy	93%	Fibers (72%), fragments (19%), films (9%),	Roy et al. (2025)
Poland	4.09	–	5000, 1000, 500, 160, 45	–	Stereomicroscope, ATR‐FTIR	–	Fibers (43%), fragment (33%), films (12.22%), foam (8.31%), beads (3.42%)	Ormaniec (2024)

Abbreviations: μ‐FTIR, micro‐Fourier transform infrared spectroscopy; ATR‐FTIR, attenuated total reflectance–Fourier transform infrared spectroscopy; FTIR, Fourier transform infrared spectroscopy; MPs, microplastics.

Additional variability arises from the use of different identification and characterization techniques, including visual observation, stereomicroscopy, Fourier transform infrared spectroscopy, micro‐Fourier transform infrared spectroscopy, Raman spectroscopy, micro‐Raman spectroscopy, attenuated total reflectance–Fourier transform infrared spectroscopy (ATR‐FTIR), fluorescence microscopy, pyrolysis–gas chromatography/mass spectrometry (Py‐GC/MS), and scanning electron microscopy‐based approaches. Visual identification alone may lead to false positive classification because natural fibers (e.g., cotton and wool) and regenerated cellulose fibers (e.g., rayon and viscose) often resemble synthetic fibers in appearance. Without polymer confirmation, the abundance of FMPs may therefore be overestimated. Consequently, the wide range of removal efficiencies reported in the literature reflects not only differences in treatment technologies, including primary, secondary, and tertiary processes, but also substantial variation in sampling, processing, and analytical methodologies. contributes additional variability in reported concentrations and polymer identification.

However, synthetic fibers remained the most dominant MP shape in municipal WWTPs regardless of overall removal performance. For example, in Turkey, effluent samples contained 49.5% fibers despite advanced analytical detection using fluorescence microscopy and ATR‐FTIR (Akdemir & Gedik, 2023). In Indonesia, despite an overall removal efficiency of 91.29%, a considerable fibrous load accounting for 68%–70.17% of the total MPs remained in the final discharge (Setiadewi et al., 2023). Similarly, in Greece, stereomicroscopy and Py‐GC/MS analyses of effluents showed fiber concentrations ranging from 50% to 78% (Ainali et al., 2024). Similarly, in India, although influent concentrations decreased from 4800 MP/L to 355 MP/L (93% removal), FMPs constituted 72% of the remaining load (Roy et al., 2025).

In general, although the removal rates of MPs by WWTPs are as high as 83.0%–99.9% (Carr et al., 2016; Magnusson & Norén, 2014), FMPs persist as the dominant residual fraction entering waters. Their elongated structures reduce their settling efficiency and facilitate their passage through filtration systems, particularly for smaller size fractions. Consequently, the lack of standardized sampling and analytical protocols not only limits inter‐study comparability but also hinders the development of accurate global estimates of WWTP‐derived FMP emissions.

5. TRANSPORT AND FATE OF FMPS IN THE ENVIRONMENT

Textile‐derived FMPs are widely distributed in the environment, moving through air, water, and soil systems with different modes of transport mechanisms and long‐term ecological effects. The fate of these FMPs is influenced by their environmental conditions, physical and chemical properties, and biological interactions. The environmental impact of FMPS is further complicated by their hydrophobic nature and high surface area; they tend to adsorb pollutants and heavy metals (Surana et al., 2024).

5.1. Aquatic transport, fate, and trophic transfer in aquatic systems

Aquatic ecosystems serve as integrative sinks for FMPs, receiving continuous inputs from terrestrial sources including untreated or insufficiently treated wastewater, urban runoff, direct shedding from textiles, landfill leachate, decomposition of fishing nets, and agricultural runoff (Priya et al., 2022). River networks serve as critical pathways linking terrestrial and marine ecosystems, acting as a primary route for the transport of MPs from land‐based sources to marine environments. WWTPs can capture around 96%–99.9% of MPs; however, the residual fraction discharged daily into rivers represents a significant cumulative input due to large volumes of treated effluent released annually (Ziajahromi et al., 2016). This highlights that even high percentage removal does not equate to low environmental loading.

When MPs reach river systems, their movement, deposition, degradation, and transformation are largely shaped by the hydraulics, water chemistry, physical characteristics, and geomorphological conditions (Kumar et al., 2021). Population density, urbanization level, and water discharge volume further modulate concentration patterns (Li et al., 2023). Despite geographical variability in reported concentrations, fibers consistently dominate freshwater MP assemblages across Europe, South America, China, and India (Table 4), suggesting a globally uniform morphology signature linked primarily to textile‐derived sources (Priya et al., 2022). This morphological consistency indicates that freshwater systems act not only as transport corridors but also as selective accumulators of high‐aspect‐ratio particles.

TABLE 4.

Distribution of microplastics in different riverine surface water environments.

Country	Study area	Average MP concentration	Major MP type	Analytical method	References
China	Alpine rivers in Qilian Mountain	0.48 ± 0.28 particles/L	Fibers	Microscopy; Raman	Q. Liu et al. (2023)
	Poyang Lake	0.2034 g/L	Fibers	Stereomicroscope/Raman	Yuan et al. (2019)
	Three Gorges Dam	12.61 particles/L	Fibers	Micro‐Raman spectroscopy	Di and Wang (2018)
	Hanjiang River and Yangtze River	1.02–10.56 particles/L	Fibers	FTIR	W. Wang et al. (2017)
Nepal	Phewa Lake	1.51  ±  0.62 particles/L	Fibers, Films and Fragments	–	Malla‐Pradhan et al. (2022)
Brazil	Guapimirim, Macacu and Maracanã Rivers	3.65 particles/L	Fibers	ATR‐FTIR spectroscopy	Drabinski et al. (2023)
Indonesia	Ciwalengke River	5.85 ± 3.28 particles/L	Fibers	Raman spectroscopy	Alam et al. (2019)
Philippines	Cagayan de Oro River	0.30 particles/L	Fibers, filament	Stereomicroscope, FTIR	Gabriel et al. (2023)
Tibet Plateau, China	Buqu River	0.97 ± 0.14 particles/L	Fibers	Raman spectroscopy	Jiang et al. (2019)
Netherland	Amsterdam canal	4800–18,700 items/m3	Fibers	FTIR	Leslie et al. (2017)
UK	Thames river	12.27 particles/L	Fibers	FTIR	Devereux et al. (2023)
	Kelvin river	0.26685 g/L	Fibers	SEM‐EDS	Blair et al. (2019)
India	Adyar River, Tamil Nadu	0.33 particles/L	Fibers	FTIR	Lechthaler et al. (2021)
	Kosasthalaiyr River, Tamil Nadu	0.67 particles/L	Fibers	FTIR	Lechthaler et al. (2021)
	Multhirappu‐hayar River, Kerala	0.20 particles/L	Fibers	FTIR	Lechthaler et al. (2021)

Abbreviations: ATR‐FTIR, attenuated total reflectance–Fourier transform infrared spectroscopy; EDS, energy‐dispersive X‐ray spectroscopy; FTIR, Fourier transform infrared spectroscopy; MP, microplastic; SEM, scanning electron microscopy.

At the marine interface, physical settling and biophysical interactions determine the environmental fate of FMPs. Approximately 70% of marine plastic debris accumulates in sediments, while smaller fractions remain in coastal waters or float at the surface through diffusion, suspension and resuspension, settlement, and burial (Cheng et al., 2022; Lamichhane et al., 2023). High‐density plastics are inherently non‐buoyant and settle within sediments, while lower‐density plastics may also sink due to interactions with suspended particles or microbial colonization, which increase their density and size (Zhang, 2017). Reported sediment concentrations range from 6.7 to 1323.3 items per kilogram (dry weight), with higher levels observed near textile manufacturing areas and predominance of colored fibers <1 mm (Deng et al., 2020). Marine sediments act as the final repository for most FMPs entering coastal waters (Zhang, 2017).

Morphology further influences biological uptake. Fiber‐type MPs, resembling natural prey such as worms and eggs, are frequently consumed by fish (Peters et al., 2017). In a study of 1381 fish specimens, 42.4% contained MPs, of which 86.4% were fibers (Peters et al., 2017). This disproportionate ingestion pattern indicates morphology‐driven bioavailability rather than random exposure.

In island systems also, FMPs were seen to be dominant in surface waters, accounting for 80% of the total collected MPs. These fibers were primarily derived from synthetic textiles used in clothing, industrial fabrics, engineering, and construction (Yu et al., 2022). The bioavailability of MP fibers is particularly concerning, as their ingestion by aquatic organisms facilitates trophic transfer within food webs, ultimately impacting higher trophic levels, including humans, in which FMPs enter the body through inhalation, ingestion, or dermal contact (C. Wang, Zhao, et al., 2021).

5.2. Terrestrial transport, fate, and soil accumulation

Several pathways contribute to the accumulation of FMPs in terrestrial environments, including plastic mulch films, irrigation with contaminated water, sewage sludge application, landfills, and atmospheric deposition. In addition, synthetic textiles are also a significant contributor to soil degradation by emitting MP fibers throughout their lifecycle, which enter agricultural soils through urban byproducts used as soil amendments.

A major source of FMPs in soil is sewage sludge, a widely used fertilizer. According to a survey in China, 22.7 × 12.1 particles per gram (p/g) were found in sewage sludge, with fibers comprising 63% of the total MPs (M. Liu et al., 2018). Similarly, in Ireland, where various stabilization treatments are applied to sewage sludge, MP concentrations range from 4.1 to 15.4 p/g, with fibers accounting for 91% of the particles in composted sludge (Mahon et al., 2017). Sludge in South America further confirmed fiber dominance with MP concentrations ranging from 18 to 41 particles/g, a median of 34 particles/g, and soil amended with sludge had 97% fiber content (Corradini et al., 2019).

Once these FMPs enter the soil, these fibers have a detrimental impact on soil organisms at high concentrations, change soil structure, and reduce microbial biomass (Heinze et al., 2024). According to studies, concentrations of 0.1%–1% by weight of soil MPs can lead to a 15% reduction in microbial biomass (de Souza Machado et al., 2018) and a 15% decline in growth rates and reproduction of soil organisms, potentially disrupting nutrient cycling, soil health, and ecological processes (Hasan & Tarannum, 2024).

Their vertical transport is aided by earthworms, which can ingest, excrete, and displace these fibers in the deep stratum under mixed layers of earth and distribution (Heinze et al., 2024). The length, density, and surface charge of MP fibers affect their migration; shorter fibers (<500 µm) penetrate deeper into the soil, whereas longer fibers tend to tangle with organic matter, which decreases mobility (Heinze et al., 2024).

FMPs in soil also pose a risk of transfer to aquatic environments. Surface runoff and erosion during heavy rainfall or irrigation can mobilize MPs, transporting them to nearby rivers and lakes (Hasan & Tarannum, 2024).

5.3. Atmospheric transport and deposition

The atmosphere plays an important role in the flow and accumulation of MPs in the environmental matrices. Recent studies have confirmed the presence of airborne MPs in both indoor and outdoor atmospheres (Din et al., 2024; Nandi et al., 2024). Noorimotlagh et al. (2024) reported that airborne MPs exhibit diverse morphologies, with fibers showing recurring dominance. Their study identified a higher occurrence of fibers (20 cases) compared to fragments (8 cases) in indoor environments, whereas outdoor samples showed 11 cases of fibers and 8 cases of fragments. Similarly, in an apartment in Paris, airborne MP concentrations ranged from 1 to 60 fibers/m^{− 3}, compared to 0.3 and 1.5 fibers/m^{− 3} outdoors. Within an Australian household, fiber deposition rates ranged from 22 to 6169 fibers/m²/day, accounting for 99% of the total deposited particles (Soltani et al., 2021). These findings indicate that indoor environments act as major sources and reservoirs of airborne FMPs. The continuous shedding of synthetic fibers from clothing, carpets, curtains, upholstery, bedding, mattresses, and other textile‐based household materials is considered a major contributor to indoor FMP load (Abbasi et al., 2023). In addition to the direct release of fibers from textiles into the atmosphere, which remains relatively understudied (De Falco et al., 2020), industrial activities, landfills, household tumble dryers, and air‐conditioning filters have been recognized as significant sources of airborne FMPs (Amato‐Lourenço et al., 2020; Y. Chen et al., 2022; O'Brien et al., 2020). Recent studies have shown that PET fibrous particles are among the most frequently detected polymer types in indoor air (Din et al., 2024; Nandi et al., 2024).

In urban outdoor settings, airborne FMPs originate from a broader range of sources, including plastic burning, open dumping, road dust resuspension, industrial activities, and textile fiber shedding, while their distribution is further influenced by regional and long‐range atmospheric transport (Nandi et al., 2024). Polymer characterization of atmospheric fallout revealed a predominance of PET and polyamide fibers in atmospheric fallout, supporting that synthetic textiles are a major source of airborne FMPs in urban environments (Dris et al., 2016). However, the spatial heterogeneity of sources, together with inconsistent sampling heights and sampling techniques (passive vs. active collection), complicates source attribution and hinders the development of emission inventories.

The atmospheric fate of FMPs is influenced by several factors, including wind speed and direction, vertical pollution gradients, precipitation, and temperature fluctuations (Prata, 2018). Their transport and deposition are further affected by local meteorological conditions, urban topography, and thermal cycling. Studies have shown that fiber deposition increases under low wind velocities and intense rainfall events, indicating the importance of wet scavenging in removing airborne particles (Elnahas et al., 2024). Wet deposition acts as a key removal mechanism, transferring airborne MPs into terrestrial and aquatic systems (Gupta et al., 2023).

The presence of MP fibers in remote snow samples from high‐altitude regions such as the Arctic and Alps (Bergmann et al., 2019) demonstrates their capacity to undergo long‐range atmospheric dispersal. Nandi et al. (2024) reported that MP abundance in Ranchi, India, was associated with air masses originating from northwestern India, while winter air mass trajectories suggested transport from neighboring countries as well as distant regions of Central Asia and North Africa.

Evidence of atmospheric exposure has also been reported in humans. Amato‐Lourenço et al. (2021) identified MP particles (<5.5 µm) and fibrous forms (8.12–16.8 µm) primarily composed of PE and PP in human lung tissues, providing direct evidence of inhalation. Collectively, these findings demonstrate that the atmospheric transport and deposition of FMPs not only contribute to widespread environmental contamination but also represent a potential pathway for human respiratory exposure. This highlights the need for improved exposure assessment, risk characterization, and the development of effective mitigation strategies targeting both emission control and indoor air quality management.

6. HEALTH IMPLICATIONS OF FMPS

6.1. Morphology‐driven physical and chemical mechanisms

FMPs pose significant environmental and biological risks because of their elongated shape, high aspect ratio, and large surface‐to‐volume ratio. Compared to non‐fibrous particles, FMPs are typically more hazardous due to their greater bioavailability and assimilation across aquatic and terrestrial ecosystems. Their tiny size further facilitates ingestion, entanglement, and prolonged retention within biological tissues (Dris et al., 2018; Surana et al., 2024).

6.1.1. Mechanical‐energetic disruption

Mechanical interference is one of the primary mechanisms through which FMPs exert toxic effects across different organisms. Their elongated, thread‐like structure causes entanglement within feeding appendages, blockage of digestive tracts, and retention within internal tissues and body fluids, ultimately interfering with energy acquisition and normal physiological functioning (Table 5) (Athey et al., 2022).

TABLE 5.

Toxicity of fibrous microplastics (FMPs) on different aquatic and terrestrial organisms.

Organisms	FMP types	Test concentrations	Results	References
Mytilus edulis (Blue Mussel)	PE, PHB	1000 MPs/mL	Decreased biochemical activity levels in gills and digestive glands, indicating a potential oxidative stress response	Magara et al. (2019)
	MFs	10–30 MF/mL	Reduced feeding/clearance rate	Woods et al. (2018)
	PA‐MFs	114 PS‐MP/mL	Biomarker enzymes and immune markers	Cole et al. (2020)
Mytilus galloprovincialis (Mussels)	PS alone or Cbz	PS (0.05–50 mg/L) Cbz (6.3 µg/L), mixture (0.05 mg/L + 6.3 µg/L)	Effects on neurotransmission, genotoxicity, and lipid peroxidation (oxidative damage)	Brandts et al. (2018)
	PET	0.0005–100 mg/L	Diminished gonadal index and sex hormones, atrophy of the digestive tubules, DNA damage, hemocyte apoptosis, and alterations in neurotoxic and antioxidant‐related enzymes in the digestive glands and gills	Choi et al. (2022)
	MFs	56–180 mg/L	Histological alterations, harm to the digestive tract and gills, and damage to DNA	Alnajar et al. (2021)
Acartia erythraea (Copepod)	PET	–	Copepods died within 24 h due to hunger and stress	Takahashi and Teh (2024)
Caenorhabditis elegans (Roundworm)	PS	1.0 mg/L	Lowest survival rate, significant decrease in body length, shortest average lifespan, and toxicity on locomotor behavior	Lei et al. (2018)
Tubifex tubifex (sewage worm)	MFs/MPs fragments	56–2544 particles/ kg	Trophic transfer and biomagnification of MPs up the aquatic food chain	Hurley et al. (2017)
Symphysodon aequifasciatus (Discus fish)	PA (L: 900 µm)	0, 20 and 200 µg/L	Decreased growth, changes in gut microbiota (greater Proteobacteria), neurotransmitter changes (increased brain, decreased gut), behavioral toxicities, and changes in neuronal activity	Huang et al. (2022)
Lates calcarifer (Fish)	PE	330.44 ± 19.12 µg/L to 250 µg/L	No immediate danger, but long‐term impacts include intestine damage, oxidative stress modification, and microbiota abnormalities	Xie et al. (2021)
Daphnia magna (Water flea)	PET, PP	1000–2000 mg/L	Reduced food intake, death, stunted growth, and intestinal injury (decrease in microvilli length)	D. Kim, Kim, An, et al. (2021)
Artemia franciscana (Brine shrimp)	PP, PET	75–1000 mg/L	Increased mortality and damage to the gut	L. Kim, Kim, Kim, et al. (2021)
Danio rerio (Zebra fish)	PP (L: 50 ± 26 µm, 200 ± 90 µm, D: 20 µm)	10–100 µg/L	dietary deficiency, oxidative damage, metabolic disturbances, and length‐dependent intestinal damage	Y. Zhao et al. (2021)
Emerita analoga (Pacific mole crab)	PP	3 MF/L	Reduced egg clutch retention, higher adult mortality, and variation in the rate of embryonic development	Horn et al. (2020)
Apostichopus japonicus (Sea Cucumber)	PES	25–40 MF/mL	MF buildup in bodily fluids, changed levels of lysozyme (LZM), and no effect on oxidative stress or movement	Mohsen et al. (2020)
Homarus americanus (Lobster)	PET	1–25 MFs/mL	lowered oxygen consumption in later larval stages and increased intake with higher concentrations	Woods et al. (2020)
Oryzias latipes (Japanese medaka)	PES, PP	10,000 MFs/L	Changes in histology	L. Hu et al. (2020)
Oryzias melastigma (Marine medaka)	PS	2–200 µg/L	Effects on reproduction and generational dynamics	J. Wang et al. (2019)
Gasterosteus aculeatus (Three‐spined sticklebacks)	PES	200 fibers/L	No alterations in blood parameters or behavior	Bour et al. (2022)
Hydroides elegans (Calcareous Tube worm)	PP	<20 µm	Abnormal growth of the embryo	Harikrishnan et al. (2024)
Crassostrea gigas	MFs	10–10,000 MF/ L	Physiological and immunological response	Détrée et al. (2023)
Artemia sp. (Brine shrimp) and Gasterosteus aculeatus (fish)	PES MFs	–	Modulation of retention time	Bour et al. (2020)
Menidia beryllina and Americamysis bahia	PP	3–30 particle/mL	Growth and behavior effect	Siddiqui et al. (2023)
Lumbricus terrestris (Earthworm)	PET	50, 500, 5000 µg MFs/g d.w. soil	Reduction in egestion, fecal production, and retention beyond depuration indicates accumulation potential.	Lahive et al. (2022)
	PES	0.1%–1.0% w/w MF	Superoxide dismutase (SOD) gene expression, metallothionein, heat shock protein, altered eating and burrowing behavior, decreased depurate synthesis, and changes in casting performance	Prendergast‐Miller et al. (2019)
Achatina fulica (Snail)	PS	0.01–0.71 g/kg (d.w. soil)	Decreased excretion, oxidative stress, damage to the gastrointestinal tract, and elevated amounts of malondialdehyde in the liver	Y. Song et al. (2019)
Plants (Calamagrostis epigejos, Festuca brevipila, Holcus lanatus, Potentilla argentea, Hieracium pilosella, Achillea millefolium, Plantago lanceolata)	PS	0.4%,	Better plant productivity, more root penetration, improved aeration, and growth inhibition caused by soil pathogens.	Lozano and Rillig (2020)
Allium fistulosum (Onion)	PES	0.2% of soil fresh weight	Alterations in the elemental composition (N to C ratio), altered water dynamics, altered soil structure, and physiological consequences due to increased water retention	de Souza Machado et al. (2019)
Fungi (Amphisphaeriaceae strain 1, Gibberella tricincta, Fusarium sp., Chaetomium angustispirale, Mucor fragilis)	PAN	0.4% (w:w)	Reduced water‐stable aggregates due to MF presence in four strains	Y. Liang et al. (2019)
Arbuscular Mycorrhizal (AM) species (Funneliformis mosseae, Funneliformis caledonium, Rhizoglomus irregulare)	PES	0.4% (w:w)	Increased colonization of AM fungus, accelerated plant growth, and adversely affected soil aggregation	Lehmann et al. (2020)

Abbreviations: Cbz, carbamazepine; MF, microfiber; MP, microplastic; PAN, polyacrylonitrile; PES, polyester; PET, polyethylene terephthalate; PHB, polyhydroxy butyrate; PP, polypropylene; PS, polystyrene.

For example, when Emertia analoga was exposed to environmentally relevant concentrations of PP rope fibers, adult crab mortality increased, retention of egg clutches decreased, and variability in embryonic development was seen with cascading implications for predators such as Surf Perf and shore birds (Horn et al., 2020). Similarly, MP fibers reduced larval survival and oxygen consumption in American lobster larvae, with stage‐dependent sensitivity influenced by food availability (Woods et al., 2020).

In fish, chronic exposure induced increased mucus production, coughing, and reduced predatory behavior in goldfish, indicating respiratory and behavioral stress (W. Liang et al., 2023), while morphological and inflammatory alterations were documented in Carassius auratus, including hepatic inflammation and gastrointestinal regression (Jabeen et al., 2018). In zebrafish (Danio rerio), gut exposure resulted in nutritional deficiency, metabolic disturbances, and length‐dependent intestinal damage (Y. Zhao et al., 2021).

When fibers accumulate within internal compartments, physical stress increases further. Microplastic fibers found in the perivisceral coelomic fluid of sea cucumbers disrupted the homeostasis of their respiratory structure and were associated with neurotoxicity and gene down‐regulation (Mohsen et al., 2023). Similarly, freshwater amphipods (Gammarus duebeni) demonstrated fiber intake and potential trophic transfer to higher food web levels (Mateos‐Cárdenas et al., 2021). Collectively, these findings suggest that FMPs induce feeding impairment, reduced oxygen utilization, energy imbalance, and compromised reproductive output.

6.1.2. Conserved oxidative and inflammatory responses

Beyond physical impairments caused by FMP exposure, oxidative stress emerges as a biological response to FMP exposure across diverse organisms. For example, in zebrafish juveniles, fiber ingestion has been associated with glycerophospholipid metabolism as well as increased levels of both enzymatic and non‐enzymatic antioxidants and with inflammation and cytotoxicity (Y. Zhao et al., 2021). PES fibers in the freshwater clam Corbicula javanicus were metabolized as xenobiotics, inducing in vivo oxidative stress responses (Esterhuizen et al., 2022).

Inflammatory liver responses and hyperemia in upper and lower jaws of goldfish were observed following fiber exposure (Jabeen et al., 2018) and gene down‐regulation in sea cucumbers (Mohsen et al., 2023). These molecular and physiological responses across marine and freshwater organisms indicate that oxidative imbalance may serve as a unifying biomarker of FMP exposure.

6.1.3. Chemical vectoring and additive toxicity

In addition to physical stress, FMPs also act as carriers of chemical contaminants. Synthetic fibers contain chemical additives used during manufacturing, such as plasticizers, dyes, and stabilizers, which can leach into surrounding environments, many of which are mutagenic, carcinogenic, or endocrine‐disrupting chemicals (Belzagui et al., 2021).

Their high sorption capacity also enables them to adsorp and transport inorganic pollutants, particularly heavy metals, through surface complexation and electrostatic interactions (Kinigopoulou et al., 2022). Likewise, organic contaminants can also bind to fiber surfaces through halogen bonding, hydrogen bonding, and electrostatic mechanisms (Kinigopoulou et al., 2022). Under acidic conditions, metal(loid)s such as cadmium, chromium, and zinc may desorb from MPs (Frost et al., 2022). When ingested by soil or aquatic organisms, these acidic conditions may enhance metal desorption, increasing their bioavailability and toxicity (Frost et al., 2022). Therefore, biological effects may not arise solely from particle‐induced stress but also from chemicals they carry. FMPs also act as carriers of pathogenic microorganisms, including Bacillus cereus, Escherichia coli, and Vibrio cholerae, facilitating their transfer through the environment and increasing the risk of biological toxicity (Leela et al., 2024).

6.2. Human exposure and systemic distribution

Humans are exposed to FMPs through multiple pathways, including inhalation, dermal contact, and the consumption of contaminated food and water (G. Liu et al., 2024). Once released into the environment, these fibers can accumulate, degrade, and migrate through different environmental compartments before entering the human body (B. Wang, Tang, et al., 2021). Evidence of human exposure has been reported in recent years, with MP fibers detected in human intestinal tracts, placental tissue, blood, and lung tissue (Ibrahim et al., 2021; Leslie et al., 2022; Pauly et al., 1998; Ragusa et al., 2021; Zhu et al., 2023). Their small size and fibrous structure may enable them to cross biological barriers, including cellular membranes, the blood–brain barrier, the placenta, and the lymphatic system, raising concerns about their potential to accumulate within the body over time (C. Wang, Zhao, et al., 2021). Physical harm may therefore arise from organ retention in the lungs, liver, kidneys, and gastrointestinal tract.

6.2.1. Inhalation, ingestion, and occupational exposure

Exposure assessments indicate that inhalation is one of the primary routes of human exposure to MPs (Cox et al., 2019). Airborne synthetic fibers are of particular concern because their elongated morphology, low density, and high aspect ratio allow them to remain suspended in the atmosphere, increasing the likelihood of inhalation.

The presence of textile fibers in human lung tissue was first reported more than two decades ago, providing early evidence of respiratory exposure (Pauly et al., 1998). Once inhaled, FMPs can be deposited in terminal bronchioles, alveolar ducts, and alveoli, where they may contribute to chronic inflammation, granuloma formation, and fibrosis (Amato‐Lourenço et al., 2020). Indoor environments are considered a major source of inhalation exposure because synthetic fibers are continuously released from textiles and household materials. Everyday activities such as walking, crawling, and vacuuming can resuspend settled dust particles, increasing the concentrations of inhalable particles within the breathing zone (Hyytiäinen et al., 2018; C. Wang, Zhao, et al., 2021). Children are likely to experience higher exposure than adults because of their proximity to floors and frequent contact with resuspended dust (Hyytiäinen et al., 2018). Indoor dust is an important reservoir of FMPs; for example, Abbasi et al. (2019) detected approximately one FMP particle per cubic meter in dust deposits from Asaluyeh, Iran, with fiber sizes ranging from 2 to 100 µm.

Recent studies have also raised concerns about the inadvertent inhalation of MPs released from face masks during the COVID‐19 pandemic. Fibers and spherical particles were identified as the dominant morphologies, with activated carbon masks releasing the highest number of MP particles, whereas N95 masks exhibited the lowest release rates (Li et al., 2021).

Occupational exposure is another important source of concern. Studies conducted in synthetic textile, flock, and vinyl chloride manufacturing environments have reported prolonged respiratory symptoms, inflammatory responses, impaired lung function, and chronic respiratory disorders (G. Liu et al., 2024; Surana et al., 2024). Supporting this evidence, Jenner et al. (2022) identified PP and PET microfibers as the predominant synthetic fibers in human lung tissues, with higher concentrations detected in lower lung regions. This suggests that the high aspect ratio and aerodynamic properties of FMPs favor their deposition in pulmonary tissues, where prolonged retention may contribute to chronic inflammatory responses.

Ingestion is another important route of human exposure to FMPs. FMPs have been detected in a wide range of food and beverage products, including drinking water, bottled beverages, seafood, sea salt, fruits, vegetables, condiments, and processed foods, indicating the widespread nature of dietary exposure (Zhu et al., 2024). Human intake is further influenced by atmospheric deposition onto food surfaces, migration from plastic food packaging, and trophic transfer through aquatic and terrestrial food webs (He et al., 2023; Vázquez‐Rowe et al., 2021). Cox et al. (2019) estimated that annual MP ingestion ranges from 39,000 to 52,000 particles depending on age and sex and may increase to 74,000–121,000 particles when inhalation is also taken into account. Drinking water appears to be an important source of exposure, with individuals relying exclusively on bottled water potentially ingesting up to 90,000 additional particles every year compared with approximately 4000 particles for tap water consumers (Cox et al., 2019).

While larger fibers are likely to pass through the gastrointestinal tract and be excreted, smaller particles may interact with the intestinal epithelium, alter the gut microbiota, and translocate through the circulatory and lymphatic pathways (Zhu et al., 2024; C. Wang, Zhao, et al., 2021). Furthermore, the large surface area and hydrophobic nature of FMPs allow them to adsorb and transport heavy metals, persistent organic pollutants, pesticides, dyes, and plastic additives, increasing the potential for combined chemical exposure. Collectively, the widespread occurrence of FMPs in air, food, and water, together with evidence of their presence in human tissues, highlights the need for standardized exposure assessment methods and long‐term epidemiological studies to better understand the health implications of chronic exposure.

6.2.2. Cellular and molecular toxicity

Evidence from in vitro studies suggests that FMPs can induce cytotoxic, genotoxic, and xenobiotic responses in human cells. Several studies have reported that FMPs possess mutagenic and genotoxic potential and are capable of inducing DNA damage (Alnajar et al., 2021). O'Connor et al. (2024) further showed that dyed MP fibers caused substantial reduction in cell viability and transepithelial electrical resistance compared to undyed fibers or unexposed control cells. Dyed FMPs, particularly those containing azobenzene dispersion dye DV93, markedly increased the expression of the xenobiotic metabolism genes CYP1A1 and CYP1B1 (O'Connor et al., 2024). These findings suggest that dyes and other fiber‐associated additives may leach into biological systems and contribute to toxicity beyond the physical effects of the polymer itself.

While definitive causal relationships between environmental FMP exposure and chronic human disease remain under investigation, the detection of fibers in multiple human tissues, combined with occupational respiratory evidence and molecular toxicity findings, underscores the need for morphology‐specific health risk assessments. Given their ability to accumulate, persist, and activate oxidative–inflammatory and xenobiotic pathways, FMPs represent a structurally active class of emerging contaminants with potential systemic implications (Figure 12).

FIGURE 12.

Overview of the reported human health effects associated with fibrous microplastic (FMP) exposure. HDPE, high‐density polyethylene; PA, polyamide; PAN, polyacrylonitrile; PE, polyethylene; PES, polyester; PET, polyethylene terephthalate; PP, polypropylene; PPE, personal protective equipment; PS, polystyrene; PU, polyurethane; PVC, polyvinyl chloride.

7. POTENTIAL CONTROL AND MITIGATION STRATEGIES

After entering the aquatic system, it is nearly impossible to remove the FMPs owing to their miniature size. Water pollution due to these microscopic particles is an emerging subject of distress and requires immediate remediation strategies for the elimination of microfiber pollutants (Mishra et al., 2020). Remediation techniques to deal with FMP pollution should focus on (1) technology development for efficient removal and remediation, (2) social awareness, and (3) government regulations.

7.1. Technology development

Technological interventions play a critical role in mitigating FMP pollution and can be broadly categorized into source‐control measures and wastewater treatment technologies.

At the source level, reducing fiber release during laundering represents one of the most effective upstream mitigation strategies. Filtration devices for washing machines have emerged as useful tools for reducing fiber emissions before they enter wastewater streams. For example, Napper et al. (2020) reported microfiber reduction between 30% and 60% through washing machine filtration devices. McIlwraith et al. (2019) reported that the Lint LUV‐R and Cora Ball reduced microfiber release from fleece fabrics by 87% and 26%, respectively. However, their effectiveness varies with the type of textile, the size of the fiber, and the washing conditions. Furthermore, widespread adoption remains limited by installation requirements, maintenance needs, user compliance, and uncertainty regarding the appropriate disposal of captured fibers. Beyond filtration technologies, manufacturers should prioritize washing systems that minimize mechanical abrasion and turbulence, while operational factors such as temperature, pH, rotation speed, and washing duration should be optimized to minimize fiber fragmentation and shedding (G. Liu et al., 2024; Periyasamy & Venkatesan, 2018).

At the wastewater treatment stage, a wide range of technologies have been investigated for MP retention and removal. Conventional treatment processes, including activated sludge systems, sand filtration, and disc filtration, have reported removal efficiencies ranging from 40% to 99%, depending on treatment configuration, particle characteristics, and operational conditions (Bayo et al., 2020; Lares et al., 2018; Talvitie et al., 2017). More advanced approaches, including membrane bioreactors (MBRs), electrocoagulation, and sol‐gel agglomeration, frequently achieve removal efficiencies exceeding 99% (Bayo et al., 2020; Perren et al., 2018; Sturm et al., 2021). Biofloculation has also emerged as a promising environmentally friendly alternative, employing naturally derived flocculants to aggregate MPs; however, its application remains largely limited to bench‐scale studies (Cunha et al., 2020). Each treatment technology presents distinct advantages and operational constraints. Sand filtration is relatively simple and cost‐effective but may be less efficient for smaller particles, whereas disc filtration is susceptible to filter clogging. Similarly, coagulation and electrocoagulation effectively remove fine MPs but may require substantial chemical inputs or periodic electrode replacement. Consequently, complementary strengths of these technologies suggest that hybrid treatment trains may offer an effective strategy for improving MP retention while overcoming the limitations of individual processes.

Among the available technologies, MBRs have demonstrated the highest MP removal efficiencies. Talvitie et al. (2017) reported 99.9% removal using a pilot‐scale MBR, while Egea‐Corbacho et al. (2023) achieved 99.69% removal in a full‐scale system, outperforming conventional activated sludge and tertiary treatment processes, including rapid sand filtration, dissolved air flotation, and disc filtration. Similarly, Upflow Anaerobic Sludge Blanket–Anaerobic Membrane Bioreactor systems removed 94% of total MPs and 87% of fibers (Pittura et al., 2021), demonstrating the potential of membrane‐based technologies for fiber retention.

Despite these advances, it was observed that fibers were more difficult to retain than other particle shapes (Egea‐Corbacho et al., 2023), while Bayo et al. (2020) attributed lower removal efficiencies (79.01%) to the escape of microfibers smaller than 1 mm through the membrane system. Their narrow diameters and elongated structures facilitate persistence in treated effluents despite overall MP removal efficiencies frequently exceeding 99%. Consequently, although wastewater treatment technologies can substantially reduce fiber loads, complete elimination remains difficult. For example, textile WWTPs have been reported to remove up to 95.1% of microfibers (Xu et al., 2018), yet the large volumes of treated effluent discharged daily may still result in significant environmental releases. Furthermore, the influence of fiber morphology on membrane fouling and retention remains insufficiently understood, and limited attention has been given to the ultimate fate of fibers captured in filters, sludge, and treatment residues. Future research should therefore focus on optimizing fiber‐specific removal mechanisms while developing sustainable management strategies for retained fibers to prevent the transfer of pollution between environmental compartments.

7.2. Social awareness

Raising public understanding of the environmental and human health impacts of FMPs can promote sustainable, ethical textile use and disposal practices. It is essential to develop comprehensive education and publicity campaigns to explain the sources, effects, and hazards of FMPs to the environment and health (G. Liu et al., 2024). Reuse strategies not only help in minimizing textile waste and the release of FMPs into the environment but also help to reduce the volume of waste entering landfills. Additionally, it has been demonstrated that consumer‐focused interventions, such as fewer washing frequencies and the use of microfiber‐capturing devices such as coral balls and grubby bags, can minimize microfiber emissions during laundering. While behavioral changes offer valuable short‐term benefits, the implementation of comprehensive legislative measures remains the most effective strategy for achieving long‐term, systemic change (Chan et al., 2025). Raising awareness at an industrial level is equally important, as implementing just three industrial pre‐washes has been considered an effective measure to significantly reduce fiber release into the environment. According to Cesa et al. (2020), three pre‐washes could reduce fiber emissions from 37% to 76%, depending on the type of fiber.

7.3. Government regulations

Despite growing concern about the impact of MP fibers on the environment, few global regulatory initiatives specifically target MP fiber pollution. The majority of current legislation focuses on MPs rather than FMPs. For instance, although several countries have banned microbeads, these policies do not address other MPs, including fibers (Sánchez‐Lizaso & Li, 2022). A few countries have taken limited legislative actions on FMPs. France has taken the lead in this regard, becoming the first country in 2020 to mandate the inclusion of microfiber filters in all new washing machines by 2025 (Chan et al., 2024). In addition to enforcing producer responsibility through legislation, governments must also prioritize enhancements in waste management systems and WWTP infrastructure, which will require substantial financial investment (Chan et al., 2021).

8. CONCLUSION AND FUTURE DIRECTIONS

FMPs represent a distinct and high‐priority class of MP pollutants because of their unique morphology, widespread occurrence, and potential environmental and human health implications. Although research on FMPs has expanded rapidly in recent years, important knowledge gaps continue to limit accurate exposure assessment, risk evaluation, and development of effective mitigation strategies. Existing studies have largely focused on fiber release during domestic laundering, while emissions from textile manufacturing processes and industrial WWTPs remain comparatively underexplored despite their potential to act as major sources of synthetic fiber emissions. In addition, the lack of standardized protocols for sampling, polymer identification, and reporting continues to hinder cross‐study comparisons, resulting in uncertainty in global emission estimates.

Current wastewater treatment technologies can achieve high overall MP removal efficiencies; however, they are not specifically designed to capture fine, flexible fibers. In addition, most studies report total MP removal rather than fiber‐specific removal, making it difficult to evaluate the effectiveness of existing technologies for FMP mitigation. The fate of FMPs retained in treatment processes, including their disposal, recovery, and potential recycling, has also received relatively little attention and remains an important area for future investigation.

Addressing these challenges will require standardized analytical methodologies, fiber‐specific monitoring frameworks, and morphology‐based risk assessment approaches. Future research should also place greater emphasis on quantifying emissions from textile manufacturing, improving source‐control measures and advancing fiber‐retention technologies, and developing sustainable management strategies for captured fibers. Integrating these technical innovations with eco‐design of textiles, strengthened regulatory frameworks, and circular economy approaches will be essential for reducing environmental emissions and human exposure. Recognizing FMPs as a distinct category of MP pollution will enable more targeted monitoring, mitigation, and policy interventions.

AUTHOR CONTRIBUTIONS

Iqra Bashir: Conceptualization; data curation; formal analysis; investigation; methodology; software; visualization; writing—original draft; writing—review and editing. Sirajuddin Ahmed: Conceptualization; supervision; validation; writing—review and editing.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.

Bashir, I. , & Ahmed, S. (2026). Global assessment of fibrous microplastic pollution: Sources, environmental distribution, and ecological impacts. Journal of Environmental Quality, 55, e70250. 10.1002/jeq2.70250