Microfibres from apparel and home textiles: Prospects for including microplastics in environmental sustainability assessment

Transforming pollution into solutions: A bibliometric analysis and sustainable strategies for reducing indoor microplastics while converting to value-added products

Microplastics (MPs), as emerging indoor contaminants, have garnered attention due to their ubiquity and unresolved implications for human health. These tiny particles have permeated indoor air and water, leading to inevitable human exposure. Preliminary evidence suggests MP exposure could be linked to respiratory, gastrointestinal, and potentially other health issues, yet the full scope of their effects remains unclear. To map the overall landscape of this research field, a bibliometric analysis based on research articles retrieved from the Web of Science database was conducted. The study synthesizes the current state of knowledge and spotlights the innovative mitigation strategies proposed to curb indoor MP pollution. These strategies involve minimizing the MP emission from source, advancements in filtration technology, aimed at reducing the MP exposure. Furthermore, this research sheds light on cutting-edge methods for converting MP waste into value-added products. These innovative approaches not only promise to alleviate environmental burdens but also contribute to a more sustainable and circular economy by transforming waste into resources such as biofuels, construction materials, and batteries. Despite these strides, this study acknowledges the ongoing challenges, including the need for more efficient removal technologies and a deeper understanding of MPs' health impacts. Looking forward, the study underscores the necessity for further research to fill these knowledge gaps, particularly in the areas of long-term health outcomes and the development of standardized, reliable methodologies for MP detection and quantification in indoor settings. This comprehensive approach paves the way for future exploration and the development of robust solutions to the complex issue of microplastic pollution.

High-quality acrylic fibers from waste textiles

The objective of this work is to develop a closed-loop recycling method specifically tailored for acrylic fibers. Recycling waste acrylic is essential, given the vast volumes of acrylic-containing textiles produced yearly and the strong capability of acrylics to generate toxic microplastics. However, none of the available closed-loop recycling, mechanical recycling, chemical recycling, and direct extrusion technologies work for acrylics. Acrylic fibers are always blended with other textile fibers, making fiber separation via mechanical recycling almost impossible. Polyacrylonitrile, an addition-polymerized thermoplastic material, cannot be depolymerized into its original monomer. Direct extrusion of waste acrylics faces issues of uncontrollable colors on fibers and pollution of spinning lines due to the influence of existing colorants. In our method, acrylic fibers were extracted from waste textiles using a novel approach involving maximized acrylic swelling and dissolution with dimethyl sulfoxide and butanediol. Cationic dyes were effectively removed through cost-effective recycling technology. This work demonstrates that cationic dyes seriously affect the acrylic dissolution, color consistency, and dyeability of regenerated fibers via direct wet extrusion. Such negative impacts of dyes have been eliminated by our cost-effective and closed-loop acrylic recycling technology, which enables the efficient separation of non-acrylic fibers and dyes from acrylic fibers. Our recycling system achieved zero discharges through recycling solvents, dyes, and acrylics. The regenerated acrylic fibers exhibited mechanical properties and dyeability comparable to virgin acrylic fibers. The material and energy costs to produce pure acrylic from waste textiles were only 40 % of those from fossils. This study successfully introduces a closed-loop recycling method for acrylic fibers from waste textiles, addressing key challenges in acrylic fiber recycling. Further research and implementation of this technology are recommended to advance its commercial viability and widespread adoption.

Life cycle assessment applications to reuse, recycling and circular practices for textiles: A review

To understand which are the best strategies for textile waste management and to analyse the effects on the environment of applying circular economy practices to textile products, a review of 45 publications where life cycle assessment (LCA) is applied to these topics has been carried out. The separate collection of textiles, followed by reuse and recycling brings relevant environmental benefits, with impacts related to reuse resulting lower than those of recycling. At the opposite, when mixed municipal solid waste is addressed to energy recovery, the textile fraction is the second most impacting on climate change, right after plastics, while for landfill disposal impacts textiles directly follow the more biodegradable fractions. Textiles manufacturing using recycled fibres generally gives lower impacts than using virgin ones, with a few exceptions in some impact categories for cotton and polyester. The circular practices with the lowest impacts are those that ensure the extension of the textiles service life. Another aim of this review is to identify the main variables affecting the life cycle impact assessment (LCIA). These resulted to be the yield and material demand of recycling processes, the use phase variables, the assumptions on virgin production replaced by reuse or recycling, the substitution factor in reuse, and transportation data in business models based on sharing. Thus, in LCA modelling, great attention should be paid to these variables. Future research should address these aspects, to acquire more relevant data, based on industrial-scale processes and on people habits towards the circular economy strategies applied to textiles.

Microplastics in wastewater and sludge from centralized and decentralized wastewater treatment plants: Effects of treatment systems and microplastic characteristics

Domestic wastewater treatment plants (WWTPs) play a vital role in limiting the release of microplastics (MP) into the environment. This study examined MP removal efficiency from five centralized and four decentralized domestic WWTPs in Bangkok, Thailand. MP concentrations in wastewater and sludge were comparable between centralized and decentralized WWTPs, despite these decentralized WWTPs serving smaller populations and having limited treatment capacity. The elimination of MPs ranged from 50 to 96.8% in centralized WWTPs and 14.2-53.6% in decentralized WWTPs. It is noted that the retained MPs concentrations in sludge ranged from 20,000 to 228,100 MP/kg dry weight. The prevalence of synthetic fibers and fragments could be attributed to their pathways from laundry or car tires, and the accidental release of a variety of plastic wastes ended up in investigated domestic WWTPs. Removal of MPs between the centralized and decentralized WWTPs was influenced by several impact factors including initial MP concentrations, longer retention times, MP fragmentation, and variations of MP concentrations in sludge leading to different activated sludge process configurations. Sewage sludge has become a primary location for the accumulation of incoming microplastics in WWTPs. The MPs entering and leaving each unit process were varied due to the unique characteristics of MPs, and their different treatment efficiencies. While the extended hydraulic retention period in decentralized WWTPs decreased the MP removal efficacy, the centralized WWTP with the two-stage activated sludge process achieved the highest MP removal efficiency.

First report of plastic and non-plastic microparticles in stomach of slandertail lanternshark and shortspine spurdog from the edge of East China Sea

This study investigates the presence of plastic and non-plastic microparticles in the gastrointestinal tracts of two deep-sea sharks, Etmopterus molleri (n = 118) and Squalus mitsukurii (n = 6), bycatch from the East China Sea continental shelf. We found a total of 117 microparticles, predominantly fibres (67.52 %), with blue (31.62 %) and black (23.94 %) being the most prevalent colours. E. molleri contained 70 microparticles (0.63 ± 0.93 items/shark), 61.42 % non-plastics like viscose and cotton, while plastics included polyethylene, polyethylene terephthalate, and acrylic. Despite S. mitsukurii's limited sample size, the results show that it takes in a lot of microparticles (47 microparticles, 7.83 ± 2.64 items/shark), 57.44 % non-plastics (viscose, cotton, and ethyl cellulose), and 42.56 % plastics. A positive correlation between microparticle presence and total length was observed for E. molleri. These results provide initial data on microparticle ingestion by these species, highlighting potential ecological risks and trophic transfer implications in deep-sea ecosystems.

Kelp forest food webs as hot spots for the accumulation of microplastic and polybrominated diphenyl ether pollutants

Kelp forests (KFs) are one of the most significant marine ecosystems in the planet. They serve as a refuge for a wide variety of marine species of ecological and economic importance. Additionally, they aid with carbon sequestration, safeguard the coastline, and maintain water quality. Microplastic (MP) and polybrominated diphenyl ethers (PBDEs) concentrations were analyzed across trophic levels in KFs around Todos Santos Bay. Spatial variation patterns were compared at three sites in 2021 and temporal change at Todos Santos Island (TSI) in 2021 and 2022. We analyzed these MPs and PBDEs in water, primary producers (Macrocystis pyrifera), grazers (Strongylocentrotus purpuratus), predators (Semicossyphus pulcher), and kelp detritus. MPs were identified in all samples (11 synthetic and 1 semisynthetic polymer) and confirmed using Fourier-transform infrared microspectroscopy-attenuated total reflectance (μ-FTIR-ATR). The most abundant type of MP is polyester fibers. Statistically significant variations in MP concentration were found only in kelps, with the greatest average concentrations in medium-depth kelps from TSI in 2022 (0.73 ± 0.58 MP g-1 ww) and in the kelp detritus from TSI in 2021 (0.96 ± 0.64 MP g-1 ww). Similarly, PBDEs were found in all samples, with the largest concentration found in sea urchins from Punta San Miguel (0.93 ± 0.24 ng g-1 ww). The similarity of the polymers can indicate a trophic transfer of MPs. This study shows the extensive presence of MP and PBDE subtropical trophic web of a KF, but correlating these compounds in environmental samples is highly complex, influenced by numerous factors that could affect their presence and behavior. However, this suggests that there is a potential risk to the systems and the services that KFs offer.

Data driven AI (artificial intelligence) detection furnish economic pathways for microplastics

Microplastics pollution is killing human life, contaminating our oceans, and lasting for longer in the environment than it is used. Microplastics have contaminated the geochemistry and turned the water system into trash barrel. Its detection in water is easy in comparison to soil and air so the attention of researchers is focused on it for now. Being very small in size, microplastics can easily cross the water filtration system and end up in the ocean or lakes and become the prospective challenge to aquatic life. This review piece provides the hot research theme and current advances in the field of microplastics and their eradication through the virtual world of artificial intelligence (AI) because Microplastics have confrontation with clean water tactics.

Are we eating plastic? Science mapping of microplastic pollution in the aquatic food chain

This study evaluates the knowledge structure of microplastic pollution and its effects on the aquatic food chain. The presence of microplastics has seriously harmed the ecosystem. Through bibliometric analysis, 216 journal publications were retrieved from the Web of Science (WoS) from 2008 to 2023 (April), with no restriction in the time frame. Applying bibliographic coupling and co-word analysis, the emerging, current, and future themes of microplastic pollution are presented. Three research streams are derived from bibliographic coupling, centralized on the source of microplastic pollution and its impact. At the same time, research streams from co-word analysis are associated with overcoming the issue of microplastics in the ecosystem. This study's implications suggest three main principles to mitigate microplastic issues: (1) educating the public on the impact of microplastic pollution, (2) implementing holistic regulations and policies, and (3) developing treatment strategies through conventional, innovative, and hybrid approaches. Microplastic pollution is a global concern, requiring a holistic and comprehensive approach to overcome it. This review is the first to present a scientific mapping of the microplastics literature, which is a fundamental basis for future research on microplastic pollution and its impact on the ecosystem. Integr Environ Assess Manag 2024;00:1-12. © 2024 SETAC.

Efficacy of bacterial cellulose hydrogel in microfiber removal from contaminated waters: A sustainable approach to wastewater treatment

Microfibers (MFs), the dominant form of microplastics in ecosystems, pose a significant environmental risk due to the inadequacy of existing wastewater treatments to remove them. Recognising the need to develop sustainable solutions to tackle this environmental challenge, this research aimed to find an eco-friendly solution to the pervasive problem of MFs contaminating water bodies. Unused remnants of bacterial cellulose (BC) were ground to form a hydrogel-form of bacterial cellulose (BCH) and used as a potential bioflocculant for polyacrylonitrile MFs. The flocculation efficiency was evaluated across various operational and environmental factors, employing response surface methodology computational modelling to elucidate and model their impact on the process. The results revealed that the BCH:MFs ratio and mixing intensity were key factors in flocculation efficiency, with BCH resilient across a range of environmental conditions, achieving a 93.6 % average removal rate. The BCH's strong retention of MFs released only 8.3 % of the MFs, after a 24-hour wash, and the flocculation tests in contaminated wastewater and chlorinated water yielded 89.3 % and 86.1 % efficiency, respectively. Therefore, BCH presents a viable, sustainable, and effective approach for removing MFs from MFs-contaminated water, exhibiting exceptional flocculation performance and adaptability. This pioneer study using BCH as a bioflocculant for MFs removal sets a new standard in sustainable wastewater treatment, catalysing research on fibrous pollutant mitigation for environmental protection.

A novel approach to analyze the impact of lytic polysaccharide monooxygenases (LPMOs) on cellulosic fibres

Enzymatic treatment of cellulosic fibres is a green alternative to classical chemical modification. For many applications, mild procedures for cellulose alteration are sufficient, in which the fibre structure and, therefore, the mechanical performance of cellulosic fibres are preserved. Lytic polysaccharide monooxygenases (LPMOs) bear a great potential to become a green reagent for such targeted cellulose modifications. An obstacle for wide implementation of LPMOs in tailored cellulose chemistry is the lack of suitable techniques to precisely monitor the LPMO impact on the polymer. Soluble oxidized cello-oligomers can be quantified using chromatographic and mass-spectrometric techniques. A considerable portion of the oxidized sites, however, remain on the insoluble cellulose fibres, and their quantification is difficult. Here, we describe a method for the simultaneous quantification of oxidized sites on cellulose fibres and changes in their molar mass distribution after treatment with LPMOs. The method is based on quantitative, heterogeneous, carbonyl-selective labelling with a fluorescent label (CCOA) followed by cellulose dissolution and size-exclusion chromatography (SEC). Application of the method to reactions of seven different LPMOs with pure cellulose fibres revealed pronounced functional differences between the enzymes, showing that this CCOA/SEC/MALS method is a promising tool to better understand the catalytic action of LPMOs.

Chemical reactivity theory to analyze possible toxicity of microplastics: Polyethylene and polyester as examples

Micro- and nanoplastics are widespread throughout the world. In particular, polyethylene (PE) and polyethylene terephthalate or polyester (PET) are two of the most common polymers, used as plastic bags and textiles. To analyze the toxicity of these two polymers, oligomers with different numbers of units were used as models. The use of oligomers as polymeric templates has been used previously with success. We started with the monomer and continued with different oligomers until the chain length was greater than two nm. According to the results of quantum chemistry, PET is a better oxidant than PE, since it is a better electron acceptor. Additionally, PET has negatively charged oxygen atoms and can promote stronger interactions than PE with other molecules. We found that PET forms stable complexes and can dissociate the guanine-cytosine nucleobase pair. This could affect DNA replication. These preliminary theoretical results may help elucidate the potential harm of micro- and nanoplastics.

Are we underestimating stormwater? Stormwater as a significant source of microplastics in surface waters

Stormwater represent a critical pathway for transporting microplastics (MPs) to surface waters. Due to complex dynamics of MPs in stormwater, its dispersion, weathering, risk, and transport are poorly understood. This review bridges those gaps by summarizing the latest findings on sources, abundance, characteristics, and dynamics involved in stormwater MP pollution. Weathering starts before or after MPs enter stormwater and is more pronounced on land due to continuous heat and mechanical stress. Land use patterns, rainfall intensity, MPs size and density, and drainage characteristics influence the transport of MPs in stormwater. Tire and road wear particles (TRWPs), littering, and road dust are major sources of MPs in stormwater. The concentrations of MPs varies from 0.38-197,000 particles/L globally. Further MP concentrations showed regional variations, highlighting the importance of local monitoring efforts needed to understand local pollution sources. We observed unique signatures associated with the shape and color of MPs. Fibers and fragments were widely reported, with transparent and black being the predominant colors. We conclude that the contribution of stormwater to MP pollution in surface waters is significantly greater than wastewater treatment plant effluents and demands immediate attention. Field and lab scale studies are needed to understand its behavior in stormwater and the risk posed to the downstream water bodies.

Microfiber Pollution: A Systematic Literature Review to Overcome the Complexities in Knit Design to Create Solutions for Knit Fabrics

The absence of standardized procedures to assess microfiber pollution released during laundering, alongside textile complexities, has caused incomparability and inconsistency between published methodologies, data formats, and presentation of findings. Yet, this information needs to be clear and succinct to engage producers and consumers in reducing microfiber pollution through solutions, such as eco-design. This review analyses source directed interventions through design and manufacturing parameters that can prevent or reduce microfiber shedding from knit fabrics during washing. Contradicting results are critically evaluated and future research agendas, alongside potential areas for voluntary and involuntary sustainable incentives are summarized. To do this, a systematic review was carried out, using the PRISMA approach to verify which fabrics had been investigated in terms of microfiber shedding. Using selected keywords, a total number of 32 articles were included in this review after applying carefully developed inclusion and exclusion criteria. The influence of fabric parameters such as fiber polymer, length of fibers and yarn twist alongside fabric construction parameters such as gauge of knit and knit structure are critically evaluated within the systematically selected studies. This review highlights the agreed upon fabric parameters and constructions that can be implemented to reduce microfiber pollution released from knit textiles. The complexities and inconsistencies within the findings are streamlined to highlight the necessary future research agendas. This information is critical to facilitate the adoption of cross-industry collaboration to achieve pollution reduction strategies and policies. We call for more systematic studies to assess the relationship between individual textile parameters and their influence on microfiber shedding. Additionally, studies should work toward standardization to increase comparability between studies and created more comprehensive guidelines for policy development and voluntary actions for the textile and apparel industry to participate in addressing more sustainable practises through eco-design.

Science-based evidence on pathways and effects of human exposure to micro- and nanoplastics

Human exposure to plastic particles has raised great concern among all relevant stakeholders involved in the protection of human health due to the contamination of the food chain, surface waters, and even drinking water as well as due to their persistence and bioaccumulation. Now more than ever, it is critical that we understand the biological fate of plastics and their interaction with different biological systems. Because of the ubiquity of plastic materials in the environment and their toxic potential, it is imperative to gain reliable, regulatory-relevant, science-based data on the effects of plastic micro- and nanoparticles (PMNPs) on human health in order to implement reliable risk assessment and management strategies in the circular economy of plastics. This review presents current knowledge of human-relevant PMNP exposure doses, pathways, and toxic effects. It addresses difficulties in properly assessing plastic exposure and current knowledge gaps and proposes steps that can be taken to underpin health risk perception, assessment, and mitigation through rigorous science-based evidence. Based on the existing scientific data on PMNP adverse health effects, this review brings recommendations on the development of PMNP-specific adverse outcome pathways (AOPs) following the AOP Users' Handbook of the Organisation for Economic Cooperation and Development (OECD).

Understanding microplastic pollution: Tracing the footprints and eco-friendly solutions

Microplastics (MPs) pollution has emerged as a critical environmental issue with far-reaching consequences for ecosystems and human health. These are plastic particles measuring <5 mm and are categorized as primary and secondary based on their origin. Primary MPs are used in various products like cosmetics, scrubs, body wash, and toothpaste, while secondary MPs are generated through the degradation of plastic products. These have been detected in seas, rivers, snow, indoor air, and seafood, posing potential risks to human health through the food chain. Detecting and quantifying MPs are essential to understand their distribution and abundance in the environment. Various microscopic (fluorescence microscopy, scanning electron microscopy) and spectroscopy techniques (FTIR, Raman spectroscopy, X-ray photoelectron spectroscopy) have been reported to analyse MPs. Despite the challenges in scalable removal methods, biological systems have emerged as promising options for eco-friendly MPs remediation. Algae, bacteria, and fungi have shown the potential to adsorb and degrade MPs in wastewater treatment plants (WWTPs) offering hope for mitigating this global crisis. This review examines the sources, impacts, detection, and biological removal of MPs, highlighting future directions in this crucial field of environmental conservation. By fostering global collaboration and innovative research a path towards a cleaner and healthier planet for future generations can be promised.

Prevalence of microplastics in Peruvian mangrove sediments and edible mangrove species

Mangrove ecosystems have been hypothesised as a potential sink of microplastic debris, which could pose a threat to mangrove biota and ecological function. In this field-study we establish the prevalence of microplastics in sediments and commercially-exploited Anadara tuberculosa (black ark) and Ucides occidentalis (mangrove crab) from five different zones in the mangrove ecosystem of Tumbes, Peru. Microplastic were evident in all samples, with an average of 726 ± 396 microplastics/kg for the sediment, although no differences between the different zones of the mangrove ecosystem were observed. Microplastic concentrations were 1.6± 1.1 items/g for the black ark and 1.9 ± 0.9 microplastics/g for the mangrove crab, with a difference in the microplastic abundance between species (p < 0.05), and between the gills and stomachs of the crab (p < 0.01). Human intake of microplastics from these species, for the population in Tumbes, is estimated at 431 items per capita per year. The outcomes of this work highlight that the mangrove ecosystem is widely contaminated with microplastics, presenting a concern for the marine food web and food security.

Microplastics Prevalence in Different Cetaceans Stranded along the Western Taiwan Strait

Microplastics (MPs) pollution is of global concern, which poses serious threats to various marine organisms, including many threatened apex predators. In this study, MPs were investigated from nine cetaceans of four different species, comprising one common dolphin (Delphinus delphis), two pygmy sperm whales (Kogia breviceps), one ginkgo-toothed beaked whale (Mesoplodon ginkgodens), and five Indo-Pacific humpback dolphins (Sousa chinensis) stranded along the western coast of the Taiwan Strait from the East China Sea based on Fourier transform infrared (FTIR) spectroscopy analysis. Mean abundances of 778 identified MPs items were 86.44 ± 12.22 items individual-1 and 0.43 ± 0.19 items g-1 wet weight of intestine contents, which were found predominantly to be transparent, fiber-shaped polyethylene terephthalate (PET) items usually between 0.5 and 5 mm. The abundance of MPs was found at a slightly higher level and significantly correlated with intestine contents mass (p = 0.0004*). The MPs source was mainly likely from synthetic fibers-laden sewage discharged from intense textile industries. Our report represents the first study of MPs in pelagic and deep-diving cetaceans in China, which not only adds baseline data on MPs for cetaceans in Asian waters but also highlights the further risk assessment of MPs consumption in these threatened species.

Microfiber pollution from Dhobi Ghats (open air laundry centers) and commercial laundries in a north Indian city

In regions like Southeast Asia, Dhobi Ghats-traditional open-air laundromats-hold cultural significance and provide livelihoods to many people. These centers are near the riverbanks for easy access to water for washing. These Dhobi Ghats are among major sources of microfibers (MFs) in the waterbodies. However, there is no ample data that confirms their level of MF release into the waterbodies. This study reports for the first time the prevalence of microfibers (MFs) in wastewater from Dhobi Ghats in a North Indian city and comparatively assess them with the MF pollution from commercial laundries. A mean microfiber concentration of 3204 ± 270 MFs/L was observed in the discharged effluents of Dhobi Ghats, while a concentration at 36,923 ± 389 MFs/L was observed in effluents from commercial laundries. Pertinently, microfibers measuring less than 75 µm dominated in effluents of commercial laundries, accounting for 53% of the total. Conversely, microfibers within the 75-150-µm range were present in effluents of Dhobi Ghats, constituting 52%. Spectroscopic analyses by FTIR showed polyester and polyamides as the main polymers released from Dhobi Ghats. Ecological risk assessment demonstrated a potential environmental risk from the MF pollution from Dhobi Ghats and commercial laundries. The study also proposed a mitigation framework prioritizing both environmental protection and the sustenance of local livelihoods for reducing the microfiber pollution by the Dhobi Ghats.

Effect of microplastics deposition on human lung airways: A review with computational benefits and challenges

Microplastics have become omnipresent in the environment, including the air we inhale, the water we consume, and the food we eat. Despite limited research, the accumulation of microplastics within the human respiratory system has garnered considerable interest because of its potential implications for health. This review offers a comprehensive examination of the impacts stemming from the accumulation of microplastics on human lung airways and explores the computational benefits and challenges associated with studying this phenomenon. The existence of microplastics in the respiratory system can lead to a range of adverse effects. Research has indicated that microplastics can induce inflammation, oxidative stress, and impaired lung function. Furthermore, the small size of microplastics allows them to penetrate deep into the lungs, reaching the alveoli, where gas exchange takes place. This raises concerns about long-term health consequences, such as the development of respiratory diseases and the potential for translocation to other organs. Computational approaches have been instrumental in understanding the impact of microplastic deposition on human lung airways. Computational models and simulations enable the investigation of particle dynamics, deposition patterns, and interaction mechanisms at various levels of complexity. However, studying microplastics in the lung airways using computational methods presents several challenges. The complex anatomy and physiological processes of the respiratory system require accurate representation in computational models. Obtaining relevant data for model validation and parameterization remains a significant hurdle. Additionally, the diverse nature of microplastics, including variations in size, shape, and chemical composition, poses challenges in capturing their full range of behaviours and potential toxicological effects.

Microplastic in fishes: the first report from a Himalayan River - Alaknanda

The present study aimed to understand microplastic (MP) ingestion by five fish species with different feeding habits namely, Schizothorax richardsonii and Crossocheilus latius (herbivore),Cyprinus carpio (omnivore), Tor chelenoid (herbi-omnivore), and Botia horii (carnivore). The fishes were sampled from River Alaknanda (one of the headwaters of River Ganga) patch at Srinagar, Garhwal, Uttarakhand. The fish gut samples were digested with 30% hydrogen peroxide and vacuum filtered through glass microfiber filter. Each filter paper was observed microscopically to count MPs, and then, selected MPs were chemically characterized using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The results revealed that all the species were contaminated with MPs and the rate of MP ingestion varied with feeding habits. The herbi-omnivore fish, Tor chelenoid, was observed to have the highest MP ingestion. Among the analyzed particles, fibers (66%) were the dominant type of MPs. The MPs were chemically characterized as High-Density Polyethylene (HDPE), Polypropylene (PP), and Polyester. This study contributes as a reference for the forthcoming researches, as it is the pioneer work on the ingestion of MP by fishes of a Himalayan River.

Microplastic contamination in edible marine fishes from the upper Gulf of Thailand

Seafood consumption is a major source of microplastic exposure for humans. Here, we demonstrated microplastic contamination in marine food fishes from the upper Gulf of Thailand. Microplastics were found in gastrointestinal tracts of 46.9 % of fishes sampled, with a mean concentration of 1.6 ± 0.5 pieces per fish or 0.04 ± 0.01 pieces/g of fish tissue. Demersal fishes had higher contamination rates than pelagic fishes. Fibrous-type and blue-colored materials were the most abundant microplastics, while the most common polymers were polyester and polyethylene. No associations between microplastics and histopathological changes were detected. Estimated daily microplastic exposure for human marine fish consumers was 0.03 to 0.1 pieces per person. Although we expect a low risk of microplastic contamination in fish muscle because of very low calculated transfer rates, we recommend continuing surveillance, including evaluations of contamination in the food chain to ensure future seafood safety in this region.

Additives of plastics: Entry into the environment and potential risks to human and ecological health

A steep rise in global plastic production and significant discharge of plastic waste are expected in the near future. Plastics pose a threat to the ecosystem and human health through the generation of particulate plastics that act as carriers for other emerging contaminants, and the release of toxic chemical additives. Since plastic additives are not covalently bound, they can freely leach into the environment. Due to their occurrence in various environmental settings, the additives exert significant ecotoxicity. However, only 25% of plastic additives have been characterized for their potential ecological concern. Despite global market statistics highlighting the substantial environmental burden caused by the unrestricted production and use of plastic additives, information on their ecotoxicity remains incomplete. By focusing on the ecological impacts of plastic additives, the present review aims to provide detailed insights into the following aspects: (i) diversity and occurrence in the environment, (ii) leaching from plastic materials, (iii) trophic transfer, (iv) human exposure, (v) risks to ecosystem and human health, and (vi) legal guidelines and mitigation strategies. These insights are of immense value in restricting the use of toxic additives, searching for eco-friendly alternatives, and establishing or revising guidelines on plastic additives by global health and environmental agencies.

A comprehensive review of micro- and nano-plastics in the atmosphere: Occurrence, fate, toxicity, and strategies for risk reduction

Micro- and nano-plastics (MNPs) have received considerable attention over the past 10 years due to their environmental prevalence and potential toxic effects. With the increase in global plastic production and disposal, MNP pollution has become a topic of emerging concern. In this review, we describe MNPs in the atmospheric environment, and potential toxicological effects of exposure to MNPs. Studies have reported the occurrence of MNPs in outdoor and indoor air at concentrations ranging from 0.0065 items m-3 to 1583 items m-3. Findings have identified plastic fragments, fibers, and films in sizes predominantly <1000 μm with polyamide (PA), polyester (PES), polyethylene terephthalate (PET), polypropylene (PP), rayon, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyacrylonitrile (PAN), and ethyl vinyl acetate (EVA) as the major compounds. Exposure through indoor air and dust is an important pathway for humans. Airborne MNPs pose health risks to plants, animals, and humans. Atmospheric MNPs can enter organism bodies via inhalation and subsequent deposition in the lungs, which triggers inflammation and other adverse health effects. MNPs could be eliminated through source reduction, policy/regulation, environmental awareness and education, biodegradable materials, bioremediation, and efficient air-filtration systems. To achieve a sustainable society, it is crucial to implement effective strategies for reducing the usage of single-use plastics (SUPs). Further, governments play a pivotal role in addressing the pressing issue of MNPs pollution and must establish viable solutions to tackle this significant challenge.

A standard analytical approach and establishing criteria for microplastic concentrations in wastewater, drinking water and tap water

The ubiquitous presence of microplastics (MPs) in natural water bodies reflects the global issue regarding these micropollutants. The main problem of MPs lies on the difficulty of removing these particles from water during wastewater and drinking water treatments. The release of MPs to the environment in treated wastewater contributed to the dispersion of these micropollutants, which enhances the harmful effect of MPs on fauna and flora. In addition, their presence in tap water entails a potential risk to human health since MPs can be directly consumed. The first step is being able to quantify and characterise these microparticles accurately. In this work, a comprehensive analysis on the presence of MPs in wastewater, drinking water and tap water has been conducted with emphasis on sampling methods, pre-treatment, MP size and analytical methods. Based on literature data, a standard experimental procedure has been proposed with the objective of recommending a methodology that allows the homogenisation of MP analysis in water samples. Finally, reported MP concentrations for influents and effluents of drinking and wastewater treatment plants and tap water have been analysed, in terms of abundance, ranges and average values, and a tentative classification of different waters based on their MP concentrations is proposed.

Exposure sources and pathways of micro- and nanoplastics in the environment, with emphasis on potential effects in humans: A systematic review

Microplastics (MPs) are emerging pollutants that are ubiquitous in the environment, and may be a potential threat to human health. This review describes the MP exposure sources and pathways through drinking water, food intake, and air inhalation. The unregulated discharge of MPs in water sources and the absence of required MP filter technology in water treatment plants are important routes of MP exposure through drinking water. The presence of MPs in food may lead to the accumulation of MPs in the body. Exposure to MPs can occur through airborne fallout and dust inhalation in both indoor and outdoor environments. This review summarizes the MP exposure sources and possible pathways in the human body, and illustrates that the intake of drinking water, food consumption, and air inhalation should be assessed in during routine activities. Integr Environ Assess Manag 2023;19:1422-1432. © 2023 SETAC.

Nanoplastics removal from spiked laundry wastewater using electro-peroxidation process

Microplastics and nanoplastics (NPs) in laundry wastewater (LWW) are major sources of plastic particles in wastewater treatment plants. Unlike microplastics, almost no information exists in the literature on the degradation of NPs in LWW. In this work, the degradation of NPs in commercial LWW by the electro-peroxidation process is investigated. The obtained results demonstrated that already existing ions in LWW such as Cl- contribute to faster degradation of NPs and a complete removal could be obtained as fast as 40 min. In addition, three-dimensional excitation and emission matrix fluorescence analysis was performed, which revealed humic acid-like, aromatic proteins-like, and fulvic acid-like compounds could be oxidized after 20, 40, and 60 min of treatment respectively. The effects of operating parameters on the process performance were then examined by response surface methodology (RSM) models. The results showed that initial TOC concentration was the most important parameter influencing negatively the percentage of NP degradation. Afterward, optimization of the process revealed that the energy consumption could be minimized at 31.2 mA/cm2, 0.025 mol/L [Na2SO4], and 52 min treatment time for 52.2 mg/L initial TOC. Finally, analysis of treated LWW showed no toxicity on Daphnia magna. This study showed that the electro-peroxidation process can completely degrade NPs in LWW without any remaining toxic compounds.

Modified polyamide fibers with low surface friction coefficient to reduce microplastics emission during domestic laundry

The widespread presence of microplastics has become a serious threat to humans and ecological environments because they carry many pollutants and can be easily ingested by aquatic organisms. Fibrous microplastics (FMPs) released from synthetic fiber garments during domestic laundry are a major source of contamination. Herein, we report a facile FMPs mitigation strategy for polyamide 6 (PA6) fibers by incorporating environmentally friendly polydimethylsiloxane (PDMS) during melt spinning. The obtained PA6/PDMS fibers showed a lower friction coefficient than the pure PA6 fibers. Surface morphology, tribology, and washing characterizations verified that a 60% reduction in FMPs shedding was achieved by reducing the friction. In addition, the low-surface-friction PA6/PDMS fabrics with high hydrophobicity exhibited improved waterproof and anti-stain behaviors. It is important to note that none of the essential properties, such as surface structure, dyeing and printing of the fabrics were compromised after PDMS blending. This study provides a green and scalable route for mitigating laundry microfibers using a fiber domain design.

First determination on two kinds of microplastic-air partition coefficients of seven per- and polyfluoroalkyl substances under environmentally relative conditions: Experiment measurement and model prediction

Microplastics (MPs) in the environment are the sink and vector of organic contaminants, including per- and polyfluoroalkyl substances (PFASs). Although PFASs are low- and non-volatile compounds, they have the potential to partition and diffuse from MP into the gas phase in the environmental functions. Herein, the MP-air partition coefficient (KPA) of seven PFASs was measured using a solid-fugacity meter. The PFAS KPA values in two MPs (high-density polyethylene (HDPE) and thermoplastic polyurethane (TPU)) were determined under different times, temperatures, and relative humidities (RH), and a model was developed to predict the PFAS KPA values based on the measured data. The results showed that the KPA of PFASs increased with the prolonged partition time until 90 mins, and higher temperature and RH facilitated the distribution of PFASs in MPs into the air phase, leading to smaller KPA values. Moreover, the derived equation for predicting PFAS log KPA values was robust with 0.79 of an adjusted square of correlation coefficient (R2adjusted = 0.79) and 0.35 of root mean squared error (RMSE = 0.35). These findings provided the first knowledge for understanding the partition behavior and fate of PFASs in the MP-air microenvironment.

From oceans to dinner plates: The impact of microplastics on human health

Microplastics, measuring less than 5 mm in diameter, are now found in various environmental media, including soil, water, and air, and have infiltrated the food chain, ultimately becoming a part of the human diet. This study offers a comprehensive examination of the intricate nexus between microplastics and human health, thereby contributing to the existing knowledge on the subject. Sources of microplastics, including microfibers from textiles, personal care products, and wastewater treatment plants, among others, were assessed. The study meticulously examined the diverse routes of microplastic exposure-ingestion, inhalation, and dermal contact-offering insights into the associated health risks. Notably, ingestion of microplastics has been linked to gastrointestinal disturbances, endocrine disruption, and the potential transmission of pathogenic bacteria. Inhalation of airborne microplastics emerges as a critical concern, with possible implications for respiratory and cardiovascular health. Dermal contact, although less explored, raises the prospect of skin irritation and allergic reactions. The impacts of COVID-19 on microplastic pollution were also highlighted. Throughout the manuscript, the need for a deeper mechanistic understanding of microplastic interactions with human systems is emphasized, underscoring the urgency for further research and public awareness.

Identification of anthropogenic debris in the stomach and intestines of giant freshwater prawns from the Trang River in southern Thailand

Background

Anthropogenic waste, especially microplastics, is becoming more prevalent in the environment and marine ecosystems, where it has the potential to spread through food chains and be consumed by humans. Southeast Asian countries are home to giant freshwater prawns, a common freshwater species that is eaten around the world. Microplastic pollution in river water, sediment, and commercially significant aquatic species such as fish and mollusks has been observed, yet few studies have been conducted on giant freshwater prawns in the rivers of southern Thailand, where microplastics may contaminate prawns via the food they ingest. The purpose of this research was to investigate the accumulation of anthropogenic material in the organs of river prawns (Macrobrachium rosenbergii).

Methods

Microplastics in the stomachs and intestines of giant freshwater prawns were the focus of this study. Samples were digested with 30 ml of 10% potassium hydroxide (KOH), heated for 5 min at 60 °C, and then digested at room temperature. The quantity, color, and appearance of microplastics were assessed using a stereomicroscope after 12 h. Furthermore, polymers were examined using a Fourier transform infrared spectrophotometer (FTIR). Microplastic counts were compared between sexes. A T-test was used to compare male and female microplastic counts in the stomach and intestine, and the Pearson correlation was used to compare the association between microplastic counts in the stomach and intestine and carapace length (CL), length of abdomen (LA), and body weight (BW) of male and female giant freshwater prawns. The threshold of significance was fixed at p < 0.05.

Results

Based on the study results, a total of 370 pieces of anthropogenic debris were discovered in the stomachs and intestines of both female and male prawns. The average number of microplastics per individual was 4.87 ±  0.72 in female stomachs and 3.03 ± 0.58 in male stomachs, and 1.73 ± 0.36 in female intestines and 2.70 ± 0.57 in male intestines. The majority of microplastics found in females were within the <100 µm range, while males contained microplastics in the range of 100-500 µm. Both male and female prawns contained fibers (72.70%) and fragments (27.30%). Various polymers were identified, including cotton, rayon, and polyvinyl chloride (PVC). The study also explored the relationship between carapace length, length of abdomen, body weight, stomach weight, and the number of microplastics. The findings reveal a significant association between the number of microplastics and stomach weight in male prawns (R = 0.495; p = 0.005). These findings provide alarming evidence of anthropogenic debris ingestion in prawns and raise concerns about the future effects of anthropogenic pollution on giant freshwater prawns.

Cellulosic and microplastic fibers in the Antarctic fish Harpagifer antarcticus and Sub-Antarctic Harpagifer bispinis

Human settlements within the Antarctic continent have caused significant coastal pollution by littering plastic. The present study assessed the potential presence of microplastics in the gastrointestinal tract of the Antarctic fish Harpagifer antarcticus, endemic to the polar region, and in the sub-Antarctic fish Harpagifer bispinis. H. antarcticus. A total of 358 microfibers of multiple colors were found in 89 % of H. antarcticus and 73 % of H. bispinis gastrointestinal track. A Micro-FTIR analysis characterized a sub-group (n = 42) of microfibers. It revealed that most of the fibers were cellulose (69 %). Manmade fibers such as microplastics polyethylene terephtalate, acrylics, and semisynthetic/natural cellulosic fibers were present in the fish samples. All the microfibers extracted were textile fibers of blue, black, red, green, and violet color. Our results suggest that laundry greywater discharges of human settlements near coastal waters in Antarctica are a major source of these pollutants in the Antarctic fish.

First quantification and chemical characterization of atmospheric microplastics observed in Seoul, South Korea

This study is the first report on atmospheric microplastics (MPs) observed in five outdoor environments, including an urban forest, a business center, commercial areas, and a public transportation hub in Seoul, South Korea. Air samples were collected using an active air pump sampler for 24 h in each area only on days without rainfall. All observed microplastics are secondary microplastics, in the form of irregularly-shaped fragments or fibers produced through various degradation processes, rather than being primarily produced like microbeads. The abundance of atmospheric MPs varied depending on the environment (i.e., region, height, and time) from 0.33 to 1.21 MP m-3, with the average number of MPs being 0.72 MP m-3 (standard deviation ± 0.39). MPs in the urban forest was observed to be 27% lower in abundance than that in the urban center which is ∼3 km away. The central business district was observed to have a 25% higher abundance during weekdays than on weekends. Our results show the ubiquity of MPs in various areas from high-rise buildings to forests tens of kilometers away from their direct sources, and a positive correlation between the abundance of MP and human activity. Morphologically, the fragment type (87.4%) predominated over the fiber type (12.6%), and chemically, polypropylene (PP) and polyethylene terephthalate (PET) components accounted for 65% of the total MP. PP polymers were found in all observation sites and contributed to 59% of the total MP fragments. The observed fibrous MPs were mainly composed of PET (72.7%) and PP (18.2%) polymers. Compared to other large cities (Shanghai, Beijing, Paris), Seoul is exposed to low levels of atmospheric MPs and high proportions of PP polymers. This study is limited to atmospheric MPs observed in summer and further investigation of MPs is needed to comprehensively understand the distribution and cycle of MPs based on long-term monitoring of atmospheric MPs.

Recent analytical techniques, and potential eco-toxicological impacts of textile fibrous microplastics (FMPs) and associated contaminates: A review

Despite of our growing understanding of microplastic's implications, research on the effects of fibrous microplastic (FMPs) on the environment is still in its infancy. Some scientists have hypothesized the possibility of natural textile fibres, which may act as one of the emerging environmental pollutants prevalent among microplastic pollutants in the environment. Therefore, this review aims to critically evaluate the toxic effects of emerging FMPs, the presence, and sources of FMPs in the environment, identification and analytical techniques, and the potential impact or toxicity of the FMPs on the environment and human health. About175 publications (2011-2023) based on FMPs were identified and critically reviewed for transportation, analysis and ecotoxicological behaviours of FMPs in the environment. Textile industries, wastewater treatment plants, and household washing of clothes are significant sources of FMPs. In addition, various characterization techniques (e.g., FTIR, SEM, RAMAN, TGA, microscope, and X-Ray Fluorescence Spectroscopy) commonly used for the identification and analysis of FMPs are also discussed, which justifies the novelty aspects of this review. FMPs are pollutants of emerging concern due to their prevalence and persistence in the environment. FMPs are also found in the food chain, which is an alarming situation for living organisms, including effects on the nervous system, digestive system, circulatory system, and genetic alteration. This review will provide readers with a comparison of different analytical techniques, which will be helpful for researchers to select the appropriate analytical techniques for their study and enhance their knowledge about the harmful effects of FMPs.

On the horns of a dilemma: Evaluation of synthetic and natural textile microfibre effects on the physiology of the pacific oyster Crassostrea gigas

Fast fashion and our daily use of fibrous materials cause a massive release of microfibres (MF) into the oceans. Although MF pollution is commonly linked to plastics, the vast majority of collected MF are made from natural materials (e.g. cellulose). We investigated the effects of 96-h exposure to natural (wool, cotton, organic cotton) and synthetic (acrylic, nylon, polyester) textile MF and their associated chemical additives on the capacity of Pacific oysters Crassostrea gigas to ingest MF and the effects of MF and their leachates on key molecular and cellular endpoints. Digestive and glycolytic enzyme activities and immune and detoxification responses were determined at cellular (haemocyte viability, ROS production, ABC pump activity) and molecular (Ikb1, Ikb2, caspase 1 and EcSOD expression) levels, considering environmentally relevant (10 MF L^-1) and worst-case scenarios (10 000 MF L^-1). Ingestion of natural MF perturbed oyster digestive and immune functions, but synthetic MF had few effects, supposedly related with fibers weaving rather than the material itself. No concentration effects were found, suggesting that an environmental dose of MF is sufficient to trigger these responses. Leachate exposure had minimal effects on oyster physiology. These results suggest that the manufacture of the fibres and their characteristics could be the major factors of MF toxicity and stress the need to consider both natural and synthetic particles and their leachates to thoroughly evaluate the impact of anthropogenic debris. Environmental Implication. Microfibres (MF) are omnipresent in the world oceans with around 2 million tons released every year, resulting in their ingestion by a wide array of marine organisms. In the ocean, a domination of natural MF- representing more than 80% of collected fibres-over synthetic ones was observed. Despite MF pervasiveness, research on their impact on marine organisms, is still in its infancy. The current study aims to investigate the effects of environmental concentrations of both synthetic and natural textile MF and their associated leachates on a model filter feeder.

Raman imaging for the analysis of silicone microplastics and nanoplastics released from a kitchen sealant

Plastic products are used ubiquitously and can potentially release microplastics and nanoplastics into the environment, for example, products such as the silicone sealant used in kitchens. It is important to develop an effective method to monitor these emerging contaminants, as reported herein. By using advanced Raman imaging to characterize microplastics and nanoplastics from hundreds of spectra in a scanning spectrum matrix and not from a single spectrum or peak, the signal-to-noise ratio can be significantly increased, from a statistical point of view. The diffraction of the laser spot usually constrains the imaging resolution (such as at ∼300 nm), which is also pushed to the limit in this report by shrinking the scanning pixel size down to ∼50 nm to capture and image small nanoplastics effectively. To this end, image reconstruction is developed to successfully pick up the meaningful Raman signal and intentionally avoid the noise. The results indicate that the silicone sealant in a kitchen can release a significant amount of microplastics and nanoplastics. Overall, advanced Raman imaging can be employed to characterize the microplastics and even nanoplastics that are smaller than the diffraction limit of the laser via Raman imaging and image reconstruction toward deconvolution.

Residential houses - a major point source of microplastic pollution: insights on the various sources, their transport, transformation, and toxicity behaviour

Municipal wastewater has been considered as one of the largest contributors and carriers of microplastics to the aquatic environment. However, the various residential activities that generate municipal wastewater are equally significant whenever the source of microplastics in aquatic system is accounted. However, so far, only municipal wastewater has received wide attention in previous review articles. Hence, this review article is written to address this gap by highlighting, firstly, the chances of microplastics arising from the usage of personal care products (PCPs), laundry washing, face masks, and other potential sources. Thereafter, the various factors influencing the generation and intensity of indoor microplastic pollution and the evidence available on the possibility of microplastic inhalation by humans and pet animals are explained. Followed by that, the removal efficiency of microplastics observed in wastewater treatment plants, the fate of microplastics present in the effluent and biosolids, and their impact on aquatic and soil environment are explored. Furthermore, the impact of aging on the characteristics of microsized plastics has been explored. Finally, the influence of age and size of microplastics on the toxicity effects and the factors impacting the retention and accumulation of microplastics in aquatic species are reviewed. Furthermore, the prominent pathway of microplastics into the human body and the studies available on the toxicity effects observed in human cells upon exposure to microplastics of different characteristics are explored.

Fibrous microplastics released from textiles: Occurrence, fate, and remediation strategies

Microplastics (MP), i.e., particles measuring less than 5 mm in size, are considered emerging pollutants. The ubiquity of MP is causing great concern among environmental and public health agencies. Anthropogenic activities are responsible for the extensive dispersal of MP in nature. Adverse effects on living organisms, interactions with other contaminants occurring in the environment, and the lack of effective degradation/removal techniques are significant issues related to MP. Most MP found in nature are fibrous (FMP). FMP originate from textile products, mainly synthetic fibers (e.g., polyester). Synthetic fibers are intensively used to produce countless goods due to beneficial characteristics such as high mechanical resistance and economic feasibility. FMP are ubiquitous on the planet and impart lasting adverse effects on biodiversity. Data on the consequences of long-term exposure to these pollutants are scarce in the literature. In addition, few studies address the main types of synthetic microfibers released from textiles, their occurrence, adverse effects on organisms, and remediation strategies. This review discusses the relevant topics about FMP and alerts the dangers to the planet. Furthermore, future perspectives and technological highlights for the FMP mitigation/degradation are presented.

Synthetic Microfiber Material Influences Ingestion by Freshwater Worms

Plastics enter the environment, amongst others, from synthetic textiles, which shed microplastic fibers (microfibers) during their production, use and disposal. We tested whether short- and long-term effects of microfibers on the aquatic worm, Lumbriculus variegatus, depend on the synthetic microfiber material. Microcosms containing L. variegatus were exposed to no microfibers (control) or one of three polymer treatments (nylon, polyester, or olefin) at 5 g of microfibers kg^-1 of sediment for 48 h or 28 days. Following exposure, L. variegatus were counted, weighed, and the number of microfibers ingested determined. Polyester microfibers occurred in higher quantities (10-12) than nylon and olefin (< one) per individual after 48 h and 28 days. Only the olefin per individual doubled after 28 days compared to 48 h. These findings indicate that polyester microfibers are more likely to affect L. variegatus and have greater potential to be ingested by higher trophic levels than other polymers.

Synthetic microfiber emissions from denim industrial washing processes: An overlooked microplastic source within the manufacturing process of blue jeans

In recent years, domestic laundry has been recognized as a relevant source of microfiber (MF) pollution to aquatic environments. Nevertheless, the MF emissions from industrial washing processes in real world scenarios have not been quantified. The aim of this study was to quantify the MF emissions from 3 industrial washing processes (rinse wash, acid wash and enzymatic wash) commonly employed in the manufacturing process of blue jeans. The blue jeans were characterized by ATR-FT-IR, SEM and TGA to study the morphology, the polymer chemical identity and the proportion of synthetic and natural fibers, respectively. The MF emissions were quantified as the MF mass and number emitted per washed jean. All the industrial washing processes released a majority of synthetic MF. The enzymatic wash produced the highest amount of MF, with 1423 MF per gram of fabric (MF/g) equivalent to 381.7 MF grams per gram of fabric (MF g/g), followed by the acid wash with 253 MF/g equivalent to 142.7 MF g/g and lastly the rinse wash with 133 MF/g equivalent to 62.3 MF g/g. Statistically significant differences between the MF sizes for all washing processes were found when evaluating the emissions by MF/g, however, the previous trend was not found for MF g/g. Moreover, the total MF emissions of an industrial washing process of a pair of blue jeans during its manufacture process are up to 10.95 times higher than the reported domestic washing estimates performed by the consumer available in the published literature. We demonstrate that studying industrial washing procedures of textile garments will improve the accuracy of the current estimates of MF emissions available in published reports, which will ultimately aid in the development of regulations for MF emissions at an industrial level.

Microplastic as an invisible threat to the coral reefs: Sources, toxicity mechanisms, policy intervention, and the way forward

Microplastic (MP) pollution waste is a global macro problem, and research on MP contamination has been done in marine, freshwater, and terrestrial ecosystems. Preventing MP pollution from hurting them is essential to maintaining coral reefs' ecological and economic benefits. However, the public and scientific communities must pay more attention to MP research on the coral reef regions' distribution, effects, mechanisms, and policy evaluations. Therefore, this review summarizes the global MP distribution and source within the coral reefs. Current knowledge extends the impacts of MP on coral reefs, existing policy, and further recommendations to mitigate MPs contamination on corals are critically analyzed. Furthermore, mechanisms of MP on coral and human health are also highlighted to pinpoint research gaps and potential future studies. Given the escalating plastic usage and the prevalence of coral bleaching globally, there is a pressing need to prioritize research efforts on marine MPs that concentrate on critical coral reef areas. Such investigations should encompass an extensive and crucial understanding of the distribution, destiny, and effects of the MPs on human and coral health and the potential hazards of those MPs from an ecological viewpoint.

Binational survey using Mytilus galloprovincialis as a bioindicator of microplastic pollution: Insights into chemical analysis and potential risk on humans

Microplastic (MP) contamination in edible mussels has raised concerns due to their potential risk to human health. Aiming to provide valuable insights regarding the occurrence, physicochemical characteristics, and human health implications of MP contamination, in the present study, two nationwide surveys of MP contamination in mussels (Mytilus galloprovincialis) were conducted in Morocco and Tunisia. The results indicated that MP frequency ranged from 79 % to 100 % in all the analyzed samples. The highest MP density was detected in mussels from Morocco (gills "GI": 1.88 MPs/g ww^-1; digestive glands "DG": 0.92 MPs/g ww^-1) compared to mussels of Tunisia (GI: 1.47 MPs g^{- 1}; DG: 0.79 MPs g^{- 1}). No significant differences in MP density were found between the two organs (GI and DG) for both countries. MPs were predominantly blue and black fibers, and smaller than 1000 μm. Seven polymeric types were identified, of which PET, PP, and PE were the most abundant, accounting for >87 % of all samples. Scanning Electron Microscopy (SEM) coupled with Energy dispersive X-ray (EDX) showed that most MPs have noticeable signs of weathering and inorganic components on their surface. The highest MP daily intake was found in children, while the lowest was estimated in women and men. Moreover, the annual dietary exposure of MPs through mussel consumption was estimated to be 1262.17 MPs/year in Morocco and 78.18 MPs/year in Tunisia. The potential risk assessment of MPs in mussels based on the polymer hazard index (PHI) was estimated in the high-risk levels, implying that MPs may pose health risks to humans. Overall, this research suggests that the consumption of mussels represents a considerable MP exposure route for the Moroccan and Tunisian populations.

Characterization of microfibers released from chemically modified polyester fabrics - A step towards mitigation

Synthetic textiles are one of the significant contributors to microfiber pollution, a subclass of microplastics. The impact of microfibers on the environment is irreversible. Several attempts were made to mitigate and control the microfiber release from synthetic textiles by introducing filters and laundry aids in washing machines, whereas some came up with methods to modify the textile materials to release fewer fibers. Studies have related different textile properties with their microfiber release potential. However, moisture properties, one of the essential properties that determine comfort, are not well explored. Hence, this research attempted to mitigate the microfiber release by altering the hydrophilicity of the polyester fabrics through chemical treatment (sodium hydroxide) with the hypothesis that hydrophilicity reduces the microfiber release. Both woven and knitted polyester fabrics were treated with different concentrations of the alkali solution (0.25 M, 0.50 M, 0.75 M, 1.00 M) and evaluated for their microfiber release. Treated fabrics also showed variations in their moisture and physical properties. Woven fabrics showed reduced shedding compared to knitted fabrics due to their compact structure. The results showed that the increase in alkali concentration significantly reduced the microfiber release up to 89.6 % reduction with woven fabric (from 17.37 ± 1.55 fibers/sq.cm to 2.63 ± 0.23 fibers/sq.cm) and a reduction of 68 % was noted for knitted fabric treated with 0.75 M alkali concentration (from 24.38 ± 1.30 fibers/sq.cm to 8.74 ± 1.39 fibers/sq.cm). A higher negative correlation (r = 94 % for woven and 89 % for knitted) was noted between alkali concentration and microfiber release. The alkali treatment significantly reduced the average fiber length from 450 to 230 μm, and 63-93 % of the fibers identified were in size range of 100-500 μm. When the moisture properties of the alkali-treated fabrics are concerned, an increase in moisture properties reduces the microfiber release. Water contact angle and absorbency time positively correlated with microfiber release. However, the study did not show any significant effect of moisture regain percentage and vertical wicking on microfiber shedding. Except for abrasion resistance, the physical properties of alkali-treated fabric did not show any relationship with microfiber release. The study noted the order of factors influencing the microfiber release of polyester fabric as fabric structural parameters (Woven/Knits) > fabric hydrophilicity > fabric physical property.

Exploration of occurrence and sources of microplastics (>10 μm) in Danish marine waters

Microplastics (MPs) were quantified in Danish marine waters of the Kattegat and the southernmost part of Skagerrak bordering to it. Kattegat is a waterbody between Denmark and Sweden that receives inflow from the Baltic Sea and direct urban runoff from the metropolitan area of Copenhagen and Malmö. MPs were measured in 14 continuous transects while steaming between monitoring stations. MP levels tended to be highest close to the Copenhagen-Malmö area, albeit this was more obvious from the abundance of particles rather than mass. The outcome of the measurements allowed a rough MP budget in the Danish Straits region, suggesting that urban waste- and stormwater discharges could not be neglected as potential MP source in these waters. The marine samples were collected by pumping and filtering water over 10 μm steel filters, hereby sampling a total of 19.3 m³. They were prepared and analyzed by FPA-μFTIR imaging, and the scans interpreted to yield MP size, shape, polymer type, and estimated mass. The average concentration was 103 ± 86 items m^-3, corresponding to 23.3 ± 28.3 μg m^-3 (17-286 items m^-3; 0.6-84.1 μg m^-3). Most MPs were smaller than 100 μm and fragments dominated the samples. The carbonyl index was assessed for polyolefins, showing that oxidation increased with decreasing MP size, but did not correlate with distance to urban areas. A rough budget of MP in the Danish Straits region suggested that MPs discharged from urban waste- and stormwaters were an import source of MPs.

Exposure to polystyrene microplastics triggers lung injury via targeting toll-like receptor 2 and activation of the NF-κB signal in mice

Microplastics are ubiquitous pollutants with a wide range of plastic applications. More recently, microplastics are in the air and can be inhaled into the lungs, causing respiratory diseases. Knowledge of the underlying mechanisms by which microplastics may induce respiratory disease is still limited. This study used intranasal instillation to develop a model of lung injury. The histopathology result showed that the mouse lung had severe inflammatory responses, apoptosis and collagen deposition with chronic exposure to different sizes (Small: 1-5 μm and Large: 10-20 μm) of polystyrene microplastics (PS-MPS), and the damage of smaller sizes was obvious. The expression levels of the Toll-like receptors (TLRs) family, evolutionarily conserved pattern recognition receptors, were detected, and the levels of TLR2 mRNA was significantly increased. In transfection experiments, PS-MPS increased the inflammatory response in HEK293 cells with TLR2 expression. Furthermore, exposure to small polystyrene microplastics promoted oxidative stress and apoptosis, and accelerated the process of fibrosis. Interestingly, inhibition of the NF-κB signal relieves inflammation and oxidative stress, reduces apoptosis, and thus controls the fibrosis process. These results suggested that PS-MPS targeted binding to TLR2 and further exacerbated fibrosis by facilitating inflammation, oxidative stress, and apoptosis with the activation of NF-κB signal.

How does particulate air pollution affect barrier functions and inflammatory activity of lung vascular endothelium?

Both particulate matter and gaseous components of air pollution have already been shown to increase cardiovascular mortality in numerous studies. It is, however, important to note that on their way to the bloodstream the polluting agents pass the lung barrier. Inside the alveoli, particles of approximately 0.4-1 μm are most efficiently deposited and commonly undergo phagocytosis by lung macrophages. Not only the soluble agents, but also particles fine enough to leave the alveoli enter the bloodstream in this finite part of the endothelium, reaching thus higher concentrations in close proximity of the alveoli and endothelium. Additionally, deposits of particulate matter linger in direct proximity of the endothelial cells and may induce inflammation, immune responses, and influence endothelial barrier dysfunction thus increasing PM bioavailability in positive feedback. The presented discussion provides an overview of possible components of indoor PM and how endothelium is thus influenced, with emphasis on lung vascular endothelium and clinical perspectives.

Microplastics and their interactions with microbiota

As a new pollutant, Microplastics (MPs) are globally known for their negative impacts on different ecosystems and living organisms. MPs are easily taken up by the ecosystem in a variety of organisms due to their small size, and cause immunological, neurological, and respiratory diseases in the impacted organism. Moreover, in the impacted environments, MPs can release toxic additives and act as a vector and scaffold for colonization and transportation of specific microbes and lead to imbalances in microbiota and the biogeochemical and nutrients dynamic. To address the concerns on controlling the MPs pollution on the microbiota and ecosystem, the microbial biodegradation of MPs can be potentially considered as an effective environment friendly approach. The objectives of the presented paper are to provide information on the toxicological effects of MPs on microbiota, to discuss the negative impacts of microbial colonization of MPs, and to introduce the microbes with biodegradation ability of MPs.

Identification and quantification of microplastics in agricultural farmland soil and textile sludge in Bangladesh

Although microplastic (MP) pollution of aquatic ecosystems is a high-priority study topic, the issue of terrestrial environment and textile manufacturing waste has received little attention. Thus, this study was carried out to investigate the presence of MPs in agricultural land near textile industries and textile sludge samples in Bangladesh. Thirty-two soil samples from four agricultural farmland and five sludge samples were collected and analyzed. We show that the MPs content from agricultural farmland soil and textile sludge samples was 2.13 × 10⁴ ± 0.13 × 10⁴ MPs/kg and 2.92 × 10⁴ ± 0.14 × 10⁴ MPs/kg, respectively. MPs with a size between 1.0 and 1.5 mm were the least frequent in both soil and textile sludge samples. Fibers were more prevalent in textile sludge and fragments in soil samples. In addition, the percentage of transparent/white MPs was higher in the soil samples, and those classified as "multicolor" and "others" were more frequent in the sludge samples. Nine types of polymers were identified in the soil samples: PS, EVA, latex, HDPE, PVC, ABS, CA, LDPE, and PP. Except for LDPE, all these polymers were also found in the textile sludge samples, in addition to PU, nylon, and FEP, totaling eleven polymer types. On the other hand, we did not find evidence to support the association between MP contamination in soil samples and MPs identified in textile sludge samples. As demonstrated in the principal components analysis (PCA), the analyzed samples were separated by PC1, which suggests that the MPs reported in the soil come from sources that are not directly related to the textile industries. Thus, further research is needed to fully reveal MPs' fate and ecological risks in the soil environment and textile sludge, and necessary action is required to control MP pollution in terrestrial ecosystems.

Cost-effective remedial to microfiber pollution from wash effluent in Kolkata and Ranaghat

The microfibers generated from Polyester and Nylon based materials during washing cause serious environmental pollution by both contaminating the aquatic environment and the livelihood of the underwater creatures as well. This study aims at investigating the microfiber-pollution in wash effluents collected from different regions of Kolkata which is believed to be one of the microfiber-polluted cities in the South-east Asia in recent times. In this work, packed bed microfiltration (PBMF) was adopted in an economic and eco-friendly manner to arrest adequate amounts of microfibers and non-biodegradable matters present in the water samples collected from different regions of Kolkata and its surrounding areas. Moreover, effective parameters such as packed bed height to diameter ratio (H/D), mess size of the adopted filtration unit were varied from 0.71 to 2.85 and 60 to 100, respectively to understand the efficacy of the approach and to justify the potential of such alternative in order to alleviate the concern as well. The present study reveals that the microfiltration efficiency of the proposed PBMF unit was achieved maximum 93.5% for sample A and 92.2% for sample D respectively to reduce the microfiber count from 7614 to 543 in an hour operation at a flow rate of 60 L h^-1. Besides, the cost of such system was found to be promising as much as 5 US$ on a yearly basis.

Review of research on migration, distribution, biological effects, and analytical methods of microfibers in the environment

Microplastics have been proven to be one of the critical environmental pollution issues. Moreover, microfibers, the most prominent form of microplastics in the environment, have likewise attracted the attention of various countries. With the increase in global population and industrialization, the production and use of fibers continue to increase yearly. As a result, a large number of microfibers are formed. If fiber products are not used or handled correctly, it will cause direct/indirect severe microfiber environmental pollution. Microfibers will be further broken into smaller fiber fragments when they enter the natural environment. Presently, researchers have conducted extensive research in the identification of microfibers, laying the foundation for further resourcefulness research. This work used bibliometric analysis to review the microfiber contamination researches systematically. First, the primary sources of microfibers and the influencing factors are analyzed. We aim to summarize the influence of the clothing fiber preparation and care processes on microfiber formation. Then, this work elaborated on the migration in/between water, atmosphere, and terrestrial environments. We also discussed the effects of microfiber on ecosystems. Finally, microfibers' current and foreseeable effective treatment, disposal, and resource utilization methods were explained. This paper will provide a structured reference for future microfiber research.