Microfibers Research Articles

Practical guidelines and challenges in the isolation and characterization of microplastics/microfibers by Raman microscopy

We address some challenges usually encountered in the analysis of microplastics (MPs) and microfibers (MFs) using Raman microscopy. Those issues are examined considering that the researchers that carry out the collection and analysis of MP contamination may not have necessarily specialized expertise in Raman microscopy or polymer chemistry. Topics such as effective particle isolation or the use of adequate substrates are approached on the base of the impact they have on the spectroscopic characterization. Issues as the control of background signal, the influence of sample digestion, and the presence of internal interferences such as pigments, dyes, and fillers, are discussed. Spectral features of the polymer families found as MP/MF contaminants are presented based upon polymer structure, properties, and applications. The use of open-source libraries to complement chemical identification is also discussed. Overall, this work aims to enhance the practice and understanding of Raman microscopy for researchers engaged in characterizing MP/MF contaminants.

Shear induced remobilization of buried synthetic microfibers

Microplastics are known to accumulate in sediment beds of aquatic environments where they can be buried. Once buried they can remobilize due to high energetic events, entering the water column again. Here, turbulence induced by an oscillating grid device was used to investigate the remobilization of microfibers (MF) buried into the sediment bed. Four different types of plastic fibers commonly used for several industrial applications (PET, PP, PA and LDPE) and two types of soils (cohesive and non-cohesive) were investigated. Particles were in depth characterized via 3D reconstruction to estimate important parameters like the Corey shape factor and the settling velocity. Experimental runs explored a wide range of shear stresses. Measurements were taken at different time steps (between 15 min and 240 min from the start of each run). The results have shown that the remobilization of MFs is directly proportional to the value of the shear rate and the duration of the disturbance. Also, buoyant MFs were found more prone to remobilize respect to the denser ones. Drawing from experimental observations of the key parameters affecting MF remobilization, a non-dimensional predictive model was developed. A comparison with previous studies was performed to validate the model in order to predict MF remobilization in aquatic environments.

Photodegradation Processes and Weathering Products of Microfibers in Aquatic Environments.

Microplastics, particularly microfibers (MFs), pose a significant threat to the environment. Despite their widespread presence, the photochemical reactivity, weathering products, and environmental fate of MFs remain poorly understood. To address this knowledge gap, photodegradation experiments were conducted on three prevalent MFs: polyester (POL), nylon (NYL), and acrylic (ACR), to elucidate their degradation pathways, changes in surface morphology and polymer structure, and chemical and colloidal characterization of weathering products during photochemical degradation of MFs. The results showed that concentrations of dissolved organic carbon, chromophoric dissolved organic matter (DOM), and fluorescent components consistently increased during weathering, exhibiting a continuous release of DOM. Scanning electron microscopy and Raman spectroscopy revealed changes in the surface morphology and polymer spectra of the MFs. During the weathering experiments, DOM aromaticity (SUVA254) decreased, while spectral slope increased, indicating concurrent DOM release and degradation of aromatic components. The released DOM or nanoplastics were negatively charged with sizes between 128 and 374 nm. The production rate constants of DOM or the photochemical reactivity of MFs followed the order ACR > NYL ≥ POL, consistent with their differences in chemical structures. These findings provide an improved understanding of the photochemical reactivity, degradation pathways, weathering products, and environmental fate of microfibers in the environment.

Surface Cleaning with a Microfiber Cloth and Water followed by Ultraviolet-C Light Exposure Achieves Non-Inferior Disinfection of a Pathogenic Staphylococcus aureus Strain versus Use of Germicidal Wipes.

We hypothesized that ultraviolet-C (UV-C) irradiation (Surfacide, Waukesha, WI) following use of microfiber cloths (Sanny Shop LLC, Longmont, CO) soaked in waterwould be noninferior to surface disinfection wipes containing a quaternary ammonium compound and alcohol (PDI Healthcare, Woodcliff Lake, NJ)for the pathogenic Staphylococcus aureus (S. aureus) sequence type 5 (ST5). This was a randomized laboratory study of disinfection approaches for S. aureusST5. A total of 270 polycarbonate slides loaded with ST5 were prepared for the standard surface disinfection group (N=18) and water-soaked microfiber cloths and UV-C treatment group (N=144), along with positive and negative microbiological controls. All 18 samples of S. aureus ST5 bacteria treated with standard chemical wipes showed complete disinfection (colony forming units (CFU) = 0). All 144 treatments with water-soaked microfiber wipes followed by UV-C exposure showed complete disinfection (CFU =0) regardless of soiling, height from the floor, or orientation to the emitters. The upper 95% exact one-sided confidence limit for any CFU >0 was 2.1%. These data affirm our hypothesis that surface wiping with a damp cloth followed by triangular UV-C irradiation delivery is noninferior to surface disinfection for S. aureusST5 using germicidal wipes, even when UV-C is compromised by height from the floor and orientation to the emitters and surface disinfection is targeted. Removing bioburden with chemical-free microfiber cloths followed by triangular UV-C delivery is a noninferior strategy to targeted surface disinfection with chemical disinfecting wipes for the pathogenicS. aureusST5 strain in the laboratory setting.

Polyester Microfibers Exposure Modulates Mytilus galloprovincialis Hemolymph Microbiome.

Microplastic (MP) contamination in the aquatic environment is a cause of concern worldwide since MP can be taken up by different organisms, altering different biological functions. In particular, evidence is accumulating that MP can affect the relationship between the host and its associated microbial communities (the microbiome), with potentially negative health consequences. Synthetic microfibers (MFs) represent one of the main MPs in the marine environment, which can be accumulated by filter-feeding invertebrates, such as bivalves, with consequent negative effects and transfer through the food chain. In the mussel Mytilus galloprovincialis, polyethylene terephthalate (PET) MFs, with a size distribution resembling that of an MF released from textile washing, have been previously shown to induce multiple stress responses. In this work, in the same experimental conditions, the effects of exposure to PET-MF (96 h, 10, and 100 μg/L) on mussel hemolymph microbiome were evaluated by 16S rRNA gene amplification and sequencing. The results show that PET-MF affects the composition of bacterial communities at the phylum, family and genus level, with stronger effects at the lowest concentration tested. The relationship between MF-induced changes in hemolymph microbial communities and responses observed at the whole organism level are discussed.

The problem of anthropogenic microfibres in karst systems: Assessment of water and submerged sediments

A new worrying micropollutant threathens natural environments: the microfibres (MFs). Natural, regenerated and synthetic MFs have been detected in different environments, as well as in organisms. While synthetic MFs are generally detected in microplastic analyses, natural and regenerated MFs are not taken into account, or are wrongly considered plastics. They are generally considered biodegradable even if their degradation processes in ecosystems are poorly known. Their potential faster degradation could release toxic compounds, and their characteristics could led to a long-term accumulation in the environment. Understanding their dangerousness and the possible impact they could have on ecosystems is fundamental for environment conservation. We collected and investigated water and submerged sediment samples in different caves and springs of the Classical Karst Region (NE Italy), rich in protected habitats and species. MFs were analysed via microscopy and spectroscopy. MFs were found in all samples, highlighting pollution in surface and subterranean habitats of the karst system. MF concentration was higher in submerged sediments respect to waters, highlighting an accumulation of MFs over time. Big microfibres were less abundant, and MF amount increased with the decrease in the considered size. More than 80% of fibres were fluorescent under UV light. Fluorescent MFs were especially transparent, while non-fluorescent ones were mainly black and blue. Most MFs were cellulosic, and synthetic MFs represent only 15–22%, highlighting a significant gap between the MF composition detected in natural environments and the global production of synthetic textiles in recent times. Synthetic MFs were more abundant in waters. Our results improve the knowledge on micropollutants in karst environments, laying the foundations for future research. MF pollution monitoring in karst areas must become a priority for species protection, habitat conservation, and waters management, improving analyses on a larger number of aquatic environments, taking into account the ecological connections between surface and subterranean habitats.

Innovative tarantula hair-inspired washing machine filters for enhanced microfiber capture

Aquatic environments are being polluted by microplastics primarily originating from the washing of synthetic textiles. Microfibers (MF), which are microplastics in synthetic fibers, are consistently introduced into the environment with each domestic laundry cycle. To address this issue, we developed a specialized MF capture “barbed filter” (BF) by transforming PET monofilaments of different diameters (0.4, 0.6, and 0.8 mm) into structures that closely resemble the characteristics of tarantula urticating hairs. BFs feature sharp barbs that effectively capture and retain microfibers of diverse lengths, surpassing the performance of conventional control filters. The BFs had a retention efficiency of 88–91 %, while the CFs had an efficiency of 79–86 %. Our findings revealed that the barbed filter significantly outperformed the conventional control filter in capturing microfibers due to its smaller pore size, shorter pore distance, and unique filter shape. This design not only enhances the surface area and friction, facilitating microfibril strong entrapment but also minimizes the probability of microfibril passage through the filter. This research offers a promising solution for reducing microfibril release from laundry and textile industrial wastewater. The implementation of BFs in real life has the potential to significantly reduce microplastic pollution and promote a cleaner and more sustainable environment.

Ingestion and depuration of polyester microfibers by Crassostrea gasar (Adanson, 1757)

The study aimed to obtain environmentally relevant microfibers (MFs) from polyester fabric and assess their impact on the oyster Crassostrea gasar. MFs were obtained by grinding the fabric, and their accumulation in oysters gills and digestive glands was analyzed after exposure to 0.5 mg/L for 2 and 24 h. Additionally, a 48 h depuration was conducted on the oysters exposed for 24 h. Sublethal effects were assessed in oysters exposed for 24 h and depurated for 48 h, using biomarkers like Catalase (CAT), Glutathione S-transferase (GST), and Glutathione Peroxidase (GPx), along with histological analyses. Polyester fabric grinding produced significant MFs (average length: 570 μm) with degraded surface and increased malleability. Oysters showed increased MF accumulation in digestive glands post-exposure, with no impact on antioxidant enzymes. Depuration decreased MFs accumulation. Histological analysis revealed accumulation in the stomach and brown cells, possibly indicating inflammation. This raises concerns about MFs bioaccumulation in marine organisms, impacting the food chain and safety.

A Feasible and Efficient Monitoring Method of Synthetic Fibers Released during Textile Washing

Microfibers (MFs) are one of the most common and hazardous forms of microplastic found in the aquatic environment. The methods of collecting and analyzing MFs released during washing have to be developed and standardized to understand and model the process of microfibers’ emission better. This study tests a new, innovative method to check if laundry fiber sampling can be approached comprehensively. Pieces of synthetic materials (aged and new polyester, polyester-cotton blend) were placed in chromium-nickel filters envelope-like folded. Then, textile weathering during washing was monitored by the quality and quantity of fibers found directly on the filter surface. Laundry parameters like temperature, detergent presence, and filter size were changed, and results were monitored by Fourier-transform infrared spectroscopy (FTIR), a well-known standard in microplastic identification. In addition, ATR spectra were collected to characterize the materials in detail and evaluate their aging level. Spectroscopy can be used to detect and examine both mechanical and chemical degradation, and the collected microfibers can be assigned to the material they come from. Finally, a quantitative comparison of fibers released during different washing conditions can be used for the process optimization to minimize its environmental impact.

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

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

Microplastic pollution in waters of the Antarctic coastal environment of Potter Cove (25 de Mayo Island/King George Island, South Shetlands)

Plastic pollution in the Southern Ocean around Antarctica is a growing concern, but many areas in this vast region remain unexplored. This study provides the first comprehensive analysis of marine microplastic (MPs) concentrations in Potter Cove, located near the Argentinian Carlini research station on 25 de Mayo/King George Island, Antarctica. Water samples were collected at 14 sites within the cove, representing various influences from the station's activities. Two sampling methods were used: a 5 L Niskin bottle and an in-situ filtering device called Microfilter, allowing for large water volumes to be filtered. MPs were found in 100 % of the samples. Microfilter samples ranged from 0.02 to 2.14 MPs/L, with a mean concentration of 0.44 ± 0.44 MPs/L. Niskin bottle samples showed concentrations from 0.40 to 55.67 MPs/L, with a mean concentration of 19.03 ± 18.21 MPs/L. The dominant types of MPs were anthropogenic black, transparent, and pink microfibers (MFs) measuring between 0.11 and 3.6 mm (Microfilter) and 0.06 to 7.96 mm (Niskin bottle), with a median length of 0.01 mm for both methods. Transparent and black irregular microfragments (MFRs) with diameters from 0.10 to 5.08 mm and a median diameter of 0.49 mm were also prevalent. FTIR-spectroscopy revealed the presence of 14 types of polymers. Cellulose-based materials and polyethylene terephthalate were the most abundant in MFs, while polyurethanes and styrene-based copolymers dominated in MFRs. MPs were more abundant near the Carlini station. Compared to other coastal Antarctic areas, the MPs in the cove were relatively abundant and mostly smaller than 1 mm. Local activities on the island were identified as the primary source of MPs in the cove, and the cyclonic water circulation likely affects the distribution of small-sized particles. To protect the ecosystem, reducing plastic usage, improving waste management, regulating MPs debris, and enhancing wastewater practices are essential.

Design and Analysis of Automated Solar Panel Cleaning System

The primary focus of this study was the development of a solar panel cleaning machine intended for the maintenance of photovoltaic solar panels after their installation. The study also encompassed detailed analysis of this machine. The accumulation of dust particles on solar panels presents a significant challenge, as it jeopardizes the optimal functionality of these panels. By obstructing crucial sunlight, dust diminishes the panels' electricity production capacity, consequently reducing overall efficiency. Moreover, this dust accumulation poses a threat to the integral electrical components of the panels, potentially causing harm to the embedded silicon wafers through overheating if left unaddressed. This situation escalates the necessity for post-installation maintenance and escalates associated repair costs. In response to these challenges, a novel automated mechanism for cleaning solar panels is introduced in this paper, effectively eliminating dust particles. The analytical findings strongly indicate that consistent and periodic cleaning of panels can uphold a stable rate of electricity generation within the power production system. This innovative system design empowers users to effortlessly operate the machine in less time, all the while delivering superior cleaning performance when compared to conventional manual methods. To establish a competitive edge in the market, it is imperative that the proposed system presents a cost-effective solution, evaluated in relation to the number of panels cleaned. Consequently, for the purpose of testing the proposed system, a solar installation was meticulously designed and implemented at PDEA’s College of Engineering in Manjari, (Bk.) Pune, Maharashtra, India. This location was deliberately selected as the experimental site to facilitate comprehensive investigations of the requisite design metrics. The prototype was subsequently simulated within this real-world system. This cleaning system utilizes high-quality microfiber cloth to effectively remove dust from panel surfaces without the need for water, making it suitable for arid areas. Additionally, provisions have been included for a water sprinkler to address stubborn stains like bird droppings that cannot be removed solely with the cloth. The overall impact of this mechanism will result in an increased rated power output from the panels, which had previously been compromised due to the mentioned issues.

MIRNA-LADEN MAGNETIC-RESPONSIVE BIOINK FOR TENDON AND ENTHESIS TISSUE ENGINEERING

Tendons and tendon-to-bone entheses don't usually regenerate after injury, and the hierarchical organization of such tissues makes them challenging sites of study for tissue engineers. In this study, we have tried a novel approach using miRNA and a bioactive bioink to stimulate the regeneration of the enthesis. microRNAs (miRNAs) are short, non-coding sequences of RNA that act as post-transcriptional regulators of gene and protein expression [1]. Mimics or inhibitors of specific miRNAs can be used to restore lost functions at the cell level or improve healing at the tissue level [2,3]. We characterized the healing of a rat patellar enthesis and found that miRNA-16-5p was upregulated in the fibrotic portion of the injured tissue 10 days after the injury. Based on the reported interactions of miRNA-16-5p with the TGF-β pathway via targeting of SMAD3, we aimed to explore the effects of miRNA-16-5p mimics on the tenogenic differentiation of adipose-derived stem cells (ASCs) encapsulated in a bioactive bioink [4,5]. Bioinks with different properties are used for the 3D printing of biomimetic constructs. By integrating cells, materials, and bioactive molecules it is possible to tailor the regenerative capacity of the ink to meet the particular requirements of the tissue to engineer [5]. Here we have encapsulated ASCs in a gelatin-methacryloyl (GelMa) bioink that incorporates miR-16-5p mimics and magnetically responsive microfibers (MRFs). When the bioink is crosslinked in the presence of a magnetic field, the MRFs align unidirectionally to create an anisotropic construct with the ability to promote the tenogenic differentiation of the encapsulated ASCs. Additionally, the obtained GelMA hydrogels retained the encapsulated miRNA probes, which permitted the effective 3D transfection of the ASC and therefore, the regulation of gene expression, allowing to investigate the effects of the miR-16-5p mimics on the tenogenic differentiation of the ASCs in a biomimetic scenario.

Exposure to bisphenol A and fiber-type microplastics induce oxidative stress and cell damage in disk abalone Haliotis discus hannai: Bioaccumulation and toxicity

Along with environmental pollution caused by rapid economic development and industrialization, plastic waste is emerging as a global concern in relation to marine ecosystems and human health. Among the microplastics, fiber-type microfibers (MF) and bisphenol A (BPA), which are widely used as plasticizers, do not decompose well in the ocean, and tend to accumulate in organisms, generating an increased oxidative stress response. This study investigated the abalones’ antioxidant and cell death responses following exposure to the environmental pollutants MF and BPA. Levels of malondialdehyde (MDA) and DNA damage increased over time, demonstrating the degree of lipid peroxidation and DNA damage in abalones exposed to individual and combined environmental conditions of MF and BPA. Compared to the single MF and BPA exposure groups, the combined exposure group showed a higher expression of antioxidant enzymes. A similar pattern was seen in the expression of the apoptosis enzyme caspase-3. Both MF and BPA caused oxidative stress and antioxidant enzymes were expressed to alleviate it, but it is believed that cell damage occurred because the stress level exceeded the allowed range.

Microfibres Release from Textile Industry Wastewater Effluents Are Underestimated: Mitigation Actions That Need to Be Prioritised

The release of microfibres (MFs) from textiles has been observed in various environments, pointing towards the impact of human activities on natural systems. Synthetic textile microfibres, a subset of microplastic fibres (MPFs), are reported to be the primary contributor to microplastic pollution. With the forecasted growth in textile production, the problem of MF pollution is expected to worsen and become more challenging to address. Wastewater treatment plants (WWTPs) are crucial in managing microfibre pollution as they can act as a sink and source of these pollutants. Studies have shown that textile industrial effluent can contain MFs at a rate of up to a thousand times higher than municipal wastewater. As more garments are made than sold and worn, the impact of industrial MF release could be higher than predicted. The detection and quantification of microfibres released in industrial wastewater effluents do not have a standard test method, and legislation to address this issue is not yet feasible. To tackle this issue, it is crucial to raise awareness in the industry and tackle it using a more holistic approach. With its urgency, but still being an underdeveloped research area, priorities for mitigation actions are examined where efforts are needed to accelerate. These include the need to raise awareness and encourage more investigations from industry and academia. A consistent protocol will help us to compare studies and find solutions of high impact and measure MFs in WWTPs, which can help define the maximum limit for MF releases and support legislation implementation.

Evaluating three water-based systems and one organic solvent for the removal of dammar varnish from artificially aged oil paint samples

A framework was developed to evaluate and compare cleaning systems and cleaning system delivery methods, collectively referred to as varnish removal methods, within art conservation practice. This framework was applied to two water-based cleaning systems, optimised for the removal of dammar varnish from an artificially aged brown earth oil paint, including the surfactant-containing microemulsion, Polar Coating B (from the Nanorestore Cleaning series) delivered via the chemical gel, Higher Water Retention (HWR) (from the Nanorestore Gel Dry series), and a surfactant-free microemulsion delivered via the microfiber cloth, Evolon. In addition, two water-based systems and one organic solvent were used to remove dammar varnish from an artificially aged lead white oil paint sample, including a xanthan gum-stabilised emulsion delivered via a synthetic brush, a surfactant-free microemulsion delivered via cotton swab rolling, and 2-propanol solvent delivered via cotton swab rolling. The evaluation framework was thus applied to two different oil paints, with different sensitivities to cleaning. Through this work, the comparative advantages and disadvantages of the varnish removal methods were demonstrated. Notably, cleaning system compatibility with multiple delivery methods afforded greater versatility, including for reducing unwanted interactions between the cleaning system and oil paint. In addition, a surfactant-free microemulsion proved to be a promising, clearance-free, inexpensive, and modifiable option within current offerings for largely water-based methods for varnish removal.

Photochemical reactivity of water-soluble dissolved organic matter from microplastics and microfibers

Plastics in aquatic environments are a source of dissolved organic matter (DOM). However, its production pathways and environmental fate remain poorly understood. This study investigated the yields, characterization, and photochemical reactivities of water-soluble DOM from seven pristine microplastics (MPs) and three microfibers (MFs). We found yields of plastic-derived DOM per unit mass of MPs or MFs, including chromophoric DOM (CDOM) and dissolved organic carbon (DOC), were significantly influenced by polymer chemical structures. Notably, MFs exhibited consistently higher DOM yields compared to MPs. In addition, plastics containing aromatic rings, such as PETE and PS, were found to generate higher CDOM yields, although PVC also showed elevated CDOM yields. The plastic-derived DOM had a diverse molecular size-range, spanning from 60 nm (polyester-DOM) to 937 nm (LDPE-DOM), while Zeta potentials, which were predominantly negatively charged, varied from −42.5 mV (nylon-DOM) to +4.6 mV (LMW-PVC-DOM). Degradation rate constants for CDOM (0.001–0.022 h−1) were generally higher than DOC (0.0009–0.020 h−1), with a shorter half-life for PETE- and PS-derived DOM. The reactivity and degradation kinetics of plastic-derived DOM were notably manifested in changes of fluorescence spectra (excitation-emission matrixes) during photochemical weathering, showing the influence of polymeric composition/structures. This baseline study provides an improved understanding of the characterization and environmental fate of microfiber- and plastic-derived DOM in aquatic environments.

Identification, removal of microplastics and surfactants from laundry wastewater using electrocoagulation method

Microplastics (MPs) and surfactants are generally recognized as emerging contaminants with complicated ecotoxicological impacts. The majority of study data refers to laundry wastewater as a substantial source of MPs and surfactants in the aquatic system, which reaches aquatic environments through sewer discharges even when wastewater treatment facilities retain them. This study focused on releasing and removing contaminants from laundry wastewater, particularly MPs and surfactants. The electrocoagulation method was used to remove the pollutants from laundry wastewater. According to the results, a reference load of 2 kg of synthetic materials releases 92,700 to 1,14,300 synthetic microfibers (MFs). MFs, surfactants, and chemical oxygen demand (COD) removal efficiency are higher at neutral pH. The percentage removal efficiency of MFs, surfactants, and COD was 97.9%, 91.2%, and 86.3%, respectively, at an operating time of 25 min, a current density of 300 A/m2 with optimum power consumption. The total operation cost of laundry wastewater treatment by electrocoagulation was US$0.53 /m3. The readers will gain a complete understanding of the removal of MFs and surfactants from laundry wastewater using the electrocoagulation technique.

Polyacrylonitrile microfibers pose a significant threat to the early-stage survival of zebrafish

Microplastic pollution, especially microfibers (MFs), presents a critical global environmental challenge in natural water bodies. Yet, research on the toxic effects of MFs, particularly during early fish development, is limited. This study aimed to investigate MFs' toxic effects and mechanisms on early-stage zebrafish. Zebrafish embryos were exposed to varying concentrations of polyacrylonitrile microfibers (PanMfs) for 7 days. Results revealed PanMfs adhering to the embryos' surface, with higher concentrations accelerating heart rate and causing pericardial edema in post-hatching larvae. Larvae ingested PanMfs, leading to their accumulation in the intestines and increased levels of reactive oxygen species (ROS) and mitochondrial quantity. Notably, lipid metabolism and calcium ion related signaling pathways underwent significant changes. Low concentration MFs affected glycometabolism pathways, with potential roles for aldob and cacng1a, exhibiting pronounced increases in ROS levels. High concentration of MFs had the most profound impact on signal transduction-related pathways, and possibly triggering micromitophagy and apoptosis in zebrafish intestinal epithelial cells through the Kras/MAPK signaling pathway, with potential roles for kras and mapk9. Although ROS increase was somewhat alleviated, it resulted in decreased survival rates and restricted growth in high concentration of MFs group. These findings highlight the significant threat of MFs to the early survival of fish. MFs pollution prevention and control hold great significance in the conservation of fishery resources.

Ingestion of microplastics and microfibers by the invasive blue crab Callinectes sapidus (Rathbun 1896) in the Balearic Islands, Spain

The blue crab Callinectes sapidus Rathbun, 1896 is native to the western coasts of the Atlantic Ocean and is currently considered an invasive species in the Mediterranean Sea. In this study, we examined the stomach contents of C. sapidus to determine the frequency of occurrence of microplastics (MPs) and microfibers (MFs) in the Balearic Islands archipelago in the western Mediterranean Sea. A total of 120 individuals were collected from six locations between 2017 and 2020. Overall, 65.8% of the individuals had MPs and/or MFs particles with an average of 1.4 ± 1.6 particles ind.−1 of which an average of 1.0 ± 1.3 items ind.−1 were MFs and an average of 0.4 ± 0.8 items ind.−1 were MPs. In terms of type, fragments were the dominant type of MPs and the most common size of items ranged from between 0.5 and 1 mm (40%) followed by 1–5 mm (31%). The most prevalent polymers were low-density polyethylene (39%) and high-density polyethylene (26%). In terms of links to human activities, MP ingestion was positively correlated with an increase in drain pipes, whereas MF ingestion was positively correlated with an increase in sewage pipelines, providing evidence of potential sources and the bioavailability of these particles in various environments. This study confirms the widespread presence of MP and MF particles, even in areas that are currently managed under different protection statuses, in the stomach contents of invasive blue crab species throughout coastal communities.