Airborne emissions of microplastic fibres from domestic laundry dryers

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.

ROS-dependent degeneration of human neurons induced by environmentally relevant levels of micro- and nanoplastics of diverse shapes and forms

Our study explores the pressing issue of micro- and nanoplastics (MNPs) inhalation and their subsequent penetration into the brain, highlighting a significant environmental health concern. We demonstrate that MNPs can indeed penetrate murine brain, warranting further investigation into their neurotoxic effects in humans. We then proceed to test the impact of MNPs at environmentally relevant concentrations, with focusing on variations in size and shape. Our findings reveal that these MNPs induce oxidative stress, cytotoxicity, and neurodegeneration in human neurons, with cortical neurons being more susceptible than nociceptors. Furthermore, we examine the role of biofilms on MNPs, demonstrating that MNPs can serve as a vehicle for pathogenic biofilms that significantly exacerbate these neurotoxic effects. This sequence of investigations reveals that minimal MNPs accumulation can cause oxidative stress and neurodegeneration in human neurons, significantly risking brain health and highlights the need to understand the neurological consequences of inhaling MNPs. Overall, our developed in vitro testing battery has significance in elucidating the effects of environmental factors and their associated pathological mechanisms in human neurons.

Mass quantification of nanoplastics at wastewater treatment plants by pyrolysis-gas chromatography-mass spectrometry

Municipal wastewater treatment plants (WWTPs) play a crucial role in the collection and redistribution of plastic particles from both households and industries, contributing to their presence in the environment. Previous studies investigating the levels of plastics in WWTPs, and their removal rates have primarily focused on polymer type, size, shape, colour, and particle count, while comprehensive understanding of the mass concentration of plastic particles, particularly those <1 µm (nanoplastics), remains unclear and lacking. In this study, pyrolysis gas chromatography-mass spectrometry was used to simultaneously determine the mass concentration of nine selected polymers (i.e., polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(ethylene terephthalate) (PET), nylon 6, nylon 66, polyvinylchloride (PVC), poly(methyl methacrylate) (PMMA) and polycarbonate (PC)) below 1 µm in size across the treatment processes or stages of three WWTPs in Australia. All the targeted nanoplastics were detected at concentrations between 0.04 and 7.3 µg/L. Nylon 66 (0.2-7.3 µg/L), PE (0.1-6.6 µg/L), PP (0.1-4.5 µg/L), Nylon 6 (0.1-3.6 µg/L) and PET (0.1-2.2 µg/L), were the predominant polymers in the samples. The mass concentration of the total nanoplastics decreased from 27.7, 18 and 9.1 µg/L in the influent to 1, 1.4 and 0.8 µg/L in the effluent, with approximate removal rates of 96 %, 92 % and 91 % in plants A, B and C, respectively. Based on annual wastewater effluent discharge, it is estimated that approximately 24, 2 and 0.7 kg of nanoplastics are released into the environment per year for WWTPs A, B and C, respectively. This study investigated the mass concentrations and removal rates of nanoplastics with a size range of 0.01-1 µm in wastewater, providing important insight into the pollution levels and distribution patterns of nanoplastics in Australian WWTPs.

Innovative overview of the occurrence, aging characteristics, and ecological toxicity of microplastics in environmental media

Microplastics (MPs), pollutants detected at high frequency in the environment, can be served as carriers of many kinds of pollutants and have typical characteristics of environmental persistence and bioaccumulation. The potential risks of MPs ecological environment and health have been widely concerned by scholars and engineering practitioners. Previous reviews mostly focused on the pollution characteristics and ecological toxicity of MPs, but there were few reviews on MPs analysis methods, aging mechanisms and removal strategies. To address this issue, this review first summarizes the contamination characteristics of MPs in different environmental media, and then focuses on analyzing the detection methods and analyzing the aging mechanisms of MPs, which include physical aging and chemical aging. Further, the ecotoxicity of MPs to different organisms and the associated enhanced removal strategies are outlined. Finally, some unresolved research questions related to MPs are prospected. This review focuses on the ageing and ecotoxic behaviour of MPs and provides some theoretical references for the potential environmental risks of MPs and their deep control.

Characterization of microplastics in outdoor and indoor air in Ranchi, Jharkhand, India: First insights from the region

The study focused on detecting and characterizing microplastics in outdoor and indoor air in Ranchi, Jharkhand, India during post-monsoon (2022) and winter (2023). Stereo microscopic analysis showed that plastic fibres had a dominant presence, fragments were less abundant, whereas fewer films could be detected in indoor and outdoor air. The atmospheric deposition of microplastics outdoors observed 465 ± 27 particles/m2/day in PM10 and 12104 ± 665 and 13833 ± 1152 particles/m2/day in PM2.5 in quartz and PTFE, respectively during the post-monsoon months. During winter, microplastic deposition rates in PM10 samples were found to be 689 ± 52 particles/m2/day and 19789 ± 2957 and 30087 ± 13402 in quartz and PTFE particles/m2/day respectively in PM2.5. The mean deposition rate in indoor environment during post-monsoon was 8.3 × 104 and 1.03 × 105 particles/m2/day in winter. During the post-monsoon period in PM10, there were fibres from 7.7 to 40 μm and fragments from 2.3 μm to 8.6 μm. Indoor atmospheric microplastics, fibres ranged from 1.2 to 47 μm and fragments from 0.9 to 16 μm present respectively during the post-monsoon season. Fibres and fragment sizes witnessed during winter were 3.6-6.9 μm and 2.3-34 μm, respectively. Indoor air films measured in the range of 4.1-9.6 μm. Fourier transform infrared analysis showed that outdoor air contained polyethylene, polypropylene, Polystyrene, whereas indoor air had polyvinyl chloride. Polyethylene mainly was present in outdoor air, with lesser polypropylene and polystyrene than indoors, where polyvinyl chloride and polyethylene were in dominant proportions. Elemental mapping of outdoor and indoor air samples showed the presence of elements on the microplastics. The HYSPLIT models suggest that the particles predominantly were coming from North-West during the post-monsoon season. Principal component analysis indicated wind speed and direction influencing the abundance of microplastics. Microplastics concentration showed strong seasonal influence and potential to act as reservoir of contaminants.

Micro- and nano-plastics in the atmosphere: A review of occurrence, properties and human health risks

The ubiquitous occurrence of micro/nano plastics (MNPs) poses potential threats to ecosystem and human health that have attracted broad concerns in recent decades. Detection of MNPs in several remote regions has implicated atmospheric transport as an important pathway for global dissemination of MNPs and hence as a global health risk. In this review, the latest research progress on (1) sampling and detection; (2) origin and characteristics; and (3) transport and fate of atmospheric MNPs was summarized. Further, the current status of exposure risks and toxicological effects from inhaled atmospheric MNPs on human health is examined. Due to limitations in sampling and identification methodologies, the study of atmospheric nanoplastics is very limited today. The large spatial variation of atmospheric MNP concentrations reported worldwide makes it difficult to compare the overall indoor and outdoor exposure risks. Several in vitro, in vivo, and epidemiological studies demonstrate adverse effects of immune response, apoptosis and oxidative stress caused by MNP inhalation that may induce cardiovascular diseases and reproductive and developmental abnormalities. Given the emerging importance of atmospheric MNPs, the establishment of standardized sampling-pretreatment-detection protocols and comprehensive toxicological studies are critical to advance environmental and health risk assessments of atmospheric MNPs.

Underestimated activity-based microplastic intake under scenario-specific exposures

Despite increasing alarms over the health impacts of microplastics (MPs) due to their detection in human organs and feces, precise exposure evaluations remain scarce. To comprehend their risks, there is a distinct need to prioritize quantitive estimates in MP exposome, particularly at the environmentally-realistic level. Here we used a method rooted in real-world MP measurements and activity patterns to determine the daily intake of MPs through inhalation and from ground dust/soil ingestion. We found that nearly 80% of this intake comes from residential sectors, with activity intensity and behavioral types significantly affecting the human MP burden. The data showed a peak in MP exposure for those aged 18-64. When compared to dietary MP intake sources like seafood, salt, and water, we identified a previously underestimated exposure from inhalation and dust/soil ingestion, emphasizing the need for more realistic evaluations that incorporate activity factors. This discovery raises questions about the accuracy of past studies and underscores MP's potential health risks. Moreover, our time-based simulations revealed increased MP intake during the COVID-19 lockdown due to more surface dust ingestion, shedding light on how global health crises may inadvertently elevate MP exposure risks.

Forecasting global plastic production and microplastic emission using advanced optimised discrete grey model

Plastic pollution has become a prominent and pressing environmental concern within the realm of pollution. In recent times, microplastics have entered our ecosystem, especially in freshwater. In the contemporary global landscape, there exists a mounting apprehension surrounding the manifold environmental and public health issues that have emerged as a result of the substantial accumulation of microplastics. The objective of the current study is to employ an enhanced grey prediction model in order to forecast global plastic production and microplastic emissions. This study compared the accuracy level of the four grey prediction models, namely, EGM (1,1, α, θ), DGM (1,1), EGM (1,1), and DGM (1,1, α) models, to evaluate the accuracy levels. As per the estimation of the study, DGM (1,1, α) was found to be more suitable with higher accuracy levels to predict microplastic emission. The EGM (1,1, α, θ) model has slightly better accuracy than the DGM (1,1, α) model in predicting global plastic production. Various accuracy measurement tools (MAPE and RMSE) were used to determine the model's efficiency. There has been a gradual growth in both plastic production and microplastic emission. The current study using the DGM (1,1, α) model predicted that microplastic emission would be 1,084,018 by 2030. The present study aims to provide valuable insights for policymakers in formulating effective strategies to address the complex issues arising from the release of microplastics into the environment and the continuous production of plastic materials.

Microplastic accumulation in bivalves collected from different coastal areas of Vietnam and an assessment of potential risks

Microplastic (MP) pollution is an emerging problem in many areas around the world and in coastal areas of Vietnam, requiring more studies dedicated to the accumulation of this pollutant in the food chain as well as its potential risk to human health. This study investigated MP levels in tissues of five common bivalve species collected from aquaculture areas along the coast of Vietnam. MPs were found in all bivalve samples, with average values of 10.84 ± 2.61 items/individual or 2.40 ± 1.34 items/g wet weight. Impacts of feeding habits of bivalves showed influences on MP abundance in the samples. Fibers were the dominant shape of MPs recorded, most of which accumulated in the gills and digestive glands of all bivalve samples, with the majority falling within the size range of 300-2000 µm. MPs found in all studied species had relatively similar chemical compositions, mainly composed of polypropylene (PP) and polyethylene (PE). In this study, a diverse diet consisting of different bivalve species and detailed data on the consumption rate of these species were used to assess the human health risk of MPs dedicated to the coastal communities of Vietnam. The results suggested a significant part of MP uptake by human could be via bivalve consumption, in which removing viscera and proper depuration should be applied prior to eating, thereby reducing the risk.

Macrolitter and mesolitter in the Thames Estuary: A temporal litter assessment and brand audit of submerged and riverbed debris

Macroplastic is a growing concern for marine environments with estuaries providing a major pathway for pollution from land-based sources to the sea. In the Thames Estuary, plastic was abundant floating below the surface and on the riverbed, with an average catch per unit effort of 0.57 ± 0.42 and 2.75 ± 2.44 item per minute respectively. Whilst the abundance of litter differed between midwater and benthic zones, the types of products recovered did not. These were identified through visual examination and use of a unique citizen science engagement protocol, allowing for the item age, brand and countries of origin to be established. The majority of litter from the present study (n = 1335) was packaging (40%), some of which was over 30-years old and may have originated from landfill run off. Also abundant was sewage-related debris, the inputs of which was related to heavy or prolonged rainfall. Peaks in this material were recorded in September 2020 following the greatest volume of rain recorded in a single day and in June 2019 after the longest period of continuous rainfall. The Covid-19 pandemic did not influence the abundance or diversity of plastic recovered between December 2018 and September 2020. The durability of plastic ensures it has high potential for harm through entanglement, deoxygenation of sediment and ingestion. The retention in the environment also increases opportunities to fragment into micro- or nanoplastics and, therefore, it is important to monitor plastics at both a macro- and micro-scale.

Biomarkers of oxidative stress, inflammation, and genotoxicity to assess exposure to micro- and nanoplastics. A literature review

The increased awareness about possible health effects arising from micro- and nanoplastics (MNPs) pollution is driving a huge amount of studies. Many international efforts are in place to better understand and characterize the hazard of MNPs present in the environment. The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology in two different databases (PubMed and Embase). The selection of articles was carried out blind, screening titles and abstracts according to inclusion and exclusion criteria. In general, these studies rely on the methodology already in use for assessing hazard from nanomaterials and particles of concern. However, only a limited number of studies have so far directly measured human exposure to MNPs and examined the relationship between such exposure and its impact on human health. This review aims to provide an overview of the current state of research on biomarkers of oxidative stress, inflammation, and genotoxicity that have been explored in relation to MNPs exposure, using human, cellular, animal, and plant models. Both in-vitro and in-vivo models suggest an increased level of oxidative stress and inflammation as the main mechanism of action (MOA) leading to adverse effects such as chronic inflammation, immunotoxicity and genotoxicity. With the identification of such biological endpoints, representing critical key initiating events (KIEs) towards adaptive or adverse outcomes, it is possible to identify a panel of surrogate biomarkers to be applied and validated especially in occupational settings, where higher levels of exposure may occur.

Toxicity assessment of microplastic (MPs); a threat to the ecosystem

Plastic is now considered part and parcel of daily life due to its extensive usage. Microplastic (MP) pollution is becoming a growing worry and has been ranked as the second most critical scientific problem in the realm of ecology and the environment. Microplastics are smaller in size than the plastic and are more harmful to biotic and as well as abiotic environments. The toxicity of microplastic depends upon its shape and size and increases with an increase in its adsorption capacity and their toxicity. The reason behind their harmful nature is their small size and their large surface area-to-volume ratio. Microplastic can get inside fruits, vegetables, seeds, roots, culms, and leaves. Hence microplastic enters into the food chain. There are different entry points for microplastic to enter into the food chain. Such sources can include polluted food, beverages, spices, plastic toys, and household (packing, cooking, etc.). The concentration of microplastic in terrestrial environments is increasing day by day. Microplastic causes the destruction of soil structure; destroys soil microbiota, cause depletion of nutrients in the soil, and their absorption by plants decreases plant growth. Apart from other environmental problems caused by microplastic, human health is also badly affected by microplastic pollution present in the terrestrial environment. The presence of microplastics in the human body has been confirmed. Microplastic enters into the body of humans in different possible ways. According to their way of entering the body, microplastics cause different diseases in humans. MPs also cause negative effects on the human endocrine system. At the ecosystem level, the impacts of microplastic are interconnected and can disrupt ecological processes. Although recently different papers have been published on several aspects of the microplastic present in the terrestrial environment but there is no complete overview that focus on the interrelationship of MPs in plants, and soil and their effect on higher animals like a human. This review provides a completely detailed overview of existing knowledge about sources, occurrences, transport, and effects of microplastic on the food chain and soil quality and their ecotoxicological effects on plants and humans.

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.

Plastics and Micro/Nano-Plastics (MNPs) in the Environment: Occurrence, Impact, and Toxicity

Plastics, due to their varied properties, find use in different sectors such as agriculture, packaging, pharmaceuticals, textiles, and construction, to mention a few. Excessive use of plastics results in a lot of plastic waste buildup. Poorly managed plastic waste (as shown by heaps of plastic waste on dumpsites, in free spaces, along roads, and in marine systems) and the plastic in landfills, are just a fraction of the plastic waste in the environment. A complete picture should include the micro and nano-plastics (MNPs) in the hydrosphere, biosphere, lithosphere, and atmosphere, as the current extreme weather conditions (which are effects of climate change), wear and tear, and other factors promote MNP formation. MNPs pose a threat to the environment more than their pristine counterparts. This review highlights the entry and occurrence of primary and secondary MNPs in the soil, water and air, together with their aging. Furthermore, the uptake and internalization, by plants, animals, and humans are discussed, together with their toxicity effects. Finally, the future perspective and conclusion are given. The material utilized in this work was acquired from published articles and the internet using keywords such as plastic waste, degradation, microplastic, aging, internalization, and toxicity.

Evaluation of levels and sources of microplastics and phthalic acid esters and their relationships in the atmosphere of highly industrialized and urbanized Gebze, Türkiye

The presence of microplastics (MPs) in the atmosphere and their relationship with other pollutants have been gaining attention due to both their ubiquity and threatening human health. As well phthalic acid esters (PAEs) regarding as plasticizers for being added in plastic materials are key role for plastic pollution. In this study, the concentrations and sources of airborne MPs together with major PAEs and their relationships were investigated for four seasons. MP particles <20 μm, constituting the majority of the samples, were successfully revealed by NR fluorescent analysis. As a result of the μATR-FTIR analyzes, it was seen that besides different polymer derivatives, dye-pigment types, some minerals and compounds, and abundant semi-synthetic fibers and natural fibers were also present. MPs concentration were found in the range of 7207-21,042 MP/m³ in summer, 7245-32,950 MP/m³ in autumn, 4035-58,270 MP/m³ in winter and 7275-37,094 MP/m³ in spring. For the same period, the concentrations of PAEs ranged from 9.24 to 115.21 ng/m³ with an average value of 38.08 ± 7.92 ng/m³. PMF was also applied and four factors were extracted. Factor 1, accounts 52.26 % and 23.27 % of the total PAEs and MPs variances, was attributed to PVC sources. Factor 2, explaining 64.98 % of the total MPs variance had the highest loading of MPs and moderate loadings of relatively low molecular weight of PAEs, was attributed to plastics and personal care products. Factor 3, explaining the 28.31 % of the total PAEs variance was laden with BBP, DnBP, DiBP and DEP and was attributed to various plastic input during the sampling campaign coming from the industrial activities. The last factor accounts for 11.65 % of the total PAEs variance and was dominated by DMEP and it was linked to a source of the activities performed in the laboratories of the university.

Impact of vented and condenser tumble dryers on waterborne and airborne microfiber pollution

Laundering of textiles is a significant source of waterborne microfiber pollution, and solutions are now being sought to mitigate this issue including improvements in clothing technology and integration of filtration systems into washing machines. Vented tumble dryers are a potential source of airborne microfiber pollution, as their built-in lint filtration systems have been found to be inefficient with significant quantities of textile microfibers being released to the external environment through their exhaust air ducts. The present study is the first to evaluate the impact of condenser dryers, finding that they are significant contributors to waterborne microfiber pollution from the lint filter (if users clean this with water), the condenser and the condensed water. Microfiber release from drying of real consumer loads in condenser and vented tumble dryers was compared, finding that real loads release surprisingly high levels of microfibers (total 341.5 ± 126.0 ppm for those dried in a condenser dryer and 256.0 ± 74.2 ppm for those dried in a vented dryer), similar in quantity to microfibers produced during the first highly-shedding drying cycle of a new T-shirt load (total 321.4 ± 11.2 ppm) in a condenser dryer. Vented dryers were found to be significant contributors to waterborne microfiber pollution if consumers clean the lint filter with water in accordance with some published appliance usage instructions, as most (86.1 ± 5.5% for the real consumer loads tested) of the microfibers generated during vented tumble drying were collected on the lint filter. Therefore, tumble dryers are a significant source of waterborne and (for vented dryers) airborne microfiber pollution. While reducing the pore size of tumble dryer lint filters and instructing consumers to dispose of fibers collected on lint filters as municipal solid waste could help reduce the issue, more sophisticated engineering solutions will likely be required to achieve a more comprehensive solution.

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.

Review of microplastics in the indoor environment: Distribution, human exposure and potential health impacts

The emergence of microplastics (MPs) pollution as a global environmental concern has attracted significant attention in the last decade. The majority of the human population spends most of their time indoors, leading to increased exposure to MPs contamination through various sources such as settled dust, air, drinking water and food. Although research on indoor MPs has intensified significantly in recent years, comprehensive reviews on this topic remain limited. Therefore, this review comprehensively analyses the occurrence, distribution, human exposure, potential health impact and mitigation strategies of MPs in the indoor air environment. Specifically, we focus on the risks associated with finer MPs that can translocate into the circulatory system and other organs, emphasizing the need for continued research to develop effective strategies to mitigate the risks associated with MPs exposure. Our findings suggest that indoor MPs impose potential risk to human health, and strategies for mitigating exposure should be further explored.

Microfiber Emissions from Functionalized Textiles: Potential Threat for Human Health and Environmental Risks

The growing worldwide population is directly responsible for the increased production and consumption of textile products. One of the key reasons for the generation of microfibers is the use of textiles and garment materials, which is expected to increase. The textile industry is responsible for the invisible pollution that is created by textile microfibers, which have been detected in marine sediments and organisms. The present review paper demonstrates that the microfibers discharged from functionalized textiles exhibit non-biodegradable characteristics and that a considerable proportion of them possess toxic properties. This is primarily attributed to the impact of textiles' material functionalization on their biodegradability. The potential for these microfibers, which are released from textiles that contain a variety of dyes, toxic chemicals, and nanomaterials, to pose a variety of health risks to both humans and other living organisms is discussed in this paper. In addition, this paper covers a wide variety of preventative and minimizing measures for reduction, which are discussed in terms of several phases ranging from sustainable production through the consumer, end of life, domestic washing, and wastewater treatment phases.

Characteristics, sources and influencing factors of atmospheric deposition of microplastics in three different ecosystems of Beijing, China

As the research on microplastics (MPs) has intensified, more attention has been paid to MPs deposition in the atmosphere. This study further explores and compares the characteristics, the possible sources and influencing factors of deposition of MPs in three different ecosystems: forest, agricultural and residential area in Beijing. It was found that the deposited plastics were mostly white or black fibres, with PET and RY as the main MPs types. The range of deposition fluxes was 67.06-461.02 item·m^-2·d^-1, with highest deposition in residential area and lowest in forest, significant differences in MPs characteristics between environments. Based on MPs composition and shape, combined with backward trajectory analysis, the main sources of MPs were found to be textiles. Deposition of MPs was found to be influenced by environmental and meteorological factors. Factors such as gross domestic product and population density had a significant impact on the deposition flux, while wind played a diluting role for atmospheric MPs. The study investigated the characteristics of MPs in different ecosystems which may help to understand the transport patterns of MPs and is of great importance for the management of MPs pollution.

Sampling strategies and analytical techniques for assessment of airborne micro and nano plastics

The atmosphere is pervasively polluted by microplastics and nano plastics (M/NPs) released into indoor and outdoor areas. However, various methodologies and their limitations along with non-standardization make the comparison of information concerning their prevalence difficult. Such diversity in techniques greatly limits the interpretation of results. Herein, We extracted data from publications on PubMed and Embase database up to the year 2022 regarding sampling strategies, identification methods, and reporting data for M/NPs quantification. In this review, 5 major areas for measuring airborne M/NPs have been identified including pre-sampling/ sampling/ post-sampling/ analysis/ and contamination avoidance. There are many challenges specific to each of those sections that need to be resolved through further method development and harmonization. This review mainly focuses on the different methods for collecting atmospheric M/NPs and also the analytical tools which have been used for their identification. While passive sampling is the most user-friendly method, the most precise and reproducible approach for collecting plastic particles is an active method which is directly followed by visual counting as the most common physical analysis technique. Polymers collected using visual sorting are most frequently identified by spectroscopy (FTIR; Raman). However, destructive analytical techniques (thermal degradation) also provide precise chemical information. In all cases, the methods were screened for advantages, limitations, and fieldwork abilities. This review outlines and critiques knowledge gaps, and recommendations to support standardized and comparable future research.

Microplastics occurrence, detection and removal with emphasis on insect larvae gut microbiota

Microplastics have been identified in all living forms including human beings, the present need is to restrain its spread and devise measures to remediate microplastics from polluted ecosystems. In this regard, the present review emphasizes on the occurrence, sources detection and toxic effects of microplastics in various ecosystems. The removal of microplastics is prevalent by various physico-chemical and biological methods, although the removal efficiency by biological methods is low. It has been noted that the degradation of plastics by insect gut larvae is a well-known aspect, however, the underlying mechanism has not been completely identified. Studies conducted have shown the magnificent contribution of gut microbiota, which have been isolated and exploited for microplastic remediation. This review also focuses on this avenue, as it highlights the contribution of insect gut microbiota in microplastic degradation along with challenges faced and future prospects in this area.

Current levels and composition profiles of microplastics in irrigation water

Land-based sources have been considered the most important sources of microplastic pollution to the coastal and marine environment. The number of research studies examining microplastic pollution in freshwater and inland water systems is increasing, but most research focuses on rivers, reservoirs, and lakes. This study investigated the spatial-temporal distribution, characteristics, sources, and risks of microplastics in irrigation water in Taiwan. The results showed that microplastics were widely and unevenly distributed along the irrigation system and were abundant at sites surrounded by a dense population and sites that received lateral canal and urban runoff input. The abundance of microplastics ranged from 1.88 items/L to 141 items/L, and samples collected in May had the highest microplastic concentrations. Polypropylene, polyethylene, and polystyrene were identified as the predominant polymers. Fibers (36-64%) were the most typical and abundant shape, and 333-1000 μm size (49-63%) and white/transparent (45-51%) were the dominant size and colors among all samples. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to assess the impact of the rainy season and typhoons and addressed the dramatic changes in distinct population densities. The polymer risk index was calculated to evaluate the environmental risk of microplastics in irrigation water, and the results revealed a high microplastic risk throughout the year except in November and January. This study provided a valuable reference and impetus for a better understanding of the microplastic profile and source apportionment in irrigation water, which was important for environmental management.

Effect of the first-flush phenomenon on the quantification of microplastics in rainwater

Precipitation of airborne microplastics (MPs) by rainfall is one of the major transport pathways of MPs from land-to-marine. While most studies examining wet precipitation of MPs collect surface runoffs, direct investigations of MPs in rainwater are hardly reported. In this study, high-frequency and direct rainwater sampling methodology considering the first-flush effect was demonstrated. The variations in MP abundance were evaluated by the inlet size of rainwater collector, time, and duration of sampling. As a result, a stable abundance of MPs was obtained when samplings were conducted at the same time and duration even with different collectors. On the other hand, the abundance increased as much as 4.5 times in samples collected at different times due to the first-flush effect of rainfall. Thus, our methodology that presents MPs concentration versus time curves based on high-frequency sampling would be helpful for easy comparison between similar rainfall studies.

Various advanced wastewater treatment methods to remove microplastics and prevent transmission of SARS-CoV-2 to airborne microplastics

Microplastics (MPs) and SARS-CoV-2 interact due to their widespread presence in our environment and affect the virus' behaviour indoors and outdoors. Therefore, it is necessary to study the interaction between MPs and SARS-CoV-2. The environmental damage caused by MPs is increasing globally. Emerging pollutants may adversely affect organisms, especially sewage, posing a threat to human health, animal health, and the ecological system. A significant concern with MPs in the air is that they are a vital component of MPs in the other environmental compartments, such as water and soil, which may affect human health through ingesting or inhaling. This work introduces the fundamental knowledge of various methods in advanced water treatment, including membrane bioreactors, advanced oxidation processes, adsorption, etc., are highly effective in removing MPs; they can still serve as an entrance route due to their constantly being discharged into aquatic environments. Following that, an analysis of each process for MPs' removal and mitigation or prevention of SARS-CoV-2 contamination is discussed. Next, an airborne microplastic has been reported in urban areas, raising health concerns since aerosols are considered a possible route of SARS-CoV-2 disease transmission and bind to airborne MP surfaces. The MPs can be removed from wastewater through conventional treatment processes with physical processes such as screening, grit chambers, and pre-sedimentation.

Airborne Microplastics in Indoor and Outdoor Environments of a Developing Country in South Asia: Abundance, Distribution, Morphology, and Possible Sources

Airborne microplastics (AMPs) have been reported in indoor and outdoor air in high-income countries and are expected to be a significant contributor to daily microplastic (MP) exposure for human beings. To date, there are only a handful of studies in lower-middle-income countries. In this study, AMPs from 5000 to 50 μm were sampled across selected areas of Sri Lanka using an active sampling technique. Suspected AMPs were further characterized using Fourier transform infrared spectroscopy. MP concentrations were higher indoors compared to outdoor air (0.13-0.93, compared to 0.00-0.23 particles/m³, respectively). The types of indoor MPs were related to indoor-generating sources, and the occupant's lifestyles. The highest outdoor MP abundance was found near an industrial zone, followed by urban and inland locations in high-density areas. The dominant size range of MPs was 100-300 μm, and the only shapes observed indoors and outdoors were fibers (98%) and fragments. Polyethylene terephthalate was the most prominent MP type, followed by polyester, indicating that textile fibers could be the major source of these AMPs. This study provides the first report on AMPs in Sri Lanka. Considering population growth and industrialization, further research should evaluate possible trends and health risks upon inhalation.

Microplastics: Occurrences, treatment methods, regulations and foreseen environmental impacts

Microplastics are a silent threat that represent a high degree of danger to the environment in its different ecosystems and of course will also have an important impact on the health of living organisms. It is evident the need to have effective treatments for their treatment, however this is not a simple task, this as a result of the behavior of microplastics in wastewater treatment plants due to their different types and nature, their long molecular chain, reactivity against water, size, shape and the functional groups they carry. Wastewater treatment plants are at the circumference of the release of these wastes into the environment. They often act as a source of many contaminations, which makes this problem more complex. Challenges such as detection in the current scenario using the latest analytical techniques impede the correct understanding of the problem. Due to microplastics, treatment plants have operational and process stability problems. This review paper will present the in-depth situation of occurrence of microplastics, their detection, conventional and advanced treatment methods as well as implementation of legislations worldwide in a comprehensive manner. It has been observed that no innovative or new technologies have emerged to treat microplastics. Therefore, in this article, technologies targeting wastewater treatment plants are critically analyzed. This will help to understand their fate, but also to develop state-of-the-art technologies or combinations of them for the selective treatment of microplastics. The pros and cons of the treatment methods adopted and the knowledge gaps in legislation regarding their implementation are also comprehensively analyzed. This critical work will offer the development of new strategies to restrict microplastics.

Insight into the microplastics release from disposable face mask: Simulated environment and removal strategy

The fight against the COVID-19 epidemic significantly raises the global demand for personal protective equipment, especially disposable face masks (DFMs). The discarded DFMs may become a potential source of microplastics (MPs), which has attracted much attention. In this work, we identified the detailed source of MPs released from DFMs with laser direct infrared spectroscopy. Polypropylene (PP) and polyurethane (PU) accounted for 24.5% and 57.1% of released MPs, respectively. The melt-blown fabric was a dominant MPs source, however, previous studies underestimated the contribution of mask rope. The captured polyethylene terephthalate (PET), polyamide (PA), polyethylene (PE), and polystyrene (PS) in airborne only shared 18.4% of released MPs. To deepen the understanding of MPs release from medical mask into the aquatic environment, we investigated the effects of environmental factors on MPs release. Based on regression analysis, the effects of temperature, incubation time, and wearing time significantly affect the release of MPs. Besides, acidity, alkalinity, sodium chloride, and humic acid also contributed to the MPs release through corroding, swelling, or repulsion of fibers. Based on the exposure of medical mask to simulated environments, the number of released MPs followed the order: seawater > simulated gut-fluid > freshwater > pure water. Considering the risk of MPs released from DFMs to the environment, we innovatively established a novel flotation removal system combined with cocoamidopropyl betaine, achieving 86% removal efficiency of MPs in water. This work shed the light on the MPs release from DFMs and proposed a removal strategy for the control of MPs pollution.

Mitigation of microfibers release from disposable masks - An analysis of structural properties

The use of disposable face masks increased rapidly among the general public to control the COVID-19 spread. Eventually, it increased the disposal of masks and their associated impacts on environmental pollution. Hence, this study aims to analyze the impact of nonwoven fabric structural parameters and weathering on the microfiber release characteristics. Spunbond polypropylene nonwoven with four different weights and meltblown nonwoven with two different weights were used in this study to analyze microfiber release at dry, and wet conditions to simulate improper disposal in the environment. Exposure to sunlight significantly increases the microfiber release from 35 to 50% for spunbond fabric and 56-89% for meltblown fabric. Weathering in sunlight structurally affected the tensile properties of the polypropylene fibers due to photodegradation. The study showed that each mask can produce 1.5 × 10² and 3.45 × 10¹ mg of microfiber/mask respectively in dry and wet states. In the case of structural parameters, a higher GSM (grams per square meter), abrasion resistance, bursting strength, and thickness showed a positive correlation with microfiber release in both fabrics. Significantly a higher microfiber release was reported with meltblown fabric than the spunbond for a given GSM. The presence of finer fibers and more fibers per unit area in meltblown fabric was noted as the main cause. Nonwoven fabric GSM and the number of fibers in a specific area showed a higher influence on microfiber release. Based on the mask consumption reported in the literature, India alone can produce around 4.27 × 10² tons of microfibers/week as an average of dry and wet conditions. The study suggests that the proper selection of physical parameters can significantly reduce the microfiber fiber release at all stages.

Theoretical investigation on the interactions of microplastics with a SARS-CoV-2 RNA fragment and their potential impacts on viral transport and exposure

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease-19 (COVID-19) pandemic spread across the world and remains difficult to control. Environmental pollution and habitat conditions do facilitate SARS-CoV-2 transmission as well as increase the risk of exposure to SARS-CoV-2. The coexistence of microplastics (MPs) with SARS-CoV-2 affects the viral behavior in the indoor and outdoor environment, and it is essential to study the interactions between MPs and SARS-CoV-2 because they both are ubiquitously present in our environment. To determine the mechanisms underlying the impact of MPs on SARS-CoV-2, we used molecular dynamic simulations to investigate the molecular interactions between five MPs and a SARS-CoV-2 RNA fragment at temperatures ranging from 223 to 310 K in vacuum and in water. We furthermore compared the interactions of MPs and SARS-CoV-2 RNA fragment to the performance of SARS-CoV-1 and Hepatitis B virus (HBV) RNA fragments in interacting with the MPs. The interaction affinity between the MPs and the SARS-CoV-2 RNA fragment was found to be greater than the affinity between the MPs and the SARS-CoV-1 or HBV RNA fragments, independent of the environmental media, temperature, and type of MPs. The mechanisms of the interaction between the MPs and the SARS-CoV-2 RNA fragment involved electrostatic and hydrophobic processes, and the interaction affinity was associated with the inherent structural parameters (i.e., molecular volume, polar surface area, and molecular topological index) of the MPs monomers. Although the evidence on the infectious potential of SARS-CoV-2 RNA is not fully understood, humans are exposed to MPs via their lungs, and the strong interaction with the gene materials of SARS-CoV-2 likely affects the exposure of humans to SARS-CoV-2.

Application of GC/MS Pyrolysis for Assessment Residues of Textile Composites after Filtration of Washing and Rinsing Effluents

Research on the sources of microplastics (MP) in the environment and the parameters that lead to the loss of microfibers from synthetic textiles during washing have recently attracted public attention. Considering the involvement of a variety of structural and process parameters, it is important to choose methods for quantifying fibers as MP pollutants that migrated during the washing process. In the research to date, various sampling techniques and analytical protocols for the identification of polymers from washed synthetic textiles have been applied. In the present research, pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS), was applied to verify the composition of the filter residue isolated from washing and rinsing effluents. A comparison with bases of polymeric materials has proven the presence of potential environmental pollutants in the form of microfibers released during the washing process. The investigation confirmed that fragments of cotton cellulose residues predominate in relation to polyester. Based on the list of identified compounds generated by Py-GC/MS results and their retention times the multivariate data analysis proved the influence in the bath composition.

Man-made natural and regenerated cellulosic fibres greatly outnumber microplastic fibres in the atmosphere

Atmospheric microplastics have been widely reported in studies around the world. Microfibres are often the dominant morphology found by researchers, although synthetic (i.e., plastic) microfibres are typically just a fraction of the total number of microfibres, with other, non-synthetic, cellulosic microfibres frequently being reported. This study set out to review existing literature to determine the relative proportion of cellulosic and synthetic atmospheric anthropogenic (man-made) microfibres, discuss trends in the microfibre abundances, and outline proposed best-practices for future studies. We conducted a systematic review of the existing literature and identified 33 peer-reviewed articles from Scopus and Google Scholar searches that examined cellulosic microfibres and synthetic microfibres in the atmosphere. Multiple analyses indicate that cellulosic microfibres are considerably more common than synthetic microfibres. FT-IR and Raman spectroscopy data obtained from 24 studies, showed that 57% of microfibres were cellulosic and 23% were synthetic. The remaining were either inorganic, or not determined. In total, 20 studies identified more cellulosic microfibres, compared to 11 studies which identified more synthetic microfibres. The data show that cellulosic microfibres are 2.5 times more abundant between 2016 and 2022, however, the proportion of cellulosic microfibres appear to be decreasing, while synthetic microfibres are increasing. We expect a crossover to happen by 2030, where synthetic microfibres will be dominant in the atmosphere. We propose that future studies on atmospheric anthropogenic microfibres should include information on natural and regenerated cellulosic microfibres, and design studies which are inclusive of cellulosic microfibres during analysis and reporting. This will allow researchers to monitor trends in the composition of atmospheric microfibers and will help address the frequent underestimation of cellulosic microfibre abundance in the atmosphere.

First evidence of microplastics isolated in European citizens' lower airway

Microplastics (MPs) have been detected in all environmental locations, including the atmosphere. However, few studies have investigated the presence of airborne MPs in the human respiratory system. Our research purpose was to investigate these pollutants in the lower human airways of 44 adult European citizens, using bronchoalveolar lavage fluid (BALF) collection as a minimally invasive method, that enables the detection of these pollutants in living patients. We studied the relationship between the patients' life habits and physiological parameters, based on background information and medical and occupational history, and the concentration of MPs isolated from their respiratory systems. Our results indicate that most MPs were in the form of microfibers (MFs) (97.06%), with an average concentration of 9.18 ± 2.45 items/100 mL BALF, and only 5.88% (0.57 ± 0.27 items/100 mL BALF) were particulate MPs, without a significant relationship with environmental, physiological, or clinical factors. The average size was 1.73 ± 0.15 mm, with the longest dimension (9.96 mm) corresponding to a polyacrylic fiber. Taken together, the results demonstrated the occurrence of MPs in the lower human airway, although more studies are necessary to elucidate the negative effects these pollutants could induce in the human respiratory system and its associated diseases.

Review on alternatives for the reduction of textile microfibers emission to water

The microplastics (MPs) are considered one of the most threatening pollutants. One of the main concerns is their continuous and cumulative flow to water environments, as they are very difficult to be removed. Microfibers (MFs) are a significant type of MPs, with textile articles as one of the most renowned sources. This review aims to provide the current status of these MFs as pollutants, discussing possible alternatives from the manufacturing until the final disposition of MFs. There are many alternatives to reduce these pollutants from reaching the environment but also gaps that need to be further evaluated and addressed. Besides, it should be noticed that alternatives could be complementary between them. Some viable and non-contaminating solutions to reduce this pollution are currently on the market. Also, one relevant aspect is the final disposition or usage of the retained MFs to avoid them from reaching aquatic environments.

Microplastics and their Additives in the Indoor Environment

Analyses of air and house dust have shown that pollution of the indoor environment with microplastics could pose a fundamental hygienic problem. Indoor microplastics can result from abrasion, microplastic beads are frequently added to household products and microplastic granules can be found in artificial turf for sports activities and in synthetic admixtures in equestrian hall litter. In this context, the question arose as to what extent particulate emissions of thermoplastic materials from 3D printing should be at least partially classified as microplastics or nanoplastics. The discussion about textiles as a possible source of indoor microplastics has also been intensified. This Minireview gives an overview of the current exposure of residents to microplastics. Trends can be identified from the results and preventive measures can be derived if necessary. It is recommended that microplastics and their additives be given greater consideration in indoor environmental surveys in the future.

Emission of airborne microplastics from municipal solid waste transfer stations in downtown

With the continuous progress of urbanization, municipal solid waste (MSW) transfer stations, which are key points for garbage collection and transportation, have moved to residential areas than before. The emission characteristics of gas-phase emerging contaminants should be comprehensively assessed in the assessment of health threats to workers and environmental risks. In this study, the emission characteristics of airborne microplastic particles (>50 μm) were analyzed on the roof vent and waste reception hall of four MSW transfer stations in Shanghai during different seasons. The average concentration of airborne microplastic particles was 2.5 ± 1.3 n/m³. The particle sizes of airborne microplastics at the four waste transfer stations were mainly in the range of 100 μm to 500 μm. Microplastics mainly occur as films and fibers. The dominant microplastic type was Rayon, which accounted for 69.4% of the total amount. The rate of microplastic particles emission into the environment for a single transfer station was estimated to be in the range of 41,297 to 82,593 n/h. Compared with the waste reception hall, the concentration of airborne microplastic particles in the roof vent decreased by 25%, which indicated that the odor treatment facility effectively reduces the concentration of microplastic particles.

Microplastic ingestion from atmospheric deposition during dining/drinking activities

Human-health risks from microplastics have attracted considerable attention, but little is known about human-exposure pathways and intensities. Recent studies posited that inhalation of atmospheric microplastics was the dominant human-exposure pathway. Herein, our study identified that atmospheric microplastics ingested from deposition during routine dining/drinking activities represent another important exposure pathway. We measured abundances of atmospheric-deposited microplastics of up to 10⁵ items m^-2 d^-1 in dining/drinking venues, with 90% smaller than 100 µm and a dominance of amorphous fragments rather than fibers. Typical work-life scenarios projected an annual ingestion of 1.9 × 10⁵ to 1.3 × 10⁶ microplastics through atmospheric deposition on diet, with higher exposure rates for indoor versus outdoor dining/drinking settings. Ingestion of atmospheric-deposited microplastics through diet was similar in magnitude to presumed inhalation exposure, but 2-3 orders of magnitude greater than direct ingestion from food sources. Simple mitigation strategies (e.g., covering and rinsing dishware) can substantially reduce the exposure of atmospheric deposition microplastics through diet.

Status and prospects of atmospheric microplastics: A review of methods, occurrence, composition, source and health risks

The global pollution of microplastics (MPs) has attracted widespread attention, and the atmosphere was an indispensable media for the global transmission of MPs. With the growing awareness of MPs, atmospheric microplastics (AMPs) have been proposed as a new topic in recent years. Compared with the extensive studies on MPs in Marine and terrestrial environments, the studies of AMPs remain limited. In this study, sampling and analysis methods, occurrence, source analysis and health risk of AMPs were summarized and discussed. According to the different sampling methods, AMPs can be divided into suspension microplastics (SAMPs) and deposition microplastics (DAMPs). Previous studies have shown that SAMPs and DAMPs differ in composition and abundance, with SAMPs generally having a higher fraction of fragments. The mechanism of the migration of AMPs between different media was not clear yet. We further collated global data on the composition characteristics of MPs in soil and fresh water, which showed that the fragment MPs in soil and fresh water was higher than that in the atmosphere. Polymers in soil and fresh water were mainly PP and PE, while AMPs in the atmosphere were mainly PET. The shape composition of the MPs in both atmospheric and freshwater systems suggests that there may be the same dominant factor. The transport of AMPs and source apportionment were the important issues of current research, but both of them were at the initial stage. Therefore, AMPs needs to be further studied, especially for the source and fate, which would be conducive to understand the global distribution of AMPs. Furthermore, a standardized manual on sampling and processing of AMPs was also necessary to facilitate the comparative analysis of data between different studies and the construction of global models.

Microfiber fallout during dining and potential human intake

The pervasiveness of microfibers, including fibrous microplastics indoors and outdoors, has drawn attention. However, some places such as the dining environment that are closely related to human diet and health have been neglected. Here, we characterized short-term microfiber fallout in different dining spots and conducted long-term monitoring in a college cafeteria. The results showed that the microfiber abundance of restaurants during the peak hour of dinnertime (75 ± 19 MFs/plate/meal) was approximately two times that of households (36 ± 23 MFs/plate/meal). The high microfiber abundance was positively correlated with strong human activities (i.e., sitting rate of people) in restaurants, which was verified by the kinetics data of the cafeteria (R² =0.871, p = 0.000). Cotton (63%), polyester (17%), and rayon (14%) were the top three detected microfibers via μ-FTIR, and cloth friction can aggravate fiber shedding significantly. Moreover, high hairiness and short staple yarn style were likely to increase the formation of microfibers. Additionally, room structure can obviously influence microfiber abundance that households without separate dining rooms showed three times higher microfiber abundance (66 MFs/plate/meal) than those (21 MFs/plate/meal) with separate dining rooms, because partition walls were verified to effectively reduce fiber transport. Collectively, microfiber fallout during dining deserves our great attention, which may induce human intake of 63-232 MFs/person/d.

PBDEs in the marine environment: Sources, pathways and the role of microplastics

Brominated flame retardants (BFRs) are an important group of additives in plastics that increase resistance to ignition and slow down the rate of burning. Because of concerns about their environmental and human health impacts, however, some of the most widely employed BFRs, including hexabromocyclododecane (HBCD) and commercial mixtures of penta-, octa- and deca- (poly)bromodiphenyl ethers (PBDEs), have been restricted or phased out. In this review, the oceanic sources and pathways of PBDEs, the most widely used BFRs, are evaluated and quantified, with particular focus on emissions due to migration from plastics into the atmosphere versus emissions associated with the input of retarded or contaminated plastics themselves. Calculations based on available measurements of PBDEs in the environment suggest that 3.5 and 135 tonnes of PBDEs are annually deposited in the ocean when scavenged by aerosols and through air-water gas exchange, respectively, with rivers contributing a further ∼40 tonnes. Calculations based on PBDE migration from plastic products in use or awaiting or undergoing disposal yield similar net inputs to the ocean but indicate a relatively rapid decline over the next two decades in association with the reduction in the production and recycling of these chemicals. Estimates associated with the input of PBDEs to the ocean when "bound" to marine plastics and microplastics range from about 360 to 950 tonnes per year based on the annual production of plastics and PBDEs over the past decade, and from about 20 to 50 tonnes per annum based on the abundance and distribution of PBDEs in marine plastic litter. Because of the persistence and pervasiveness of plastics in the ocean and diffusion coefficients for PBDEs on the order of 10^-20 to 10^-27 m² s^-1, microplastics are likely to act as a long-term source of these chemicals though gradual migration. Locally, however, and more important from an ecotoxicological perspective, PBDE migration may be significantly enhanced when physically and chemically weathered microplastics are exposed to the oily digestive fluids conditions of fish and seabirds.

Human airway organoids and microplastic fibers: A new exposure model for emerging contaminants

Three-dimensional (3D) structured organoids are the most advanced in vitro models for studying human health effects, but their application to evaluate the biological effects associated with microplastic exposure was neglected until now. Fibers from synthetic clothes and fabrics are a major source of airborne microplastics, and their release from dryer machines is poorly understood. We quantified and characterized the microplastic fibers (MPFs) released in the exhaust filter of a household dryer and tested their effects on airway organoids (1, 10, and 50 µg mL^-1) by optical microscopy, scanning electron microscopy (SEM), confocal microscopy and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). While the presence of MPFs did not inhibit organoid growth, we observed a significant reduction of SCGB1A1 gene expression related to club cell functionality and a polarized cell growth along the fibers. The MPFs did not cause relevant inflammation or oxidative stress but were coated with a cellular layer, resulting in the inclusion of fibers in the organoid. This effect could have long-term implications regarding lung epithelial cells undergoing repair. This exposure study using human airway organoids proved suitability of the model for studying the effects of airborne microplastic contamination on humans and could form the basis for further research regarding the toxicological assessment of emerging contaminants such as micro- or nanoplastics.

Microplastics in Wastewater by Washing Polyester Fabrics

Microplastics have become one of the most serious environmental hazards today, raising fears that concentrations will continue to rise even further in the near future. Micro/nanoparticles are formed when plastic breaks down into tiny fragments due to mechanical or photochemical processes. Microplastics are everywhere, and they have a strong tendency to interact with the ecosystem, putting biogenic fauna and flora at risk. Polyester (PET) and polyamide (PA) are two of the most important synthetic fibres, accounting for about 60% of the total world fibre production. Synthetic fabrics are now widely used for clothing, carpets, and a variety of other products. During the manufacturing or cleaning process, synthetic textiles have the potential to release microplastics into the environment. The focus of this paper is to explore the main potential sources of microplastic pollution in the environment, providing an overview of washable polyester materials.

The impact of fabric conditioning products and lint filter pore size on airborne microfiber pollution arising from tumble drying

Vented tumble dryers release moist warm air from the drying process to the external environment, usually through pipework linking the appliance to a vent in an exterior wall. Although such dryers contain a lint filter to remove fibers from this air stream, recent reports suggest that this process is incomplete, leading to microfibers being released in the ducted warm air and subsequently polluting the external environment. Microfiber release from wash loads comprising 10 100% cotton and 10 100% polyester T-shirts (total load mass ratio 48% cotton, 52% polyester) was measured at different stages of the washing and drying process to compare the quantities of fibers released ‘down the drain’, collected in the dryer lint filter, and released to air from the tumble dryer. Testing under both European and North American washing conditions found that the quantities of microfibers released to air during tumble drying were significant and comparable to levels released ‘down the drain’ during washing. Use of conventional rinse-added liquid fabric conditioner increased microfiber accumulation on the dryer lint filter, with reduced release from the dryer exhaust observed at the highest fabric conditioner dose tested (21.6% and 14.2% reduction under North American and European conditions, respectively). Conventional liquid fabric conditioner did not significantly impact microfiber release from the washing machine, in line with previous studies. A fabric conditioner specially designed for anti-wrinkle performance reduced microfiber release from the dryer exhaust at all levels tested (by 17.6–35.6%, depending on dose), apparently by increasing the efficiency of microfiber accumulation in the lint filter. Tumble dryer sheets were also found to cause a reduction in microfiber release from the dryer exhaust (by 14.1–34.9%, depending on the dose/product), likely driven by collection of liberated fibers on the sheet during the drying process. The use of both antiwrinkle liquid fabric conditioner and dryer sheet enabled a 44.9% reduction in microfiber emissions from the dryer exhaust. In all studies, the fiber mass collected on the lint filter or emitted from the dryer exhaust was richer in cotton fibers (range 83.4–96.3% on the lint filter, 93.0–99.8% from the dryer exhaust) than the wash load composition (48% cotton). Moreover, fibers collected by the lint filter contained a higher proportion of polyester than emissions from the dryer exhaust (range 3.7–16.6% on the lint filter, 0.2–7.0% from the dryer exhaust). There is significant variation in the porosity of lint filters among installed vented tumble dryers. Single-variable testing of the impact of lint filter design concluded that reducing screen pore size significantly reduces airborne microfiber release during tumble drying; a reduction in lint filter pore size from 0.2 mm² to 0.04 mm² reduced release by 34.8%. As some lint filters have pore sizes of around 1 mm², there is enormous scope to reduce microfiber release from dryers though improved lint filter design. However, it is suggested that a step-change in appliance design away from vented dryers to only fully-sealed condenser dryers might be necessary to eliminate the contribution of tumble drying to airborne microfiber pollution.

Enhanced impacts evaluation of Typhoon Sinlaku (2020) on atmospheric microplastics in South China Sea during the East Asian Summer Monsoon

Atmospheric transport is an important pathway through which microplastics (MPs) are widely exchanged between marine and terrestrial environments. However, the impacts of frequent extreme weather events, such as typhoons, on atmospheric MPs is poorly understood. To address this issue, we collected suspended atmospheric MPs (SAMPs) and rainfall samples in the South China Sea during Typhoon Sinlaku (2020). Our results revealed a higher abundance of suspended MPs (1.05 ± 0.55 n/100 m³) during the typhoon than in the pre-typhoon period (0.59 ± 0.48 n/100 m³). Nine polymer types were identified by micro-FTIR, among which the dominant were polyethylene terephthalate (PET, 62.82%) and polypropylene (PP, 19.23%). Moreover, rainfall appeared more inclined to remove larger sizes, more colors and more polymer types of MPs from the atmosphere. The trajectory source-receptor plot indicated that the typhoon significantly changed the pathway of MP transport in the atmosphere, including the direction and distance. To our knowledge, this is the first study to elucidate the impact of typhoons on atmospheric MP transportation. Our results indicate that airborne MPs may pose unexpected ecological risks to marine and coastal ecosystems due to their increased abundance from more distant sources, resulting from typhoon events.

Laundering of face masks represents an additional source of synthetic and natural microfibers to aquatic ecosystems

From the onset of Covid-19 pandemic, the use of face masks has been adapted as one of the main measures to slow down the transmission of the SARS-CoV-2 virus worldwide. The inadequate handling and management of face masks lead to a massive dispersal in the environment, resulting in a new source of microfibers because of their breakdown and/or degradation. In addition, the laundering of reusable face masks of different polymeric composition can represent an additional sources of microfibers to natural ecosystems, but it was largely neglected. The present study explored the release of synthetic or natural microfibers from reusable and disposable face masks of five different fabrics when subjected to a cycle of laundering in a domestic washing machine. After a single wash, face masks released an average (± SE) of 284.94 ± 73.66 microfibers, independently of the fabrics. Focusing on the fabrics composing the face masks, polyurethane (541.33 ± 51.84 microfibers) and cotton-based (823.00 ± 112.53 microfibers) face masks released the highest amount of synthetic and natural microfibers, respectively. Considering the crucial role of face masks to counteract the pandemic and the increasing trend of their use, further studies represent a priority to estimate the contribution of face mask-derived microfibers to freshwater contamination.

Characteristics and influencing factors of airborne microplastics in nail salons

Airborne microplastic particles (MPs) are emerging contaminants. Although some studies have investigated the characteristics of indoor MPs in homes or offices, information regarding MPs in nail salons with potentially higher MP pollution is unavailable. In this study, we collected indoor and outdoor air samples from nail salons to analyze the concentrations, physical characteristics, and polymers of MPs and further assessed the exposure through inhalation and influencing factors. Our data displayed that the average indoor MP concentration was 46 ± 55 MPs/m³. The estimated average annual exposure to indoor MPs was 67,567 ± 81,782 MPs/year. The predominant shape and size of indoor MPs were fragment and <50 μm, respectively. The predominant polymer in indoor air was acrylic (27%), followed by rubber (21%), and polyurethane (13%). Air conditioner, nail treatment, ceiling and flooring with plastic materials, and number of occupants were factors affecting indoor MP concentrations. We concluded that MP pollution was more severe in nail salons and the physical characteristics and polymer compositions differed between nail salons and other indoor spaces reported in other studies. Air conditioner usage induced higher MP emission, and higher MP concentrations were observed in nail salons with plastic ceiling and flooring or more occupants.