Quantification and characterization of microplastics in commercial fish from southern New Zealand

Microplastics in Morocco's most consumed fisheries: Chemical characterization, ecological traits, and implications for human health

The pervasive presence of microplastics (MPs) in the environment is well established, yet many critical questions remain about their distribution and potential impacts on both ecological and human health. To assess the risks that MPs pose, especially through marine ecosystems and human consumption, monitoring their ingestion by fish in natural environments is essential. This study investigated the contamination of 12 fish species, the most commonly consumed in Morocco, collected from the Atlantic Ocean off the Moroccan coast. Analysis of 240 fish (20 individuals per species) revealed that 100 % of the samples contained microplastics. MPs were detected in the gills, gonads, and gastrointestinal tracts of all 12 species. The average abundance of microplastics per fish ranged from 20.6 to 133.2 MPs, with the forms identified as fragments (60 %), fibers (30 %), films (8 %), and pellets and foams (1 %). Additionally, omnivorous and demersal species presented the highest levels of MP contamination. Infrared spectroscopy (ATR-FTIR) analysis identified seven polymers, with high-density polyethylene (34 %), polyethylene terephthalate (30 %), and polypropylene (17.5 %) being the most prevalent. The microplastics were predominantly dark or light in color, with a notable presence of red and blue particles. Fish ingest various sizes of microplastics, primarily particles smaller than 1 mm. Scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX) revealed that most MPs exhibited visible signs of weathering and contained inorganic components on their surfaces. The potential risk of MPs to fish, as assessed by the polymer hazard index (PHI), was categorized as level V, indicating that MPs may pose significant risks to human health. The highest estimated daily intake (EDI) of microplastics was found in children (1620 MPs/year), whereas the lowest intake was estimated in women (350 MPs/year) and men (337 MPs/year). Given the widespread presence of microplastics in commonly consumed fish species in Morocco, there is an urgent need for regulatory measures to ensure the safety of fisheries, both for domestic consumption and export. Policymakers should consider the development of guidelines for acceptable levels of microplastic contamination in fish to safeguard public health.

Microplastics in seawater and fish acquired from the corresponding fishing zones of the Baltic Sea

Microplastics in seawater and fish from the Baltic Sea were analyzed. The significant contribution of the study is due to extensive collection of fish and surface water samples from corresponding fishing zones. Microplastics were detected in 100 % of seawater and 61 % of fish samples. The abundances of microplastics were 19,984 ± 8858 items/m3 (seawater) and 3.3 items/fish in the fish organs. The average dimension was 1.08 ± 1.19 mm (seawater), and 0.77 ± 0.84 mm (fish). In 106 out of 178 specimens (61 %), MPs were found in the gills (46 %), digestive tract (38 %), or liver (16 %). Fiber was the most dominant shape found in seawater (91.7 %) and fish (68.3 %), while the dominant color of items was blue. Items were mostly composed of polyethylene (21 %), polypropylene (20 %), cellophane (16 %), polyamide (9 %), and polyacrylate (8 %).

Exploring the detrimental effects of microplastics on Asian seabass (Lates calcarifer) fingerlings survival and health

Microplastics (MPs) are widely used and disposed of indiscriminately, posing a potential threat to aquatic life. Herein, Asian seabass (Lates calcarifer) fingerlings were exposed to various concentrations (1, 10 and 100 ppt or g/kg) of dietary polyethylene MPs for 16 days. The results indicated a significant increase in mortality among the fish fed with dietary MPs compared to the control. Furthermore, histological analysis of the liver revealed moderate-to-severe morphological alterations, hepatocyte necrosis and vacuolisation as the concentration gradient of MPs increased. The severity of the alterations was highest at a concentration of 100 ppt, indicating a direct correlation between MP and liver damage. In addition, RNA sequencing and Gene Ontology term enrichment analysis revealed that a total of 4137 genes were significantly differentially expressed, with 1958 upregulated and 2179 downregulated genes. The significantly enriched terms included 'oxidoreductase activity', 'endocytosis', 'mitochondrial', 'immune system process' and 'lipid catabolic process'. Moreover, the Kyoto Encyclopaedia of Genes and Genomes enrichment analysis demonstrated that dietary MPs triggered oxidative stress, immune response and adaptive mechanism pathways in fish. Thus, MPs can induce metabolic disorders in L. calcarifer, highlighting their potential threat to aquatic organisms.

Polyester fibres slowly degrade in marine sediments

Microplastics are everywhere, including marine sediment. In this study, we evaluated the degradation of polyester, rayon, and cotton sewing threads over nine months when buried in marine sediment in Waitematā Harbour, Auckland, New Zealand. Polyester tensile strength was tested pre- and post-burial to track changes over time. Fourier-transform infrared spectroscopy (FTIR) analysis enabled the examination of the change to the chemical structural integrity of the polyester molecules over time. After one month, rayon and cotton degraded and were invisible to the eye, while visible signs of polyester degradation were apparent after 6 months of burial. This was confirmed by both tensile strength testing and FTIR chemical analysis. While microplastic pollution remains a serious problem, these findings show that at least one type of common plastic does degrade when buried in marine sediments. This likely has implications for seafloor ecosystem functionality and provides hope for plastic circular economy infrastructure.

Microplastics in water resources: Global pollution circle, possible technological solutions, legislations, and future horizon

Beneath the surface of our ecosystems, microplastics (MPs) silently loom as a significant threat. These minuscule pollutants, invisible to the naked eye, wreak havoc on living organisms and disrupt the delicate balance of our environment. As we delve into a trove of data and reports, a troubling narrative unfolds: MPs pose a grave risk to both health and food chains with their diverse compositions and chemical characteristics. Nevertheless, the peril extends further. MPs infiltrate the environment and intertwine with other pollutants. Worldwide, microplastic levels fluctuate dramatically, ranging from 0.001 to 140 particles.m-3 in water and 0.2 to 8766 particles.g-1 in sediment, painting a stark picture of pervasive pollution. Coastal and marine ecosystems bear the brunt, with each organism laden with thousands of microplastic particles. MPs possess a remarkable ability to absorb a plethora of contaminants, and their environmental behavior is influenced by factors such as molecular weight and pH. Reported adsorption capacities of MPs vary greatly, spanning from 0.001 to 12,700 μg·g-1. These distressing figures serve as a clarion call, demanding immediate action and heightened environmental consciousness. Legislation, innovation, and sustainable practices stand as indispensable defenses against this encroaching menace. Grasping the intricate interplay between microplastics and pollutants is paramount, guiding us toward effective mitigation strategies and preserving our health ecosystems.

The occurrence and exposure of microplastics in bivalves from Qingdao, China

This study investigated the regional, seasonal, and species abundance and characteristics of microplastics (MPs) in bivalves from Qingdao, China and assessed the dietary exposure of MPs through bivalve consumption. The average abundance was 1.17 ± 1.07 items/individual or 0.17 ± 0.22 items/g wet weight. Fiber was the dominant shape (91.5 %). The average size of MPs was 995.63 ± 796.59 μm. Rayon, PE, and PET contributed mostly to the MPs composition. There were no significant regional or seasonal differences in MPs abundance (p > 0.05), while there were significant species differences (p < 0.05) when describing the abundance by wet weight. The estimated daily intakes of MPs through bivalve consumption by general population, consumer only population, and coastal residents in China were 3.32 × 10-3, 0.08, and 0.16 μg/kg BW, respectively. The exposure assessment method by converting the quantity of MPs into mass may facilitate the risk characterization in the future.

Exploring the trophic transfer and effects of microplastics in freshwater ecosystems: A focus on Bellamya aeruginosa to Mylopharyngodon piceus

Microplastics (MPs) can enter aquatic food webs through direct ingestion from the environment or indirectly via trophic transfer, but their fate and biological effects within local freshwater food chains remain largely unexplored. In this study, we conducted the first investigation on the trophic transfer and impacts of fluorescently labeled polystyrene microplastics (PS-MPs) (100-nm and 10-μm) in a model freshwater food chain consisting of the snail Bellamya aeruginosa and the commercially important fish Mylopharyngodon piceus, both prevalent in Chinese freshwater ecosystems. Quantitative analysis revealed substantial accumulation of MPs in B. aeruginosa, reaching an equilibrium state within 12 h of exposure. While steady-state was not observed, a pronounced time-dependent bioaccumulation of MPs was evident in M. piceus over a five-week period following dietary exposure through the consumption of contaminated B. aeruginosa. Notably, MPs of both sizes underwent translocation from the gastrointestinal tract to the muscle tissue in M. piceus. High-throughput sequencing of the gut microbiota revealed that exposure to 100-nm MPs significantly altered the microbial community composition in M. piceus, and both particle sizes led to increased relative abundance of potentially pathogenic bacterial genera. Our findings provide novel insights into the trophic transfer, tissue accumulation, and biological impacts of MPs in a model freshwater food chain, highlighting the need for further research to assess the ecological and food safety risks associated with microplastic pollution in freshwater environments.

Phthalate migration potential in vacuum-packed fish

Phthalates or phthalate esters (PAEs) have become a serious concern due to their toxicity and risks of migration from contact materials to food matrices and the environment. The aim of this study is to monitor the possible migration potential of PAEs in pelagic fish stored in vacuum packaging depending on the storage time and to determine the polyethylene polymers. In order to achieve this goal, sea bass (Dicentrarchus labrax) and anchovy fish (Engraulis encrasicolus) were randomly packaged in vacuum bags and then stored for 90 days. Phthalate content was determined by GC/MS technique in the muscle tissue of each fish species at certain periods (0, 30, and 90 days) of storage, and on the first day in the packaging material and fish meat. As a result of the analysis performed in µ-Raman spectroscopy, no microplastics were detected in both fish species' meats. FTIR spectroscopy results of the packaging material determined nylon in the chemical content of the packaging material before processing. It has been determined that the chemical composition of the packaging used in the vacuum packaging process is affected by the temperature, depending on the storage period, and different polymer types are formed in the processed package material. It was determined that the dominant PAE homologues were Di-n-pentyl phthalate (DPENP) in both fish meat and Di-(2-ethylhexyl)-phthalate (DEHP) in the package. However, during storage, Dibutylphthalate (DBP) became dominant in anchovies and DPENP became dominant in sea bass, differing according to fish species and storage time.

Investigating the metabolic and oxidative stress induced by biofouled microplastics exposure in Seriola lalandi (yellowtail kingfish)

Microorganisms quickly colonise microplastics entering the ocean, forming a biofilm that, if ingested, is consumed with the microplastics. Past research often neglects to expose fish to biofouled microplastics, opting only for clean microplastics despite the low likelihood that fish will encounter clean microplastics. Here, we investigate the physiological impacts of biofouled polyethylene microplastic (300-335 μm) exposure in juvenile fish. Intermittent flow respirometry, antioxidant enzyme activity, and lipid peroxidation were investigated after fish were exposed to clean, biofouled, or no microplastic beads. Fish exposed to biofouled microplastics had a wider aerobic scope than those exposed to clean microplastics while antioxidant enzyme and lipid peroxidation levels were higher in clean microplastics. Clean microplastic exposure indicated higher fitness costs, potentially due to a nutritional advantage of the biofilm or varying bioavailability. These findings highlight the importance of replicating natural factors in exposure experiments when predicting the impacts of increasing pollutants in marine systems.

Phospholipidomics in Clinical Trials for Brain Disorders: Advancing our Understanding and Therapeutic Potentials

Phospholipidomics is a specialized branch of lipidomics that focuses on the characterization and quantification of phospholipids. By using sensitive analytical techniques, phospholipidomics enables researchers to better understand the metabolism and activities of phospholipids in brain disorders such as Alzheimer's and Parkinson's diseases. In the brain, identifying specific phospholipid biomarkers can offer valuable insights into the underlying molecular features and biochemistry of these diseases through a variety of sensitive analytical techniques. Phospholipidomics has emerged as a promising tool in clinical studies, with immense potential to advance our knowledge of neurological diseases and enhance diagnosis and treatment options for patients. In the present review paper, we discussed numerous applications of phospholipidomics tools in clinical studies, with a particular focus on the neurological field. By exploring phospholipids' functions in neurological diseases and the potential of phospholipidomics in clinical research, we provided valuable insights that could aid researchers and clinicians in harnessing the full prospective of this innovative practice and improve patient outcomes by providing more potent treatments for neurological diseases.

Evaluation of phthalate migration potential in vacuum-packed

In recent years, the presence and migration of PAEs in packaging materials and consumer products has become a serious concern. Based on this concern, the aim of our study is to determine the possible migration potential and speed of PAEs in benthic fish stored in vacuum packaging, as well as to monitor the storage time and type as well as polyethylene (PE) polymer detection.As a result of the analysis performed by µ-Raman spectroscopy, 1 microplastic (MP) of 6 µm in size was determined on the 30th day of storage in whiting fish muscle and the polymer type was found to be Polyethylene (PE) (low density polyethylene: LDPE). Depending on the storage time of the packaging used in the vacuum packaging process, it has been determined that its chemical composition is affected by temperature and different types of polymers are formed. 10 types of PAEs were identified in the packaging material and stored flesh fish: DIBP, DBP, DPENP, DHEXP, BBP, DEHP, DCHP, DNOP, DINP and DDP. While the most dominant PAEs in the packaging material were determined as DEHP, the most dominant PAEs in fish meat were recorded as BBP and the lowest as DMP. The findings provide a motivating model for monitoring the presence and migration of PAEs in foods, while filling an important gap in maintaining a safe food chain.

Occurrence of microplastics in fish gastrointestinal tracts belongs to different feeding habits from the Bangladesh coast of the Bay of Bengal

The Bay of Bengal (BoB) is home to a range of commercially important species with different food habits and feeding features. Microplastic (MP) contamination in the fish of BoB, like in many other marine environments, is a significant environmental concern. The study aimed to investigate the presence of microplastics (MPs) in the gastrointestinal tracts (GITs) of selected commercial marine fishes from the Bangladesh coast of the BoB. Six fish species (Escualosa thoracata, Tenualosa ilisha, Johnius belangerii, Trichiurus lepturus, Planiliza parsia, and Mystus gulio) were investigated (n = 120) following hydrogen peroxide digestion, and floatation (saline solution) protocols. After analyses, a total number of 696 MPs (dimension 0.3 to 5 mm) were identified. Moreover, the highest occurrence of MPs in fish GITs was found in planktivorous fish (average of 7.7 items/individual), followed by omnivorous (average of 5.2 items/individual), and carnivorous fish (average of 4.6 items/individual) (p < 0.001). However, planktivorous E. thoracata showed the highest number of MPs per g of GIT (average of 30.99 items/g GIT), whereas T. ilisha showed the lowest count (average of 0.77 items/g GIT). Different types of MPs (fibers (19 to 76%), fragments (6 to 61%), films (8 to 35%), microbeads (0 to 5%), and foams (0 to 2%)) were also observed. In terms of the color of MPs, the transparent, black, green, and blue types were the most common. Polymers were found as polyethylene (35 to 43%), polyethylene terephthalate (28 to 35%), polyamide (20 to 31%), and polystyrene (0 to 7%). The study provides a significant incidence of MPs in fish from the Bangladesh part of the BoB, which is very concerning. Therefore, long-term research is indispensable to ascertain the variables affecting the presence of MPs in fish, their origins, and their potential effects on the BoB fisheries. Stringent policies on plastic use and disposal should be strongly urged in this coastal region.

Fate, abundance and ecological risks of microcystins in aquatic environment: The implication of microplastics

Microcystins are highly toxic cyanotoxins and have been produced worldwide with the global expansion of harmful cyanobacterial blooms (HABs), posing serious threats to human health and ecosystem safety. Yet little knowledge is available on the underlying process occurring in the aquatic environment with microcystins. Microplastics as vectors for pollutants has received growing attention and are widely found co-existing with microcystins. On the one hand, microplastics could react with microcystins by adsorption, altering their environmental behavior and ecological risks. On the other hand, particular attention should be given to microplastics due to their implications on the outbreak of HABs and the generation and release of microcystins. However, limited reviews have been undertaken to link the co-existing microcystins and microplastics in natural water. This study aims to provide a comprehensive understanding on the environmental relevance of microcystins and microplastics and their potential interactions, with particular emphasis on the adsorption, transport, sources, ecotoxicity and environmental transformation of microcystins affected by microplastics. In addition, current knowledge gaps and future research directions on the microcystins and microplastics are presented. Overall, this review will provide novel insights into the ecological risk of microcystins associated with microplastics in real water environment and lay foundation for the effective management of HABs and microplastic pollution.

Insight into microplastics in the aquatic ecosystem: Properties, sources, threats and mitigation strategies

Globally recognized as emergent contaminants, microplastics (MPs) are prevalent in aquaculture habitats and subject to intense management. Aquaculture systems are at risk of microplastic contamination due to various channels, which worsens the worldwide microplastic pollution problem. Organic contaminants in the environment can be absorbed by and interact with microplastic, increasing their toxicity and making treatment more challenging. There are two primary sources of microplastics: (1) the direct release of primary microplastics and (2) the fragmentation of plastic materials resulting in secondary microplastics. Freshwater, atmospheric and marine environments are also responsible for the successful migration of microplastics. Until now, microplastic pollution and its effects on aquaculture habitats remain insufficient. This article aims to provide a comprehensive review of the impact of microplastics on aquatic ecosystems. It highlights the sources and distribution of microplastics, their physical and chemical properties, and the potential ecological consequences they pose to marine and freshwater environments. The paper also examines the current scientific knowledge on the mechanisms by which microplastics affect aquatic organisms and ecosystems. By synthesizing existing research, this review underscores the urgent need for effective mitigation strategies and further investigation to safeguard the health and sustainability of aquatic ecosystems.

Microplastic ingestion in key fish species of food webs in the Southwest Atlantic (Marine Protected Area Namuncurá / Burdwood Bank)

Microplastics (MPs) are currently one of the main problems of marine pollution, being found in all environmental matrices. Due to their size, they can be ingested by organisms directly (from the environment) or indirectly (with their prey). The objective of this study was to analyze the occurrence, abundance, concentration, and chemical nature of MPs present in the gastrointestinal tract of two fish species, Patagonotothen guntheri and Patagonotothen ramsayi, both of which are key in the food web of the Marine Protected Area Namuncurá/ Banco Burdwood (MPA N/BB). The analyzed species presented high values of MPs per individual (MPs/ind.) and occurrence compared to other studies. P. guntheri tended to have a lower number of MPs/ind. and occurrence than P. ramsayi (P. guntheri: 2.50 ± 1.93 MPs/ind., 82.50  %; P. ramsayi: 3.93 ± 2.91 MPs/ind., 90.60  %). While fibers were the predominant MPs in both species, P. ramsayi had a greater number of fragments and a greater variety of MPs chemical composition than P. guntheri. The prevailing chemical composition was cellulosic material (cellulose and cellulose mixed with polyamide and polyester). Synthetic fibers and fragments such as polyester (PET), alkyd resin, polyurethane, polyethylene, polyacrylic fiber and poly(ethylene-co-vinyl acetate-co-vinyl chloride) were also found. Although both species have a generalist diet, the differences found may be due to the fact that P. guntheri has benthopelagic feeding habits while P. ramsayi has demersal-benthic. Our study is the first report on the presence and characterization of MPs in organisms relevant to food webs in the Southwest Atlantic.

Advances on micro/nanoplastics and their effects on the living organisms: A review

Micro/nanoplastics (MPs) are attracting increasing attention owing to the potential threats they pose to the sustainability of the environment and the health of living organisms. Thus, a comprehensive understanding of the influence of MPs on living organisms is vital for developing countermeasures. We conducted an extensive literature search to retrieve the articles related to MPs via the Web of Science. Accordingly, 152 articles published in the last decade and in influential journals were selected to analyze the effects of MPs on plants, animals, microorganisms, and humans as well as the current status, hotspots, and trends of studies on MPs. The results showed that owing to the special characteristics of MPs and anthropogenic activities, MPs have become ubiquitous worldwide. MPs are ingested by plants and animals and enter the human body through various pathways, resulting in numerous adverse effects, such as growth inhibition, oxidative stress, inflammation, organ damage, and germ cell lesions. Moreover, they affect microorganisms by reshaping the structure and function of microbial communities and changing the spread pathway. However, microorganisms can also contribute to the degradation of MPs. With increasing evidence of the adverse effects of MPs on biota, coping with MP pollution and mitigating harmful outcomes have emerged as major challenges. This review focuses on (1) the main effects of MPs on living organisms, ranging from microorganisms to humans, (2) the current status and hotspots of studies related to MPs, and (3) the challenges and prospects of further studies on MPs.

Plastic mulching, and occurrence, incorporation, degradation, and impacts of polyethylene microplastics in agroecosystems

Polyethylene microplastics have been detected in farmland soil, irrigation water, and soil organisms in agroecosystems, while plastic mulching is suggested as a crucial source of microplastic pollution in the agroecosystem. Plastic mulch can be broken down from plastic mulch debris to microplastics through environmental aging and degradation process in farmlands, and the colonization of polyethylene-degrading microorganisms on polyethylene microplastics can eventually enzymatically depolymerize the polyethylene molecular chains with CO2 release through the tricarboxylic acid cycle. The selective colonization of microplastics by soil microorganisms can cause changes in soil microbial community composition, and it can consequently elicit changes in enzyme activities and nutrient element content in the soil. The biological uptake of polyethylene microplastics and the associated disturbance of energy investment are the main mechanisms impacting soil-dwelling animal development and behavior. As polyethylene microplastics are highly hydrophobic, their presence among soil particles can contribute to soil water repellency and influence soil water availability. Polyethylene microplastics have been shown to cause impacts on crop plant growth, as manifested by the effects of polyethylene microplastics on soil properties and soil biota in the agroecosystems. This review reveals the degradation process, biological impacts, and associated mechanisms of polyethylene microplastics in agroecosystems and could be a critical reference for their risk assessment and management.

Investigations of hemato-biochemical and histopathological parameters, and growth performance of walking catfish (Clarias batrachus) exposed to PET and LDPE microplastics

Fish inhabiting various trophic levels are affected differently as the presence of microplastic (MP) in the water column and their ingestion by fish varies. Walking catfish (Clarias batrachus) inhabits the bottom of the water bodies. To understand the effects of MP, we exposed C. batrachus to two types of MP - polyethylene terephthalate (PET) and low-density polyethylene (LDPE) for 60 days. After exposure, hematological indices, mainly red blood cells and hemoglobin levels decreased, and white blood cells increased significantly compared to the control group (p < 0.05). A significant increase in the levels of blood urea and glucose was observed, and serum glutamic pyruvate transaminase and serum glutamyl oxaloacetic transaminase activity remained elevated (p < 0.05). Histopathological examination of the liver, kidney, intestine, and gills showed morphological alterations. Moreover, MP exposure caused growth retardation (p < 0.05) in C. batrachus. Widespread pollution of water bodies by MP may impose serious ecological risks to bottom-feeding fish in Bangladesh.

Riverine Microplastic Pollution: Insights from Cagayan de Oro River, Philippines

Rivers are vital water sources for humans and homes for aquatic organisms. Conversely, they are well known as the route of plastics into the ocean. Despite being the world's number one emitter of riverine plastics into the ocean, microplastics (MPs), or plastic particles less than 5 mm, in the Philippines' rivers are relatively unexplored. Water samples were collected from six sampling stations along the river channel of the Cagayan de Oro River, one of the largest rivers in Northern Mindanao, Philippines. The extracted microplastics' abundance, distribution, and characteristics were analyzed using a stereomicroscope and Fourier transform infrared spectroscopy (FTIR). The results showed a mean concentration of 300 items/m³ of MPs dominated by blue-colored (59%), fiber (63%), 0.3-0.5 mm (44%), and polyacetylene (48%) particles. The highest concentration of microplastics was recorded near the mouth of the river, and the lowest was in the middle area. The findings indicated a significant difference in MP concentration at the sampling stations. This study is the first assessment of microplastic in a river in Mindanao. The results of this study will aid in formulating mitigation strategies for reducing riverine plastic emissions.

Investigating the impacts of biofouled marine plastic debris on the olfactory behaviour of juvenile yellowtail kingfish (Seriola lalandi)

Marine microplastics are rapidly colonised by a microbial community which form a biofilm unique from the surrounding seawater that often contains infochemical-producing species associated with food sources. Here, we investigated whether juvenile kingfish (Seriola lalandi) were more attracted to biofouled plastics compared to clean plastics. Plastics were exposed to unfiltered seawater for one month to cultivate a microbial community. An olfactory behavioural experiment showed little difference in their response to the biofilm compared to clean plastic and control treatment. Further, ingestion experiments demonstrated that S. lalandi ingested fewer biofouled microplastics compared to clean microplastics. However, this was likely due to the bioavailability of the biofouled microplastics. This study highlights that while juvenile kingfish will ingest microplastics, they are not more attracted to those with a naturally acquired biofilm.

The toxicity of nano polyethylene terephthalate to mice: Intestinal obstruction, growth retardant, gut microbiota dysbiosis and lipid metabolism disorders

Polyethylene terephthalate (PET) are widely used in our daily life while they may be broken to smaller fractions as nano-sized PET (nPET) in the environment. The toxicity of nPET is still less studied. This work first evaluated the LD50 of different size of nPET (200 nm, S-nPET; 700 nm, B-nPET) in mice, then studied the health effects of single exposure to S/B-nPET at 200 mg/kg bw for 30 days. It was found that the LD50 was 266 mg/kg bw for S-nPET and 523 mg/kg bw for B-nPET, respectively, showing a size-dependent effect. S-nPET caused weight loss, cyst, intestinal obstruction, organ damage and mortality (40%), and perturbed gut microbiome and metabolome especially lipid metabolism, such as upregulated cholesterol, glycocholic, propionic acid, niacinamide, ectoine and xanthine, and downregulated arachidonic acid, anserine, histamine, while B-nPET did not. Serological analysis found S-nPET brought more lipid metabolic immune and neurological damage than B-nPET, confirming the size-dependent effect. To the best of our knowledge, this is the first report on the systematic toxicity of nPET to mice. Further studies are warranted for life-long effects of nPET. The protocol applied in this work may also be used for the study of the health effects of other plastics.

Unraveling the potential human health risks from used disposable face mask-derived micro/nanoplastics during the COVID-19 pandemic scenario: A critical review

With the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), disposable face masks (DFMs) have caused negative environmental impacts. DFMs will release microplastics (MPs) and nanoplastics (NPs) during environmental degradation. However, few studies reveal the release process of MPs/NPs from masks in the natural environment. This review presents the current knowledge on the abiotic and biotic degradation of DFMs. Though MPs and NPs have raised serious concerns about their potentially detrimental effects on human health, little attention was paid to their impacts on human health from DFM-derived MPs and NPs. The potential toxicity of mask-derived MPs/NPs, such as gastrointestinal toxicity, pneumotoxicity, neurotoxicity, hepatotoxicity, reproductive and transgenerational toxicity, and the underlying mechanism will be discussed in the present study. MPs/NPs serve as carriers of toxic chemicals and pathogens, leading to their bioaccumulation and adverse effects of biomagnification by food chains. Given human experiments are facing ethical issues and animal studies cannot completely reveal human characteristics, advanced human organoids will provide promising models for MP/NP risk assessment. Moreover, in-depth investigations are required to identify the release of MPs/NPs from discarded face masks and characterize their transportation through the food chains. More importantly, innovative approaches and eco-friendly strategies are urgently demanded to reduce DFM-derived MP/NP pollution.