Microplastic Fibers Research Articles

A Simple Sample Preparation Method to Significantly Improve Fourier Transform Infrared (FT-IR) Spectra of Microplastics.

Spectroscopic analysis has become an essential part of the rapidly growing field of microplastic (MP) research. Here, we introduce a simple sample preparation method that dramatically improves results from Fourier transform infrared (FT-IR) analysis of MP and other environmental fibers. Our method provides cost-effective, reliable, high-quality spectra that achieve high-matching scores to polymer libraries. The efficacy of this method is demonstrated with two environmental datasets from Singapore and Phnom Penh that were collected while sampling for atmospheric MPs. The method developed and applied in this study is a simplification of the KBr method, where the analyzed fiber is pressed to a thickness of <10μm; however, no KBr powder is required. For the combined dataset, 379 non-pressed fibers were analyzed with 193 (51%) returning a search score of ≥80% (chosen minimum search score threshold) and 259 pressed fibers, with 254 (98%) returning a search score of ≥80%. Direct comparisons of fibers before and after pressing show that the highest individual search score, and average search score from multiple single-point measurements, is overwhelmingly higher following our method. Our method immobilizes and improves the surface of the fiber, by creating a wider and uniform area for measurements. For FT-IR operators, this saves considerable time, improves reliability of the analysis, and, importantly, provides reproducibility of the spectra generated.

Evaluation of the adsorption efficiency of carcinogenic PAHs on microplastic (polyester) fibers—preliminary results

Paper presents the results of investigations on sorption capacity of selected carcinogenic polycyclic aromatic hydrocarbons (PAHs) on microplastics fibers. Accumulation of organic micropollutants such as PAHs is indicated as one of the important problems in the case of microplastics present in surface water, including sea water. Concentrations of the micropollutants can reach even several mg/kg of microplastics. An unrecognized problem are sorption capacities of microfibers towards PAHs. Recent research works indicate that microfibers are commonly present in sewage sludge. Content of the fibers in this waste material can reach over 23000 particles per 1 kg of sludge dry matter. The fibers mainly come from cloth washing. It is obvious that the adsorption capacity of the fibers can affect the concentration of PAHs in sewage sludge. The aim of the study was to evaluate sorption capacities of polyester fibers towards PAHs. Adsorption of PAHs were provided under static conditions. After 24 h of adsorption 1255 μg/g of carcinogenic PAHs was adsorbed onto the polyster fibers. Amount of 6-ring PAHs was equal to 154 μg/g, whereas 5- i 4- ring ones, 562 and 539 μg/g, respectively. The results have confirmed that hydrophobic PAHs can be adsorbed onto polystyrene fibers and as a result cumulate in sewage sludge.

Quantifying shedding of microplastic fibers from textile washing

Fiber fragments from synthetic textile materials are a subgroup of microplastics, and the presence of this debris in the environment may have its origin from some different sources. In order to investigate the formation of these residues during domestic washing, washings were simulated on samples of textile articles consisting of three different synthetic materials (polyamide, acrylic, and polyester). The effluent generated was collected and filtered, retaining the microplastic fibers shed. Through a gravimetric process, the mass of particles adhered to the filters was determined, and with the use of a fluorescent dye (Nile Red), these particles were quantified under a fluorescence microscope. This study concluded that the different textile compositions shed microplastic fibers during five washing cycles. Acrylic samples shed the highest mass value (40.9 mg) and polyamide samples shed the lowest value (7.5 mg). It has been estimated that an acrylic blouse can shed 726 mg of microplastic fibers in a single washing. Regarding the size of these particles, dimensions ranging from 11µm to 3mm were observed. Visualization in a 1.2μm filter also suggests the existence of particles in nano-dimensions. In general, it was possible to establish that the domestic washing of textile articles highly contributes to the insertion of these pollutants into the water environment. From a national perspective, approximately 13,800 tons of synthetic fibers can be released into water resources annually from washing clothes.

Polyethylene terephthalate microplastic fibers increase the release of extracellular antibiotic resistance genes during sewage sludge anaerobic digestion

Microplastic fibers (MFs), as the most frequently detected microplastic shape in sewage sludge, have posed emerging concern for sludge treatment and disposal. However, the effect of MFs on antibiotic resistance genes (ARGs), especially extracellular ARGs (eARGs) during sludge treatment remains far from explicit. Therefore, this study investigated the potential impact of MFs on eARGs during sludge anaerobic digestion (AD), a commonly used sludge treatment method, through long-term operation. The qPCR results showed that both absolute and relative abundances of eARGs increased with the MFs exposure during sludge AD. The average absolute and relative abundances of eight tested eARGs in the AD reactor with the highest MFs dosage (170 items/gTS) were 1.70 and 2.15 times higher than those in the control AD reactor. The metagenomics results further comfirmed the increase of eARGs abundance during sludge anaerobic digestion after MFs exposure and the enhancement did not show significant selectivity. The identification of the potential hosts of eARGs suggested the host numbers of eARGs also increased with MFs exposure, which may suggest enhanced horizonal transformation as a result of increased eARGs. Further exploring the mechansims showed that the genes involved in type IV secretion system was upregulated after MFs exposure, suggesting the active release of eARGs was enhanced with MFs exposure. In contrast, the MFs may not affect the passive release of eARGs as its impact on cell membrance damage was insignificant. The enhanced eARGs in sludge AD process may further accelerate the transport of ARGs in environment, which should be considered during sludge treatment and disposal.

Performance of Electrocoagulation Process for Microplastic Fibre Removal from Laundry Wastewater

Laundry wastewater contains not only detergent but also contains fabric fibres and threads. Microplastic fibres have been discovered as a potential source of microplastic fibres in synthetic clothing washed in the environment. To reduce microplastic concentration in wastewater, many approaches have been developed. Electrocoagulation is one of them. Using both synthetic microplastics and laundry wastewater samples, this study examined the performance of electrocoagulation methods to remove microplastics. The flocculation and deposition mechanisms remove microplastic fibre. This research was set up by using a reactor with a volume of 1 L, 60 V of voltage and 60 minutes of contact time. Electrical current of 5A and 10A was applied to remove microplastic fibres during electrocoagulation (EC). The removal efficiency of polyester fibre was 55-68 per cent for 60 minutes with a current of 5A and 42-85 per cent for 60 minutes with a current of 10A. Polyamide fibre removal efficiency in 60 minutes is 53 per cent to 74 per cent at 5A current and 57 per cent to 72 per cent at 10A current. According to this study, it can be concluded that EC can remove microplastic fibre from laundry effluent.

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.

Incidence of microplastic fiber ingestion by Common Terns (Sterna hirundo) and Roseate Terns (S. dougallii) breeding in the Northwestern Atlantic

Ingestion of microplastics has been documented across marine species, but exposure remains sparsely described in many seabird species. We assess microplastic (between 0.2 and 5.0 mm) ingestion in two Northwestern Atantic - breeding species for which exposure to microplastics is entirely or largely undescribed: Common Terns (Sterna hirundo) and Roseate Terns (S. dougallii). Common Tern microplastic load did not vary between life stages (p = 0.590); microplastic load did differ in Common Tern adults breeding at two of three colonies explored (p = 0.002), with no other regional differences observed. Roseate Terns ingested significantly more microplastics than Common Terns (p = 0.007). Our results show that microplastic ingestion by terns varies regionally and interspecifically, but not by life stage, trends potentially explained by dietary differences. We provide the first quantification of microplastic fiber ingestion by terns in the Northwestern Atlantic and identify trophic dynamics related to microplastic ingestion, representing an important step toward understanding the risk of the pollutant to terns across regions, as well as toward the use of terns as potential bioindicators of microplastics.

The Occurrence of Microplastics in Sediment Cores from Two Mangrove Areas in Southern Thailand

Mangroves are areas that connect the land and sea, and are important to the ecosystem. They are important places for food sources and the habitat of aquatic fauna in the tidal areas. However, the existence of plastic debris poses a risk to the aquatic environment. This study aimed to investigate the accumulation of microplastics (MPs) in sediment cores from two mangrove areas. The first mangrove area is in the outer section of the Songkhla lagoon (SK), while the second is in the coastal area of Pattani province (PN). Sediment core sampling was performed from SK = 8 stations and PN = 5 stations. Surface enrichment of MP was observed, especially in sediments of 0–4 cm. MPs were found throughout the depth in both areas, while fewer MPs were found in deeper sediment core layers (p &lt; 0.05) at some stations inside the mangrove zone. Simple linear regression of the observed MPs and distance in the horizontal were found to be significant at SK within the mangrove zone with r2 = 0.79 (p &lt; 0.05). MP fibers were the most commonly found MP type in both areas and were less than 1 mm. Blue and black MPs were the most abundant colors found in both areas. The six polymer types reported in this study comprised polyethylene, rayon, rubber, styrene, Poly (vinyl acetate), and paint. The findings of the present study suggest that long-term monitoring of marine debris along coastlines is necessary to help improve national policies and measures related to marine plastic debris.

Microplastic Contamination in Blood Cockles and Mussels in Bandon Bay, Suratthani Province, Thailand

Widespread microplastic contamination has been of growing concern worldwide and poses a growing threat to the marine environment, particularly the impact on the food chain. This study quantified the presence of microplastics in two bivalves of commercial interest at the Pak Kadae Estuary, Bandon Bay, Surat Thani province, Thailand: green mussel Perna viridis (L.) and cockles Tegillarca granosa (L.). Data collection was carried out over two seasons: dry season (April - May 2019) and wet season (June - August 2019). Microplastics were extracted using a 10 % potassium hydroxide (KOH) digestion method and then identified under a microscope. Results confirmed the presence of microplastics in both cockles and green mussels, during the dry season, with mean concentrations of 0.30±0.07 and 1.26±0.10 items/individual, respectively. During the wet season, the mean microplastic concentrations were 0.20±0.07 and 0.56±0.15 items/individual in the cockles and green mussels, respectively. There was a greater concentration of microplastics found in green mussels compared to cockles (P &lt; 0.05) with no seasonal variation being observed. Five different shapes of microplastics, including fiber, fragment, pellet, rod, and film, were detected in the soft tissues of the bivalves. Fibers were the most common shape in green mussels (49 - 69 %) during both seasons. Cockles, in contrast, predominantly contained the pellet shape in the dry season (49 %) and fiber in the wet season (59 %). In addition, the microplastic concentrations were positively correlated to shell heights of the bivalves (P &lt; 0.01). The number of microplastics recorded in the two commercially exploited species demonstrated the need for controlling plastic pollution in coastal ecosystems.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Green mussels showed higher contamination with microplastics than blood cockles&#x0D; An average (Mean±SD) of 0.28±0.05 to 2.14±0.36 items/individual in cockles and 0.65±0.13 to 3.43±0.21 items /individual in mussels were obtained&#x0D; Microplastic fibers were the dominant shape found in shellfish&#x0D; Blue microplastics was the most frequently found in green mussels whereas the black color dominated in cockles&#x0D; &#x0D; GRAPHICAL ABSTRACT

First observation of microplastics in surface sediment of some aquaculture ponds in Hanoi city, Vietnam

A large amount of plastic waste has been released into the environment during the increase in global plastic production in the 21st century. Microplastics (0.1 µm to 5 mm in size) existing in hydro-systems, especially in aquatic sediments, can enter organisms and then human body through food chain. This paper provided the preliminary observation results on microplastic presence in the surface sediment of the aquaculture ponds (fish) in Hanoi city in 2021. Our results showed that microplastic concentrations ranged from 2,767 ± 240 to 2,833 ± 176 items.kg−1 dry weights for the surface sediment of the two aquaculture ponds. Two main shape groups of fiber and fragment were detected, of which fibers were dominated (62% and 82% for the two ponds observed). For microplastic fibers, green, white, black and red were main colors, whereas for fragments, yellow, blue and white were main ones. Polyethylene (PE) and polypropylene (PP) were two main polymer types found in the sediment samples. The sources may mainly come from the microplastic contaminated water of the Nhue River, and the direct aquaculture activities. The results of this study contributed to build a dataset on microplastic pollution in aquatic environment, especially aquaculture ponds in Vietnam. Our study also revealed the need for microplastic observation in different environments and organisms, especially in aquaculture zone in Vietnam.

Relative contributions of different local sources to riverborne microplastic in a mixed landuse area within a tropical catchment

Information on the relative contributions of microplastics coming from different sources is important to help prioritise measures to reduce river contamination levels and limit human and ecological health risks. This paper reports on work which aimed to quantitatively assess the relative concentrations and types of microplastic delivered from differed sources to a second order river. The study was undertaken in a mixed landuse area within a rapidly urbanising catchment in Malaysia. Over a six-week period, water samples were collected from road culverts and drains in residential and industrial areas across the area to assess microplastic concentrations, while inputs from atmospheric deposition and wastewater treatment plants (WWTPs) were also quantified. Microplastic fibres and fragments were the dominant material in all sources, with the majority consisting of styrene-butadiene rubber and nylon. Culverts draining main roads were the main contributor to riverborne microplastic, delivering 42.20 ± 35.29 particles/L directly to the river channel. Road inputs were up to seven times greater than those from residential (8.53 ± 9.91 particles/L) and industrial (5.67 ± 4.88 particles/L) areas. The five WWTPs had removal efficiencies of between 30.95 ± 5.51% and 69.94 ± 22.17%, with their outflows delivering microplastics to the river in concentrations similar to those in uncontrolled residential and industrial drains. Atmospheric deposition across the study area was estimated to be 76.07 ± 32.85 particles/m2/day (=8.35 ± 5.11 particles/L). Mitigation strategies in the study area should focus on improving management of water draining roads, and re-routing discharges from domestic and industrial areas to WWTPs rather than allowing them to flow directly to the river. The low efficiencies of some of the WWTPs are not unusual, and indicate the need for additional water treatment to deal with microplastic present in wastewater.

Microplastic Pollution in Surface Waters of Urban Watersheds in Central Texas, United States: A Comparison of Sites With and Without Treated Wastewater Effluent

Most studies of microplastics in freshwater have investigated presence in creeks and rivers below sewage effluents and storm drains. This study examines microplastic distribution in surface waters, including springs and primary streams, located within small, urban Karst watersheds, with and without sources of wastewater treatment discharge. Study locales were in Texas, United States, either in Waco on the Brazos River or in or downstream from San Marcos on the San Marcos River. Research teams collected 800 ml surface water from four different small watersheds and an urban pond (n = 779) and filtered them through 53 μm Nitex mesh. Teams collected samples from springs or primary streams to the lower end of creeks and across stream transects based on distance from the bank and the presence of vegetation and debris. Teams also replicated samples seasonally. Stereo microscopy examined each filter for microplastic particles and subsequently color and type (i.e., fragment, fiber, or sphere). Additionally, we analyzed the influence of urbanization and land use on the origin and transport of the microplastics. Overall, the filters recovered 1,198 microplastic fibers and fragments. On average, 56.7% of all samples at each study locale contained microplastics. Particle abundance was the highest at Proctor Springs (x¯=3.38) and lowest at the pond (x¯=0.98), both headwaters. Local human use and runoff were thus potentially important factors in microplastic presence, while sewage discharge was not unilaterally the primary determinant of microplastic abundance. Peak pollution events occurred in June, September, and October, indicating seasonality of rainfall and recreation affected microplastic frequency and type.

In vivo oxidative stress responses of the freshwater basket clam Corbicula javanicus to microplastic fibres and particles

Microplastics have been detected in several aquatic organisms, especially bivalves such as clams, oysters, and mussels. To understand the ecotoxicological implication of microplastic accumulation in biota, it is crucial to investigate effects at the physiological level to identify knowledge gaps regarding the threat posed to the environment and assist decision-makers to set the necessary priorities. Typically, xenobiotics elicit an overproduction of reactive oxygen species in organisms, resulting in oxidative stress and cellular damage when not combated by the antioxidative system. Therefore, the present study aimed to establish the impacts of microplastic particles and fibres on the freshwater basket clam Corbicula javanicus. We measured the oxidative stress responses following microplastic exposure as the specific activities of the antioxidative enzymes glutathione S-transferase and catalase. When exposed to polyester fibres from the fleece jackets, the enzyme activities increased in the clams, while the enzyme activities decreased with high-density polyethylene microplastic fragments from bottle caps. All the exposures showed that the adverse effects on the antioxidative response system were elicited, indicating the negative ecotoxicological implications of microplastic pollution.

Toward an All-Optical Fingerprint of Synthetic and Natural Microplastic Fibers by Polarization-Sensitive Holographic Microscopy

Microplastic fibers from synthetic textiles have been indicated as a major source of pollution because millions of fibers are released into the environment by laundry washing. In fact, such types of microplastics usually bypass wastewater treatment processes and filters, thus reaching the oceans and other water natural reservoirs in huge quantities. Nowadays, several approaches are available for characterizing microplastics, but unfortunately, there is no unique and standard method for this aim. Among the various methodologies, several microscopy techniques such as optical microscopy (OM), scanning electron microscopy coupled with energy dispersive X-ray (SEM–EDX) analysis, or OM combined with molecular spectroscopy can be used for visual detection and measurements. Our proposal is a non-destructive method based on a digital holographic microscope in a configuration fully sensitive to the polarization of light transmitted by the fibers with a micron dimension. Our aim is to prove that the proposed approach allows for the precise characterization of synthetic and natural fibers in water. The method exploits all the advantages of digital holography such as numerical refocusing, non-invasive testing, and quantitative measurements of the complex wave field by adding access to the polarization of light that conveys meaningful information about materials. We intend to show that a unique all-optical fingerprint can be retrieved using the Jones-matrix formalism for the major classes of synthetic microfilaments used in the textile industry (i.e., polyamide 6, polyamide 6.6, polypropylene, and polyester) and for the most common natural fibers (i.e., wool and cotton) prepared according to previously developed appropriate protocols. Our results show that the proposed technology identifies new features for micron-sized fibers based on optical anisotropy through quantitative digital holography that could open future routes for automatic and all-optical identification of textile contaminants in water.

Acute toxicity of microplastic fibers to honeybees and effects on foraging behavior

Microplastics (MPs) are considered emerging and persistent pollutants, although most of the research has been conducted on marine environments. Declines in honeybee populations have been reported globally, and recently, microplastic pollution has been considered a possible cause of this. Thus, we aimed to determine acute toxicity of polyester fibers and their effects on foraging behavior in honeybees. To test this, we conducted an oral acute toxicity bioassay, testing the effect of MPs on individual honeybees, and we studied the foraging behavior of honeybees when exposed to food and water containing MPs. We observed no mortality in honeybees fed with sucrose solution containing 100 mg MP/L after 24 and 48 h. Upon bee dissection of the digestive tract, we found 1.27 ± 1.5 fibers per bee, showing a mean (±SE) of 0.92 (±1.14) and 0.32 (±0.70) in their gut and crop respectively. The length of these microfibers ranged between 0.05 and 1.24 mm with a mean (±SE) of 0.42 (±0.25) mm. Although we did not find any preference or avoidance of MPs when presented in sucrose solutions and water; bees consumed MP-free solutions faster than solutions with 10 and 100 mg MPs/L. This might be due to changes in the viscosity of the solutions containing plastic and has implications for the impact of microplastic pollution on insects. Results suggest that MPS do not pose a threat to honeybees in the short term, based on the lack of acute mortality. However, bee foraging behavior does not prevent them from ingesting MPs present in water or resources which potentially might cause lethal long-term effects of MPs.

The significance of trophic transfer in the uptake of microplastics by carnivorous gastropod Reishia clavigera

The present study compared the relative significance of prey consumption and respiration as routes of microplastic (MP) intake in a carnivorous muricid gastropod, Reishia clavigera. The time-dependent accumulation of MPs within 14-day exposure and their removal through depuration were also investigated for two forms of MPs (fibre, fragment) at an environmentally relevant concentration (10 items L−1) and two higher concentrations (100 and 1000 items L−1). At 1000 items L−1, the number of MPs in R. clavigera on Day 14 was 1.8 ± 0.2 fibres individual−1 or 0.8 ± 0.3 fragments individual−1, equivalent to 64.6% of the fibres or 9.4% of the fragments retained by the variable mussel Brachidontes variabilis, a prey of R. clavigera. Consumption of B. variabilis was the most important route of MP intake in R. clavigera, although a small number of MPs were adhered to the gills during ventilation. Depuration in clean seawater without MPs was very effective in eliminating MPs in the body of R. clavigera but the possibility of long-term bioaccumulation of MPs could not be ruled out. The high percentage of MPs transferred from the prey to predator indicates the potential of trophic transfer as a significant route of uptake for MPs in higher predators.

Less impact than suspected: Dietary exposure of three-spined sticklebacks to microplastic fibers does not affect their body condition and immune parameters

Microplastic fibers are frequent anthropogenic contaminants in most aquatic environments and have consequently been detected in the digestive tract of many fish species. Upon ingestion, microplastic fibers pose risks of interference with nutrient uptake, impaired intestinal health, and as a consequence may alter growth performance and fitness. In addition, foreign particles such as fibers might cause tissue irritations and stress, and thus interfere with immune parameters. In nature, fish regularly encounter microplastic fibers as well as fiber debris from natural sources and materials. Thus, we wanted to test the potential impact of microplastic fibers on growth, organosomatic indices, and immune parameters of subadult fish and compare these to possible effects caused by natural fibers. We administered sticklebacks diets, which were supplemented with either polyester or cotton fibers (each at concentrations of 0.2 mg/g and 2 mg/g feed) or a control diet without fiber supplementation for nine weeks. Mortalities did not occur and sticklebacks grew equally well across treatments. Neither organosomatic indices nor immune parameters revealed significant differences between treatments. While natural differences between males and females were observed for some parameters, no treatment-related gender-specific effects were detected. Our results suggest that the dietary uptake of polyester fibers does not affect growth, body condition, gonad development, and immunity of sticklebacks – even at fiber concentrations higher than what can be encountered in the wild. Furthermore, virgin microplastic fibers do not seem to affect fish differently than fibers from natural origin. The present study implies that at least some species are resilient towards pollution with (virgin) microplastic fibers even at high concentrations.

Microplastics can alter phytoplankton community composition

Microplastic pollution is a growing concern globally due to the risks they may pose to ecological communities. Phytoplankton are key ecological community in aquatic ecosystems providing both energy to food webs and have critical roles in ecosystem functions such as carbon cycling. To date studies on how microplastics effect phytoplankton have largely been limited to laboratory exposure studies using monocultures of algae. It remains unknown how the structure of phytoplankton communities will be influenced by growing microplastic pollution. The aim of this study was to determine how different concentrations microplastic fibers influence phytoplankton community structure. Two six-day microcosm studies were conducted testing the response of the phytoplankton community to low, medium, and high microplastics concentrations on the Georges River, Australia. The results showed the highest concentrations of microplastics significantly altered the structure phytoplankton community. These differences were largely driven by increased abundances of cyanobacteria taxa Aphanocapsa and Pseudanabaena, and to a lesser extent reduced abundances of taxa including Crucigenia and Chlamydmonas. There were no significant differences between controls and the low and medium treatments in either experiment. The high concentrations used in this experiment whilst likely rare in the environment are environmentally relevant and equivalent to some of more polluted ecosystems. The results highlight the potential risk to food webs and ecosystem functioning through altering the dynamics of primary production and provide evidence for further study examining the response of ecological communities to microplastics in the environment.

Intelligent polarization-sensitive holographic flow-cytometer: Towards specificity in classifying natural and microplastic fibers

Micron size fiber fragments (MFFs), both natural and synthetic, are ubiquitous in our life, especially in textile clothes, being necessary in modern society. In the Earth's aquatic ecosystem, microplastic fibers account for ~91% of microplastic pollution, thus deserving notable attention as one of the most alarming ecological problems. Accurate automatic identification of MFFs discharges in specific upstream locations is highly demanded. Computational microscopy based on Digital Holography (DH) and machine learning has been demonstrated to identify microplastics in respect to microalgae. However, DH is a non-specific optical tool, meaning it cannot distinguish different types of plastic materials. On the other hand, materials-specific assessments are pivotal to establish the environmental impact of different textile products and production processes. Spectroscopic assays can be employed to identify microplastics for their intrinsic specificity, although they are generally low-throughput and require large concentrations to enable effective measurements. Conversely, MFFs are usually finely dispersed within a water sample. Here we rely on a polarization-resolved holographic flow cytometer in a Lab-on-Chip (LoC) platform for analysing MFFs. We demonstrate that two important objectives can be achieved, i.e. adding material specificity through polarization analysis while operating in a microfluidic stream modality. Through a machine learning numerical pipeline, natural fibers (i.e. cotton and wool) can be clearly separated from synthetic microfilaments, namely PA6, PA6.6, PET, PP. Moreover, the proposed system can accurately distinguish between different polymers under investigation, thus fulfilling the specificity goal. We extract and select different features from amplitude, phase and birefringence maps retrieved from the digital holograms. These are shown to typify MFFs without the need for sample pre-treatment or large concentrations. The simplicity of the DH method for identifying MFFs in LoC-based flow cytometers could promote the use of polarization resolved field-portable analysis systems suitable for studying pollution caused by washing processes of synthetic textiles.

Adaptive Neuro-Fuzzy Inference System to Predict the Release of Microplastic Fibers during Domestic Washing

Abstract Microplastic particles are a burgeoning population crisis in marine environments. This work is to predict the release of microplastic fibers from jeans made from polyester during domestic washing by using of adaptive neuro-fuzzy inference system (ANFIS) model. The advantage of the ANFIS model is to predict the variations between the randomly chosen parameters. This prediction model can be cost-effective and slowed down to study behavior more closely. The consequence of washing duration, temperature, spin speed, detergent types, and conditioner usage was investigated against the microplastic fiber release. The washing temperature, washing duration, spin speed, detergent types, and addition of conditioner are the main factors for this research work. The forecast presentations have been exposed by having a considerably lowered root mean square error value of 3.23 compared with the variant of the experiment as exposed by its standard deviation for the ANFIS version. This ANFIS model will be able to provide a theoretical understanding to enhance and inhibit microplastic fiber release from jeans.