Microplastics (MPs) are ubiquitous in all ecosystems, affecting wildlife and, ultimately, human health. The complexity of natural samples plus the unspecificity of their treatments to isolate polymers renders the characterization of thousands of particles impractical for environmental monitoring using conventional spectroscopic techniques. Two primary solutions are to analyze a small fraction of the sample or to measure only a subset of particles present over a holder, known as subsampling. A strategy to subsample reflective Kevley slides and gold-coated filters using quantum-cascade laser-based infrared imaging is proposed here, as this technology is a promising tool for MPs monitoring. In contrast to most previous approaches that struggle to propose general subsampling schemes, we introduce the concept of sample-based subsampling. This can be applied ex-ante always and it highlights the best subsampling areas for a sample after a preliminary assay to count the total number of particles on a holder. The error at this stage acts as a proxy to minimize errors when evaluating the number of particles and MPs, significantly enhancing the feasibility of large-scale MPs monitoring. The predictive ability of the approach was tested for fibres and fragments, for total amounts of particles and MPs. Further, the evaluations were disaggregated by size and polymer type. In most situations the reference values were contained in the confidence intervals of the predicted values (often within the 68 % ones) and relative errors were lower than 25 %. Exceptions occurred when very scarce (one or two) items of a given size or polymer were present on the overall holder. The approach was compared to other systematic ad-hoc strategies.

It has been demonstrated that microplastics and nanoplastics (MNPs) can be found in soil and that MNPs can be taken up by plants. In order to conduct a risk assessment for human consumption, it is necessary to have an estimate of the mass concentration of plastics in crops. A new thermal extraction and desorption coupled with gas chromatography and mass spectrometry (TED-GC/MS) method has been developed for the analysis of polystyrene (PS) in pak choi.

In this study, a thermogravimetric analyser (TGA) equipped with a thermal absorption unit (TAU), was coupled with a GC system equipped with a thermal desorption unit (TDU2), a (5%-phenyl)-methylpolysiloxane GC column and a GC/MSD single quadrupole mass spectrometer. The systems were connected via an MultiPurposeSampler (MPS). Samples were pyrolyzed in the TGA; the pyrolysis products were trapped on a PDMS polymer bar, desorbed in the TDU, separated and analysed on the GC/MS system.

The purpose of this study was to investigate the qualitative and quantitative detection of PS MNPs in pak choi. The determined limit of detection (LOD) was 0.09 μg, and the limit of quantification (LOQ) was 0.28 μg PS absolute. Plants treated with 100 nm of particles 19.0 ± 6.7 μg/g DM PS and in the plants treated with 500 nm of particles 64.1 ± 8.6 μg/g DM PS have been found.

This study was the first to use a TED-GC/MS method for the detection of PS nanoplastics of different sizes in pak choi and thus provides an important basis for the determination and risk assessment of PS in vegetables.

Microplastics are an emerging pollutant that poses a threat to local ecosystems. Recent studies have revealed that microplastics have penetrated the Qinghai-Tibetan Plateau. While previous studies have investigated the migration and distribution of microplastics and their effects on soil properties, their effects on soil fauna communities remain underexplored. Here, we conducted a 1-year microplastic addition experiment to evaluate the responses of soil nematode communities and employed piecewise structural equation modeling to disentangle the direct and indirect effects of microplastics on these communities. We found that: (1) nematode abundance, diversity, and metabolic footprints exhibited a hump-shaped response to microplastic treatments, peaking at the 0.1 % treatment; (2) nematode biomass was significantly affected by microplastics, with the lowest biomass observed at the 10 % treatment; (3) the direct effects of microplastics on nematode abundance outweighed indirect effects, particularly influencing fungivores and omnivorous nematodes; (4) although microplastics did not significantly alter energy flow within nematode communities, the relationship between the energy flow of fungivores and omnivorous was stronger than those among other trophic groups. Our study offers insights on microplastics' impact on nematode communities and their varied responses to microplastic concentrations, crucial for understanding ecological effects on soil ecosystems.

Microplastics (MPs) have garnered widespread attention as an emerging global contaminant. However, the impacts of MPs on black soil health remain unclear. A meta-analysis of 337 cases from 33 studies was conducted to elucidate the effects of MPs on black soil health. The analysis incorporated 35 indicators, including soil properties, soil enzymes, plant growth, soil animal health, and soil microbial diversity. We investigated the effects of MPs properties, such as particle type, size, concentration, and exposure duration, on soil health. Results showed that MPs led to notable increases in SOM, DOC, available nitrogen by 31.84 %, 14.35 %, and 12.45 %, respectively, while decreasing nitrate nitrogen by 12.89 %. In addition, MPs exposure enhanced soil urease activity by 11.24 % but reduced phosphatase activity by 6.62 %. MPs also diminished microbial alpha-diversity, caused oxidative damage in earthworms, and suppressed plant germination rates. Notably, smaller MPs, higher concentrations, longer exposure periods, and conventional MPs have more detrimental effects on soil health. By applying the entropy weight method combined with the analytical hierarchy process, we quantified the overall impact of MPs on black soil health as a 12.09 % decrease. Our findings underscore the risks of persistent MPs pollution to black soil health.

The persistence of plastics, particularly polypropylene (PP), and their conversion into microplastics (MPs), specifically PP-MPs, have emerged as serious ecological threats to soil and aquatic environments. In the present study, we aimed to isolate a microbial consortium capable of degrading PP-MPs. The results revealed that three microbial consortia (CPP-KKU1, CPP-KKU2, and CPP-KKU3) exhibited the ability to degrade PP-MPs, achieving weight losses ranging from 11.6 ± 0.2 % to 17.8 ± 0.5 % after 30 days. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the degradation through oxidation, as evidenced by the presence of new functional groups (-OH and -C=O). In particular, CPP-KKU3 showed the highest degradation efficiency, with scanning electron microscopy (SEM) analysis revealing surface cracking after treatment. Additionally, gas chromatography-mass spectrometry (GC-MS) analysis identified various intermediate compounds, including heterocyclic aromatic compounds, phenyl groups, methylthio derivatives, and ethoxycarbonyl derivatives, indicating complex biochemical processes that were likely mediated by microbial enzymes. Furthermore, polyhydroxybutyrate (PHB) production by these consortia was also investigated. The result showed that both CPP-KKU2 and CPP-KKU3 successfully produced PHB, with CPP-KKU3 demonstrating superior performance in terms of PP-MP degradation and PHB production. Metagenomic analysis of CPP-KKU3 revealed abundant carbohydrate-active enzymes (CAZymes), particularly glycosyl transferases and glycoside hydrolases, which are associated with MP digestion. This study presents a promising bioremediation approach that addresses plastic waste degradation and sustainable bioplastic production, offering a potential solution for environmental plastic pollution.

Micro and nanoplastics (MNPs) are widespread environmental and food web contaminants that are absorbed by the intestine and distributed systemically, but the mechanisms of uptake are not well understood. In a triculture small intestinal epithelial model, we previously found that uptake of 26 nm polystyrene MNPs (PS26) occurred by both passive diffusion and active actin- and dynamin-dependent mechanisms. However, studies in a more physiologically relevant model are required to validate those results. Here, a microfluidic intestine-on-a-chip model was developed using primary human intestinal epithelial organoids from healthy and Crohn's disease donors, and used to evaluate the toxicity and mechanisms effectuating uptake of 25 nm polystyrene shell-gold core tracer MNPs (AuPS25). AuPS25 caused minimal toxicity after 24 h exposure in either healthy or Crohn's IOC models. RNAseq analysis of epithelial cells identified 9 genes dysregulated by AuPS25, including downregulation of IFI6 (interferon alpha-induced protein 6). Because IFI6 has important antiviral and immunosuppressive functions in the intestine, its downregulation suggests impairment of innate immune function, which could have important negative health consequences. Inhibitor studies revealed that AuPS25 uptake in the IOC occurred by both passive diffusion and active actin- and dynamin-dependent mechanisms, consistent with our previous findings in the triculture model.

Microplastics (MPs) in soil, groundwater, and human (SGH) present a significant global challenge due to their ecological and human health impacts. However, current protocols for detecting MPs in these environments and humans are limited, inconsistently applied, and vary significantly, particularly during the pretreatment stages of MP analysis. Moreover, no study has investigated the impact of methodological flaws on MP detection. This study conducted a thorough global assessment of the existing soil and groundwater (SG) pretreatment methods, using statistical tests to evaluate their effectiveness. It also reviewed filtration and analytical techniques for MPs in SGH samples. The analysis included research articles from PubMed, Google Scholar, Scopus, and Web of Science published between 2015 and 2024. Findings show that pretreatment using more than 100 g of soil can impact MP quantification, likely due to soil heterogeneity, while groundwater volume did not significantly affect MP quantification, likely due to the homogeneity of groundwater. During SGH pretreatment, various salts (e.g., ZnCl2 and NaCl) can be used for density flotation. Fenton's reagent was found to be a better choice than H2O2 for organic material removal because less heat was released. Post treatment MPs in SGH samples can be analyzed using various instruments and resolutions such as FTIR down to 1-5 µm, ATR-FTIR down to 2 µm, micro-Raman down to 500 nm, and LDIR down to 1 µm. This study lays the foundation for developing an effective MP analysis in SGH.

Nanoplastics (NPs) are ubiquitous in agricultural environments and may exacerbate environmental risks of pesticides. This study investigates how NPs influence the toxicity of tebuconazole in lettuce. In a hydroponic model, NPs (10 and 50 mg/L) enhanced tebuconazole accumulation in roots and exacerbated its toxicity. To elucidate the underlying mechanisms, a combination of in vivo, in vitro, and in silico models was employed. The results indicated that NPs were taken up by roots through apoplast pathway, predominantly accumulating in roots (35.6-40.7 %) due to aggregation in root sap and adhesion to cell wall. Tebuconazole adsorbs onto NPs with a high adsorption capacity (123.7 mg/g), enabling NPs to serve as carriers that facilitate tebuconazole entry into roots. Once in the root sap, tebuconazole desorbed from NPs and accumulated in cell walls, leading to higher residue in the roots (7.19-9.85 mg/kg). Furthermore, tebuconazole bound to key proteins involved in auxin biosynthesis (e.g., YUC) and signaling (e.g., TIR), thereby inhibiting tryptophan-dependent auxin biosynthesis pathway and disrupting TIR1/AFB-mediated auxin signaling. Additionally, tebuconazole suppressed the phenylalanine pathway, reducing antioxidant secondary metabolites such as flavonols. When NPs are present, co-exposure intensified the inhibition of auxin and phenylalanine pathways, thereby amplifying the toxicity of tebuconazole, as evidenced by impaired plant phenotypes (e.g., biomass, root tips) and disrupted antioxidant systems. This study reveals threats posed by NPs and tebuconazole in agricultural systems and highlights the novel carrier effect of NPs in enhancing tebuconazole toxicity, emphasizing the urgent need to assess the fate and toxicity of NPs and coexisting pollutants.

Fishing nets (FNs) represent a significant source of plastic waste, but their contribution to pollution by micro- and nanoplastics (MNPs) and associated additives is poorly understood. We studied the degradation of a high-performance-polyethylene-polypropylene (HPPE-PP) trawl net and two trammel nets made of polyamide 6 (PA6) or biodegradable polybutylene-succinate-polybutyrate-adipate-terephthalate (PBS-PBAT). Accelerated artificial ageing (AA) was performed using UV irradiation under environmental or extreme conditions followed by abrasion in water with glass microbeads. FN degradation and organic compound release were studied as well as the toxicity of leachates on the marine bacteria Allivibrio fischeri and larvae of the fish Oryzias latipes. AA of FNs under environmental conditions caused slight polymer degradation and did not produce significant MNPs. However, under extreme conditions, PA6 and PBS-PBAT FNs produced 9.1 × 104 MP/mL and 2.0 × 104 MP/mL, respectively. FNs released a total of 27 organic compounds in the leachates from which 7 were quantified at concentrations between 0.35 µg/L (Phthalimide) to 200 µg/L (Succinic-acid 2-methylallyl-undecyl-ester). Only the PBS-PBAT FN leachates induced significant toxicity on bacteria, bioluminescence inhibition ranging from 26 % to 56 %. Exposure of fish larvae to leachates of AA FNs disrupted their behavior. PBS-PBAT FN leachates caused the highest behavior stress indicator at day 12 (8.5), followed by PA6 at day 25 (8) and HPPE-PP at day 12 (7). We concluded that the toxicity of FN leachates was related more to the release of organic compounds than to the release of MPs. The toxicity of bio-based and biodegradable FNs should be further evaluated before their wider implementation in the fishing sector.

Microplastics and nanoplastics (MNPs) have implicated in cardiovascular disease in preclinical studies. Our objective is to investigate the relationship between MNPs in the coronary arteries and major adverse cardiac events (MACE) in patients with myocardial infarction (MI).We conducted a prospective observational study involving patients undergoing coronary angiography for MI. Coronary blood samples were analyzed for the presence of MNPs using pyrolysis-gas chromatography-mass spectrometry. A total of 142 patients were enrolled, with 110 completing a 31.5-month follow-up. Among them, 48 (43.6 %) had detectable polystyrene, 79 (71.8 %) had polyethylene, 105 (95.4 %) had polyvinyl chloride (PVC), and 68 (61.8 %) had polyamide 66 in their coronary blood. PVC concentration was higher in patients who experienced MACE. Furthermore, PVC levels were positively associated with proinflammatory factors (IL-1β, IL-6, IL-18, and TNF-α), and associated with higher odds of MACE (OR: 1.090, 95 %CI: 1.032-1.1523, P = 0.002). Notably, for each 10-unit increase in PVC, there was a 1.374-fold increase in the risk of MACE (OR=2.374, 95 %CI: 1.366-4.128, P = 0.002). Additionally, we collected blood and thrombus samples from an additional 21 MI patients, finding that PVC levels in coronary thrombi were positively correlated with inflammatory markers and monocyte/macrophage infiltration.

Microplastics (MPs) are emerging environmental pollutants that are increasingly being detected in various human tissues. However, their impact on ocular health is underexplored. This study investigated the presence of MPs in tear fluid and meibum of 45 patients with dry eye disease (DED). Various examinations were conducted, including the Schirmer I test, fluorescein tear film break-up time (FBUT) and other dry eye-related assessments. MPs were identified in the tear fluid and meibum and were categorized into five distinct types, with polyethylene (PE) being the most predominant. Notably, PE levels exhibited significant correlations with key DED parameters, such as Schirmer I test scores and FBUT. In in-vitro studies, PE exposure reduced the viability and induced apoptosis of human corneal epithelial cells and conjunctival epithelial cells in a dose-dependent manner. In mouse models, topical exposure to PE drops, which imitate airborne PE exposure, induced typical dry eye signs, reduced goblet cell numbers, and triggered conjunctival inflammation. PE-treated meibomian glands exhibited changes, but these changes were not statistically significant, possibly because of the limited duration of the study. This study is the first to confirm the presence of microplastics (MPs) in human tear fluid and meibum while also offering novel insights into the potential pathogenic effects of airborne MP exposure on ocular health.

Microplastics (MPs) can adsorb antibiotics (ATs) to cause combined pollution in the environment. Research on this topic has been limited to specific types of MPs and ATs, resulting in inconsistent findings, particularly for the influencing factors and adsorption mechanisms. Therefore, this study combined meta-analysis and machine learning to analyze a dataset comprising 6805 records from 123 references. The results indicated that polyamide has the highest adsorption capacity for ATs, which is primarily attributed to the formation of hydrogen bonds by its N-H groups, and MPs exhibited the strongest affinity for chlortetracycline because the CO and -Cl groups in chlortetracycline form hydrogen and halogen bonds with MPs. Moreover, the particle size, MP and AT concentrations, and pH were key factors affecting the adsorption process with notable interaction effects. Hydrogen bonding and electrostatic interaction were commonly involved in the adsorption of ATs onto MPs. Finally, an interactive graphical user interface was deployed to predict the adsorption amount, affinity constant, and maximum adsorption capacity of MPs for ATs, with results aligning well with the latest published data. This study provides crucial insights into the behavior of MPs carrying ATs, thereby facilitating accurate assessment of the combined environmental risks of them.

As important methane hydrate storage sites, cold seep areas are threatened by microplastics (MPs) contamination. To assess the environmental impact of MPs on microbial communities in cold seep sediments, an incubation experiment was conducted using cold seep sediment amended with different concentration of polyamide (PA), polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP) microplastics. The results showed that the different type and concentration of MPs significantly altered the prokaryotic community structures. The PE and PET addition highly changed the relative abundance of bacterial taxa in the bacterial community, while the proportion of archaeal species in the archaeal community was significantly altered in 0.5 % MPs treatments. All of the MPs reduced the network complexity of the bacterial and archaeal communities, such as the lower average degree and greater average path length. Furthermore, the MPs treatments also significantly decreased the network stability of prokaryotic communities. The lower network complexity led to lower network stability was observed in the archaeal community. The formation of oxidative functional groups on PE and PET MP surface based on FTIR analysis suggested that biodegradation could occur in cold seep sediment. Together, these results provide new evidence that MPs could change the structures and species coexistence of prokaryotic communities in cold seep sediments.

Combined pollution with heavy metals and microplastics (MPs) is widespread in farmland soil, and MPs can affect the efficiency and capacity of cadmium (Cd) uptake by hyperaccumulators. However, there is a significant knowledge gap regarding the response of hyperaccumulators under such conditions. This study utilized Solanum nigrum L. (S. nigrum), a well-known Cd hyperaccumulator, to investigate the combined effects of polyethylene microplastics (PE-MPs) and Cd contamination on Cd accumulation in S. nigrum, and to systematically explore the underlying mechanisms. The results demonstrated that high doses of PE-MPs significantly inhibited S. nigrum growth and reduced Cd concentration and accumulation in plants. Meanwhile, the decrement of bioavailable Cd content and the formation of C-H and -COO in rhizosphere soil were observed with the presence of PE-MPs. The simultaneous exposure of PE-MPs and Cd caused the significant increase in the proportions of Proteobacteria and Acidobacteriota, indicating that certain PE-degrading microorganisms may play a pivotal role in aforementioned processes. More importantly, the relative abundance of the genera Pseudolabrys, DEV008, and Flavobacterium was significantly elevated, likely contributing to the response of S. nigrum to combined toxicity. Co-exposure caused a significant downregulation of biosynthetic processes, involving carbohydrates and adenosine. Additionally, the biosynthesis of ABC transporters, phenylpropanoids, flavonoids, and organic acids was also significantly affected. The findings provide a comprehensive understanding of the soil-plants ecosystem under combined pollution and provide valuable information for advancing phytoremediation strategies.

Ionic liquid-catalyzed methanolysis emerges as an efficient technique for transforming PET into premium-grade dimethyl terephthalate (DMT). However, incomplete depolymerization remains a major obstacle to the further industrial application of IL-catalyzed PET methanolysis. The proposed method utilized dimethyl carbonate (DMC) as the solvent for the complete methanolysis of waste PET under mild conditions, resulting in pure DMT and ethylene carbonate (EC) within 2.5 ​h. The use of 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) as the IL catalyst significantly enhanced the reaction efficiency. Spectroscopic analyses using 1H NMR and FT-IR confirmed the pivotal role of [EMIm][OAc] in establishing multiple hydrogen bonds with the reactants (PET, DMC, and MeOH) and the intermediate [ethylene glycol (EG)] during the catalytic process. This catalytic system exhibited remarkable performance, achieving complete conversion of PET, which resulted in the production of DMT and EC with yields of 99% and 91%, respectively. Moreover, this versatile approach is applicable to the upcycling of a wide variety of commercial polyesters and polycarbonates, underscoring its potential as a comprehensive solution for plastic waste management.

This study examines the impact of microplastics on the fate of spilled crude oil in water. Batch adsorption experiments were conducted using polyethylene microplastics ranging in size between 300 and 600 μm. Environmentally relevant concentrations of crude oil and microplastics were tested. Samples processing involved liquid-liquid extraction (LLE) followed by quantitative analysis using Gas-Chromatography coupled to Mass Spectrometry. Kinetic analyses employed the most commonly used models in microplastic adsorption studies, including the pseudo-first order, pseudo second-order, Elovich, and intra-particle diffusion models. Results mainly conformed to the Elovich model, followed by the pseudo-second order model, suggesting chemisorption. Isotherm evaluations involved the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models, selected for their effectiveness in describing the behavior of microplastics in adsorption studies. These models revealed diverse behaviors: alkanes from nC11-nC21 conformed to the Freundlich isotherm, suggesting multilayer adsorption. While nC10, nC27-nC29, nC33, and nC34 were best described by the Langmuir model, and nC22-nC26 and nC30-nC32 adhered to the Temkin model, both indicative of monolayer adsorption. Notably, nC35 adsorption was best described by the Dubinin-Radushkevich model. The different PAHs exhibited preferences for either the Freundlich or the Langmuir model. The maximum adsorption capacities of the contaminants onto polyethylene were 263.12 and 101.57 mg.g-1 for the targeted alkanes and PAHs, respectively, corresponding to a maximum adsorption of 5.75 mg of targeted hydrocarbons per m2 of polyethylene. The study highlighted the potential role of microplastics in influencing the environmental fate of selected crude oil hydrocarbons and provided insights into their interaction and partitioning behavior in water.

Plastic floating at sea is difficult to measure due to its high spatial and temporal variation. White-chinned Petrels Procellaria aequinoctialis are surface-foraging seabirds found in the Southern Ocean that often ingest plastic. They are susceptible to being caught accidentally on long-line fishing gear, providing carcasses that can be used to monitor changes in the incidence and characteristics of plastic floating at sea. Of the 2486 White-chinned Petrels sampled off South Africa between 1979 and 2024, 57 % contained plastic. Data were grouped into time periods to determine temporal variation while accounting for unequal yearly sample sizes. The proportion of birds containing plastic has not changed since 1979. The number of plastic items ingested increased from an average of 2 items per bird in the early 1980s to 7 in 2017-24, mainly due to an increase in the last 5 years, but there has been no change in the total mass of ingested plastic. The proportion of pellets declined from 25 % to 17 %, with the average number of pellets per bird following a similar trend until two highly impacted birds were found in 2022 and 2023, possibly reflecting recent large pellet spills at sea off South Africa. White-chinned Petrels ingest more flexible plastics (threads and films) than other petrels, potentially linked to their behaviour of scavenging behind ships. Some birds contained fibrous gastroliths, up to 20 mm in diameter. Recording plastic loads in White-chinned Petrels offers a useful method to monitor long-term changes in floating plastic at sea.

This study describes a sediment sampling protocol using a Kinoshita-type grab (K-grab) sediment sampler to collect and analyze microplastics (<5 mm) and macroplastics (>5 mm) in marine sediments. During the GB24 geological survey cruise aboard the Bosei-maru, 133 surface sediment samples were collected from depths of 20-800 m. The K-grab, equipped with a head-slide weight mechanism, enhanced sampling efficiency across various sediment types. For microplastics, stainless steel containers and J-shaped aluminum tubes minimized contamination while maintaining sample integrity. Macroplastics were separated using a 5 mm mesh and analyzed on board. Method verification confirmed high-spatial-resolution sampling with minimal contamination. These results demonstrate that the K-grab is a reliable tool for microplastic and macroplastic analysis, providing valuable data on plastic pollution in marine sediments.•This study describes a sediment sampling protocol using a grab sampler to collect and analyze microplastics (<5 mm) and macroplastics (>5 mm) in marine sediments.•During the survey, 133 surface sediment samples were collected from depths of 20-800 m, with microplastics handled using J-shaped aluminum tubes and stainless steel containers to minimize contamination while maintaining sample integrity.•Macroplastics were separated using a 5 mm mesh and analyzed on board. Method verification confirmed high-spatial-resolution sampling with minimal contamination.

Macrolitter pollution risks coastal ecosystems, impacting biodiversity and human activities. This study compares macrolitter composition and abundance in beach and mangrove environments on the Ajuruteua Peninsula, Pará, Brazilian Amazon, an area designated as an Environmental Protection Area (APA). In field research (2021-2024), litter was classified according to material composition. Plastic was the predominant material, comprising 43.78 % of beach litter and 39.66 % of mangroves. Fishing-related litter, such as nets and ropes, represented 23.80 % on beaches and 24.42 % in mangroves, indicating its significant contribution. The density of macrolitter was significantly higher in mangroves (0.89 ± 0.11 kg/m2) compared to beaches (0.10 ± 0.02 kg/m2), demonstrating the impact of tidal retention and dense vegetation. The findings highlight the urgent need for targeted management strategies in mangroves where litter poses ecological risks. Community engagement and improved waste management practices are relevant for preserving the environmental health of Amazonian coastal ecosystems.

The improper disposal and degradation of plastics causes the formation and spread of micro and nano-sized plastic particles in the ecosystem. The widespread presence of these micro and nanoplastics leads to their accumulation in the biotic and abiotic components of the environment, thereby affecting the cellular and metabolic functions of organisms. Despite being classified as xenobiotic agents, information about their sources and exposure related to reproductive health is limited. Micro and nano plastic exposure during early developmental stages can cause abnormal embryonic development. It can trigger neurotoxicity and inflammatory responses as well in the developing embryo. In embryonic development, a comprehensive study of their role in pluripotency, gastrulation, and multi-differentiation potential is scarce. Due to ethical concerns associated with the direct use of human embryos, pluripotent cells and its 3D in vitro models (with cell lines) are an alternative source for effective research. Thus, the 3D Embryoid body (EB) model provides a platform for conducting embryotoxicity and multi-differentiation potential research. Pluripotent stem cells such as embryonic and induced pluripotent stem cells derived embryoid bodies (EBs) serve as a robust 3D in vitro model that mimics characteristics similar to that of human embryos. Thus, the 3D EB model provides a platform for conducting embryotoxicity and multi-differentiation potential research. Accordingly, this review discusses the significance of 3D in vitro models in conducting effective embryotoxicity research. Further, we also evaluated the possible sources/routes of microplastic generation and analyzed their surface chemistry and cytotoxic effects reported till date.

Surfactant-modified microfibrillated cellulose (S-MFC) enhanced the barrier properties of biobased packaging films for food applications. MFC of varying dimensions was mechanically produced from hardwood cellulosic fibers by applying different cumulative energy levels. The MFC was then modified employing a cationic surfactant, viz., cetyltrimethylammonium bromide (CTAB), and a non-ionic surfactant (NS), alcohol ethoxylate, followed by solution casting to develop packaging films. The MFC and S-MFC were characterized by using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The packaging films were evaluated for barrier and mechanical properties, including air permeability, water vapor transmission rate (WVTR), oil and grease resistance, hot oil resistance, water contact angle and surface energy, tensile, and stretch properties. The incorporation of hydrophobic long alkyl chains from the surfactant onto the surface of the MFC through electrostatic and hydrophobic interactions contributed to improved barrier properties of the films. The S-MFC-based films demonstrated a 38 % reduction in WVTR, zero air permeability, the highest oil and grease resistance (kit level 12), and passed the hot oil absorption (<4 %), with increasing fibrillation levels and surfactant modifications. S-MFC films showed the highest contact angle of ~81° and the lowest surface energy (37.2 mN/m).

Biodegradable plastics (BPs) are considered a promising alternative to conventional plastics; however, their biodegradation necessitates specific conditions and can persist in the environment for extended periods, posing toxicological effects on aquatic ecosystems and their organisms similar to conventional microplastics. The studies on biodegradable microplastics (BMPs) are limited and therefore, this study, aimed to evaluate the BMP presence in the gastrointestinal tract (GIT) and edible tissues of wild-caught and cage-cultured fishes of Periyar River, Kerala, India. Etroplus suratensis (n = 300) and Oreochromis mossambicus (n = 300) were collected from both sources. The study found BMPs in the GIT of all fishes sourced from cages and wild, with a higher but statistically insignificant abundance in wild fishes: 0.06 ± 0.26 items/individual (0.01 ± 0.00 items/g) in E. suratensis and 0.03 ± 0.23 items/individual (0.01 ± 0.01 items/g) in O. mossambicus. No BMPs were found in the edible tissues of cage-cultured fish, but they were detected in wild-caught fishes, i.e., 0.02 ± 0.13 items/individual (0.02± 0.01 items/g) in E. suratensis and 0.01 ± 0.11 items/individual (0.02± 0.01 items/g) in O. mossambicus. Poly (butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA) were the only BMPs obtained in fish from both sources with the former being the dominant one. The potential annual average human exposure risk from the wild-caught fish was estimated from both fish species and the findings suggest children have a higher risk of exposure, i.e., 551 items/year followed by adults, i.e., 394 items/year and aged individuals, i.e., 239 items/year. The documented harmful impacts of BMPs on aquatic organisms, combined with the findings of this study, suggest the need for a thorough reassessment of BP production and disposal practices. Additionally, implementing robust monitoring systems is essential to food safety and public health.

Peat-forming wetlands (PFW) are crucial in the global C-cycle, yet they are increasingly threatened by various anthropogenic pressures, including microplastic (MP) pollution. We investigate the impacts of polyvinyl chloride (PVC) and its additive, calcium carbonate (CaCO3) on organic matter (OM) degradation in PFW. We conducted two experiments: first, by mixing peat soil with increasing concentrations of crushed sanitary PVC-MP (0.3 %, 3 %, and 30 %) and second, by assessing the role of CaCO₃ in modulating these impacts. Our findings revealed significant alterations in peat chemical properties largely mediated by CaCO3 (i.e. increased pH, and Ca2+, Mg2+, K+ concentrations). PVC-MP increased carbon dioxide (CO2) and methane (CH4) production, as well as dissolved organic carbon release. CaCO3 may have enhanced CO2 release through its dissolution and contributed to CH4 production as a C source for a more diverse and active methanogenic community (higher mcrA gene abundance). Shifts in microbial community composition (e.g. reduction of Acidobacteriae and increase in active fermenters, such as Clostridia) and metabolism (higher lignin-like compounds degradation and P-uptake activity but lower activity of labile-C degrading enzymes) also contributed in the C-cycle alterations. PVC-MP enhanced denitrification (narG gene abundance) but reduced relative proportion of the ammonia-oxidizing archaea Nitrososphaeria, leading to inhibition of nitrification. The effects of PVC-MP were concentration-dependent, with CaCO₃ strongly influencing on the C cycle, while its impact on the N cycle was only partial, suggesting potential effect of other additives, such as plasticisers. Overall, our results highlight a significant disruption of microbial processes due to MP pollution, leading to increased greenhouse gas emissions and significant implications on the role of PFW as global C-sinks.

In recent times, the presence of microplastics (MPs) in rivers and groundwater has been widely reported. Even though the drinking water treatment process is effective, MPs can reach drinking water and compromise its safety. In this study, we determine the six main types of polymers (polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PE), polystyrene (PS) and polycarbonate (PC)) in surface and drinking water. A previously developed and validated method based in pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC-MS) was used. The study site is the Llobregat river basin (the main source of drinking water in Barcelona) and in 5 areas of the Barcelona drinking water distribution network. In the Llobregat river and its tributaries (n = 17 samples), ΣMPs increased downstream to 544 μg/L at the inlet of the Sant Joan Despí drinking water treatment plant (DWTP). Most of the MPs were eliminated during the water treatment process and were detected in drinking water at an average concentration of ΣMPs of 0.49 μg/L in 9 samples out of 21 analyzed. PE and PVC were the main polymers detected both in the surface water and in the drinking water supply network, followed by a punctual detection of PP in drinking water. The proposed strategy is in line with Decision (EU) 2024/1441 laying down the methodology to measure MPs in water intended for human consumption.

Microplastics, particularly polymethyl methacrylate (PMMA), have emerged as significant environmental pollutants, with growing concerns about their impact on various biological processes. However, the effects of chronic PMMA exposure on hepatic lipid metabolism remain insufficiently studied. This research aimed to examine the consequences of chronic exposure to PMMA particles of different sizes (100 nm and 2 μm) on hepatic lipid metabolism in mice. Female C57BL/6J mice were administered PMMA particles in drinking water over an 8-week period, and the effects on intestinal and liver morphology and function were evaluated. Histopathological analyses, gut microbiota profiling, and serum and liver assays were conducted to assess oxidative stress, lipid metabolism-related biomarkers, and liver metabolomics. The results revealed that PMMA particles accumulated in both the liver and colon, causing liver injury characterized by elevated ALT and AST levels. The exposure also induced oxidative stress by inhibiting the NRF2/HO-1 signaling pathway. Furthermore, PMMA exposure resulted in significant alterations to the gut microbiota and hepatic metabolism. These changes were linked to increased microbial diversity, which impacted cholesterol metabolism through the gut-liver axis. Additionally, the activation of the PI3K/AKT/PPARγ signaling pathway disrupted hepatic lipid metabolism, leading to increased cholesterol synthesis and hepatic lipid accumulation. This study underscores the potential of PMMA to disrupt both hepatic lipid metabolism and gut microbiota composition, suggesting a novel mechanism by which PMMA exposure could contribute to metabolic disorders and liver disease.

Marine plastic pollution is a global issue that requires innovative ways of monitoring and mitigation. Information on how the size, mass and polymer type of floating plastic items are changing over time may improve our understanding of the complex dynamics governing fragmentation rates, dispersal, longevity, input rates and abundance at the sea surface. Procellariiform seabirds directly ingest floating meso- and microplastics, which they retain in their gizzards. As a result, petrels can be used as biomonitors to document trends in the abundance and characteristics of marine plastics. We compare the characteristics of plastics collected from regurgitated Brown Skua Catharacta antarctica pellets containing the remains and plastics ingested by four petrel taxa breeding at Inaccessible Island, South Atlantic Ocean, at roughly decadal intervals from 1987─2024. To assess if trends persist across biotic (ingested) and abiotic (beaches) compartments, we compare this to the characteristics of meso- and microplastics (2-25 mm) sieved from South African beaches from 1984─2023. Plastics were collected from beaches far from local urban source areas in an attempt to track changes in plastic floating at sea rather than local, land-based sources. Overall, there was little evidence of trends in the size and mass of ingested or beached plastics. The average mass of industrial pellets from beaches decreased up to 2015, suggesting an old, gradually eroding cohort of legacy pellets, but increased in 2023 after two major pellet spills off the South African coast. Nearly all ingested and beached plastics were polyethylene (PE) or polypropylene (PP), but the ratio of PP to PE in hard fragments increased over time, while recent increases in PE:PP ratios in industrial pellets match recent pellet spills at sea. Identifying polymer types in ingested and beached plastics is valuable for future studies, as it may be useful for marine pollution management.

Polyethylene (PE) is widely regarded as non-biodegradable in natural environments, despite reports suggesting partial biotic degradation. Using multi-omics analysis, this study investigated the biodegradation mechanisms of n-alkanes-structural analogs of PE-to determine the threshold carbon number in PE that allows for environmental biodegradation. n-Alkanes with 6-40 carbons (C6-C40) were biodegraded in the soil, whereas C44 and PE were not. 16S rRNA gene amplicon sequence analysis identified distinct microbial communities associated with non-degradable compounds (PEs and C44) and biodegradable alkanes (C6-C40). Notably, the microbial community composition for C40 differed from those associated with biodegradable alkanes below C36. Multi-omics analysis identified the genera Aeromicrobium, Nocardia, Nocardioides, Rhodococcus, Acinetobacter, and Fontimonas as key degraders of n-alkanes at C36 and below, utilizing alkane hydroxylases such as alkane monooxygenase (AlkB), LC-alkane monooxygenase from Acinetobacter (AlmA), and cytochrome P450 (CYP153). Conversely, the biodegradation of C40 was facilitated by taxa, including the order Acidimicrobiales and the genera, Acidovorax, Sphingorhabdus, Prosthecobacter, and Roseimicrobium using AlmA and CYP153-type hydroxylases. This difference in key degraders and alkane hydroxylases may explain the reduced biodegradability of n-alkanes above C40, including PE.

The Hindu Kush Himalayas (HKH), often referred to as the Third Pole and the Water Tower of Asia, represents a vital geo-ecological asset, providing essential services to millions of people. However, this once-pristine environment is increasingly threatened by the influx of microplastics. This study provides a comprehensive overview of the current state of microplastic pollution in the HKH region, identifies key research gaps, and highlights areas for future research. A review of existing literature reveals the lack of standardized protocols for microplastics analysis, which hinders cross-study comparisons. The reported microplastic abundances vary widely across environmental matrices including 0.14-31,200 MPs m-3 in river water, 0.072-26,000 MPs kg-1 in river sediments, 180-5500 MPs kg-1 in lake sediments, 55-2380 MPs kg-1 in lake shoreline sediments, 30-871.34 MPs L-1 in glaciers, and 2.23-130 MPs L-1 in lake surface water. Polymer characterization using spectroscopic techniques has identified 54 polymer types across different environmental matrices in the HKH region with polypropylene (PP) being the most dominant, followed by polyethylene (PE), and polystyrene (PS). The sources of microplastics in the HKH region include both local activities and long-range atmospheric transport. Although research on microplastics in the region has gained momentum in recent years, significant knowledge gaps remain regarding their fate, degradation mechanisms, and environmental impacts. Further studies are essential to investigate the role of microplastics as light-absorbing impurities that may accelerate glacier melting, as well as their implications for biodiversity and human health in the region.

The effects of micro- and nano-plastics (MNPs) on human health are of global concern because MNPs are ubiquitous, persistent, and potentially toxic, particularly when bound to atmospheric fine particles (PM2.5). Traditional quantitative analysis of MNPs by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) is often inaccurate because of false positive signals caused by similar polymers and organic compounds. In this study, a reliable analytical strategy combining HNO3 digestion and chromatographic peak reconstruction was developed to improve the precision of pyrolysis-gas chromatography-mass spectrometry analysis of multiple MNPs bound to PM2.5. The optimized HNO3 digestion method using high-pressure oxidation conditions effectively removed organic matter within two hours, giving recovery rates of 64 %-110 % for eight target MNPs. The chromatographic peak reconstruction procedure minimized interferences caused by similar polymers and achieved high accuracy (101 % ± 10 %) for polyvinyl chloride, polyethylene terephthalate, and polystyrene, whose concentrations are often overestimated due to overlapping pyrolysis products. Quantification uncertainties for MNPs in real PM2.5 samples were up to 52 % lower using the new method than using previous methods. The method was validated using PM2.5 from urban Guangzhou. The total concentrations of the eight target MNPs in the PM2.5 samples were 100-990 ng/m3 (median 277 ng/m3) and the dominant MNPs were polyethylene, polyethylene terephthalate, and polyvinyl chloride, which contributed > 90 % of the MNPs. The new method allows the robust and accurate quantification of MNPs in atmospheric fine particles and will be useful in future studies on the environmental behaviors of MNPs and risks they pose.

Increasing evidence has highlighted the effects of biodegradable microplastics (MPs) on soil organic matter (SOM), but the role of soil type and incubation time remains unclear. This study investigated the effects of polylactic acid microplastics (PLA-MPs) on the amount and molecular composition of dissolved organic matter (DOM) across three paddy soil types (Ferralsol, Alfisol, and Mollisol) and incubation times, revealing soil-specific patterns in DOM transformation: PLA-MPs reduced DOM content in Ferralsol and Alfisol by 29.3-68.2 mg/kg and 27.3-30.9 mg/kg, respectively, but initially increased it in Mollisol (30 d: 220.9 mg/kg; 60 d: 622.0 mg/kg). Molecular analyses revealed a decrease in DOM component diversity at both 30 and 180 d, potentially due to PLA-MPs stimulating microbial activity and accelerating native SOM decomposition. PLA-MPs promoted the formation of CHO (containing carbon (C), hydrogen (H), and oxygen (O)) compounds, whereas microbes selectively decomposed CHONS (containing C, H, O, nitrogen (N), and sulfur (S)) compounds to meet C and N demands, particularly in Ferralsol and Alfisol. This study enhances the understanding of biodegradable MPs' impact on SOM, emphasizing the role of soil properties.

Benzotriazole UV-Stabilizers (BZT-UVs), compounds added to plastics to reduce ultraviolet degradation, are considered contaminants of emerging concern given their environmental persistence and documented toxicity in humans and animals. UV328 is a BZT-UV that has been recently listed to Annex A of the Stockholm Convention; therefore, understanding species exposure is critical information to fulfill international and domestic regulatory obligations. We evaluated hepatic accumulation of 12 plastic additives (including nine BZT-UVs) in Larus gulls in Atlantic Canada. BZT-UV accumulation was assessed in relation to ingested plastics, hepatic heavy metal accumulation, and body condition. Ninety-six percent of gulls had at least one BZT-UV at detectable hepatic concentrations. The most frequently detected BZT-UVs were UVP (91.4 %) and UV328 (76 %), suggesting ubiquitous exposure across individuals. We demonstrated interspecific differences in the relationship between ingested plastics and accumulated contaminants, with a positive relationship detected between ingested plastics and both UVP and UV328 in American herring gulls (Larus argentatus smithsonianus), and a positive relationship between hepatic UV328 and Pb concentrations detected in great black-backed gulls (Larus marinus). We provide evidence that Larus gulls feeding at a coastal landfill are highly exposed to BZT-UVs, and that the relationship between ingested plastics and plastic-associated contaminants varies across sympatric species.

The study addresses a significant environmental issue: the accumulation of microplastics (MPs) in municipal solid waste (MSW) dumpsites and their migration into deeper soil and groundwater (GW). Given the global increase in plastic production and limited waste management, this topic is highly relevant. Furthermore, many studies lack robust methodologies for tracking MP movement through complex soil strata. This study presents an innovative approach, employing advanced site characterisation and sampling techniques, including cone penetration test (CPT), hydraulic profiling tool (HPT), continuous soil sampling, and discrete GW sampling. This integrated method facilitates the identification of high-permeability zones, enabling large-depth sampling while reducing cross-contamination risk. Key findings reveal a substantial MSW layer containing plastics, textiles, and metals in specific zones, while natural soils dominate other areas. Unsaturated zones are mainly sandy, with occasional low-compressibility clay layers. MP concentrations are notably high at the MSW-soil interface 6600-8800 items/kg and decrease significantly with depth to 300-700 items/kg in saturated zones. Smaller MPs (<500 µm), mainly polyethylene, polypropylene, polyamide, and polyester, dominate soil samples. In GW, MP levels range from 26 to 171 items/L, with fibers (<250 µm) comprising about 80 % of MPs, highlighting subsurface soils as partial barriers to MP migration.

This study explores the role of thermoplastic starch (TPS) in accelerating the degradation of low-density polyethylene (LDPE), a widely used single-use plastic that contributes significantly to environmental pollution. By blending TPS with LDPE, the research focuses on the abiotic degradation of these plastic films under simulated environmental conditions through photo-oxidation via accelerated weathering tests. Over a 10-week period-representing approximately nine months of natural exposure-the films were exposed to light, air, moisture, and heat. The degradation mechanisms were analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC), while film disintegration was closely monitored. An additional 8-week seedling experiment assessed the impact of the degraded films on plant growth. Results indicated that LDPE/TPS blends began disintegrating after 6 weeks (approximately 5.4 months), achieving a 36 % degradation rate and reaching complete disintegration at 10 weeks. This surpassed the degradation performance of both standard biodegradable plastics and Oxo-PE. The primary degradation driver was water infiltration, which induced film swelling and contraction, leading to LDPE molecular chain breakdown. These findings provide critical insights into the disintegration mechanisms of LDPE/TPS blends and present a promising approach to accelerating plastic degradation, potentially reducing environmental plastic waste.

Atmospheric microplastics play an important role in the microplastic cycle. However, their behaviors in high-altitude remote areas were still poorly constrained. Based on one year of samples from the northeast Tibetan Plateau, we investigated the status of atmospheric microplastics and their relationships with dust. The results indicated that number-based concentrations of atmospheric microplastics were 4.07 ± 2.37 items m-3 with the maximum in spring, while mass-based concentrations were 0.126 ± 0.152 μg m-3 with the maximum in winter. Atmospheric microplastics < 50 μm accounted for 92.9 %, with 95.4 % being fragments, emphasizing the pervasive occurrence of small-sized fragmented microplastics in the northeast Tibetan Plateau. Analysis of Lagrangian particle dispersion model combined with potential source contributions revealed that dust emission in potential source regions significantly impacted atmospheric microplastic concentrations. The threshold shear velocity of microplastics and dust exhibited similar values, supporting their co-emissions from potential source regions. Once microplastics are entrained into the airflow, the lower updraft wind speed required for microplastic suspension facilitates long-range atmospheric transport. This study enhanced our insights into the atmospheric microplastic sources and supported future mitigation strategies for microplastic exposure in the remote ecosystem.

Microplastics (MPs) are gaining attention for their widespread presence and toxicity in ecosystems. However, their role as a carbon source in urban wetland carbon sinks is still unclear. In this study, the microplastic-carbon (MP-C) was firstly quantified based on the abundance and occurrence characteristics, including MP morphology, size and type in the Sanyang Wetland, a typical urban wetland of China. MP abundances ranged from 2.4 ± 0.6-14.9 ± 1.5 items/L in surface water and 6.6 ± 1.2 × 103 to 46.3 ± 5.9 × 103 items/kg in sediment. The predominant morphological characterization of MPs was fragments smaller than 200 μm in size, consisting of PP, PE, and PET, which suggests that the main source was domestic wastewater discharge nearby. Notably, in the Sanyang wetland, the contribution of MP-C to total organic carbon (TOC) was estimated to be 0.0230.20 % in water and 0.0260.28 % in sediment. With the continuous production of plastics globally, these values were predicted to increase to 0.12 0.71 % and 0.83 4.12 % by 2100, respectively. Although the estimations relied on simplified geometric assumptions for MP volume and theoretical carbon content, these approaches provide a reasonable basis for understanding MP-C dynamics in wetlands under current analytical constraints. The integration of MP-C characterization during environmental monitoring and management strategies would enhance our understanding of MP pollution's role in the carbon cycle.

Currently, although many studies have successfully screened microorganisms with the ability to degrade microplastics (MPs), few studies have focused on their practical application and impacts on the soil-microbe-plant ecosystem. By adding polystyrene-microplastics (PS-MPs) and Acinetobacter radioresistens to the soil, this study aimed to assess their effects on the soil-microbe-plant ecosystem. The findings indicated that PS-MPs enhanced the growth of cucumber (Cucumis sativus L.) and significantly increased the height, stem length, and leaf surface area of cucumber seedlings after inoculation with Acinetobacter radioresistens. The microbial community structure in the rhizosphere soil of cucumber seedlings underwent changes in the high-concentration PS-MPs treatment groups, resulting in a significant increase in both the Shannon index and Simpson index of microorganisms. Compared to the high-concentration PS-MPs treatment, the inoculation treatment increased the soil pH, total potassium content, and iron content, but decreased the total nitrogen content, available phosphorus content, and available potassium content. The transcriptome results showed that cucumber seedlings may respond to environmental changes by regulating photosynthesis, water usage, and phytohormone synthesis. In this study, the growth of cucumber seedlings contaminated with PS-MPs was promoted by the application of Acinetobacter radioresistens. This provides a new perspective for the remediation of PS-MPs contamination in soil.

This study assessed the toxicity of virgin and recycled plastic food contact materials (FCMs) at various recycling stages, migrated in four food simulants (water, 20 % ethanol, 4 % acetic acid, and n-heptane), using cytotoxicity and high-content screening (HCS) bioassays. Toxicity was correlated with migrating substances identified through chemical analyses, and samples were ranked by toxicity priority. Recycled polyethylene terephthalate (rPET) and 20 % ethanol exhibited the highest reduction in cell viability, whereas virgin PET (vPET) showed even lower viability. Pellets did not trigger oxidative responses in HepaRG and HK-2 cells; however, bales and flakes affected their cell morphology and mitochondrial function. rPET-flake migration in 4 % acetic acid was most toxic to HepaRG cells, while rPET-bale migration in 20 % ethanol and rPP-flake migration in water were most toxic to HK-2 cells. Nonetheless, the negative effects on cell viability and HCS parameters were mostly mitigated at the final pellet stage. In HepaRG cells exposed to 4 % acetic acid, antimony negatively correlated with cell viability and positively with cellular area, indicating its role in rPET-induced necrosis. ToxPi ranking identified vPET migration in n-heptane and water as top priorities given the nephrotoxic risks. This study emphasizes refining recycling methods and testing plastics to minimize FCM cytotoxicity.

Microplastic pollution, a major global environmental issue, is gaining heightened attention worldwide. Marginal seas are particularly susceptible to microplastic contamination, yet data on microplastics in marine sediments remain scarce, especially in the Beibu Gulf. This study presents a large-scale investigation of microplastics in the surface sediments of the Beibu Gulf to deciphering their distribution, sources and risk to marginal seas ecosystems. The results reveal widespread microplastic contamination, with an average abundance of 391 ± 27 items/kg in sediments. The spatial variability of microplastic abundance was significant, with lower levels in the western Beibu Gulf and higher concentrations in the northeastern and southeastern regions. The spatial distribution of microplastics was largely driven by geological features, hydrodynamic conditions, and human activity, with minimal influence from local environmental factors such as water depth, sediment grain size, organic carbon content, and sediment types. The pollution load index (PLI) suggests a low level of microplastic contamination, but the polymer hazard index (PHI) identified a high ecological risk, likely due to the presence of PVC, a polymer with higher chemical toxicity. Our findings highlight the significant role of hydrodynamic processes in determining microplastic distribution in the Beibu Gulf. These insights enhance our understanding of microplastic dispersal and its governing factors in semi-enclosed marginal seas, providing foundation for targeted pollution control strategies.

Developing degradable plastics with excellent mechanical strength and wet stability from renewable and biodegradable biomass resources remains challenging. Here, we propose a simple one-step strategy for the in-situ multiscale dissolution of cellulose and crosslinking with 1,4-butanediol diglycidyl ether (BDDE) within a mixture of BDDE and AlCl3/ZnCl2 aqueous solution at room temperature. This strategy enables the synthesis of cellulosic paper-based bioplastics with high mechanical strength and wet stability from cellulose paper. In this process, conventional cellulose paper is partially dissolved, and simultaneously, BDDE forms chemical crosslinking with undissolved micro-level, nano-level cellulose fibers and dissolved cellulose macromolecules through an autocatalytic effect from AlCl3/ZnCl2 aqueous solution, resulting in multiscale physicochemical entanglements and multiple hydrogen bonds. Hence, the prepared bioplastic's dry and wet strength reached 58.2 MPa and 24.2 MPa, respectively, about 6.9 times and 71.2 times higher than untreated paper-based materials. The prepared bioplastic showed excellent wet stability, biosafety, and biodegradability. The density functional theory (DFT) simulation data indicates that Al3+, Zn2+ ions, and freely hydrated hydrogen protons are crucial to the dissolving-co-crosslinking system. This strategy involves only green and recyclable chemicals, offering a promising pathway for producing strong and biodegradable cellulosic paper-based bioplastics as an alternative to nondegradable plastics.

Microplastics (MPs) are emerging environmental pollutants which represent a serious threat to ecosystems and human health and have received significant attention from the global community. Currently, a growing number of studies have found the presence of MPs in groundwater. This study exhaustively reviewed varying degrees of recent publications in Web of Science database and investigated the characteristics of MPs (concentration, types, sizes and shapes) in groundwater ecosystems, their migration characteristics, and interactions with co-occurring contaminants. Results suggested that current global research on MPs in groundwater has primarily focused on countries such as India, South Korea, China, Italy and United States. Pollution levels of MPs in groundwater show significant variability, ranging from 0 to 6832 n/L. The predominant plastic polymer types include PP, PE, PS, PA, PET and PVC. The sources of MPs in groundwater are primarily classified as associated with natural processes and anthropogenic activities. The physical, chemical and biological properties can influence the migration of MPs into groundwater. Furthermore, MPs can act as carriers, interacting with co-occurring contaminants, thereby enhancing their migration and toxicity, potentially posing a threat to groundwater ecosystems and human health. Consequently, the major challenges and associated recommendations for forthcoming research on MPs in groundwater are proposed.

Microplastics are omnipresent, raising significant concerns in marine environments. This study investigates how different beach morphodynamics and local management practices (i.e. pollutant sources, tourism, beach cleaning) influence microplastic pollution in sandy beach sediments in Vietnam by comparing tidal zonation patterns across three beaches with varying slopes and management approaches. Environmental variables (Chlorophyll a, total organic material, grain size) and microplastics polymer composition, size and concentrations were measured at the high and the low water marks of each beach. Microplastics were found on all beaches, with high variation. The dominance of denser MPs, like PET, on reflective beaches coupled with the prevalence of lighter MPs in the high tidal zone, demonstrates the role of beach morphodynamics and tidal flows in shaping microplastic distributions. Furthermore, local waste management practice and input from tourism activities can contribute to the patchy microplastics distribution. For instance, the larger size of microplastics at the beach with most macrolitter suggests the role of fragmentation down to microplastics as a pollution source which can pose risks to benthic ecology and human health in regional communities. Our findings highlight a complex interplay between beach morphodynamics and local pollution sources in driving microplastic distribution. Addressing the issue of MPs pollution on sandy beaches will therefore require targeted management strategies that reduce pollution sources in relation to natural processes that set the deposition of microplastics in beach sediments.

The East Asian region is an area of high human and fishery activity, where a substantial amount of plastic, especially expanded polystyrene (EPS), is discharged into the environment and reaches sandy and rocky seashores. EPS pollution and its impact on organisms inhabiting sandy and rocky areas may be suspected. In a field study conducted in the West Japan sandy and rocky seashore region, wharf roaches, Ligia spp., which are ubiquitous and cosmopolitan organisms in the Pacific area, were found to ingest EPS more frequently than polypropylene and polyethylene microplastics. Furthermore, the results of our feeding experiment indicate that wharf roaches are capable of not only grazing on EPS, but also fragmenting EPS to microplastics ranging from 2 to 214 μm in diameter when estimated as circles. We conclude that wharf roaches may contribute to the decomposition and fragmentation of EPS microplastics.

Microplastic (MPs, size <5 mm) is an emerging category of contaminants with detrimental effects on human health, climate, and ecology. The atmospheric pathway is a crucial transport route for the migration of MPs from source to receptor locations. This long-range transport leads to the ubiquitous presence of MPs across all environmental matrices and constrains the source-transport pathway-sink interaction. During atmospheric transport, MPs experience aging and adsorption as a result of interactions with winds, solar radiation, moisture, pH, and atmospheric pollutants, which alters their hydrophilicity, structure, surface area, size, color, and the capacity for adsorption, often resulting in elevated toxicity and associated risks. However, the multifaceted dynamics of atmospheric aging of MPs and consequent impacts are poorly understood. This review presents a critical assessment of three major factors that determine the nature and degree of MP aging and adsorption in the atmosphere, namely: intrinsic MP properties such as the degree of unsaturation, crystallinity, presence of functional groups, charge, specific surface area, and structural defects; environmental factors such as temperature, pH, moisture, and the presence of chemical species; and pollutant characteristics such as charge and hydrophilicity/hydrophobicity that influence adsorption, with an emphasis on potential mechanisms. Additionally, the review presents a comparative assessment of the critical factors and mechanisms responsible for aging and adsorption in atmosphere with those in other environmental media. Further, the potential impacts of atmospherically aged MPs on climate, the biosphere, cryosphere, pedosphere, and hydrosphere are summarized. The review finally identifies key knowledge gaps and outlines perspectives for future research.

Recycling Li from spent lithium ion batteries (SLIBs) in an efficient and highly selective manner could protect the environment and introduce the circular economy principle to society. Simultaneously, the urgent need to address plastic waste, particularly polyvinyl chloride (PVC), has become a global concern. In this work, a strategy for Li extraction through synergetic pyrolysis of LiMn2O4 cathode materials (LMO) and PVC is proposed. Under optimal conditions, the recovery rates of lithium and manganese reached 99.89 % and 0.02 %, respectively, demonstrating efficient separation of these elements. Temperature was found to play a critical role in the leaching rates of lithium and manganese by promoting the decomposition and reduction of LMO. Additionally, kinetic analysis shows that the activation energy (Ea) of the synergetic pyrolysis is 139.60 KJ/mol, and the pyrolysis mechanism satisfies third-order reaction process. Eventually, the proposed mechanism involves the synergistic effects of chlorination and reduction reactions. First, HCl is generated by PVC pyrolysis under the catalytic effect of LMO. Then, the chlorination of HCl with LMO occurs by capturing structural oxygen and generating LiCl and MnCl2. Simultaneously, the reduction reaction between the reducing species generated by PVC pyrolysis and LMO occurs to form Li2O and MnO, ultimately enabling the separation of lithium and manganese. Overall, this paper presents a novel approach for future applications by providing a theoretical basis for selective Li extraction.

Microplastic ubiquity has been demonstrated in several studies. They are polluting the environment, as well as food and water for human consumption, where the most significant concern has arisen over the ingestion of microplastics. However, there are very few studies on the potential health risks associated with nanoparticles, including those related to polyethylene terephthalate (PET). In this work, PET nanoparticles (253 ± 16 d nm) with irregular shape obtained under controlled conditions, were used for ex vivo analysis of rat intestinal tissue (n = 3 each condition) and their effects on the muscle tone related to peristalsis were determined. Twenty-minute treatment with increasing concentrations of PET-NPs from 0.1 to 100 μg/mL (low concentrations) and from 250 to 750 μg/mL (high concentrations) were assayed. The results showed the rapid capability of PET nanoparticles to cross the intestinal barrier, assessed by fluorescence microscopy and corroborated by RAMAN micro-spectroscopy. Furthermore physiological analysis in isolated rat intestinal segments have demonstrated the effects of PET, especially at 10 μg/mL, on tissue contraction. These results evidenced the potential health risk related to nano-plastic ingestion, due to PET nanoparticles tissue accumulation and the effects on contraction and relaxation tissue functions.

Microplastics (MPs) pose a major environmental challenge owing to their persistence and interactions with emerging contaminants (ECs). Their co-occurrence raises concerns about combined effects on aquatic ecosystems. MPs transport hydrophobic pollutants, affecting water quality. Studies show MPs can adsorb ECs at concentrations up to 106 times higher than their natural levels, increasing bioavailability. MPs and ECs accumulate in aquatic organisms, with evidence of trophic transfer. Their combined toxicity is often greater than their individual effects, causing physiological stress, reduced survival rates and microbial alterations, including enhanced antibiotic resistance. Beyond aquatic ecosystems, MPs and ECs pose risks to human health via bioaccumulation in the food chain. This review analyzes the mechanisms of interactions between MPs and ECs, including uptake, accumulation, and toxicity in aquatic organisms. These findings highlight the need for an integrated environmental impact assessment. Finally, future research directions are proposed, emphasizing key parameters to advance understanding in this field.

The extensive presence of nanoplastics has raised concerns about their effects on ecosystems and human health. Because of the heightened ecological and biological risks posed by nanoplastics, effective removal strategies for these particles are essential. This study focuses on the use of additive manufacturing techniques to fabricate a three-dimensional (3D) structure with integrated powdered activated carbon (PAC) as an active adsorbent for the removal of various types of polymer nanoplastics. The 3D-printed porous PAC scaffold was characterized using various analysis methods, and its adsorption kinetics and mechanisms for polystyrene (PS) nanoplastics were elucidated. The 3D PAC's versatility was verified against several other nanoplastics, including polyethylene terephthalate, low-density polyethylene, polypropylene, and polyvinyl chloride. The results demonstrated that the 3D PAC scaffold effectively adsorbs PS nanoplastics through pore filling and chemical processes and that the adsorption exhibits pseudo-first-order kinetics and conforms to the Langmuir isotherm model. The 3D PAC maintained its adsorption performance under various environmental conditions and exhibited promising results when used to remove nanoplastics from real freshwater samples. This research demonstrates the potential of 3D-printed PACs to address the growing challenge of plastic pollution.