Microplastics doi: 10.3390/microplastics5030177

Authors: Mehedi Hasan Sanoar Rahman

Microplastic pollution has become a major concern for the environment in freshwater ecosystems due to its persistence, distribution, and impacts. However, research about microplastic pollution in the Illinois portion of the Mississippi River and its tributaries is still limited. This research examined the occurrence, geographical distribution, properties, and potential sources of microplastics in the Mississippi River and its major tributaries in Illinois. Surface water samples from 24 locations were collected and examined by stereomicroscopy to detect and quantify microplastics. The relationships between microplastic levels and physicochemical and land cover variables were examined using Spearman’s rank correlation. Microplastics were identified at every sampling site, with concentrations ranging from 4.5 to 76 particles per liter (average: 25.95 ± 18.15 particles/L), and fibers comprised over 71% of the total particles. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) analysis identified four types of polymers: nylon, polystyrene, polypropylene, and high-density polyethylene. Microplastic levels exhibited a negative correlation with dissolved oxygen (ρ = −0.617) and a direct correlation with pH (ρ = 0.500). The results include fundamental data about microplastic pollution at specific sites throughout the Illinois portion of the Mississippi River and emphasize possible correlations between microplastic levels, adjacent land cover, and water quality parameters.

Microplastics doi: 10.3390/microplastics5030176

Authors: Tanja Bogdanović Silvio Špičić Zoran Vatavuk Goran Marić Zvonimir Jažo Alessio Gomiero Vedrana Marić Sandra Petričević Eddy Listeš Federica Di Giacinto Chiara Profico Irena Listeš Jelka Pleadin

The widespread presence of microplastics (MPs) and associated plastic-derived compounds, bisphenols (BPs), in the environment—originating from plastic production or adsorption of environmental pollutants—results in unavoidable human exposure. Therefore, assessing their occurrence in human biological samples is essential for understanding potential health risks. In this study, pyrolysis gas chromatography–mass spectrometry was used to analyse human intraocular fluids—aqueous humour (AH) and vitreous humour (VH)—to identify 11 microplastic polymer clusters. A method based on dansyl chloride derivatisation combined with ultra-performance liquid chromatography–tandem mass spectrometry was employed to screen for five bisphenols (BPs) in blood serum collected from the same patients. Potential MPs isolated from ocular samples were qualitatively assessed by stereomicroscopy. The number of particles ranged from 14 to 69 per gram in AH and from 21 to 34 per gram in VH. Among AH samples, the most frequently detected polymer clusters were C-PVC, C-PMMA, C-PET, and C-PP, with average levels ranging from 0.41 to 0.84 µg/g. The three VH samples contained only C-PMMA, with an average concentration of 0.55 ± 0.12 µg/g. Polymers such as C-PA66 (0.30 ± 0.21 µg/g) and C-PA6 (0.15 ± 0.44 µg/g) were occasionally observed in AH. Analysis of 13 human serum samples demonstrated exposure to bisphenol A (BPA; 4.05–5.18 ng/mL) and bisphenol AF (BPAF; 2.13–4.54 ng/mL), but no clear correlation was observed between serum BP levels and intraocular MPs within the limitations of the present dataset. These findings suggest the presence of MPs and BPs in human biological samples; however, the results should be interpreted with caution owing to potential background contamination and the pilot nature of the study.

Microplastics doi: 10.3390/microplastics5030175

Authors: Chelo Escrig Rondán Celia Sevilla Gil Elena Domínguez Solera Juan Francisco Ferrer Crespo Juan Bellas Juan Ignacio Bertucci

Agricultural soils have been identified as significant sinks for plastic waste from mulch films, which in turn can reach aquatic ecosystems. As an alternative to conventional materials, there has been growing interest in biodegradable mulch films, but their environmental behavior and ecotoxicological effects are not yet fully established. In this study, the effects of residues from a conventional mulch film and a biodegradable mulch film on model organisms representative of edaphic (Hordeum vulgare and Cucurbita maxima) and aquatic (Paracentrotus lividus) ecosystems were evaluated. During this study, the residues of the mulches in seawater were also analyzed, considering natural aging conditions, using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). The results of the ecotoxicological tests showed that the residues of both types of mulch films did not generate any significant adverse effects on the selected terrestrial and marine bioindicators in the two end-of-life scenarios, with the exception of the residues of conventional mulch, unaged and aged for one month, at medium-high concentrations from an environmental point of view on P. lividus. The natural weathering assay in a marine environment showed that residues from conventional mulch film remained essentially unaltered, with similar concentrations detected throughout the 12-month exposure period. In contrast, the biodegradable mulch film exhibited significant degradation from the initial time point, reaching concentrations below the analytical detection limit after the first month.

Microplastics doi: 10.3390/microplastics5030174

Authors: Maud Gautier Séverine Le Faucheur Sandra Mounicou Javier Jiménez-Lamana Virginie Pellerin Marisol Goñi-Urriza Claire Gassie Stéphanie Reynaud Bruno Grassl

The plastisphere critically modulates interactions among microplastics (MPs), biofilms, and trace metals under environmentally realistic conditions, governing the interfacial reactivity of plastisphere-coated microplastics. Here, we investigated cobalt (Co) adsorption onto large polypropylene (PP) primary microplastics (~4 mm) exposed for 28 days in a flow-through riverine mesocosm across a gradient of Co concentrations (0–60 µg·L−1). A multi-technique analytical approach was employed, combining inductively coupled plasma mass spectrometry (ICP-MS), laser ablation ICP-MS (LA-ICP-MS), quantitative PCR (qPCR), and scanning electron microscopy (SEM). Cobalt accumulation increased linearly with time, consistent with apparent first-order dependence on aqueous Co concentration under constant exposure, reaching 38 ± 3 mg·kg−1 after 28 days at 60 µg·L−1, with no saturation observed. The concentration-dependent Co accumulation was well described by an empirical power-law model (Q = KC0n), with the empirical coefficient K increasing linearly over time, reflecting the progressive increase in Co accumulation at a given aqueous concentration. Microbial colonization developed rapidly on MPs, with 16S and 18S rRNA gene copy numbers stabilizing after 14 days, while surface-normalized Co signals increased sharply after day 21, indicating a time-dependent modification of biofilm properties influencing Co retention. SEM confirmed complex microbial structures, including diatom-like cells. No cobalt adsorption was observed under sterile conditions, confirming the key role of biofilm presence. These findings highlight the dynamic role of the plastisphere as a chemically and biologically active interface under environmentally realistic riverine conditions, with implications for contaminant fate, bioavailability, and risk assessment in freshwater systems affected by plastic pollution.

Microplastics doi: 10.3390/microplastics5030173

Authors: Assiddik Sapii Yahsin Carlito Baltazar Tabelin Theerayut Phengsaart Janna R. Andalan Alissa Jane S. Mondejar Merrah Joy Blaya Subebe Aileen H. Orbecido William Ka Fai Tse Yukiko Ogino Mylah Villacorte-Tabelin

Microplastics (MPs) are emerging pollutants widespread in aquatic environments; however, their effects across the different life stages of aquatic organisms remain poorly understood. This systematic review integrates recent experimental results on the developmental, physiological, and neurobehavioral effects of MP exposure on zebrafish (Danio rerio), a popular model organism for ecotoxicology research. A PRISMA-guided search using Web of Science (WoS) and Scopus as databases generated 581 articles, which were screened to 60 eligible articles. The collated results showed that MP toxicity at various life stages of zebrafish was strongly related to the physicochemical properties of MPs and exposure conditions. In terms of developmental toxicity, peer-reviewed publications assessing specific MP physicochemical properties—polymer type, size, concentration, shape, and degree of aging—reported concentration-dependent effects, with increasing MP concentrations generally associated with growth inhibition, cardiac dysfunction, increased malformations, and lower hatching rate, particularly at ≥10 mg/L to ≥100 mg/L. However, several studies noted that under particle-based exposure scenarios, MP toxicity exhibited threshold-like or non-monotonic responses, attributed to aggregation, bioavailability, and uptake dynamics. Weathered and artificially aged MPs exhibited higher embryotoxicity and neurodevelopmental toxicity, including changes in gene expression of neurons, decreased integrity of motor neurons, and impaired retinal development, compared with “virgin” MPs. In terms of physiological endpoints, oxidative imbalance like changes in the activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)), lipid peroxidation, inflammation, and disruption of tight junctions have been reported as key toxicity pathways. Chronic MP exposure in zebrafish also caused changes in the gut microbiota, hepatic metabolism, endocrine disruption, reproductive damage, thyroid function disruption, and genotoxicity in zebrafish. In terms of neurobehavioral effects, changes in locomotor activity, anxiety response, neurotransmitter homeostasis, and acetylcholinesterase function, have been observed, in both larvae and adults, with a potentiation effect in aged MP exposure. Finally, this systematic review found major limitations for inter-study comparisons because of inconsistencies and differences in methodology applied related to MP concentration, simulation of natural MP aging, and MP dose measurements.

Microplastics doi: 10.3390/microplastics5030172

Authors: Katerina Bačeva Andonovska Aleksandra Ivanoska-Dacikj Trajče Stafilov Richard K. Cross Felicity Hayes

Atmospheric microplastics have emerged as an important environmental contaminant due to their widespread occurrence, persistence, and potential ecological and human health implications. However, information regarding atmospheric microplastic deposition in southeastern Europe remains extremely limited. The present study provides a preliminary moss-based assessment of atmospheric microplastic deposition at selected locations in North Macedonia. Moss samples were collected from sites representing different degrees of anthropogenic influence and analyzed following sample preparation procedures consistent with previous national-scale surveys. Microplastic particles were identified using micro-Fourier Transform Infrared (μ-FTIR) spectroscopy. Microplastics were detected in all investigated moss samples, confirming their widespread atmospheric deposition across the country. The highest concentration was recorded at Vodno–Skopje (16.72 MP g−1 dry weight), followed by Majdan (7.10 MP g−1) and Bojančište (3.29 MP g−1). Pronounced differences in polymer composition were observed among the sampling locations: Vodno–Skopje exhibited the greatest polymer diversity, with polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA), and cellulose acetate (CA) all detected above their respective limits of detection, whereas Majdan was characterized almost exclusively by polyethylene terephthalate (PET) and Bojančište primarily by cellulose acetate (CA) and PLA. The detected microplastic concentrations were within the range of values reported in some European studies, although direct comparisons should be interpreted with caution because of the differences in sampling and analytical methodologies. The findings demonstrate the potential of moss-based biomonitoring as a complementary approach for assessing atmospheric microplastic deposition. However, studies covering a larger number of sampling locations and different temporal periods are required to further evaluate and validate this approach.

Microplastics doi: 10.3390/microplastics5030171

Authors: Farhanah Edora Mohamed Kasturi Beevenna Kaur Darmindar Singh Suresh Kumar Muhammad Danial Che Ramli

Background: Airborne microplastics (AMPs) are an emerging air pollutant and there are growing concerns about their potential effects on respiratory health due to their persistence, inhalability and ability to carry other toxic pollutants. Methods: Relevant peer-reviewed studies released from 2015 to 2025 were located by searches on PubMed, Scopus, and Web of Science. Data from experimental, epidemiological, and review research were amalgamated to investigate sources of airborne microplastics, routes of exposure, analytical methodologies, respiratory toxicological processes, and regulatory viewpoints. Results: Modern studies suggest inhaled antimicrobic peptides can reach the lower respiratory tract and cause chronic pulmonary inflammation via induction of oxidative stress, mitochondrial dysfunction, epithelial barrier damage, inflammasome activation, immune system imbalance and extracellular matrix remodeling. These pathways have been associated with chronic respiratory diseases, such as chronic obstructive pulmonary disease, asthma, pulmonary fibrosis, and lung carcinoma. Toxicity can be increased by the accumulation of heavy metals, persistent organic pollutants and microbiological impurities. However, the lack of standardised protocols for exposure assessment, inconsistency of sampling and analytical methods and limited human epidemiological data hamper health risk assessment. Conclusions: Airborne microplastics are an emerging environmental health concern with potentially significant effects on respiratory health. Harmonised surveillance strategies, standardised analytical methods, improved inhalation exposure models and prolonged epidemiological studies are urgently needed to improve risk assessment and enable evidence-based air quality policy for the protection of respiratory health.

Microplastics doi: 10.3390/microplastics5030170

Authors: Taeng On Prommi Korn Likitamnuaychai Kanisorn Chokthananukoon Ponviwat Doungmee

Microplastic (MP) analysis in various environmental media currently faces significant challenges due to the complex and transportable nature of these materials. This study employed Fourier-transform infrared spectroscopy (FTIR) to investigate the presence of MPs in caddisfly larval cases, which incorporate vegetative fragments, sediment grains, and MP particles as building materials. The analysis of MPs in 2049 caddisfly larval cases revealed a total of 7553 items, resulting in an average of 3.7 items/case. The lowest recorded rate was 0.8 items/case, while the highest reached 18.2 items/case. Fiber MPs comprised 39.2% of the total, followed by fragment MPs at 30.8% and spherical MPs at 30%. Among the colors analyzed, blue MPs were the most prevalent, accounting for 36.6%, with white/transparent MPs at 22.1% and red MPs at 14.1%. MPs smaller than 100 µm were the most common, accounting for 37%, followed by MPs in the 100–250 µm range at 23.9%, larger than 500 µm at 22.3%, and those between 250 and 500 µm at 15.8%. Cellulose acetate was discovered to be the most abundant MP among different polymer types, followed by cellulose acetate butyrate, polyethylene terephthalate, poly(vinyl propionate), poly(ethylene glycol), poly(acrylonitrile-co-butadiene), cellulose propionate, hydroxyethyl cellulose, polyvinyl alcohol, glycerol triacetate, polystyrene, and poly(propylene glycol) methacrylate. These findings show the existence of MP in biotic components of these ecosystems, which has implications for aquatic biota health and freshwater quality, particularly in places influenced by human activity.

Microplastics doi: 10.3390/microplastics5030169

Authors: Christos Giamvrias Sofia Marka Georgia Moschopoulou Katerina Kalliampakou Maria Daoutakou Spyros Kintzios

Carboxyl-modified polystyrene microplastics (cPS-MPs) may accumulate in the liver and interfere with cellular metabolism; however, their effects may differ substantially between cancerous and non-cancerous hepatocytes. In this study, we compared the responses of HUH-7 hepatocellular carcinoma cells and immortalized human hepatocytes (IHHs) to two cPS-MP size fractions, M1 (2.1 µm) and M2 (0.49 µm), at concentrations of 10–1000 µg/mL for 24, 48 and 72 h. Cell viability was evaluated by the MTT assay, while mitochondrial morphology and membrane potential (ΔΨm) were assessed using MitoTracker fluorescence microscopy and fluorescence measurements. HUH-7 cells exhibited concentration- and time-dependent loss of viability, with the strongest cytotoxicity observed after 72 h exposure to M2 particles, when viability decreased to approximately 48% at concentrations ≥750 µg/mL. In contrast, IHH cells showed no significant cytotoxicity and exhibited metabolic stimulation under several M1 exposure conditions. Brightfield microscopy further revealed pronounced accumulation of cPS-MPs in association with HUH-7 cells, whereas IHH cells showed substantially less apparent particle accumulation. In HUH-7 cells, prolonged exposure to high cPS-MP concentrations caused extensive mitochondrial network rearrangement, loss of nuclear integrity and heterogeneous changes in ΔΨm, including pronounced hyperpolarization in individual cells and depolarization that predominated at the population level. IHH cells largely maintained mitochondrial network integrity and stable ΔΨm. Based on the experimental dataset, HepatoMP, an open-source web-based Predictive Modelling Tool, was developed as a proof-of-concept framework integrating concentration-, particle size- and time-dependent responses for interactive data visualization and extrapolation. Overall, the findings demonstrate markedly different responses of hepatoma and immortalized hepatocytes to cPS-MPs and identify particle accumulation and mitochondrial dysfunction as prominent features associated with cPS-MP cytotoxicity in HUH-7 cells. HepatoMP provides a complementary hypothesis-generating framework for guiding future experimental investigation of hepatic microplastic toxicity.

Microplastics doi: 10.3390/microplastics5030168

Authors: Nguyen Truong Thanh Huynh Vuong Thu Minh Pham Van Toan Nguyen Van Tuyen Kim Lavane Nguyen Vo Chau Ngan Huynh Long Toan Vo Thanh Toan Pankaj Kumar

Macroplastic pollution in rivers is an increasing environmental concern because rivers function simultaneously as active transport pathways and temporary storage compartments for land-based plastic waste. This study investigated the spatial distribution, composition, and size characteristics of riverbank and floating macroplastic debris in the Can Tho River, a tidal tributary of the Hau River in the Mekong Delta, Vietnam, to improve understanding of macroplastic transport, selective retention, and environmental partitioning between active transport and temporary storage compartments. Riverbank debris was surveyed at twelve sites spanning urban, peri-urban, and rural sections, while floating debris was quantified using a net-based sampling system. Riverbank accumulations exhibited pronounced local spatial heterogeneity, although litter density and mass density did not differ significantly among river sections. Plastics dominated both environmental compartments, accounting for 53–60% of accumulated debris and more than 95% of floating debris by abundance. Riverbank accumulations were dominated by plastic bags, food packaging, and beverage containers, whereas floating debris was dominated by expanded polystyrene foam products. Significant differences were also observed in material composition, plastic-product composition, and size distribution. Riverbank accumulations contained proportionally larger macroplastics (100–500 mm), whereas floating debris was dominated by smaller macroplastics (50–200 mm), supporting the role of size-dependent transport and selective retention in environmental partitioning. These findings show that floating debris and riverbank accumulations represent complementary components of the riverine plastic continuum, linking active transport and temporary storage through selective environmental partitioning. Integrating floating and riverbank monitoring provides a more comprehensive framework for understanding macroplastic transport and environmental fate while informing management strategies to reduce downstream plastic transport to the Hau River and ultimately estuarine and coastal ecosystems.

Microplastics doi: 10.3390/microplastics5030167

Authors: Zahra Beyzaei Heydar Izadneshan Bita Geramizadeh Sara Karimzadeh Ralf Weiskirchen

Microplastics (MPs) and nanoplastics (NPs) accumulate in human hepatic and gastrointestinal (GI) tissues. However, differences in sampling strategies, tissue preparation, analytical techniques, and quality assurance procedures have resulted in substantial methodological heterogeneity, limiting the comparability and reproducibility of published findings. Therefore, this review aims to critically evaluate current analytical methodologies for the detection and characterization of MPs and NPs in hepatic and GI tissues, highlight methodological strengths, limitations, and emerging technologies, and identify priorities for methodological standardization. Studies demonstrate that no single analytical technique can simultaneously provide comprehensive information on particle size, morphology, polymer composition, spatial localization, and concentration. While Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), and emerging multimodal imaging techniques each offer distinct advantages, reflecting their different underlying detection principles, methodological variability remains a major barrier to cross-study comparison. Human tissue studies are further constrained by limited sample availability, contamination risks, and inconsistent quality assurance procedures. Future progress will depend on harmonized, organ-specific analytical workflows integrating optimized tissue digestion, rigorous contamination control, complementary spectroscopic approaches, and standardized reporting metrics. Establishing unified methodological guidelines is essential to improve reproducibility, facilitate quantitative evidence synthesis, and advance both environmental exposure assessment and clinical research on MPs and NPs in hepatic and gastrointestinal tissues.

Microplastics doi: 10.3390/microplastics5030166

Authors: Ezia Guatteo Maria Zelinda Romano Nicola Berretta Mario Ruggiero Antonietta Santoro Filomena Mazzeo Rosaria Meccariello

Plastic contamination (plastamination) has become a pervasive environmental threat with growing implications for human health. Among plastic-derived contaminants, micro- and nano-plastics (MNPs) are of particular concern due to their persistence, widespread distribution, and capacity to interact with biological systems. Humans are exposed to MNPs through ingestion, inhalation, dermal contact, and maternal transfer, and these particles can cross biological barriers, including the blood–brain barrier, reaching the central nervous system. MNPs disrupt cellular homeostasis by inducing oxidative stress, mitochondrial dysfunction, and inflammation. In the brain, these processes drive glial activation and chronic neuroinflammation, which are closely associated with neuronal damage and neurological disorders, including Parkinson’s disease (PD). MNPs can also affect systemic pathways such as the gut–brain axis (GBA) and neuroendocrine regulation, suggesting broader physiological consequences. This narrative review synthesizes current evidence on the neurotoxic and pro-inflammatory potential of MNPs. Since MNPs may promote the aggregation of proteins implicated in neurodegeneration, such as alpha-synuclein, their possible role in PD is discussed. Despite several knowledge gaps, MNPs may be emerging environmental risk factors for brain health and neurodegenerative diseases such as PD. Nevertheless, there is a need for further studies in the field, standardized methodologies and longitudinal studies to implement effective mitigation strategies.

Microplastics doi: 10.3390/microplastics5030165

Authors: Yiannis Kiouvrekis Ioannis Psomadakis Theodor Panagiotakopoulos

Microplastics are a pervasive contaminant of aquatic, terrestrial, and atmospheric systems, with accumulating evidence of ecological harm and human exposure. Conventional workflows, manual microscopy, FTIR, and Raman spectroscopy, are labor-intensive and operator-dependent, motivating artificial intelligence (AI) and machine learning (ML) as scalable alternatives. Following PRISMA guidelines, five databases were searched; 936 records were screened and 113 primary studies met the eligibility criteria, analyzed through dual-reviewer extraction across seven dimensions. Contrary to the assumption that deep learning dominates, classical and chemometric estimators (46.0% of studies) were at least as prevalent as deep learning (36.3%), with support-vector machines the single most used family (35.4%). Method choice tracked input modality rather than recency: chemometric classifiers such as SVM and PLS dominate spectroscopic data (FTIR, Raman; 53.1% of studies), whereas deep learning concentrates in the image-based minority, where representation learning outperforms manual feature engineering. Detection/identification remained the principal task (65.5%), although 19.5% addressed predictive modeling of sorption, toxicity, distribution, and remediation. Characterization coverage was uneven: origin and polymer type were reported in 88.5% and 72.6% of studies, but size and shape in only 50.4% and 28.3%. Reported accuracies, often exceeding 90%, derive from heterogeneous, non-comparable datasets. Future progress depends on open benchmarks, standardized reporting, and explainable methods.

Microplastics doi: 10.3390/microplastics5030164

Authors: Shun Xiao Andi Wang Ningning Zhang Suixin Liu Linsheng Yang

Atmospheric microplastics are increasingly recognized as mobile particulate contaminants that can be emitted, resuspended, transported, and deposited across indoor, terrestrial, marine, high-altitude, and remote environments. However, reported abundances and particle characteristics remain difficult to compare because studies differ in sampling design, reporting units, particle-size limits, contamination control, and polymer identification. This review combines concise bibliometric mapping with a critical narrative synthesis. A Web of Science Core Collection search for 2000–2024 retrieved 356 English-language articles and reviews, of which 280 met the eligibility criteria. Publication output increased rapidly after 2020. Co-citation and keyword analyses identified three major themes: occurrence, transport, and deposition; sampling and analytical characterization; and exposure and potential ecological and health implications. The synthesis shows that active air sampling and passive deposition collection measure different atmospheric processes, while inconsistent blank correction, recovery assessment, and polymer confirmation limit inter-study comparability. Field observations and modelling support long-range transport and the importance of particle morphology, but quantitative source attribution remains uncertain. Current evidence supports inhalation exposure and biological plausibility, yet is insufficient to establish population-level risks or causal links with specific diseases. Future research should prioritize harmonized monitoring, stronger QA/QC, improved detection of small particles and nanoplastics, and integrated transport–exposure assessment.

Microplastics doi: 10.3390/microplastics5030163

Authors: Joaquín Hernández-Fernández Rafael González-Cuello Rodrigo Ortega-Toro

Polystyrene (PS) thermal degradation involves localized molecular bond-cleavage events that are not directly equivalent to the apparent kinetic parameters obtained from bulk thermal analysis. In this study, a finite hydrogen-terminated PS oligomeric model was examined using density functional theory at the M06-2X/LANL2DZ level, whereas the non-isothermal degradation behavior of a PS sample was independently evaluated by thermogravimetric analysis under nitrogen. The computational analysis considered frontier molecular orbital distributions and site-specific thermodynamic descriptors associated with homolytic C–C cleavage and radical-mediated β-scission reactions. The calculated HOMO–LUMO gap of 742.62 kJ mol−1 indicated a comparatively large orbital-energy separation within the selected oligomeric model, while the localization of the frontier orbitals over aromatic and benzylic regions revealed a spatially heterogeneous electronic distribution. Homolytic C–C cleavage exhibited bond dissociation energies ranging from 414.09 to 481.24 kJ mol−1, demonstrating that the thermodynamic requirement for radical generation depends on the local molecular environment of the evaluated structure. The Gibbs free-energy changes calculated for the selected radical β-scission reactions ranged from 55.44 to 189.41 kJ mol−1. These quantities represent model-dependent reaction thermodynamics and should not be interpreted as activation barriers because transition states were not calculated. Thermogravimetric analysis showed systematic increases in Tonset and Tmax with increasing heating rate, consistent with kinetic delay and thermal-lag effects under non-isothermal conditions. The Kissinger method yielded a global apparent activation energy of 186.61 kJ mol−1, whereas the residual-mass-corrected Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods produced average apparent activation energies of 180.81 and 178.49 kJ mol−1, respectively, over α = 0.05–0.95. Across the same conversion interval, the FWO apparent activation energy increased from 143.10 to 221.71 kJ mol−1, while the KAS values increased from 140.10 to 220.23 kJ mol−1, indicating an evolving macroscopic degradation response with greater uncertainty toward high conversion. The computational and experimental datasets were therefore interpreted as complementary but non-equivalent scale-dependent descriptions: DFT compares the relative thermodynamics of selected molecular reactions within a finite isolated oligomer, whereas TGA characterizes the global apparent kinetic behavior of the condensed polymer sample. No direct numerical correspondence was established between the molecular reaction energies and the TGA-derived apparent activation energies, and no individual cleavage reaction was assigned to a specific conversion interval. Extrapolation of these results to high-molecular-weight, polydisperse, additive-containing, cross-linked, or environmentally aged PS microplastics should therefore be made with caution.

Microplastics doi: 10.3390/microplastics5030162

Authors: Yadong Xu Haifeng Zhang Xin Cao Taiping Zhang

As microplastics act as ubiquitous carriers for endocrine-disrupting additives in aquatic environments, understanding their leaching dynamics is of critical concern. This study systematically investigated the effects of ultraviolet (UV) aging on the release behavior of phthalates (di-n-butyl phthalate [DnBP] and di(2-ethylhexyl) phthalate [DEHP]) from polyvinyl chloride (PVC) microplastics across diverse environmental conditions, along with the underlying mechanisms. Kinetic analyses and experimental results indicated that the release of plasticizers under UV irradiation was driven by a dynamic competition between the photochemical stability of the plasticizers and the aging of the microplastics: the apparent cumulative amount of photolabile DnBP decreased as irradiation time increased. In contrast, the release of photoresistant DEHP significantly exceeded that under dark conditions in the later stages of aging. Furthermore, highly variable environmental factors exhibited significant selectivity in regulating the release: high ionic strength inhibited plasticizer release through salting-out and cationic bridging effects, with divalent ions (Mg2+) in particular suppressing DEHP release by up to 96%; conversely, dissolved humic acid caused a 13-fold surge in DEHP release via robust hydrophobic solubilization. Comprehensive multitechnique characterizations (including SEM, FTIR, XRD, and XPS) confirmed that UV-induced aging—encompassing intense dehydrochlorination reactions, a marked increase in polar oxygen-containing functional groups and the amorphization of crystalline regions—fundamentally dismantled the internal mass transfer resistance, thereby creating physical pathways for the outward migration of internal plasticizers. Ultimately, this study emphasizes that the synergistic interactions between material aging and complex hydrochemical conditions must be fully integrated into assessments of long-term ecological risks and predictions of the real-world environmental fate of microplastic-associated contaminants.

Microplastics doi: 10.3390/microplastics5030161

Authors: Joaquín Hernández-Fernández Juan López-Martínez

Polyethylene (PE) microplastics are environmentally persistent contaminants whose progressive fragmentation suggests that degradation may not be governed by uniform backbone stability. In this work, density functional theory and non-isothermal thermogravimetric analysis were combined to evaluate PE degradation from complementary molecular and kinetic perspectives. A C90H182 polyethylene oligomer was optimized at the M06-2X/def2-TZVP level, and position-resolved C–H and C–C bond dissociation energies were calculated along the chain. The C–H bonds showed comparatively high and homogeneous stability, whereas the C–C backbone displayed lower dissociation energies and a localized energetic depression in the central region. The minimum C–C BDE was found at C44, with a value of 85.73 kcal·mol−1, identifying a model-specific low-BDE region within the finite all-trans-derived oligomer that may favor backbone scission under the evaluated computational conditions. Thermogravimetric analysis under nitrogen at 5, 10, and 20 °C min−1 showed a dominant degradation event, with DTG maxima shifting from 462.6 to 494.6 °C as the heating rate increased. Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose analyses revealed a progressive increase in apparent activation energy from approximately 170–175 kJ·mol−1 at low conversion to 280–285 kJ·mol−1 at high conversion. Although BDE and apparent activation energy are not directly equivalent, their combined interpretation supports a heterogeneous degradation model in which PE fragmentation preferentially initiates at localized low-BDE C–C environments before progressing toward regular backbone scission and secondary degradation reactions.

Microplastics doi: 10.3390/microplastics5030160

Authors: Asli Baysal Hasan Saygin Elif Aydin

Previous studies have indicated that polyethylene terephthalate (PET) micro/nanoplastics (MNPs) may coexist with antibiotics in environmental and biological matrices; however, their combined behavior in blood remains insufficiently characterized. This study examined PET MNPs prepared from water bottles at 0.5, 2.5, and 7.5 mg/mL together with tetracycline (2–50 µg/mL) in defibrinated horse blood. After 24 h exposure and particle removal, UV–visible absorbance, intrinsic fluorescence, redox indicators, and subsequent Escherichia coli responses were evaluated. The blood biochemical results showed condition-dependent changes in hemoglobin-associated absorbance, tryptophan-dominated fluorescence, reactive oxygen species, reduced glutathione, superoxide dismutase, and lipid peroxidation. When treated blood supernatants were applied to Escherichia coli, tetracycline alone reduced bacterial OD600, whereas selected PET MNP–tetracycline co-exposures partially restored bacterial proliferation and modified oxidative-stress responses. ATR–FTIR analysis of Escherichia coli pellets showed dose-dependent modulation of phosphate-, lipid-, and protein-associated bands, indicating changes in bacterial biochemical fingerprints under specific exposure combinations. Overall, the findings suggest that PET MNPs can modify tetracycline-associated spectral, redox, and bacterial response patterns in a blood matrix. Future studies incorporating adsorption assays, free tetracycline quantification, protein-corona profiling, time-course exposure designs, and antibiotic susceptibility testing would further clarify the mechanistic basis and biological relevance of these matrix-dependent interaction effects.

Microplastics doi: 10.3390/microplastics5030159

Authors: Maria Fiore Lorenzo Lo Cicero Eloise Pulvirenti Luca Zanoli Marco Palella Federica Bivona Chiara Timperanza Maria Valentina Longo Alfina Grasso Antonio Cristaldi Chiara Copat Montse Marquès Ana González-Ruiz Paolo Maria Riccobene Sabrina Carola Carroccio Gea Oliveri Conti Margherita Ferrante Pasquale Mario Fatuzzo

Patients with chronic kidney disease (CKD), particularly those receiving hemodialysis (HD), may be more vulnerable to exposure to micro- and nanoplastics (MNPs) and bisphenol A (BPA) because of impaired renal clearance and frequent contact to plastic-based medical devices. This study aimed to assess and compare the levels of blood MNPs and urinary BPA in HD patients, non-dialysis CKD patients, and healthy subjects with a focus on sex-related differences and the potential role of hemodialysis as an additional source of exposure. A cross-sectional human biomonitoring study was conducted. Blood and urine samples were collected to quantify BPA using gas chromatography–mass spectrometry (GC–MS) and MNPs using scanning electron microscopy coupled with an Energy-Dispersive X-ray Detector (SEM-EDX). Descriptive statistics included medians, interquartile ranges (IQRs), 95% confidence intervals, frequencies, and percentages. Blood MNP levels were higher in HD [9889 (4525–14,939) p/mL] and non-dialysis CKD patients [9234 (3354–15,429) p/mL] than in healthy subjects [5755 (2488–9042) p/mL]. Urinary MNP levels were also higher in non-dialysis CKD patients [1231 (0–8281) p/mL] than in healthy subjects [411 (0–1636) p/mL]. Urinary MNPs were smaller in non-dialysis CKD patients than in healthy subjects. In contrast, urinary BPA levels were lower in non-dialysis CKD patients [0.16 (0.12–0.16)] than in healthy subjects [0.98 (0.60–2.36)]. Sex-specific patterns were observed. Females had higher blood MNP levels than males among HD patients (median 9907 vs. 9063 p/mL) and healthy subjects (6627 vs. 4131 p/mL), whereas the opposite pattern was observed in non-dialysis CKD patients (10,083 vs. 7340 p/mL). Overall, these findings suggest an increased systemic burden of MNPs and altered BPA elimination in non-dialysis CKD and HD patients. The observed sex-specific patterns suggest that biological sex may contribute to differences in internal exposure within this vulnerable population.

Microplastics doi: 10.3390/microplastics5030158

Authors: Valeria Cristancho-Arias Valentina Arias-Pérez Seyli Julibeth Gómez-Guardado Adriana Pulido-Villamarín Moises Aranda-Silva Luis David Gómez-Méndez

Microplastics (MPs) are widely distributed among humans and companion animals. Fecal samples from members of the university community at the Pontifical Javeriana University in Bogotá, Colombia, and their companion animals (pets) were analyzed to investigate a possible association between MP loads in humans and their dogs and/or cats. Structures compatible with microplastics were detected in the feces of 97.78% of humans and 100% of companion animals. No significant correlation was found between MP loads in humans and their companion animals (p = 0.6846), suggesting that exposure is not determined solely by the shared household environment. If the home were the dominant and exclusive source of exposure, a positive correlation between owners and their companion animals would be expected. Instead, the results indicate the existence of species-specific exposure routes. This exploratory study provides the first report of MP-like structures in fecal samples from humans and their companion animals in Colombia.

Microplastics doi: 10.3390/microplastics5030157

Authors: Hriddhi Sarker Umar Hasnain Monabbi Goutam Saha Awnon Bhowmik B. M. Rabby Hossain

The rapid growth in plastic production and consumption has led to the widespread contamination of the environment with microplastics (MPs), raising increasing concerns about their potential impacts on human health. In recent years, advances in analytical techniques have revealed the presence of MPs in a wide range of human biological samples, suggesting that these particles can enter, circulate within, and accumulate throughout the human body. This narrative review provides a comprehensive overview of the current evidence on the occurrence and distribution of MPs in human tissues, organs, and biological fluids. MPs have been detected in blood, urine, stool, semen, breast milk, amniotic fluid, ocular fluids, and lavage fluids, as well as in several organs and tissues including the lungs, placenta, heart, kidneys, liver, vascular tissues, and reproductive organs. Among the identified polymers, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), and polyvinyl chloride (PVC) are reported most frequently. This narrative review also summarizes the major analytical techniques used for MP detection and characterization, including Raman spectroscopy, μ-FTIR, LDIR spectroscopy, and Py-GC/MS, which highlight their advantages and limitations. Collectively, the available evidence demonstrates that MPs are not confined to the external environment but are now detectable in multiple compartments of the human body, including highly protected biological systems. However, important questions remain regarding their long-term persistence, transport mechanisms, biological fate, and potential health effects. Further methodological standardization and large-scale human studies are needed to better understand the extent of human exposure and the implications of MP accumulation for human health.

Microplastics doi: 10.3390/microplastics5030156

Authors: Lisete Fernandes Jaynne C. Guimarães José R. Fernandes Pedro B. Tavares

Micro and nanoplastics (MNPs), defined as particles under 5 mm down to the submicron scale (<1 µm or 1–1000 nm), have shifted from an environmental concern into a general potential contaminant of our global food supply. As plastic production escalates, the fragmentation process disperses particles across soils, water bodies and the atmosphere, resulting in their reported detection in a variety of food products and, in some studies, in human biological matrices including the bloodstream to major organs. However, confirming their presence is not equivalent to tracing their journey. Current scientific understanding of how these contaminants migrate remains uncertain, since most studies focus on isolated sources rather than the interconnected stages of production and exposure. To address this, we propose the Farm-to-Table Microplastic Exposure Cascade (FT-MPEC), an integrated concept designed to describe the potential progressive accumulation of MNPs across the food continuum. This review synthesizes the trajectory of particles from primary production into the food chain, evaluating potential transfer pathways during post-harvest handling, industrial processing and domestic preparation. By mapping these routes, we identify critical knowledge gaps and research priorities necessary to improve future monitoring, exposure assessment and mitigation strategies for public health.

Microplastics doi: 10.3390/microplastics5030155

Authors: Jerome Otiti Lelethu UnathiNkosi Peter Heshula Trishan Naidoo Linda Lunga Sibali Anthony Ifeanyi Okoh

Microplastic pollution has emerged as a pervasive stressor in aquatic ecosystems, with aquatic invertebrates playing central roles in particle uptake, retention, and transfer within food webs. This review synthesises evidence on microplastic ingestion, bioaccumulation, trophic transfer, and biomagnification across major aquatic invertebrate groups, including arthropods, molluscs, sediment-associated worms, suspension feeders, and echinoderms. A structured literature search identified 66 studies spanning freshwater, estuarine, and marine environments. Evidence indicates that microplastic uptake occurs through multiple pathways, including filter feeding, deposit feeding, grazing, and predator–prey interactions. Across the reviewed studies, feeding strategy, habitat-specific exposure, and particle characteristics were recurrently associated with variation in microplastic ingestion, retention, and trophic transfer. While ingestion and bioaccumulation were widely documented, quantitative understanding of trophic transfer within aquatic invertebrate food webs remained limited, and no conclusive evidence of biomagnification was identified. To interpret recurring patterns, this review proposes the Trait–Habitat–Particle (THP) framework as a conceptual tool linking biological and functional traits, habitat-mediated exposure, and particle properties. Methodological inconsistencies, limited representation of certain taxa and habitats, and insufficient quantification of trophic transfer remain important knowledge gaps. Future research should prioritise methodological standardisation and ecologically realistic long-term studies.

Microplastics doi: 10.3390/microplastics5030154

Authors: Raissa Okwuosa Thendo Mutshekwa Jeffrey Lebepe

Microplastics are increasingly recognized as prevalent contaminants in freshwater ecosystems, where they interact with a wide range of co-occurring pollutants, including heavy metals, pesticides, pharmaceuticals, and persistent organic pollutants. Evidence indicates that microplastics can act as vectors, enhancing pollutant mobility and facilitating trophic transfer, while also modulating toxicity through synergistic or antagonistic effects. Ecotoxicological studies reveal adverse impacts on aquatic organisms, ranging from physiological stress and impaired reproduction to altered community dynamics, with implications for ecosystem functioning and human health. Despite growing knowledge, significant gaps remain in understanding long-term environmental behavior, standardized methodologies, and risk assessment frameworks. This review synthesizes current findings on microplastic–pollutant interactions in freshwater systems, highlights emerging ecotoxicological risks, and identifies critical research needs to inform effective management and policy interventions.

Microplastics doi: 10.3390/microplastics5030153

Authors: Xinhuan Deng Joaquim I. Goes Yu-Jin Jung Huiming Yin Beizhan Yan

Polyethylene terephthalate (PET) is a common plastic widely used in food packaging, especially plastic bottles, and in fibers and textiles. The widespread use of PET and its intentional and unintentional release and disposal over the past few decades have placed significant pressure on the environment, necessitating the development of green, low-cost, and efficient recycling technologies to mitigate this impact. This article reviews recent advances in microwave-assisted catalytic depolymerization of PET. It begins by outlining the fundamental principles of PET materials science and depolymerization mechanisms. The article then reviews the historical evolution of this research and presents a benchmark comparison of different depolymerization methodologies. Finally, through a critical analysis and comparison of state-of-the-art approaches, the article identifies emerging trends and highlights promising directions for future research in the field. A comprehensive comparison of conventional and microwave heating methods is presented, indicating that catalyst-assisted microwave systems can shorten reaction times and achieve high product yields under optimized conditions. Key advantages and limitations are highlighted, and persistent challenges are discussed. Overall, this article surveys the latest progress in the chemical recycling of PET and provides critical insights for future research and further development of microwave-assisted catalytic PET depolymerization technology.

Microplastics doi: 10.3390/microplastics5030152

Authors: Shangchen Shi Jindong Zhang Ben Liu Bo Wu Siyuan Huo Xinqi Yu

Airborne microplastics (AMPs) are recognized as emerging pollutants, exerting widespread impacts on both the ecological environment and human health. While existing research has predominantly focused on the occurrence characteristics, studies addressing human exposure patterns remain limited. In this study, a typical campus in Zhenjiang, a city in East China, was selected as the research site. By integrating students’ daily activity trajectories, active sampling methods were employed to estimate 24 h inhaled AMP intake, alongside simultaneous monitoring of environmental parameters such as temperature, relative humidity, and air pressure. Each participant used one filter throughout the 24 h monitoring period. The results revealed average AMPs abundances of 0.49 items/m3 and 0.82 items/m3 during the sampling period, with fibers being the most prevalent morphology (63%), followed by fragments (27%) and pellets (10%). μ-Raman spectroscopy analysis identified polypropylene (PP), polystyrene (PS), and polymethyl methacrylate (PMMA) as the primary polymer types, constituting 70% of the total. PP and PS were the dominant polymer types in the two trajectory-integrated samples; however, polymer identity alone did not permit definitive source attribution. A large proportion of the μ-Raman-identified particles fell within the 1–5 μm range; however, this fine-size fraction should be interpreted cautiously because representative spectra and particle-specific spectral matching records were not available for further verification. Based on the activity trajectories, the estimated daily inhalation intake of AMPs by students in campus micro-environments was approximately 91.5 items/day per person. PMMA was identified in Sample A, whose trajectory included the volleyball gym; however, the integrated sampling design did not permit location-specific source attribution or comparison of individual activity locations. This study provides preliminary information on AMP occurrence characteristics and estimated inhaled intake. This study is a preliminary pilot study, with 24 h personal exposure monitoring conducted on only two participants. We will increase the sample size in follow-up experiments to draw broader conclusions regarding airborne microplastic exposure across the campus.

Microplastics doi: 10.3390/microplastics5030151

Authors: Katarzyna Chojnacka

Waste-derived fertilising materials, including sewage sludge, compost, digestate, food-waste-derived products and commercial organic or organo-mineral fertilisers, return nutrients to farmland but can also transfer microplastics to agricultural soil. This critical review examines their occurrence across these streams, analytical constraints, fate after application and the EU regulatory framework. Reported abundances span orders of magnitude and cannot be pooled because extraction, polymer identification and reporting are not harmonised, while particle-counting and mass-based methods measure different quantities. Field evidence indicates topsoil retention and accumulation after repeated application, whereas crop transfer and field-scale ecological effects remain poorly quantified. Regulation (EU) 2019/1009 sets no microplastic-specific product limit. For compost qualifying as CMC 3 and digestate other than fresh crop digestate qualifying as CMC 5, it controls plastic impurities above 2 mm by mass, while smaller particles remain outside that criterion. Waste-derived fertilisers can therefore form a recurrent, incompletely regulated pathway for microplastic transfer to soil. Controlled studies demonstrate hazard potential for selected particles and exposure conditions, but the magnitude and likelihood of effects under field conditions remain uncertain. The immediate priority is harmonised monitoring and reporting of the sub-2 mm fraction, including a stated lower size limit, polymer-confirmed particle counts and minimum QA/QC.

Microplastics doi: 10.3390/microplastics5030150

Authors: Elius Paz-Cruz Lourdes Vela Rafael Tamayo-Trujillo Cristina Mideros-Mora Cristian Ayala Viviana A. Ruiz-Pozo

Global plastic production and inadequate waste management have led to widespread environmental contamination with microplastics (MPs), now detected in food, water, and air. Their small size, diverse polymer composition, and capacity to carry chemical additives and co-pollutants facilitate intestinal uptake and raise concerns about their potential impact on gut microbiota. This review synthesizes current evidence on how MPs influence gut microbial composition and function, gut barrier integrity, and associated inflammatory and metabolic pathways. We conducted a narrative review of in vivo animal studies, in vitro simulated gut systems, and human observational studies that assessed MP exposure, gut microbiota profiles, and downstream toxicological outcomes. MPs originate from primary and secondary sources and can act as vectors for metals and organic pollutants. Following ingestion, they may cross the intestinal barrier via endocytic and persorption routes, acquire a protein corona, and be recognized by immune cells, activating TLR/NF-κB, and MAPK pathways alongside oxidative stress. In these models, MP exposure induces dysbiosis, characterized by loss of beneficial SCFA-producing bacteria (e.g., Bifidobacterium, Lactobacillus, Bacteroides) and expansion of pathobionts (e.g., Escherichia/Shigella, Staphylococcus, Enterobacteriaceae), accompanied by altered bile acid metabolism. These microbiota and metabolic alterations are linked to increased gut permeability, intestinal inflammation, metabolic dysfunction, and, in some studies, reproductive and neurobehavioral effects. Current evidence supports MPs as emerging modulators of gut microbial and intestinal homeostasis. However, heterogeneity across experimental models, reliance on high exposure doses, and lack of standardized MP characterization limit robust risk assessment. These limitations underscore the need for harmonized methodologies, longitudinal large-scale human studies, and the development of targeted mitigation strategies.

Microplastics doi: 10.3390/microplastics5030149

Authors: Khushaboo Soni Payal Chaurasia Srishti Singh Sanjay Singh Alok Kumar Singh Soubhagya Keshari Chand Suresh Kumar Yatirajula Sasmita Chand Jagdeep Kumar Nayak A. R. Palaniappan

The world is facing a triple global crisis: climate change, loss of biodiversity, and pollution. Plastics, man-made polymers from primary fossil fuel sources, have pervasively entered almost every sector and thereby caused huge environmental pollution. Microplastic (MPs) sizes range between 1 μm and 5 μm, and nanoplastics are less than 1 μm in size, respectively. Behaviour, accumulation and movement of plastics in soil, water and air depend on their size. Smaller sizes of microplastics and nannoplastics can easily enter cells, tissues, and finally, the food chain, and pose growing ecological and health concerns due to their persistence. It also acts as an adsorbent and has the ability to penetrate food webs. Their diverse shapes, especially fibres, increase their dispersal and bioavailability in aquatic ecosystems. Recent findings indicate that microalgae contribute to the mitigation of microplastic pollution. Microalgae, diverse photosynthetic microorganisms ranging from 0.5 to 200 μm, interact with microplastics through processes such as adsorption, aggregation, and potential biodegradation mechanisms, including toxin systems or enzymes produced by the microalgae, utilising plastic polymers as carbon sources. The filamentous morphology of some species, such as Spirulina sp., increases the entrapment and potential degradation of microplastic fibres. It is essential to understand these interactions to construct sustainable means of mitigating microplastic pollution and recovering the aquatic ecosystem health. Microalgae produce enzymes such as lipases, esterases, and cellulases, which facilitate the biodegradation of plastics. Microalgae form biofilm on the surface of microplastics. They also secrete sticky extracellular polymeric substances (EPS) that cause the microplastic to sink to the bottom of the water body, which helps to remove microplastics from surfaces. This review summarises knowledge on microalgae–microplastic interactions, with a focus on their potential for bioremediation of microplastics and also sustainable conservation of the environment.

Microplastics doi: 10.3390/microplastics5030148

Authors: Xiaohong Li Yanxiang Chen Ruirong Wang Muzamil Abbas Nadia Sarwar Shan Hussain Muhammad Jafir Talha Nazir

Nanoplastics (NPs; <1000 nm) are persistent soil contaminants that suppress extracellular enzyme activity, the biochemical engine of terrestrial nutrient cycling. Despite a rapidly expanding primary literature, no comprehensive meta-analysis has systematically integrated quantitative effect-size synthesis with interpretable machine learning (ML) approaches to identify and rank the physicochemical drivers of NP-induced soil enzymatic toxicity. Following the PRISMA 2020 statement, we systematically searched four databases (Web of Science, Scopus, PubMed, Google Scholar) from database inception through December 2024 and extracted 413 effect sizes from 113 peer-reviewed studies. Hedges’ g was estimated using three-level random-effects models with restricted maximum likelihood (REML) estimation implemented in the metafor package. Three supervised ML algorithms—random forest (RF), gradient boosting machines (GBMs), and support vector regression (SVR)—were trained using 18 study-level predictors derived from the complete meta-analytic dataset, and SHapley Additive exPlanations (SHAP) were applied to quantify and rank the relative importance of individual predictors. The overall meta-analysis demonstrated a significant inhibitory effect of NPs on soil enzyme activity (Hedges’ g = −0.94; 95% CI: −1.14 to −0.73; k = 413; I2 = 78.4%; τ2 = 0.412). Among the evaluated enzymes, dehydrogenase activity exhibited the greatest inhibition (g = −1.12), whereas polystyrene nanoplastics produced the strongest adverse effects (g = −1.15). Particles smaller than 100 nm caused approximately 2.6-fold greater inhibition than particles larger than 500 nm, and dose–response meta-regression identified a nonlinear increase in toxicity at concentrations exceeding 200 mg kg−1. The RF model demonstrated the highest predictive performance, explaining 73% of the variance in an independent testing dataset (R2 = 0.73; test set n = 83). SHAP analysis identified particle diameter as the most influential predictor, revealing an approximate critical threshold of 150 nm, below which inhibitory effects increased markedly. Higher soil organic carbon concentrations partially mitigated enzymatic inhibition, likely through competitive adsorption and reduced nanoplastic bioavailability. Overall, our findings demonstrate that NP-induced inhibition of soil enzymatic activity is widespread and primarily governed by particle size, exposure concentration, and soil properties. The identified 150 nm threshold should be interpreted as a data-driven hypothesis requiring further validation under environmentally realistic exposure scenarios rather than as a universal regulatory limit. Nevertheless, the integration of three-level meta-analysis with interpretable machine learning (SHAP) provides a robust and reproducible framework for identifying key toxicity drivers and supports future ecological risk assessment and evidence-based regulatory decision-making for nanoplastics.

Microplastics doi: 10.3390/microplastics5030147

Authors: Israel Mejía-Vigueras Martha Lucia Arenas-Ocampo Antonio R. Jiménez-Aparicio Francisco Rodríguez-González Daniel Tapia-Maruri Argelia López-Bonilla Amalinali Portillo-Ayala

Tortillas are an essential food in Mexico, and they are usually packaged in low-density polyethylene (LDPE) bags, but these packages can release microplastics (MPs) into the food. On the other hand, MPs have been associated with conditions such as the release of toxic substances, damage to mitochondrial membranes, and the generation of oxidative stress and inflammation, among others. Currently, there are no studies on the presence of MPs in corn tortillas, so the objective of this work was to study samples of tortillas acquired at five points of sale in central Mexico, namely, supermarkets (A and B) and tortilla shops (C, D, and E), as well as to evaluate the presence of MPs and their identification by Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and scanning electron microscopy (SEM). In addition, an abundance interval and an estimate of the consumption rate were established considering the available information on per capita consumption of tortillas in Mexico. The results show that the samples of tortillas purchased at sampling points A and B presented MPs in the form of films with an abundance between 155.56 and 177.78 MPs/kg of tortilla; however, no microplastics were identified in the samples of tortillas acquired at sites C, D, and E. The analysis suggests that the identified MPs may have come from the plastic bags in which tortillas are packaged. In addition, it was established that the daily consumption rate of microplastics per person is 2.48 to 5.15 pieces.

Microplastics doi: 10.3390/microplastics5030146

Authors: Anamaria Cristina Bunea Madalina Andreea Badea Anca Dinischiotu Mihaela Balas

The detection of microplastics (MPs) and nanoplastics (NPLs) in biological samples is critical for understanding their environmental distribution and investigating human exposure, bioaccumulation and their potential health effects. This review provides an overview of current approaches used to detect plastic particles in in vitro and in vivo studies, focusing on microscopic, spectroscopic, spectrometric, chromatographic and flow-cytometry-based methods. Microscopy techniques, including optical, confocal, fluorescence, scanning electron (SEM), transmission electron (TEM), cryogenic electron (cryo-EM), and atomic force microscopy (AFM), enable the visualization and characterization of MPs and NPLs. Spectroscopic approaches, such as Fourier transform infrared (FT-IR) and Raman spectroscopy, are widely employed for polymer identification through characteristic molecular fingerprints. Spectrometric techniques, including single-cell inductively coupled plasma mass spectrometry (scICP-MS) and single-cell inductively coupled plasma time-of-flight mass spectrometry (scICP-TOFMS), provide sensitive elemental analyses, while flow cytometry offers high-throughput particle detection. Chromatographic approaches, particularly double-shot gas chromatography–mass spectrometry (Py-GC/MS), enable sensitive and specific polymer characterizations. Recent technological advances, including automated and high-resolution analytical approaches, are also discussed together with practical considerations for selecting appropriate methods according to the sample type and analytical objective. Collectively, these methods contribute to the assessment of plastic particle occurrence, bioaccumulation, and biological effects, supporting future environmental monitoring, human biomonitoring and risk assessment.

Microplastics doi: 10.3390/microplastics5030145

Authors: Simon Baniya Tusher Mohanta Moayad Yacoub Utsav Darlami Aihua Li Ishan Subedi Kirsten Nicholson Subodh Sharma Bangshuai Han

Microplastic contamination is an emerging global concern, but its occurrence in high-altitude protected areas has been understudied. This study systematically assessed microplastic abundance, morphology, and spatial distribution in Sagarmatha National Park (SNP), Nepal, a UNESCO World Heritage Site. Soil samples were collected from 25 sites across four land-use types, including settlement, farmland, forest, and floodplain, at two depths along the Lukla–Phortse trekking corridor during the pre-monsoon season of 2023. Samples were pretreated by density separation and Fenton’s reagent digestion, and microplastics were then detected using a YOLOv11n-seg instance segmentation model. A subset of extracted particles was chemically confirmed by optical photothermal infrared (O-PTIR) spectroscopy. Microplastics were present in all samples, with concentrations ranging from 80 to 960 particles·kg−1. Fragments were the dominant morphological type, accounting for 65.7% of all particles, followed by fibers and films. Negative binomial regression revealed significant effects of land use and soil depth and their interaction on microplastic abundance. Settlement soils showed the highest concentrations with significant surface enrichment, while farmland soils showed no significant depth effect, consistent with human-dominated plastic sources and tillage-driven redistribution. Elevation was not a significant predictor of contamination. Hotspot analysis identified statistically significant clustering around Lukla and Namche, the two primary tourism hubs. The baseline established in this study provides a foundation for long-term monitoring and targeted waste management in SNP and offers insights to other protected high-altitude environments. Meanwhile, the application of deep learning and O-PTIR to balance the counting efficiency and accuracy is a novel approach that could be adopted by other researchers.

Microplastics doi: 10.3390/microplastics5030143

Authors: Dhouha Belhaj Sghaier Noureddine Zaaboub Ines Chniti Thouraya Barhoumi-Slimi Micha J. A. Rijkenberg Monia El Bour

The pollution caused by microplastics (MPs) in marine sediments has been a concern of many researchers thanks to these substances’ persistence and potential ecological effects. To our knowledge, this study represents the first comprehensive investigation of MP contamination in marine sediments collected from multiple regions of the Mediterranean Sea, encompassing a wide bathymetric range from coastal areas to deep-sea environments, down to approximately 4000 m water depth. Sediment samples were taken from several sites in the Mediterranean and the northern Aegean Sea. Thanks to microscopic analysis, fragments and filaments were the dominant MP forms; their color and size varied, and the most frequent particle colors were red, transparent and blue. FTIR spectroscopy revealed diverse types of polymers, including polystyrene (PS), propylene (PP), ethylene–vinylacetate (EVA), polyamide (PA), and Acrylonitrile Butadiene Styrene (ABS) polymer. The 1-H NMR analyses confirmed the presence of PA, EVA, PP, polyethylene (PE), and PS, thereby supporting the FTIR results. This spatial variability in polymer composition probably reflects both regional anthropogenic inputs and hydrodynamic factors affecting sedimentary deposits. These results detail the complex and generalized nature of MP contamination in Mediterranean sediments and offer a basis from which to start assessing ecological risks and developing targeted mitigation strategies.

Microplastics doi: 10.3390/microplastics5030144

Authors: Elizabeth S. Gordon Maeve H. Ahern Nicole E. Burdick Kaitlyn E. Prentiss Paulina Torres Daniel P. Welsh

Microplastic pollution is an increasingly important environmental concern, especially in aquatic ecosystems. However, research on microplastics has historically been skewed towards marine systems and large freshwater systems, leading to an incomplete picture of the potential prevalence and scope of this type of pollution. In order to understand the potentially ubiquitous nature of freshwater microplastics, our study focused on 11 small headwater streams in north–central Massachusetts (USA) and a small freshwater fish species, the Blacknose dace (Rhinichthys atratulus). Microplastics were found in all sampled streams. Considerable variation in the number of stream microplastics existed, with concentrations ranging from 0.3 to 45.1 pieces per cubic meter of water. Microplastics were assessed in 14–20 fish from each of five of these streams. The vast majority of all fish had microplastics, with some individuals having over 200 pieces in their digestive tract. The number of fish microplastics was not found to be statistically related to the amount of water microplastics, the length of the fish, or the land use surrounding the streams. Together, these results illustrate that microplastics are prevalent and that small freshwater ecosystems need to be considered when assessing the full impact this source of pollution may have on ecosystems.

Microplastics doi: 10.3390/microplastics5030142

Authors: Mahrosh Javed Galina Lujanienė Sergej Šemčuk Tayyab Tahir Aušra Selskienė Vidas Pakštas Audrius Drabavičius Martynas Talaikis

With high mobility, long-term durability, and potential risks to aquatic ecosystems and human health, polyethylene nanoplastics (PE–NPs) are a developing environmental issue. Therefore, graphene oxide (GO) was utilized to functionalize chitosan (CS) and microcrystalline cellulose (MCC) in order to create sustainable polysaccharide-based composites that resulted in graphene oxide–chitosan (GO–CS), graphene oxide–MCC–50 µm and graphene oxide–MCC–90 µm adsorbents in order to evaluate the adsorption performance of sustainable GO–polysaccharide composites toward laboratory-prepared polyethylene nanoplastics under controlled conditions. The novelty of this study lies in the comparative evaluation of GO–chitosan and GO–microcrystalline cellulose composites with two MCC particle sizes (50 μm and 90 μm) for the adsorption of laboratory-prepared polyethylene nanoplastics, providing insight into the influence of adsorbent composition and particle size on adsorption performance. The prepared adsorbents were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), point of zero charge (pHpzc), and X-ray diffraction (XRD) in order to analyze adsorption behavior by morphology, chemical structure, surface chemistry, and particle crystallinity. According to the results, GO–CS has the maximum adsorption capacity (50.25 mg·g−1), followed by GO–MCC–50 µm (38.31 mg·g−1) and GO–MCC–90 µm (27.02 mg·g−1). Smaller MCC particle sizes of adsorbent resulted in improved adsorption performance, as demonstrated by the increased adsorption capacity of GO–MCC–50 µm as opposed to GO–MCC–90 µm. The difference between the graphene oxide–MCC–50 µm and graphene oxide–MCC–90 µm composites’ adsorption capacities demonstrates that adsorption capacity greatly increases with small adsorbent particle sizes. Stronger interaction sites, hydrophobic contacts, and a large number of functional groups are all responsible for the improved performance. The findings provide insight into the influence of polymer type and particle size on polyethylene nanoplastic adsorption and support the further development of GO-based biopolymer adsorbents.

Microplastics doi: 10.3390/microplastics5030141

Authors: Carol Adrianne Smith Saroj Pramanik

Anoplophora glabripennis (ALB) is an invasive wood-boring cerambycid that causes extensive damage to hardwood host trees through sequential tissue penetration from the bark to the sapwood. Developmental biology of ALB is well established. However, interactions among its life cycle, environmental contaminants, and fungal associates remain poorly understood. In particular, the ecological relationships among microplastics, entomopathogenic fungi, and the fungal symbiont Fusarium solani (FSSC) within ALB-associated woody tissues remain largely uncharacterized. This review develops a conceptual anatomical framework integrating ALB developmental biology, fungal associations, frass deposition pathways, and potential microplastic interactions within woody host tissues. The framework was constructed through ecological literature synthesis and anatomical reconstruction. To our knowledge, this represents the first conceptual framework integrating ALB developmental anatomy, fungal symbiosis, and potential microplastic interactions within host tree gallery systems. A longitudinal cross-sectional model was developed to illustrate oviposition, larval gallery formation, pupation, and adult emergence in relation to the outer bark, cambium/phloem, sapwood, and heartwood. FSSC isolates previously documented on ALB egg surfaces following oviposition and within ALB frass were examined, thereby positioning the fungal symbiont both within and outside galleries produced by ALB throughout its life cycle. Previous studies have demonstrated that microplastics can be taken up by plant stem tissues and accumulate on the forest floor through atmospheric deposition. This widespread presence suggests that micro- and nanoplastics may penetrate sapwood and heartwood galleries through xylem and phloem flow. These transport pathways may overlap with regions where late-instar larvae actively forage. The integrative framework presented here highlights potential ecological interactions within the gallery microhabitat and provides a foundation for future experimental investigations into contaminant–pathogen–host dynamics in xylophagous insects. While we refrain from proposing specific management strategies, we present a conceptual framework to elucidate how microplastics may serve as incidental contact points for cerambycid anatomy and fungal propagules. We hypothesize that these interactions link microplastic pollution to invertebrate ecology. Microplastics may function as substrates for fungal spores within forest canopies and gallery systems, potentially influencing fungal persistence, contaminant transport, and ecological dynamics within infested forest habitats.

Microplastics doi: 10.3390/microplastics5030140

Authors: Pratyusha Nayak Nishigandha Muduli Smruti Prajna Pradhan Subhashree Nayak Sthitaprajna Nath Sharma Lipika Patnaik

Microplastic (MP) pollution in marine ecosystems is a matter of concern worldwide, as their ingestion and accumulation in marine fauna pose a significant health risk associated with MP pollution. This detailed study is the first of its kind in the Chandipur coastal waters, Bay of Bengal to comprehensively evaluate MP pollution, and associated pollution load in commonly consumed edible fish and shrimp species. Samples of Harpadon sp., Setipinna taty, Coilia dussumieri, Johnius belangerii, Pampus sp., Arius arius, and Penaeus monodon were collected from Chandipur, Odisha, East coast of India and examined using wet peroxide oxidation, followed by FTIR spectroscopy. A relatively higher concentration of MPs was observed in the muscle tissues (4628 ± 11,702 particles/g of tissue) compared to the gastrointestinal tract (GIT) (4296 ± 9687 particles/g of tissue). The abundance of MPs was maximum in Coilia dussumieri and minimum in Arius arius. Comparatively higher retention of MPs (11,309 ± 15,448 particles/g of tissue) was obtained in the monsoon season than in the pre- and post-monsoon. Microscopic examination revealed the presence of mostly fiber- and fragment-type MPs, in addition to black fibers. The commonly encountered size class was 1–50 µm with 63.4%. FTIR analysis revealed eighteen different types of MPs and polyvinyl chloride (PVC), polyethylene terephthalate (PET), and cellulose acetate (CA) with occurrence percentage between 91.6 and 100%, whereas polyamide (PA) was the most uncommon and least found in all the samples. The Polymer Hazard Index (PHI) revealed the presence of extremely hazardous polymers such as polyurethane (PU), PVC, and PET in tissues, and Pollution Load Index (PLI) values indicate low pollution levels.

Microplastics doi: 10.3390/microplastics5030139

Authors: Varsha Deepali Chandra Rajnandini Verma Niharika Ajey Singh Pradeep Kumar

Plastic pollution has emerged as a major environmental concern due to its persistence and widespread accumulation in terrestrial ecosystems. The extensive utilization of plastics across a diverse range of products, from packaging to healthcare, construction, and transportation, poses a significant risk due to their enduring and non-biodegradable nature. Micro/nanoplastics (MNPs) derived either from the fragmentation of larger plastics or direct release are increasingly detected in agricultural soils, where they interact with plant systems. In addition, chronic exposure of MNPs alters soil structure, microbial diversity, and nutrient cycling, further impacting agroecosystem functioning. Plants have been shown to absorb MNPs mostly from contaminated soil and irrigated water through their root systems, allowing their subsequent translocation to aerial tissues. MNPs can enter plants through the aquaporins, apoplast pathways, crack entry modes, and leaf stomata, disrupting nutrient uptake, photosynthesis, and growth processes, ultimately affecting crop productivity and quality, while their accumulation in edible tissues raises concerns regarding food safety and trophic transfer. To address these challenges, it is crucial to have standard detection methods for identifying MNPs and to bridge the gap for further mitigation. This review further discussed effective mitigation strategies, including nanomaterial and phytohormone-based interventions under increasing plastic contamination.

Microplastics doi: 10.3390/microplastics5030138

Authors: Mina Popović Nevenka Rajić

The global proliferation of microplastics demands sustainable remediation alternatives to energy-intensive conventional disposal methods, shifting research focus toward polymer-degrading microbial communities within the “plastisphere.” The primary objectives of this study are twofold: first, to systematically decode the sequential biophysical mechanisms underlying microplastic colonization and enzymatic degradation; and second, to establish an empirically validated, scalable treatment framework that employs both a novel biological isolate and a hybrid engineering architecture. Experimentally, we investigate the multi-stage colonization process and demonstrate that “Phase Zero” conditioning films modulate the surface zeta potential (ζ) to anchor pioneer r-strategists. To evaluate degradative efficacy under accelerated conditions without abiotic pretreatment, the newly isolated carp gut strain Hafnia paralvei UUNT_MP29 was exposed to pristine low-density polyethylene (LDPE) and polystyrene (PS). Over a 16-day biotic incubation period, structural and chemical alterations were distinctly polymer-specific: bacterial action on the polyolefin LDPE yielded a Carbonyl Index of 0.4594 and a 10.95 °C reduction in thermal stability (Tmax), whereas the aromatic PS matrix exhibited a Carbonyl Index of 0.3235 alongside a 10.80 °C decrease in Tmax, with both substrates showing intense surface pitting. To standardize these complex tracking metrics across the field, a universal four-pillar Biodegradability Index (BI) was formulated. Based on these findings, we recommend an immediate transition from passive waste containment to a closed-loop engineering approach. Specifically, we propose integrating an artificial intelligence (AI)-managed hybrid bioprocess configuration that couples Advanced Oxidation Processes (AOPs) with Membrane Bioreactors (MBRs). This dual-stage configuration is recommended to overcome polyolefin crystallinity, accelerate stoichiometric mineralization, and actively mitigate additive-mediated toxicity at the industrial scale, providing a vital blueprint for the circular bio-economy.

Microplastics doi: 10.3390/microplastics5030137

Authors: Lorenzo A. Picos-Corrales Anette López-Guardado Ana M. Morales-Burgos Alfonso Talavera-Lopez Jose Alfredo Hernández Oscar Joaquín Solís-Marcíal Levy N. Inzunza-Camacho Jose P. Ruelas-Leyva

Concerns have increased significantly in recent years due to the presence of microplastics in different environmental compartments given that this pollutant can cause adverse effects on the environment and human health. The present review integrates representative studies of Mexican researchers proposing solutions to these concerns, addressing ecological risk and the human food chain, microplastic ingestion by animals, water and sediment pollution, physical/chemical methods for microplastic removal from water, and chemical recycling as a research direction in plastic waste management. Several publications from Mexican institutions are limited to the occurrence and identification of polymers, and a smaller number of documents are focused on solutions to microplastic pollution. Fibers, fragments, spheres, films, and foams have been found in aquatic compartments, sediment, and animals. High ecological risk has been documented in some aquatic compartments. There is a lack of standardized protocols for sampling, extraction, identification, and reporting. Flocculation is a cost-effective approach and may be one of the most promising options for removing microplastics from fresh water. Bioremediation using microorganisms and chemical recycling appear to be the two most widely considered approaches to reverse plastic pollution. National databases, permissible limits, and mandatory monitoring programs should be developed, as these are essential components of an effective regulatory framework.

Microplastics doi: 10.3390/microplastics5030136

Authors: Nguyen Truong Thanh Pham Van Toan Huynh Vuong Thu Minh Kim Lavane Nguyen Vo Chau Ngan Le Thi Kim Ngan Vo Thanh Toan Nguyen Van Tuyen Pankaj Kumar

Microplastic pollution in tropical urban rivers has become an increasing environmental concern due to rapid urbanization, inadequate waste management, and hydrological transport processes. This study investigated the occurrence, characteristics, and spatiotemporal distribution of microplastics in the Can Tho River, Vietnam, along an urban–peri-urban–rural gradient during dry and wet seasons. Surface-water samples were collected at 15 sites and analyzed for microplastic abundance, density, shape, color, and size composition using stereomicroscopic identification and statistical analyses. Microplastics were detected at all sampling sites in both seasons, indicating widespread contamination throughout the river system. Although seasonal differences in overall abundance and density were not statistically significant at the basin scale, clear spatial variability was observed, particularly in urban and peri-urban regions. Fibers and fragments were the dominant shapes, while blue, purple, and green particles were the most common color categories. Particles larger than 1000 µm accounted for the largest proportion of detected microplastics, and continuous size-distribution analysis revealed broadly similar overall distributions, although a greater proportion of smaller particles was observed during the dry season. The results suggest that hydrological conditions, urbanization, and land-use characteristics may contribute to the observed spatial and seasonal patterns of microplastic distribution in the Can Tho River. Peri-urban zones exhibited the greatest seasonal variability, highlighting their role as transitional areas that may influence microplastic redistribution in tropical river systems. This study provides baseline information for understanding microplastic pollution in the Mekong Delta and supports future river management strategies.

Microplastics doi: 10.3390/microplastics5030135

Authors: Joaquin Hernandez-Fernandez Michel Murillo Acosta

Polypropylene (PP) waste, including microplastic debris, motivates molecular-scale studies of the intrinsic factors governing thermal degradation. In this work, the bond dissociation energies (BDEs) of C–C and C–H bonds were systematically evaluated in a finite isotactic polypropylene oligomer containing fifteen propylene repeat units, (–C3H6–)15, using Density Functional Theory at the M06-2X/LANL2DZ level. Thermochemical corrections were evaluated at 873.15 K, a temperature relevant to pyrolysis studies. Within the selected oligomer model, C–C bonds exhibited lower BDE values (82.28–87.41 kcal·mol−1) than C–H bonds (90.18–104.93 kcal·mol−1), indicating a thermochemical preference for backbone scission. The lowest calculated BDE values were associated with specific tertiary carbon environments, including sites C24 and C28. A mixed-effects model identified bond type and carbon type as the principal factors associated with BDE variation, while principal component analysis summarized the covariation among the electronic and thermodynamic descriptors. These results provide a molecular-scale description of intrinsic scission tendencies within the selected PP oligomer and establish a basis for subsequent kinetic, catalytic, and experimental studies.

Microplastics doi: 10.3390/microplastics5030134

Authors: Francisco Alvirde-Díaz Fredy Cuellar-Robles Javier Illescas Alethia Vázquez-Morillas María del Carmen Carreño de León María del Consuelo Hernández-Berriel

Microplastics (MP) in landfill leachate represent an analytical challenge due to matrix complexity and the need for methods that remove interferents without degrading polymers. This study evaluated the efficiency of four digestion methods (30% H2O2, Fenton, 10% NaOH, and 20% HCl) and three density separation solutions (CaCl2, NaI, and ZnCl2) for MP quantification in leachate from the Zinacantepec Sanitary Landfill, Mexico. Samples were spiked with seven polymer types (polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), and polyamide (PA)). Results analyzed by ANOVA (p < 0.05) showed that Fenton reagent was the most efficient digestion method, achieving 99% MP recovery, whereas alkaline and acid digestions caused degradation of PET, PS, and PA. Regarding density separation, ZnCl2 (1.7 g/cm3) achieved recovery exceeding 99% for all polymers. The proposed protocol enables effective isolation and identification of degraded microplastics, contributing to advance the understanding of degradation processes and transformation pathways of MP in complex environmental matrices. The combination of Fenton digestion and ZnCl2 separation showed the highest overall performance, with an efficiency greater than 96%, supporting its use as a reliable protocol for MP quantification in leachate and contributing to methodological standardization in this field.

Microplastics doi: 10.3390/microplastics5030133

Authors: Juzhuang Wang Shengwang Yu

This study systematically investigated microplastics (MPs) in Pingshan River, Shenzhen—a representative urban river with short channel length, rapid flow, and limited environmental capacity. Surface water and sediment samples from seven sites were analyzed for MP abundance, size, morphology, color, and polymer composition. Results revealed significant MP pollution: surface water abundance ranged from 132 to 423 items/L (mean 311.42 ± 90.78 items/L), while sediment abundance ranged from 334 to 756 items/kg (mean 508.85 ± 151.79 items/kg). Spatial heterogeneity was pronounced, with the highest abundance at a construction-influenced site (Site 6) and the lowest at a less-impacted site (Site 2). MPs were predominantly 300–1000 μm in size. Fibers dominated surface water, while fragments prevailed in sediment. Transparent particles constituted >77% of all MPs. Polymer composition was dominated by polypropylene (PP) and polyethylene (PE). Key factors controlling spatial distribution included proximity to construction/industrial activities, aquatic vegetation cover, and hydrological conditions during the dry season. Polymer hazard risk index (H) classified all sites as Category II (10 ≤ H < 100), indicating low ecological risk despite high abundances. This research provides a scientific foundation for targeted pollution control in urban river systems, emphasizing the need to consider both abundance and polymer-specific toxicity in risk assessment.

Microplastics doi: 10.3390/microplastics5030132

Authors: Jhosin Jaik B. Pardillo Jay Rumen U. Maglupay Najiha B. Amer Rodolfo A. Romarate II Ruei-Feng Shiu Hernando P. Bacosa

Microplastic pollution is an emerging environmental concern in coastal ecosystems, particularly in developing regions. However, research remains compartmentalized, limiting an integrated understanding of microplastic distribution, transport dynamics, and ecological risks across interconnected environmental matrices. In this study, a multi-matrix assessment was conducted to evaluate microplastic abundance, characteristics, and associated ecological risks. A total of 93 microplastic particles were identified, with the mangrove site exhibiting the highest concentration (200 items/kg), while the seagrass bed and estuary showed the lowest concentration (3.33 items/kg). The dominant microplastic type was primarily fiber (55.91%), with most particles ranging from 0.1 to 1 mm, and polypropylene (66.67%) was the predominant polymer type, reflecting the widespread contribution from plastic packaging and fishing gear. Significant correlations were observed between microplastic abundance and contamination factor (CF), pollution load index (PLI), and potential ecological risk index (PERI), whereas the polymer hazard index (PHI) showed no significant relationship due to its dependence on polymer composition. Non-metric multidimensional scaling (NMDS) revealed distinct distribution patterns of microplastic shape and polymer type across matrices. Overall, microplastic distribution across environmental matrices is driven by heterogeneous sources and transport pathways, with mangrove sediments enhancing retention, underscoring the need to elucidate seaward and landward source contribution and coastal fluxes.

Microplastics doi: 10.3390/microplastics5030131

Authors: Ramesh Ganpisetti Sanjay Giridharan Mehmet Remzi Dokmeci Radhika Chandankere

The plastic pieces of synthetic polymers, which were previously regarded as primary pollutants of the environment, are increasingly being discovered as internal pollutants of the human body. This review provides a comprehensive overview of the available evidence on human exposure, tissue distribution, and associated biological effects of micro- and nanoplastics. Ingesting contaminated food and water is the major exposure pathway, with inhalation and dermal contact being secondary routes. Various organ systems have been identified as containing polymer particles through the use of advanced analytical methods, including blood, liver, lungs, placenta, breast milk, and brain tissue. Experimental animal studies suggest associations with tissue injury, metabolic illness, and neurotoxicity. Polyethylene, polypropylene, polystyrene, and polyethylene terephthalate are the most frequently found polymers in human samples. New clinical findings indicate potential health implications, though current human evidence remains largely associative rather than causal: a cardiovascular study observed more than a two-fold rise in mortality among patients with polymer-containing arterial plaques, and recent evidence demonstrates over-accumulation of polymers in brain tissue, raising questions about neuroinflammatory processes. Detection technologies have advanced substantially, with deep learning-based polymer classification achieving 95–99% accuracy and ultrasensitive electrochemical and surface plasmon resonance biosensors reaching detection limits approaching 10−11 M. Despite these advances, critical issues remain, including lack of standardized analytical procedures, absence of chronic exposure models for humans, and insufficient longitudinal epidemiological data. To address these gaps, physiologically relevant experimental systems including organoids and organ-on-chip platforms will be required, in addition to well-designed prospective cohort studies.

Microplastics doi: 10.3390/microplastics5020130

Authors: Florinela Pirvu Iuliana Paun Florentina Laura Chiriac

Microplastics (MPs; <5 mm) represent a growing environmental concern that increasingly challenges environmental monitoring, governance, and evidence-based decision-making. This review critically examines how current scientific understanding of microplastic sources, classification, occurrence, and environmental behavior can support environmental governance. MPs are classified as primary and secondary particles; however, persistent inconsistencies in size definitions, shape descriptors, and polymer identification limit the comparability of monitoring data and constrain the development of coherent regulatory frameworks. Evidence on the occurrence of MPs in surface waters and sediments highlights widespread contamination and pronounced spatial variability, raising challenges for risk assessment and policy harmonization across regions. Key transport pathways, including atmospheric deposition, terrestrial runoff, and riverine fluxes, are analyzed to illustrate how local emissions translate into large-scale environmental impacts. Rivers emerge as key components linking sources to receptors, offering relevant points for policy intervention and management measures. The review evaluates current policy responses to microplastic pollution, identifying significant gaps in standardized monitoring, data integration, and risk assessment approaches. It emphasizes the need for stronger alignment between scientific outputs and policy requirements, including the co-production of knowledge involving scientists, regulators, and stakeholders. By outlining pathways through which scientific evidence can inform regulatory design and environmental management, this study provides actionable insights for improving policy effectiveness. Advancing harmonized methodologies and integrating science into decision-making processes are essential steps toward mitigating microplastic pollution and supporting sustainable environmental governance.

Microplastics doi: 10.3390/microplastics5020129

Authors: Raffaelina Mercogliano Alessandro Avolio Stefano Capone Margherita Ferrante Gea Oliveri Conti Rossella Di Palo Maria Carmela Ferrante

The seasonal distribution of microplastics, as a representative case, was examined in Mytilus galloprovincialis from a pilot farm in the Gulf of Naples (Italy). The influence of marine parameters on microplastic uptake rate was assessed. A destructive patented method was used, and two microplastic size classes (<10 µm; >10 µm) were defined. Estimated Daily Intakes were calculated for different age groups. Results showed a significant abundance of small microplastics (9683.92 ± 6911 vs. 41.85 ± 13.98). In mussels, the highest levels (19,738.13 ± 3406.04) were detected in summer, and the lowest in autumn (4145.56 ± 2364.93). Summer variations in seawater temperature, oxygen, and pH were significantly different from those in winter and spring. High exposure levels, mainly of microplastics < 10 µm, were observed in the elderly (318.08 ± 227.00), followed by adults (225.29 ± 160.78) and children (212.29 ± 151.50), with the lowest in teenagers (127.51 ± 91.00). Despite the high variability of factors influencing mussel filtration and microplastic uptake, the study provided data on the seasonal microplastic distribution pattern and a size-based screening exposure level. Results highlight the importance of geographic and seasonal conditions, and particle size in assessing microplastic exposure through farmed mussel consumption.

Microplastics doi: 10.3390/microplastics5020128

Authors: Jana Rammal Assi Al Moussawi Chaden Haidar Mikhael Bechelany Dalia El Badan Ismail Hijazi Akram Hijazi

Microplastics (MPs) have emerged as persistent environmental contaminants due to their persistence, widespread distribution, and potential risks to the environment and human health. This review focuses on the sources of MPs, their potential environmental risks, and human impacts, as documented in the recent literature from 2020 to 2026. Recent studies focusing on pathways, environmental weathering, and toxicity were evaluated and synthesized into the analysis. Previous studies have demonstrated that microplastics are transported across and between environmental compartments. Environmental degradation, driven by ultraviolet radiation, mechanical fragmentation, and oxidation, can alter microplastics’ surface characteristics, which may affect microplastic mobility, reactivity, and the solid-state adsorption of contaminants. Human exposure occurs primarily through ingestion and inhalation, with dermal and occupational exposure also contributing under certain conditions. Emerging evidence from in vitro, animal, and human tissue studies suggests that smaller particles, particularly nanoplastics, may contribute to oxidative stress, inflammation, and cellular injury; however, important uncertainties remain regarding environmentally realistic exposure levels, long-term health outcomes, and the extrapolation of experimental findings to real-world human health risk. Overall, the current literature highlights the need for standardized methodologies, improved integration of environmental monitoring and exposure assessment, and stronger evidence to support risk assessment and policy development.

Microplastics doi: 10.3390/microplastics5020127

Authors: Joaquín Alejandro Hernández Fernández Juan Carrascal Jose Alfonso Prieto Palomo

The pyrolysis of polypropylene (PP) microplastics offers a potential route to convert plastic waste into fuel-range hydrocarbon mixtures and chemical feedstocks. However, the elementary radical pathways underlying the formation of medium-chain hydrocarbon fragments remain insufficiently resolved. In this study, a representative isotactic PP oligomer model (C45H92) was evaluated using a comparative density functional theory (DFT) framework. The main mechanistic analysis was based on M06-2X, ωB97X-D, and M11 calculations combined with the def2-TZVP basis set, whereas LANL2DZ was retained only as a lower-cost comparative level during reaction-pathway exploration. Thermochemical profiles were evaluated over a temperature range of 298–923 K. Three selected pathways involving mid-chain homolytic cleavage, intramolecular hydrogen transfer (backbiting), radical rearrangement, and β-scission were examined. Within the selected reaction set, Route 1 exhibited a comparatively more favorable thermochemical profile than Routes 2 and 3 and provided a mechanistically plausible sequence toward medium-chain hydrocarbon fragments. The −TΔS contribution strongly influenced the calculated Gibbs free-energy profiles because fragmentation increases the number of molecular species under the ideal-gas thermochemical approximation. Accordingly, the ΔG values were interpreted comparatively and were not treated as direct evidence of spontaneous fragmentation under condensed-phase pyrolysis conditions or as quantitative predictions of experimental product selectivity. Differences among the evaluated functionals further indicate that the relative description of radical intermediates and transition-state regions is method-dependent. These results provide a molecular-level framework for future studies integrating quantum-chemical calculations, microkinetic modeling, and experimental product characterization.

Microplastics doi: 10.3390/microplastics5020126

Authors: Melinda Haydee Kovacs Emoke Dalma Kovacs

Background: Soil mulching is a widely adopted agricultural practice known to regulate soil microclimate and enhance crop productivity; yet the biochemical mechanisms by which intact plastic and biodegradable mulch films influence soil nitrogen (N) cycling at the metabolic pathway level remain largely unexplored. Understanding these nitrogen transformation pathways is critical for assessing the long-term impacts of mulching materials on soil microbial communities, soil health, and sustainable agricultural management. This study focuses on the biochemical effects of intact mulch film application on soil N metabolism. Methods: N cycle-related soil metabolites were profiled using GC–MS/MS and MALDI TOF/TOF MS and then integrated with multivariate statistical modelling and pathway-level metabolic network perturbation analysis to compare conventional plastic and biodegradable plastic mulch film application against unmulched controls. Results: A panel of 62 KEGG-annotated N-cycle metabolites was profiled, and material-dependent metabolome separation was confirmed by OPLS-DA (R2Y 0.893–0.956; Q2 0.546–0.786). Both mulching materials significantly perturbed soil N-metabolite pools but differed in terms of pathway identity, magnitude, and directionality. Conventional plastic mulching caused the greatest disruption—near-complete suppression of N-storage and stress-adaptation pools (NES of −1.16; impact score of 10.01) and severe impairment of aspartate-centred metabolism—with L-aspartate identified as a critical stoichiometric hub. Biodegradable mulching material imposed a distinct profile dominated by inhibition of branched-chain amino acid catabolism and lysine degradation, with L-pipecolate as a treatment-specific critical impact node. Conclusions: These findings support that mulching material choice is a primary determinant of soil N-cycling biochemistry. The observed metabolite-level perturbations are suggestive of potential consequences for nitrogen retention. Though this inference is based on metabolite pool size differences and network topology metrics rather than directly measured process rates, it should therefore be interpreted with appropriate caution.

Microplastics doi: 10.3390/microplastics5020125

Authors: Sneha Siwach Padma Dolkar Aarzoo Yadav Apoorva Atri Meenu Chaurasia Pankaj Yadav Themchuirin L. Sonia Nongmaithem Vyakhya Singh Aviral Singh Ram Krishan Negi

Microplastic (MP) contamination is an emerging threat to aquatic ecosystems. However, species-specific bioaccumulation patterns across trophic guilds in tropical river ecosystems remain scarcely understood. This study assessed the occurrence, organ-level distribution, polymer composition, and ecological risk of MPs in 220 fish representing 12 species, spanning across multiple trophic guilds, sampled from four sites along a pollution gradient of the river Yamuna, India. MPs were detected in all examined species, confirming extensive distribution across the river ecosystem. A total 1678 MPs were recovered, with significantly higher abundance in fish from the highly urban Delhi stretch than in those from upstream regions (Kruskal–Wallis, H = 11.03, p = 0.011). The highest species-specific MP load was recorded in omnivorous Oreochromis niloticus from Sonia Vihar (436 MPs), whereas the carnivorous species Xenentodon cancila exhibited the lowest accumulation (37 MPs). Surface- and mid-water herbivores and omnivores accumulated more MPs than benthic carnivores and detritivores. Nonetheless, spatial pollution gradients exerted a stronger influence on MP accumulation, compared to trophic guilds. The gastrointestinal tract exhibited the highest MP abundance (751 MP particles), followed by gills (605) and muscle tissues (322), confirming ingestion as primary uptake route, and suggesting possible tissue translocation. Fibers dominated in the assemblage (77.8%), while transparent (44%) and blue (19.5%) were most abundant colors. ATR–FTIR analysis confirmed 10 diverse polymers, with polyethylene (≈24%) and polypropylene (≈21%) together accounting for nearly half of the identified particles. The Polymer Hazard Index analysis classified the recovered MP mix as Category IV (high ecological hazard). These findings identify the Delhi stretch of the Yamuna as a high MP contamination zone and highlight the combined influence of urban pollution and fish ecology on MP bioaccumulation.

Microplastics doi: 10.3390/microplastics5020124

Authors: Yusmila Helguera Pedraza Nathalie Bernard Ana Flavia Roldan Ramos Dariadelys Reyes Noa Joán I. Hernandez-Albernas Anamary Acosta Valladares Marco A. Garcia Varens Arianna García Chamero Marc Metian Lorena Rios Francois Oberhaensli Carlos Alonso-Hernandez

Microplastic contamination in coral reef environments is increasingly recognized as a global concern; however, the extent to which polymer composition can help distinguish contamination sources and transport-related processes remains poorly understood. In this study, we assessed the abundance, composition, and diversity of microplastics (20–300 µm) across multiple reef systems in the Cuban archipelago using high-resolution Laser Direct Infrared (LDIR) spectroscopic analysis. Microplastic abundance varied substantially among sites, with a median concentration of 66 particles L−1 (IQR: 45–115 particles L−1), ranging from 8 to 218 particles L−1. A total of 11 polymer types were identified, with polyethylene (PE), polypropylene (PP), and polyamide (PA) dominating the assemblages and accounting for approximately 77% of detected particles. While these polymers were consistently observed across all sites, suggesting a pervasive regional background signal, highly impacted reefs exhibited more heterogeneous polymer profiles, including increased contributions of polyurethane (PU), polytetrafluoroethylene (PTFE), and polyvinyl chloride (PVC), consistent with localized anthropogenic influence. Multivariate analysis revealed moderate compositional structuring among reef sites and suggested broad differences in polymer assemblages associated with contrasting contamination settings. Notably, some reefs exhibited elevated microplastic abundances while remaining dominated by common polymers, indicating a partial decoupling between contamination levels and polymer-specific signatures. This pattern is consistent with the influence of regional transport and mixing processes across the Caribbean basin, potentially including circulation associated with the Yucatán Channel, although hydrodynamic processes were not directly assessed in this study. Overall, the findings highlight the value of polymer-resolved analysis for improving interpretation of microplastic contamination patterns in coral reef environments. The integration of polymer composition with abundance and diversity metrics provides a useful framework for distinguishing between localized contamination signals and broader regional background influences. This study represents a regional baseline assessment of small microplastics in Caribbean coral reef systems using high-resolution spectroscopic characterization.

Microplastics doi: 10.3390/microplastics5020123

Authors: Angeliki Tsachouridou Dimitra Voutsa

Background/Objectives: Tire (or tyre) wear particles (TWPs), originating from road traffic, have been recognized as a significant emerging contaminant for terrestrial ecosystems. The aim of this study is to attempt a critical review of the existing articles, to identify trends and directions in research, highlight any knowledge gaps, limitations and drawbacks, and develop respective proposals and recommendations. Methods: A comprehensive literature search was conducted in the PubMed and Web of Science databases for the period 2020–2025 according to PRISMA-based protocols. Results: The final studies were methodically grouped into specific representative themes. Conclusions: This study focuses on the factors affecting the emissions of TWPs, their size distribution, processes that affect their environmental fate and methodological approaches for characterization/determination of TWPs. This article also explores the occurrence and toxicity of TWPs in the terrestrial environment, as well as the management approaches and policies in order to minimize their impact.

Microplastics doi: 10.3390/microplastics5020122

Authors: Erica Sparaventi Rafael Nuez María Pilar Yeste Miguel Ángel Cauqui Marta Sendra

Microplastics (MPs) are routinely detected throughout wastewater treatment plants (WWTPs), yet current treatment trains were not designed specifically to remove them. This study quantified and characterized visually identified MPs in influent and effluent waters from seven urban WWTPs in Andalusia (southern Spain) during a six-month monitoring period (July–December 2020). The targeted analytical size range was 45–5000 µm, and a subset of particles was further characterized by FTIR. MPs were detected in all sampling campaigns. Concentrations ranged from 6 to 78 items/L in influent and from 12 to 65 items/L in effluent. Fibers were the dominant morphology, and the 100–500 µm size class was the most represented fraction. Among the subset analyzed by FTIR, PA, PP, PVC and LDPE were the most frequent polymer assignments, with PA predominating in the fiber-rich fraction. However, because influent and effluent 24 h time-composite samples were not hydraulic retention time (HRT)-paired and FTIR interpretation was based on a selected subset of particles, the dataset is best interpreted as describing spatiotemporal variability during the study period rather than robust process-specific removal efficiency. Overall, the results support WWTPs as an ongoing pathway for MP release to receiving environments.

Microplastics doi: 10.3390/microplastics5020121

Authors: Sabela Fernandez-Sanchez Maria Garcia-Marti Jesus Simal-Gandara Juan C. Mejuto

In recent decades, plastic consumption has risen across various industries and everyday products, leading to greater plastic use and the generation of waste, which results in the leaching of micro- and nanoplastics into the environment. This review summarizes recent analytical methods for the detection of nanoplastics (NPs) in several marine matrices, divided into three main stages: extraction, separation, and identification. The literature reviewed indicates that chemical and enzymatic digestion are the most commonly used procedures for the extraction step. For the separation step, flotation, filtration, and centrifugation are the most used techniques. Finally, two groups of techniques may be used for the identification step. The first category consists of methods used for qualitative identification, with spectroscopic methods such as Raman and FTIR being the most frequently used. The second category comprises those used for the quantitative analysis of NPs, where fluorescence-based methods and nanoparticle tracking analysis are increasingly used for this assessment. Despite these advances, significant challenges remain, such as matrix interferences caused by salinity and organic matter, low environmental concentrations of NPs, and the lack of standardized protocols. This review highlights the need for standardized protocols, validated reference materials, and integrated multi-technique approaches to improve the comparability of nanoplastics measurements in marine environments.

Microplastics doi: 10.3390/microplastics5020120

Authors: Umair Sarfraz Shazia Alam Yinsen Qian Quan Ma Min Zhu Jinfeng Ding Chunyan Li Wenshan Guo Xinkai Zhu

The sustainability, crop production, and food safety of agriculture are increasingly challenged by microplastic pollution, as agricultural soils are the largest reservoirs and may serve as points of contact for plastic particles in the food chain. This review provides a comprehensive overview of plant materials, fate and uptake pathways, detection techniques, and the possible risks of microplastics in agriculture. Agroecosystems are also a source of microplastics, such as plastic mulch films, sewage sludge, compost and manure additives, wastewater irrigation, polymer-coated fertilizers, greenhouse materials, atmospheric deposition, and decomposition of discarded agricultural plastics. Their distribution and mobility in soil are controlled by polymer composition, particle size, morphology, density, surface ageing, soil texture, organic matter content, tillage practices, runoff, leaching, and soil biota. Recent data show that microplastics, especially smaller microplastics and nanoplastics, can attach to root surfaces, penetrate plants via cracks in roots, areas of lateral root development, and apoplastic pathways, and eventually move to tissues aboveground. Plant tissue detection is often accomplished by digestion of the sample, density separation, visual and fluorescence microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, pyrolysis–gas chromatography mass spectrometry, and electron microscopy, but standardization of these methods remains a significant challenge. Microplastics can disrupt seed germination, root structure, nutrient absorption, photosynthesis, oxidative homeostasis, biomass buildup, yield development, and quality. Further, their capacity to transport additives, plasticizers, heavy metals, and persistent organic pollutants raises concerns about the transfer of contaminants to edible plant parts and their potential transfer to human diets. Further studies are needed focusing on field-realistic exposure conditions, long-term crop–soil interactions, nanoplastics behaviour, standardised analysis procedures, uptake and translocation pathways, edible crop risk assessments, and sustainable mitigation approaches to reduce microplastics in agroecosystems.

Microplastics doi: 10.3390/microplastics5020119

Authors: Jillian A. Verble Michael L. McKinney

Plastic pollution is an increasing concern in freshwater ecosystems, yet the roles of polymer chemistry, environmental context, and microbial community composition in governing degradation remain poorly resolved. This study examined plastic–microbe interactions across river, creek, and pond environments using gravimetric mass loss, scanning electron microscopy (SEM), and 16S rRNA gene sequencing. Four polymers were evaluated: biodegradable polyhydroxyalkanoate (PHA) and polylactic acid (PLA), and conventional low-density polyethylene (LDPE) and polyethylene terephthalate (PET). Rapid biofilm formation occurred on all plastic surfaces, indicating widespread microbial colonization; however, measurable degradation was strongly polymer-dependent. PHA exhibited rapid and extensive mass loss across environments, approaching complete degradation after four months in river and pond settings, whereas PLA, LDPE, and PET showed limited mass loss despite substantial colonization. Environmental context influenced degradation intensity, but these effects amplified degradation only when polymer chemistry permitted breakdown. Microbial community analyses showed that substrate presence influenced beta diversity more than alpha diversity, and differential abundance patterns revealed overlapping enriched taxa across polymers. Overall, degradation was governed primarily by polymer chemistry and environmental conditions, while microbial composition played a secondary, indirect role.

Microplastics doi: 10.3390/microplastics5020118

Authors: Aly Castillo Marta Lores Manuel Aira Jorge Domínguez

Applying sludge from wastewater treatment plants to agricultural soils is a major pathway for microplastics (MPs) to reach terrestrial ecosystems, with critical implications for food and environmental safety. A longitudinal analysis (13 months) was conducted to evaluate vermicomposting (with Eisenia andrei) as a remediation strategy, comparing fresh sludge, worm casts, mature vermicompost, and control (earthworm-free) compost. MPs were isolated by chemical digestion and density separation and characterized by optical microscopy and μ-Raman spectroscopy. The MP content of fresh casts (584 ± 45 MP·g−1; p = 0.036), driven by the mechanical and digestive activity of earthworms, showed a significant increase relative to sludge, in contrast to the invariant results observed in the control compost. The MP content of the vermicompost initially increased to 755 ± 88 MP·g−1 after 3 months of maturation due to gradual fragmentation by microbial degradation. However, after 13 months, the MP content in vermicompost, compared to the initial sludge, decreased by 62% (reduction of 625 ± 49 MP·g−1; p < 0.001), more than the 56% (reduction of 560 ± 83 MP·g−1; p = 0.001) observed in the control compost, suggesting a net long-term decrease. Morphological, colorimetric, and compositional changes, reflected by browning and reduced particle size and natural fiber content, revealed a temporal lag, with earlier transformation in vermicomposted samples. Overall, the findings show the potential of vermicomposting to reduce the MP content of sewage sludge used as a soil amendment.

Microplastics doi: 10.3390/microplastics5020117

Authors: Fidel Vallejo Diana Yánez Lorena Molina Ernesto Pino-Cortés Andrea Espinoza-Pérez Lorena Espinoza-Pérez

Microplastics constitute an emerging contaminant of major concern in Latin America, where human exposure predominantly occurs through ingestion of drinking water and marine/estuarine food chains. This review synthesises available evidence on occurrence, exposure pathways, toxicological mechanisms, and regional public health risks, while examining regulatory and monitoring limitations that constrain effective risk management. Reported concentrations in drinking water show a wide range (1–1194 particles/L), dominated by PET, PP, and PS, with fibres and fragments as the main morphotypes. In commercial marine species, prevalence reaches 70–100%, with burdens up to 44 particles/g in oysters and ~90 particles/250 g in mussels. Estimated Daily Intake is 2–5 times higher in children (e.g., Chile: 13.03 vs. 5.59 particles/day in adults). Toxicological mechanisms include oxidative stress, chronic inflammation (NF-κB pathway), endocrine disruption, intestinal dysbiosis, systemic translocation, and placental transfer, exacerbated by vectorization of local co-contaminants (Hg from mining, Cd/Pb from agriculture). Risk indices indicate extreme danger in Brazil, Chile, and Ecuador, where data are available. Significant geographic and methodological gaps persist, with Brazil dominating research (~50–60%). Multicenter biomonitoring, harmonised surveillance networks, and SDG-aligned policies are urgently needed to reduce exposure burdens, protect vulnerable populations, and advance toward comprehensive regional risk assessment.

Microplastics doi: 10.3390/microplastics5020116

Authors: Andros M. Po Rodolfo A. Romarate Cordulo P. Ascaño Christine Joy M. Pacilan Mei-Fang Chien Hernando P. Bacosa

Atmospheric microplastics are increasingly recognized as emerging contaminants in urban air, yet evidence from Philippine cities outside Metro Manila remains limited. This study provides a preliminary roadside baseline assessment of airborne microplastics in Cagayan de Oro City, southern Philippines. Atmospheric particles were collected from 12 roadside stations distributed across four urban roads, with three stations per road, during a standardized dry-season midday sampling period, and were subsequently subjected to alkaline digestion, microscopic screening, and ATR-FTIR confirmation. Of 99 visually suspected particles, 44 were verified as synthetic polymers and retained in the final dataset. Mean atmospheric microplastic concentrations ranged from 0.0079 to 0.0212 items m−3, with J.R. Borja Street showing the highest concentration and Nazareth Street the lowest. Abundance did not differ significantly among roads, whereas particle shape, color, and polymer composition showed significant differences within the confirmed dataset, while size-class distribution did not. Fibers were the dominant morphology (56.8%), transparent particles were the most common color class (52.3%), and polypropylene and polyethylene terephthalate were the predominant polymers. Taken together, the findings confirm the presence of airborne microplastics across roadside environments in Cagayan de Oro City and suggest that, under the sampled conditions, spatial variation was more evident in particle characteristics than in overall abundance. This study contributes an initial polymer-confirmed roadside dataset for a secondary Philippine city and highlights the value of composition-based assessment in urban air quality monitoring.

Microplastics doi: 10.3390/microplastics5020115

Authors: Taiwo Ayorinde Amanda K. Charlton-Sevcik William C. Hockaday Christie M. Sayes

Microplastics (MPs) in wastewater treatment plants are exposed to oxidative conditions during disinfection and advanced oxidation processes (AOPs), which can alter morphology and surface chemistry and influence interactions with coexisting contaminants. Here, accelerated chemical oxidation was simulated using heat-activated potassium persulfate (K2S2O8) and sodium hypochlorite (NaOCl) to examine the oxidative aging of MPs made from polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP). Changes in particle morphology and surface chemistry before and after oxidant treatment were characterized using scanning electron microscopy (SEM) for morphological analysis and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy for chemical characterization. Carbonyl formation, an indicator of polymer oxidation, was evaluated using the carbonyl index (CI). Both oxidants induced surface morphological defects and carbonyl functional groups in the MPs, with CI increasing with degradation time. The CI trends suggest that MP oxidation varies with polymer type and oxidant. The effect of oxidative aging on MP sorption capacity was also investigated using copper ions as a model inorganic constituent. Although oxidative aging introduced oxygen-containing functional groups, no statistically significant differences in copper sorption were observed between pristine and oxidized MPs, indicating that MPs can act as vectors for copper regardless of their degree of surface oxidation.

Microplastics doi: 10.3390/microplastics5020114

Authors: Eleonora Monfardini Maria Letizia Costantini Tommaso Valente Laura Ciaralli Giulio Careddu Giovanna Jona Lasinio Daniela Berto Federico Rampazzo Greta Panunzi Maila Severini Martina Radicioli Cecilia Silvestri Marco Matiddi

Microplastic (MP) pollution is an emerging environmental stressor in marine ecosystems, yet its relationship with trophic ecology remains poorly understood in deep-sea environments. This study investigated MP ingestion in relation to trophic ecology in three deep-sea fish species (Chlorophthalmus agassizi, Hoplostethus mediterraneus, and Coelorinchus caelorhincus) from the central Tyrrhenian Sea (Western Mediterranean). Stable isotope analysis (δ13C and δ15N) was combined with detailed characterisation of ingested MPs to assess trophic niches, trophic position, and species-specific ingestion patterns. The three species showed distinct isotopic signatures, with C. agassizi occupying a lower trophic position, while H. mediterraneus and C. caelorhincus overlapped at higher trophic levels. MPs were detected in all species, with an overall frequency of occurrence of 34.4%, and no significant interspecific differences in occurrence or abundance were observed. However, significant differences emerged in MP characteristics. C. caelorhincus, which exhibited the widest isotopic niche, ingested larger and more diverse particles, whereas C. agassizi showed lower occurrence but higher particle loads in affected individuals. These results suggest that trophic ecology is not clearly associated with MP ingestion rates but may influence the size and diversity of ingested particles, highlighting ecological drivers of exposure in deep-sea ecosystems.

Microplastics doi: 10.3390/microplastics5020113

Authors: Mónica G. Silva Adelina Gama Sílvia C. Nunes Mariana Fernandes Maria Manuel Oliveira Francisco Peixoto

Current knowledge on the toxic effects of microplastics (MPs) on human health relies on the extrapolation of data collected from in vivo studies. These studies, however, present limitations, as the particles used often differ from their environmental counterparts. Nevertheless, they provide valuable insights into the mechanisms underlying MPs’ toxicity. In this study, we targeted the mitochondria to investigate the effects of two types of polyethylene microplastics (PE MPs, 27–32 µm), fluorescent and non-fluorescent, on kidneys from FVB/n mice. Animals were exposed for 28 days to two environmentally relevant concentrations of PE MPs (0.002% (w/w) and 0.006% (w/w)). Results reveal that both MPs induce mitochondrial dysfunction, as indicated by oxygen flux depletion in different coupling-controlled states. Complex II dysfunction, particularly at the highest concentration of fluorescent particles, and alterations in other components of the electron transport chain were identified as one of the causes of mitochondrial dysfunction. MPs’ exposure also induced subtle remodelling of the mitochondrial membrane lipid profile, marked by shifts in specific saturated and unsaturated fatty acids, suggesting an adaptive response to preserve membrane integrity. These alterations were accompanied by oxidative stress, evidenced by decreased SOD and CAT activities, particularly under high concentrations of fluorescent PE MPs. Overall, fluorescent MPs triggered stronger mitochondrial and metabolic disruptions in the kidney. All together, these findings reinforce mitochondria as pivotal targets of MPs’ toxicity and highlight the need for improved experimental models that better reflect environmentally relevant exposure scenarios.

Microplastics doi: 10.3390/microplastics5020112

Authors: Jonita Perfanova Lev Tribis Gergana Kuncheva Momtchil Dimitrov Hristo Valchovski Veselinka Petrova Milena Kercheva

Microplastic pollution threatens soil health by disrupting chemical and microbial balances and impairing nutrient cycling, with effects that vary depending on soil properties. The objective of this study is to determine the effects of contamination with three types of microplastics (<5 mm)—polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET)—on the microbiological and chemical parameters of four soil types in Bulgaria: Calcic Chernozem, Vertisol, Luvisol, and Fluvisol. A controlled 180-day laboratory incubation experiment was performed, where each soil type was contaminated with microplastics at three concentrations to monitor changes in key microbiological and chemical properties. It was established that microplastics contamination suppressed abundance of key microbial groups and limited nutrient availability, inducing a state of biological and chemical imbalance in the soil. PET exerted the strongest impact on soil chemical properties, with the agrochemical properties of Fluvisol being the most sensitive to MP contamination. PE and PET had the greatest influence on microbial communities, with Vertisol and Luvisol being the most affected in this regard. PP contamination altered key metabolic processes, with the specific impact being highly dependent on soil type and most pronounced in Chernozem. Furthermore, the concentration influenced the measured parameters, with the effects varying depending on the soil type and the microplastic type. Among the factors influencing soil responses to microplastic contamination, soil type appears to be the most decisive, followed by the type of microplastic.

Microplastics doi: 10.3390/microplastics5020111

Authors: Vyoma Jani Shenghua Wu

Following discussions between the Editorial Board and the authors, the original published references 15, 61, and 175 and their citations in the original publication [...]

Microplastics doi: 10.3390/microplastics5020110

Authors: Olga Iakobson Sergey Silonov Viktor Korzhikov-Vlakh Pavel Chelushkin Elizaveta Shtro Vladimir Isakov Natalia Shevchenko

The scientific literature lacks sufficient data on the transport of various toxic pollutants by polymer particles. Investigating how the structure of microplastic particles formed during the degradation of polymeric materials affects pollutant sorption processes will improve our ability to predict environmental behavior. General-purpose polystyrene, expanded polystyrene, ABS plastic (acrylonitrile–butadiene–styrene) and crosslinked polystyrene are produced on an industrial scale. Copolymers of styrene with divinylbenzene are used on a large scale as sorbents for gel permeation chromatography (Styragel brand sorbents), in the production of catalysts on a polymer substrate or ion-exchange resins. In this study, non-spherical, crosslinked polystyrene microparticles with varying polystyrene chain packing densities were used as model microplastic particles representative of crosslinked polystyrene. It was shown that the adsorption of a hazardous chemical rhodamine B was influenced by both the packing density of the polystyrene chains and the presence of ionic functional groups, i.e., the “degree of aging” of the microplastic particles. The sorption capacities of these model microparticles were compared with those of natural origin (silicon dioxide, quartz powder, and microcrystalline cellulose). A viability assay using HEK293 and HeLa cell lines exposed to leachates from both pristine and rhodamine B-loaded microparticles revealed that all unmodified microparticles, regardless of their nature, exhibited no cytotoxicity at concentrations up to 1000 μg/mL. In contrast, microparticles with adsorbed rhodamine B significantly reduced cell viability to 20–40% at concentrations of 100 μg/mL.

Microplastics doi: 10.3390/microplastics5020109

Authors: Alex Graça Contato Carlos Adam Conte-Junior

Microplastic pollution has become a significant environmental concern due to its persistence and widespread impact across ecosystems. These plastic particles (1 μm to 5 mm), originating from larger plastic debris or industrial sources, accumulate in diverse habitats, affecting biodiversity and human health. Microplastics resist natural degradation, posing challenges to both ecological sustainability and waste management strategies. Although numerous studies have explored microbial degradation, most existing research focuses primarily on bacteria, leaving the role of filamentous fungi comparatively underexplored. This represents a significant research gap, because fungi secrete a variety of extracellular enzymes, including laccases, peroxidases, and esterases, which play crucial roles in the breakdown of synthetic polymers. These enzymes facilitate the depolymerization of microplastics by targeting polymer chains and increasing their susceptibility to further microbial degradation. However, the underlying enzymatic mechanisms and their effectiveness in microplastic remediation remain insufficiently characterized. Here, we critically review the potential of filamentous fungi for microplastic biodegradation, emphasizing their oxidative and hydrolytic enzyme systems, biosurfactant production, and mechanisms of adsorption and mineralization. The novelty of this review lies in consolidating the most recent mechanistic insights into fungal-driven depolymerization pathways, integrating them with advances in genetic engineering, bioprocess scale-up, and regulatory perspectives, areas rarely combined in previous reviews. We identify current limitations related to environmental applicability, enzyme accessibility, and the lack of standardized protocols, and propose strategies to overcome these challenges through enzyme immobilization, microbial consortia design, and synthetic biology approaches. By addressing these gaps, filamentous fungi may contribute to the development of sustainable strategies for plastic pollution mitigation and support circular economy approaches toward polymer biodegradation.

Microplastics doi: 10.3390/microplastics5020108

Authors: Raymond Infante Leira Centeno Travis A. Courtney Juan J. Cruz Motta Roy A. Armstrong

Microplastic pollution has become a global concern due to its widespread impacts on organisms and ecosystems. While there have been a few studies quantifying microplastics in inland areas of Puerto Rico, none, to our knowledge, have studied nearshore coastal surface waters. This study, therefore, presents the first assessment of microplastic concentrations and descriptions in the surface waters of La Parguera Natural Reserve, southwestern Puerto Rico. Using 333-micron plankton net trawls, we found low mean ± standard deviation microplastic concentrations of 0.02 ± 0.07 microplastic particles m−3 (95% confidence interval = 0.01 to 0.04 microplastic particles m−3). The most prevalent polymers were high-density polyethylene (48%) and polyethylene (32%), followed by polypropylene (11%) and polystyrene (7%). The most common colors were white (50%), blue (34%), black (8%), red (5%), and colorless (3%). Subsequently, the common structures found were fragments (78%), filaments (12%), films (8%), and fibers (2%). No clear coastal gradient or seasonal patterns were detected (p < 0.05), and mean concentrations were similar to previously surveyed oceanic waters from the Caribbean, suggesting coastal sources of marine microplastics were minimal compared to oceanic sources. This study provides a foundational understanding of microplastics in the coastal waters of La Parguera Natural Reserve and provides critical baseline data for detecting potential future changes in microplastic concentrations.

Microplastics doi: 10.3390/microplastics5020107

Authors: Lisete Fernandes Abderrazzak Ait Bassou José R. Fernandes Pedro B. Tavares

Micro and nanoplastics (MNPs) are increasingly recognized as contaminants in food systems; however, the specific packaging elements responsible for particle release remain poorly resolved. Most studies treat packaging as a single material category, without covering distinct contributions from the different units of modern food contact materials (FCMs). We propose a packaging structure taxonomy based on functional elements: container (C), closure (CL), and functional layers (F), including operational interfaces (+I), designed to enable components attribution of possible origins of plastic fragments in foods and beverages. Through a structured synthesis of the current literature, we map the primary processes leading to MNP generation across these modules, including tribological abrasion at closure contact interfaces, thermally driven polymer degradation in containers and delamination or shedding from coatings, adhesives and multilayer structures. Available evidence indicates that repeated mechanical actions such as opening and closing cycles can generate measurable particle release from closure assemblies. The proposed C/CL/F + I framework introduces standardized descriptors and reporting units that improve comparability across studies and supports origin attribution. By explicitly separating packaging parts and their operational interaction zones, the taxonomy provides a methodological bridge between analytical microplastic detection and engineering strategies aimed at minimizing particle formation. Its adoption can facilitate harmonized experimental design, strengthen regulatory risk assessment and guide the development of packaging configurations that minimize plastic particle shedding into foods.

Microplastics doi: 10.3390/microplastics5020106

Authors: Marko Jugo Christopher M. Reddy Bryan D. James Tarzan Legović

Plastic pellet spills are a growing environmental concern, yet response strategies remain limited and poorly adapted. This study evaluates whether existing oil spill recovery tools, including booms, skimmers, and specialized vessels, can be repurposed to respond to acute releases of plastic pellets at sea. Plastic pellets, although small (typically 1–5 mm in diameter), exhibit variation in physical properties, including polymer type, size, shape, color, and density. These features strongly influence dispersion dynamics and the feasibility of cleanup. Our analysis reveals critical limitations in current response technologies, primarily due to their oil-centric design and lack of consideration for the unique behavior of plastic pellets. By bridging expertise in oil spills and emerging plastic threats, we outline opportunities for adaptive, cross-sector response strategies tailored to the realities of plastic-pellet spills. This study includes a field demonstration in the Northern Adriatic Sea, where oil-spill skimmers and booms were successfully tested for plastic pellet recovery under real-world marine conditions.

Microplastics doi: 10.3390/microplastics5020105

Authors: Elena Bisinicu

Microplastic pollution is a pervasive and ecologically significant threat to aquatic systems. Zooplankton, as key mediators of energy transfer and carbon cycling, are particularly vulnerable to microplastic ingestion due to size overlap with natural prey. This systematic literature review synthesises 250 peer-reviewed studies on zooplankton–microplastic and nanoplastic interactions, identified through a Web of Science search (403 initial records, 2012–2026) and screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Bibliometric and narrative thematic analyses were conducted to evaluate publication trends, taxonomic coverage, biological endpoints, experimental design, particle characteristics, and geographic distribution. Publication output increased rapidly after 2019, with nanoplastics emerging as a major research focus. The literature is strongly biassed toward model organisms such as Daphnia magna and Artemia salina, with limited representation of marine taxa. Ingestion and oxidative stress are the most studied endpoints, while trophic transfer, carbon flux, and multi-stressor interactions remain underexplored. Reported experimental designs are predominantly laboratory-based and frequently employ supra-environmental concentrations and simplified particle types. A major geographic gap is identified for the Black Sea, with minimal coverage and no data for dominant regional species. Future research should prioritise ecologically realistic conditions, broader taxonomic and geographic representation, and integrated multi-stressor approaches to support ecosystem-based management. This review characterises publication patterns and knowledge gaps; it does not constitute a formal evidence synthesis, and frequency distributions reflect research coverage rather than strength of evidence.

Microplastics doi: 10.3390/microplastics5020104

Authors: Ivan Josué Vargas-Lopez Alexandra Vera Anderson Rivadeneira Werner Brämer-Escamilla Gema González Sarah Briceño

Microplastics have emerged as a major environmental health concern due to their environmental persistence, fragmentation, and widespread distribution. Conventional adsorption strategies often have limited efficiency, reuse, and scalability, and may generate secondary pollutants. This work explores the use of ferrotitaniferous sand milled for 4, 8, 12, 16, 32, and 52 h and subsequently functionalized with polyethylene glycol (PEG) for the removal of Polyethylene Terephthalate(PET) microplastics. The samples were characterized using Fourier-Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). The average particle size of the samples decreases with the milling time from 60±35 μm to 3±1 μm. The magnetic properties enable rapid separation of sand–microplastic aggregates from water using magnets. Ferrotitaniferous sand exhibits soft ferrimagnetic behavior, with a maximum saturation of 50.09 emu/g. The remanence and coercivity increase as the average particle size decreases. Ultraviolet–visible (UV-Vis) spectroscopy was used to quantify the hydrothermally fragmented PET microparticles in water. The maximum microplastic adsorption removal was 95% within 30 s for the 12 h milled sample coated with PEG. The results show that PEG increases the samples’ adsorption capacity from 20.48 to 32.36 mg/g. The novelty of this work lies in the use of magnetic Ferrotitaniferous sands as a promising, sustainable resource for magnetic separation technologies.

Microplastics doi: 10.3390/microplastics5020103

Authors: Subramani Thirunavukkarasu Manickkam Jayakumar Maduraiveeran Ramachandran Santhosh Jeferson Poovazhagi Rajendran Jishnu Panamoly Ayyappan Murugan Vasanthakumaran Priyanka Muthu Jiang-Shiou Hwang

Microplastic contamination in wetland ecosystems is an escalating environmental threat, compromising ecosystem services, biogeochemical cycling and biodiversity conservation. This study assessed the occurrence, distribution and physicochemical characteristics of microplastics in the Ramsar-designated Pallikaranai wetland, southern India. Six representative subsamples were collected from spatially distinct locations and analyzed using density separation, followed by polymer identification via Raman spectroscopy and energy-dispersive X-ray spectroscopy (EDS). Microplastics were ubiquitously detected across both sediment and water matrices, with significantly higher abundances in sediments, indicating their role as a major sink. The dominant polymer types, polyethylene (PE), polypropylene (PP) and polystyrene (PS), along with prevalent morphotypes such as fragments, fibers, beads and foams, reflect diverse and persistent anthropogenic inputs. The compositional profile strongly implicates mismanaged domestic and urban waste as the primary source. The widespread presence and accumulation of microplastics in this ecologically sensitive wetland raise concerns over potential impacts on trophic interactions, habitat quality and long-term ecosystem resilience. These findings underscore the urgent need for targeted waste management strategies, pollution mitigation frameworks and continuous monitoring to safeguard the ecological integrity of the Pallikaranai wetland and similar Ramsar-listed ecosystems.

Microplastics doi: 10.3390/microplastics5020102

Authors: Hriddhi Sarker Goutam Saha Awnon Bhowmik Amlan Ganguly

Microplastics (MPs) are increasingly detected environmental contaminants in both marine and freshwater ecosystems, with reported concentrations ranging from a few to thousands of particles per cubic meter depending on location and methodology. Although growing evidence suggests potential risks to aquatic organisms, the extent of their ecological and biological impacts is still under active investigation. Their size, persistence and capacity to transport chemical additives and co-contaminants allow them to enter biological systems by ingestion and respiration. When ingested, MPs cause oxidative stress, inflammation, and metabolic disorders, resulting in the destruction of vital tissues in major body organs including liver, gills, intestines, and brain. They also change gene expression, cause endocrine and immune pathway perturbation, induce apoptosis, and cause gut microbiome dysbiosis, all of which worsen the health and survival of the organism. MPs also serve as vectors of heavy metals, antibiotics, pesticides, and pathogens and enhance toxicity due to the Trojan horse effect and enable bioaccumulation in food webs. Due to their widespread presence in water, soil, air, and food, MP pollution has direct effects on human, animal, and ecosystem health. This review synthesizes current knowledge on the sources of MPs, the mode of exposure, and the mechanism of toxicity and new ecological implications. It also presents mitigation measures, and stresses a One Health paradigm as the key to taking concerted action on the international level to minimize MP pollution and protect both the environment and human health.

Microplastics doi: 10.3390/microplastics5020100

Authors: Md Imran Hossain Md Shofiqul Islam Yi Zhang Alessandra Sutti Zoran Najdovski Mohammad Anwar Hosen Maryam Naebe

The widespread release of microplastics (MPs), especially fibrous microplastics (FMPs) originating from synthetic textiles, poses a growing threat to environmental systems due to their persistence, mobility, and potential for bioaccumulation in aquatic and terrestrial ecosystems. Conventional gravimetric methods (GMs) remain the primary approach for assessing FMP shedding, yet they are hindered by moisture-sensitive filters, false positives from detergents and minerals, environmental contamination, and the labor-intensive manual measurement of individual fibers. To address these limitations, we developed an automated image analysis (AIA) framework that integrates an attention-based U-Net architecture with meta-learning modules to quantify FMP number, length, diameter, and mass from stitched microscopic images of entire filter membranes. This approach enables detection of fibers down to 28 μm in diameter with the spatial resolution of 2.17 µm/pixel, supports both target-color and multi-color analysis, and eliminates the need for manual characterization or extrapolation from partial membrane segments. The method achieved the highest accuracy of approximately 98% in color-specific fiber detection, correctly identifying 257 of 263 white fibers, and demonstrated similarly robust performance for black, red, and green fibers, while minimizing interference from non-target colors, even when their fibers overlapped. Multi-color detection was further validated using effluent water samples containing mixed-color fibers. Overall, the developed system enhances the accuracy, efficiency, and reproducibility of FMP analysis, offering a standardized and scalable approach for environmental monitoring of MP pollution.

Microplastics doi: 10.3390/microplastics5020101

Authors: Teresa Fracchiolla Stefania Nunzia Lisco Angela Rizzo Corrado Sasso Francesco Veneziano Roberta Trani Alessia de Luca Angela Stufano Giusto Lo Bue Massimo Moretti

This study investigates the distribution and concentration of microplastics (MPs) across the littoral profile of a beach, from dune base to offshore sector, including an estuarine channel and Sabellaria alveolata bioconstructions. The research was conducted at Pino di Lenne beach (Taranto, Ionian Sea), a wave-dominated, microtidal littoral system representing a unique natural laboratory with minimal anthropogenic pressure. An eco-friendly extraction protocol was used, combining methods that were already known in the literature. Olive oil proved highly effective in isolating a wide range of MP densities from sediment samples. Statistical analysis identified key accumulation zones, with the highest mean concentrations found in the submerged sandbar (2435 MPs/kg), Sabellaria bioconstructions (2324 MPs/kg), and the base of the dune (2065 MPs/kg). Fibres were the predominant morphology across all sub-environments. Distribution is interpreted as controlled by hydrodynamic processes and biological activity. The submerged beach drives MP transport, with the sandbar and shoreface acting as dynamic sinks. Sabellaria bioconstructions function as biological trap, actively incorporating MPs into their tubular structures. The dune base acts as a sink for wind-blown and storm-deposited plastics. These sub-environments function as critical littoral traps for MPs, essential for developing targeted monitoring and remediation strategies in similar coastal systems.

Microplastics doi: 10.3390/microplastics5020099

Authors: Aleksandra Bozic Branka Hadzic Zorica Lazarevic Milica Curcic

Sunlight-driven UV weathering is a major transformation pathway of environmental microplastics, promoting surface oxidation, molecular degradation, embrittlement, and progressive fragmentation toward smaller size fractions. However, comparisons across studies remain difficult because weathering is often described using descriptors that probe different aspects of degradation without being clearly distinguished. Surface-sensitive oxidation metrics, such as carbonyl or oxidation indices (CI/OI), are frequently emphasized, whereas fragmentation and embrittlement are more directly governed by bulk molecular-weight loss, mechanical weakening, and particle-size evolution. This review examines UV weathering of common polymers through a coupled chemico-mechanical perspective relevant to the micro-to-nano transition. We distinguish surface chemical descriptors, bulk molecular and mechanical descriptors, and fragmentation-related metrics, and critically assess the analytical methods used to measure them, including FTIR, Raman spectroscopy, GPC/SEC, thermal methods, mechanical testing, and particle-size analyses. We argue that no single metric is sufficient to describe weathering progression, and that meaningful interpretation requires joint reporting of oxidation state, Mn/Mw changes, mechanical deterioration where available, and particle-size distribution as a function of cumulative or spectrum-weighted UV dose. We further propose a minimal QA/QC reporting framework including UV metadata, temperature, oxygen availability, blanks, replicates, recovery tests, and matrix-specific detection limits. By separating what different methods actually probe and linking them to fragmentation mechanisms, this review provides a more operational basis for interpreting UV-aged microplastics in environmental sampling and biomonitoring.

Microplastics doi: 10.3390/microplastics5020098

Authors: Mina Popovic Luka Dragacevic Milan Kojic Daria Tsibulskaia Neveka Rajic

This study highlights the strong ability of a new bacterial strain, Hafnia paralvei UUNT_MP29, isolated from the gastrointestinal tract (GIT) of common carp (Cyprinus carpio), to break down polystyrene (PS). As an omnivorous bottom feeder, C. carpio is constantly exposed to microplastics, creating a unique environment that favors the evolution of specialized microbiota capable of degrading polymers. Genomic analysis of the isolate identified key homologs involved in xenobiotic breakdown, including alcohol dehydrogenase (Adh), 3-hydroxybutyrate dehydrogenase (HDH), and a small glutamine-rich tetratricopeptide repeat-containing protein (SGTA), showing a strong metabolic system for processing long-chain hydrocarbons. Growth experiments showed the strain quickly adapted, reaching maximum cell density and forming mature biofilms by Day 16. Gravimetric analysis confirmed that H. paralvei UUNT_MP29 uses PS as its primary carbon source, with a significant weight loss of 16.76% over 16 days. Kinetic modeling indicated the degradation follows first-order kinetics (R2 = 0.9243) with a high degradation rate constant (k) of 0.2078 day−1. Surface analyses using FTIR and SEM confirmed extensive oxidative changes, as evidenced by the rising Carbonyl Index and surface erosion. TGA also showed reduced thermal stability of the treated polymer, suggesting microbial chain scission. These findings demonstrate the strong degradative ability of H. paralvei UUNT_MP29 and highlight the GIT of plastic-exposed aquatic animals as a promising area for discovering powerful biocatalysts for microplastic cleanup.

Microplastics doi: 10.3390/microplastics5020097

Authors: Fabio D’Ottaviano Kyle Hart

Detection and quantification of microplastics are undermined by the absence of appropriate methods in some contexts—such as a statistically principled LOD for particle-count data—but more pervasively by the uncritical application of ostensibly simple rules outside the conditions under which they are valid. This paper examines the statistical and study-design decision points where such failures most commonly occur and articulates principled constraints on valid inference at each step. Specifically, it (1) distinguishes exploratory from confirmatory research and advocates preregistration to prevent HARKing; (2) argues for field-blank-based limits to improve internal validity; (3) shows how multiple simultaneous comparisons against the LOD inflate the family-wise error rate and how to adjust α accordingly; (4) demonstrates that the LOD multiplier kD depends on blank sample size and critiques fixed-multiplier heuristics lacking statistical justification; (5) examines the consequences of distributional misspecification for LOD estimation; (6) demonstrates that an LOD for summed polymer concentrations exists only under restrictive conditions; (7) clarifies why subtracting limits from individual measurements is not quantification, and that cohort-level inference requires a median comparison via log-transformed data with a corresponding confidence interval; and (8) introduces a Bayesian framework for particle-count LODs that accounts for partial filter inspection. These discussions are summarized in a minimum reporting checklist designed as an evaluative aid—not a prescriptive recipe—to help researchers make analytical choices explicit and support reviewers in assessing methodological validity.

Microplastics doi: 10.3390/microplastics5020096

Authors: Ignazio Allegretta Concetta Eliana Gattullo Mohammad Yaghoubi Khanghahi Carlo Porfido Fani Sakellariadou Carmine Crecchio Matteo Spagnuolo Roberto Terzano

Soils are increasingly affected by microplastic (MP) contamination, mainly coming from industrial activities, agricultural practices, atmospheric or waterborne transport, and improper waste disposal. Despite the increasing attention to the fate of MPs in soil over the last few years, research in this area is still limited compared to aquatic ecosystems. The introduction of MPs into the soil environment can modify not only the soil properties but also the interactions among soil components, plants, and microorganisms, thus affecting the mobility and availability of other contaminants, such as potentially toxic elements (PTEs). This review critically examines the complex dynamics between MPs and PTEs in the soil ecosystem, with a focus on the conditions under which MPs can act as a source or a sink of PTEs. Indeed, on the one hand, MPs can adsorb or complex PTEs on their surfaces (similarly to natural soil colloids), thus reducing their mobility and availability; on the other hand, they can release/mobilize PTEs after MP degradation or act as micro-/nano-vectors of PTEs. Understanding such mechanisms is relevant when evaluating the environmental risks associated with the co-presence of MPs and PTEs in soil, a situation likely to occur in most contaminated sites and in many agricultural soils.

Microplastics doi: 10.3390/microplastics5020095

Authors: Gea Oliveri Conti Paola Rapisarda Eloise Pulvirenti Giovanna Deiana Maria Anna Coniglio Giuseppe Mancini Paolo Castiglia Antonio Azara Margherita Ferrante Marco Dettori

Plastics are now ubiquitous in the environment, in this, the “Plasticene” era. Microplastics (MPs) and Nanoplastics (NPs) are emerging contaminants of global concern. This systematic review, registered on PROSPERO and conducted according to PRISMA guidelines, investigated the presence, distribution, and characteristics of MPs in tap water (TW) worldwide, and estimated the population’s Estimated Daily Intake (EDI) by age group, including pregnant women. A comprehensive search across PubMed, Scopus, Web of Science, and Cochrane identified 22,650 records, of which 8 studies were included. MPs were detected in treated water (TW) in the studies included in this review, although the currently available evidence remains limited. Calculated EDIs were highest in children aged 6 months to 3 years (up to 39 MPs/kg bw/day), followed by pregnant women (up to 14.96 MPs/kg bw/day), reflecting differences in water intake per body weight. These estimates must be interpreted as indicative, estimated by methodological variability among studies. The widespread presence of MPs in TW calls for standardized methods, improved treatments, and thorough monitoring to assess risks and protect public health.

Microplastics doi: 10.3390/microplastics5020094

Authors: Aleksandra Blazhenko Anastasiia Mikhel Marina Kostina Mikhail Goikhman Pavel Chelushkin Andrey Korenevsky

There are currently no published methods for the controlled introduction of microplastic particles into the European rabbit (Oryctolagus cuniculus) as an animal model. The aim of this pilot study was to establish a novel rabbit-based experimental model for assessing the impact of microplastic particles by evaluating the physiological and biochemical responses to an eight-day oral administration of polystyrene latex (1 and 5 mg/kg/b.w./day), providing a foundation for future studies. This study was also aimed at evaluating the possibility of using Raman spectroscopy and Fourier-transform infrared spectroscopy to analyze the distribution of microplastics in rabbit samples. We observed a dose-dependent decrease in water and food consumption in the high-dose (5 mg/kg) study group. In addition, a decrease in alanine aminotransferase and total calcium levels, along with an increase in phosphorus levels, was detected. The rabbit’s stomach was the only organ where polystyrene microparticles were identified, with the colon, kidneys, ovaries, and uterus not showing any evidence of polystyrene presence. The selected doses of microplastics did not lead to pronounced toxic effects in rabbits and may be used on larger animal samples. Physiological and biochemical data obtained indicate predominantly negative metabolic shifts associated with the intake of microplastics, which warrants further study.

Microplastics doi: 10.3390/microplastics5020093

Authors: Kuok Ho Daniel Tang

Micro- and nanoplastic (MNP) pollution has emerged as a global environmental and health concern, driving the rapid development of sensor technologies for faster, more sensitive, and field-deployable detection. This review synthesizes recent advances in optical, electrochemical, and biosensor platforms for MNP analysis and compares their analytical performance and practical feasibility. Optical sensors, including plasmonic, spectroscopic, and colorimetric systems, enable label-free and often rapid detection with material discrimination capability, and are well-suited for screening applications, though they commonly exhibit higher detection limits and matrix interference. Electrochemical sensors demonstrate the highest analytical sensitivity overall, frequently reaching low µg L−1 to ng mL−1 levels, with strong potential for miniaturization and on-site deployment; performance is further enhanced by nanostructured electrodes, photoelectrochemical designs, and signal amplification strategies. Biosensors incorporating peptides, aptamers, enzymes, or engineered proteins provide improved polymer selectivity and enable targeted detection, but face challenges related to stability, cross-reactivity, and reproducibility in complex samples. Practically, portable electrochemical and simple optical colorimetric platforms are currently the most feasible for field use, while hybrid bio-electrochemical systems show the highest performance potential. Future research should prioritize robust selective recognition elements, antifouling interfaces, standardized validation protocols, mixed-polymer quantification models, and integration with machine learning to enable reliable, real-world MNP monitoring.

Microplastics doi: 10.3390/microplastics5020092

Authors: Timur Nizamutdinov Ivan Kushnov Anastasia Vainberg Evgeny Abakumov

Soil micro- and nanoplastic contamination is escalating globally, yet its potential to interfere with routine agrochemical analyses remains poorly quantified. Standard operating procedures (SOPs) were calibrated for natural soil matrices and may not account for synthetic, carbon-rich polymers. This controlled model study quantified the analytical sensitivity of FAO/GLOSOLAN/ISO standard procedures to polystyrene nanoparticle (50 nm) contamination across a 0–0.5% (w/w) gradient in a Luvic Chernozem. Key parameters—pH, soil carbon, total nitrogen (TN), cation exchange capacity (CEC), and clay fraction—were measured following standardized protocols. The Walkley–Black method exhibited a strong dose-dependent increase in measured SOC (r = 0.93), reflecting systematic overestimation due to dichromate co-oxidation of polymer matrix, likely facilitated by exothermic heating above polystyrene’s glass transition temperature. The Dumas method showed moderate correlation (r = 0.59) but higher replicate variability driven by small aliquot size and heterogeneous nanoparticle distribution. The pH measurements displayed non-linear responses and elevated variability at low doses, whereas TN, CEC, and clay content remained statistically stable. These findings demonstrate that nanoplastic contamination can introduce significant analytical artifacts in oxidation-based SOC determinations, potentially leading to misinterpretation of soil carbon trends. Given the single-soil, single-polymer design, results represent a system-specific proof of analytical vulnerability rather than a universally quantified bias. Laboratories analyzing potentially contaminated soils should exercise caution with wet-oxidation SOC data, and broader SOP revisions must await multi-soil, multi-polymer validation campaigns.

Microplastics doi: 10.3390/microplastics5020091

Authors: Luciana Banquero Paul E. Sacks Fnu Joshua Lei Zhai Joshua S. Sacks Linda J. Walters

Many filter-feeding invertebrates consume microplastics (MP) under laboratory conditions, but little is known about newly settled, field-collected juveniles. To address this information gap, we collected 3439 juvenile invertebrates in the Indian River Lagoon (IRL), FL, USA. Previous studies suggest that the IRL is a MP hotspot. A total of 70% of IRL adult oysters (Crassostrea virginica) contained MP (mean: 2.3 MP/individual), and MP number and MP length were positively correlated with animal size. We predicted that juvenile C. virginica and other sessile invertebrates would contain MP with a positive correlation to animal size. Five species were examined; 51% were C. virginica (mean shell length ± SD: 6.3 ± 4.7 mm). Overall, 117 (3.4%) animals contained potential MP (fibers: 90.7%). Of these particles that matched FTIR databases with a score of 70% or greater, 51% were plastic and 49% were anthropogenically modified particles. No correlations to animal size were found for particle presence (logistic regressions: p ≥ 0.20 for all species) or particle length (linear regressions: p ≥ 0.23 for all species). Thus, even though found in a MP hotspot, our extrapolated results suggest few juveniles (<1%) contained MP. This information is important for understanding the relationship between MP and the life histories of filter-feeding animals, especially for species considered biological indicators of MP.

Microplastics doi: 10.3390/microplastics5020090

Authors: W. Rosado-Martínez B. Pamplona K. García-Uitz J. C. Cruz L. G. Arriaga J. Ledesma-García M. P. Gurrola

Microplastic pollution is a major environmental concern due to its persistence, global distribution, and potential impacts on ecosystems and human health. This systematic review, conducted according to PRISMA 2020 guidelines, analyzes research trends in microplastics with a focus on physicochemical characterization and removal technologies. A literature search was performed in Scopus and Web of Science (1972–2025) using predefined inclusion and exclusion criteria. After screening and duplicate removal, 89 studies were included in the final analysis. It is considered that with this dataset, it is possible to capture the main analytical and technological developments in the field. As a bibliometric-oriented study, no formal risk-of-bias assessment was conducted. However, a qualitative consideration of potential biases was undertaken, particularly regarding publication bias, database coverage limitations, and the predominance of English-language peer-reviewed studies. These aspects were considered when interpreting the results. The Methodi Ordinatio approach was then used to rank publications based on scientific relevance and citation impact. Results show the predominance of FTIR and Raman spectroscopy for microplastic characterization, while removal technologies remain heterogeneous and less standardized, with most approaches still at laboratory scale. Key gaps include the lack of standardized analytical protocols and limited integration between detection and remediation strategies. Overall, this review highlights critical research trends and supports the development of scalable solutions for microplastic pollution.

Microplastics doi: 10.3390/microplastics5020089

Authors: Aswir Abd Rashed Nurliayana Ibrahim Mohammad Adi Mohammad Fadzil

Introduction: Microplastic (MP) contamination can endanger marine ecosystems and indirectly affect the well-being of humans through the ingestion of marine species. While most research investigates the digestive system, such as the gills and gastrointestinal tract of fish, it still fails to address a major oversight in understanding MP deposition in edible tissues, which is the primary route of human exposure. The differences in contamination levels among pelagic, demersal, and benthic fish in Malaysian waters remain poorly understood. This preliminary study uses Laser Direct Infrared Imaging (LDIR), a new, high-resolution, automated technique, to examine synthetic MP contamination in the edible portion of fish. Materials and Methods: The MPs were extracted from the edible tissue of three fish species representing pelagic (Fish A), benthic (Fish B), and demersal (Fish C) using KOH and sieved onto a gold mesh filter before analysis using LDIR. Results and Discussion: LDIR identified 162 MP particles, revealing clear differences by polymer type and habitat. Pelagic species mostly contained polyethylene (PE) and rubber (n = 8). Demersal species had mostly polyethylene terephthalate (PET) with small amounts of PE and rubber (n = 57). Benthic species showed the highest load, dominated by PET and polypropylene (PP) (n = 97). The morphological assessment of the MPs indicated that the polymers in pelagic fish were smaller, with an area of 2047.82 µm2 and a circularity range of 0.14–0.74, indicating consistent shape. Conversely, MPs are irregular and larger in benthic fish, with areas up to 38,837.50 µm2 and circularities ranging from 0.02 to 0.81. This pattern reflects specific accumulation related to habitat and potential environmental degradation processes. Conclusions: This preliminary study demonstrates the effectiveness of LDIR for detecting MPs in edible fish tissues. The findings provide a fundamental dataset on MP contamination in edible tissue and emphasize its distribution across ecological zones. Nevertheless, broader research is required to substantiate these data and assess the implications of MP contamination for the environmental stability of human and marine well-being.

Microplastics doi: 10.3390/microplastics5020088

Authors: Jose Javier Flores Laura Cortés-Corrales Adrián Rosa García Alfredo Alcayde Amadeo R. Fernández-Alba Maria Jesús Martínez Bueno

Microplastics (MPs) in water treatment plants (WTPs) represent a critical environmental concern, particularly when treated effluent is reused for agricultural irrigation. This study investigates the occurrence, removal efficiency, and characterization of MPs in tertiary-treated wastewater destined for agricultural reuse in water-scarce regions. Additionally, the study examines the influence of sample volume on extrapolated MP concentrations. Despite advanced treatment processes including ultrafiltration achieving removal efficiencies of 89%, substantial quantities of MPs remain in final effluents at concentrations ranging from 89 to 399 MPs/m3 (equivalent to 0.1–0.4 MPs/L) with a mass load of 2 µg/L at the outlet. Morphological analysis revealed a shift from fragment-dominated influent (~50%) to film-dominated effluent (~51%), with blue particles being most prevalent. Size distribution analysis showed distinct peaks: 50–100 µm for fragments, 100–250 µm for films, and 250–500 µm for fibres. Polytetrafluoroethylene (PTFE) emerged as the dominant polymer across all morphotypes. Finally, converting particle counts to mass loads indicated an average decrease from ~11 µg/L at the inlet to ~2 µg/L at the outlet, underscoring that number- and mass-based metrics provide complementary information for risk assessment.

Microplastics doi: 10.3390/microplastics5020087

Authors: Matheus Sousa Silva Katerin Manuelita Encina Oliva Márcio Rocha Francelino Alexandre ten Caten

With the global increase in microplastic pollution, even environments considered pristine have shown signs of being affected by these contaminants. In this context, it becomes essential to conduct studies that identify and quantify the presence of microplastics in remote regions such as Antarctica. This continent is particularly relevant due to its low anthropogenic influence and its essential role in regulating planetary ecosystems and biodiversity. In this study, 49 Antarctic samples were analyzed using pretreatment techniques with NaCl and ZnCl2 saline solutions, followed by fluorescence microscopy using Nile Red dye to estimate the microplastic abundance index. Both solutions showed good performance in the separation and identification of particles. Approximately 37% of the samples showed contamination by potential microplastics (PMPs), with a higher concentration of particles retained on paper filters and fibers observed in the supernatants. The results indicate that the presence of MPs in Antarctica is irregular and not ubiquitous, differing from other studies that suggest a wider distribution. It is speculated that the observed contamination results from oceanic transport from other regions of the planet and from sources associated with human activities on the Antarctic continent (e.g., tourism and research).

Microplastics doi: 10.3390/microplastics5020086

Authors: Kristen A. Marcellus Michal Scur Michael G. Wade Santokh S. Gill

Rising plastic production worldwide is contributing to the increasing amounts of micro- and nanoplastics found in the environment. The consumption of microplastics by humans is plausible due to the presence of plastic particles in various food commodities, yet the potential impact of microplastics on human health remains unknown. Several studies have detected microplastics in human tissues and research using mammalian in vivo and in vitro models have noted toxicity after exposure to microplastics. Using both mono- and co-culture liver cell models, we assessed the impact of environmentally relevant, cryo-milled plastic particles on hepatotoxicity. We observed that only cryo-milled polyethylene terephthalate and polystyrene altered mitochondrial energy metabolism, while the other plastic particles did not. The pristine, spherical polystyrene particles were taken up at all sizes and cryo-milled polystyrene was taken up by cells. Evidently, polymer type and shape play a critical role in hepatotoxicity. Further research is required to fully elucidate the effect the physiochemical properties of plastic particles may have on toxicity.

Microplastics doi: 10.3390/microplastics5020085

Authors: Maria Râpă Carmen Gaidău Ecaterina Matei Florin-Aurel Dincă

Blended polyester (PET)-based textiles comprise a significant portion of post-consumer waste, posing substantial challenges to circular economy initiatives while contributing to microfiber (MF) pollution. Despite the considerable recycling potential of PET textiles, no commercially viable technologies currently exist that can efficiently separate and recycle blended PET-based textile waste on an industrial scale. This review provides a comprehensive analysis of recycling strategies for post-consumer blended PET-based textiles and their subsequent valorization pathways. Mechanical, chemical, and biological recycling processes are mostly not yet market-ready, although chemical approaches are considered particularly promising. The findings highlight a critical need for advanced sorting technologies, enhanced material traceability, and robust MF mitigation strategies to foster circularity and contribute to the United Nations Sustainable Development Goals (SDGs). The results further indicate that mechanical recycling of blended PET textiles leads to significant MF release due to fiber fragmentation, whereas chemical recycling offers the potential for improved material recovery, but remains limited by high energy demand and solvent-related challenges. While closed-loop approaches support true circularity by maintaining textile-to-textile material flows, open-loop pathways repurpose textile waste for high-value non-textile applications.

Microplastics doi: 10.3390/microplastics5020084

Authors: Immacolata Liotta Roberto Avolio Rachele Castaldo Federico Olivieri Gennaro Gentile Andrea Sorrentino Andrea Camedda Giuseppe Andrea de Lucia Maria Emanuela Errico Mariacristina Cocca

Plastic waste is estimated to represent 40–80% of the total amount of marine litter, with polyethylene (PE) and polypropylene (PP) being the most abundant polymeric components. The recovery and recycling of marine plastic debris are therefore essential to mitigate environmental pollution and limit the generation of secondary microplastics. In this work, a mechanical recycling strategy was investigated for the valorization of a polyethylene-rich plastic fraction (PE-rf) recovered from the marine environment, characterized by high heterogeneity and persistent inorganic contamination. Different pre-treatment routes, including cryogenic grinding and planetary ball milling, as well as blending approaches with recycled polyethylene and compatibilizing additives, were explored. The effects of composition and processing on the thermal, mechanical, and morphological properties of the resulting materials were systematically analyzed. The results show that intense mechanical homogenization and chemical compatibilization are not sufficient to overcome the intrinsic limitations imposed by contamination and compositional variability. As a proof of concept, selected formulations were processed into filaments and tested in fused filament fabrication, demonstrating basic 3D printability.

Microplastics doi: 10.3390/microplastics5020083

Authors: Phyo Bo Bo Aung Yuya Haga Sota Manabe Wakaba Idehara Mii Hokaku Yuto Motoyama Ayaha Mori Kazuma Higashisaka Yasuo Tsutsumi

Microplastics (MPs), i.e., plastic particles <5 mm, and nanoplastics (NPs), i.e., plastic particles <1 µm, are widespread in the environment. MPs and NPs (MNPs) have also been detected in human tissues. Environmental MNPs exhibit diverse physicochemical properties such as size, shape, and surface degradation. However, most experimental studies have used pristine MNPs, which poorly represent real-world conditions, and only a limited number of studies have focused on preparing environmentally relevant MNPs. Therefore, we focused on the key physicochemical properties of MNPs, particularly their shape, size, and surface degradation, using polyvinyl chloride (PVC) as the model polymer. In this study, fragment and spherical PVC-MNPs were utilized, and surface degradation was introduced through exposure to vacuum ultraviolet (VUV) radiation at a wavelength of 172 nm. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) analysis revealed the formation of additional carbonyl groups after VUV exposure. We investigated the cytotoxic effects of the degraded and non-degraded PVC-MNPs on A549, Caco-2, and THP-1 cells. The results indicated that the degraded PVC-MNP-treated groups induced higher cytotoxic effects than those in the non-degraded groups. Notably, the degraded PVC-NPs induced stronger cytotoxicity than the degraded PVC-MPs. These findings highlight the potential health risks associated with environmental MNPs.

Microplastics doi: 10.3390/microplastics5020082

Authors: Domenica Mosca Angelucci Marco Manetti Enrica Donati Maria Concetta Tomei

This study investigates the sorption process of selected pollutants, namely naphthalene (NAP), pentachlorophenol (PCP), sulfamethoxazole (SMX), and ibuprofen (IBU), onto different real microplastics (MPs) under controlled laboratory conditions. Sorption tests reveal variable affinities depending on the chemical and physical interactions between polymers and pollutants. NAP showed the greatest uptake on the majority of tested MPs, followed by PCP and SMX, while IBU exhibited negligible sorption. Kinetic tests indicate a general rapid initial uptake, followed by lower sorption rates leading to equilibrium within days. Theoretical thermodynamic affinity estimations, based on the Hansen solubility parameter (HSP) method, previously tested only on antibiotics, are applied for the first time to commercial MPs and several pollutant categories such as PAHs, pesticides and other pharmaceuticals. Predictions have been validated with experimental results and generally show very good agreement with the affinity ranking derived by experimental data. However, some limitations occur due to the heterogeneity of the real MPs and different environmental conditions. Factors affecting, to different extents, MPs’ uptake include hydrophobicity and electrostatic forces, as well as pH and particle size. This work advances understanding of MPs’ role as vectors of pollutants in aquatic environments and validates the use of an innovative combined experimental–theoretical approach useful as a tool to predict associated risk.

Microplastics doi: 10.3390/microplastics5020080

Authors: Xingru Yin Yi Jing Peiwen Zeng Congcong Li Yue Shi Jinyi Zhang Lingjun Yan Wei Sun Guowei Pan

Introduction: It is accepted that nano- and micro-plastic (NMP) pollutants threaten ecosystems and human health by their bioaccumulation but, interestingly, their toxicity is shape-dependent. However, a clear definition of irregular NMPs, as the dominant shape in environmental and biological samples, is currently lacking when compared to spherical and fibrous NMPs. Objectives: This study quantifies morphometric descriptors in order to develop a standardized definition for irregular NMPs. Methods: Hyperspectral images of 34 spherical, 50 fibrous, and 45 irregular NMPs were collected from the literature. All shape-related features reported previously were analyzed using a machine learning model. Using five-fold cross-validation, a decision tree-based ensemble classifier with fixed parameters and Gini coefficient was established to screen key morphometric descriptors and their optimal interval ranges. The model was independently validated, enabling the accurate distinction of irregular NMPs from spherical and fibrous NMPs. Results: Three morphometric descriptors, including circularity, roundness, and perimeter-to-area ratio, were identified using five-fold cross-validation as optimal indicators for NMP shape classification. Optimal interval ranges for irregular NMPs were as follows: circularity (0.388 ± 0.004–0.768 ± 0.004), roundness (0.248 ± 0.01–0.752 ± 0.06) and perimeter-to-area ratio (>11.608 ± 1.39). This approach generated a 96.0% macro-averaged accuracy across these NMPs, with 100% precision and 89.0% recall. Conclusions: Irregular NMPs may be characterized using three morphometric descriptors, such as circularity, roundness, and perimeter-to-area ratio. The three-descriptor combination has highly accurate discrimination from spherical and fibrous NMPs.

Microplastics doi: 10.3390/microplastics5020081

Authors: Vesela Yancheva Stela Stoyanova Elenka Georgieva Desislava Arnaudova László Antal Ifeanyi Emmanuel Uzochukwu Bartosz Bojarski Carlos Gravato Krisztián Nyeste

Microplastic (MP) contamination is increasingly recognized as a global environmental problem affecting aquatic ecosystems, food quality, and animal and human health. Farmed fish represent an important and increasing component of the human diet. Therefore, understanding potential human exposure to MPs is essential for ensuring food safety. In the current paper, we present the results of a preliminary study conducted in Bulgaria on MP contamination in the muscle tissue of rainbow trout [Oncorhynchus mykiss (Walbaum, 1792)] reared in freshwater aquaculture systems. Edible tissues were analyzed using Laser Direct Infrared (LDIR) imaging spectroscopy, a highly sensitive method enabling rapid detection and accurate identification of polymer types present in samples. MPs were detected in all examined specimens, demonstrating that these particles are bioavailable and capable of accumulating in fish muscle tissues commonly consumed by humans. Moreover, the presence of multiple polymer types suggests diverse contamination sources within aquaculture environments. Although the present findings do not allow direct conclusions about human health risks, they indicate potential risks of trophic transfer and highlight the need for improved monitoring strategies and management practices in farmed fish production. Overall, this study provides novel data on MP exposure in aquaculture species and emphasizes the preventive importance of assessing plastic pollution in fish intended for human consumption.

Microplastics doi: 10.3390/microplastics5020079

Authors: Subrata Saha Rachita Saha Manjil Gupta Debangana Saha Ananya Paul Surovi Roy Alolika Bose Sulagna Chandra Koustav Kundu Elena I. Korotkova Muhammad Saqib Pradip Kumar Kar

Microplastic (MP) and nanoplastic (NP) pollution has emerged as a pervasive and still insufficiently quantified pressure on terrestrial ecosystems, yet its consequences for wild herbivores remain incompletely understood. As key links between primary producers and higher trophic levels, wild herbivores occupy a critical ecological position and may serve both as exposed receptors and as biological vectors of plastic contamination. This manuscript presents a narrative review that synthesizes recent advances in understanding the physiological, behavioural, and ecological implications of MP and/or NP exposure in free-ranging herbivorous mammals, integrating evidence from field surveys, experimental studies, ecological modelling, and supportive mechanistic findings from livestock and experimental mammalian systems. Available evidence indicates that MPs and NPs are consistently detected in wild herbivores from both human-modified and protected landscapes, demonstrating widespread terrestrial exposure. Reported biological effects include oxidative stress, digestive dysfunction, inflammatory and immune responses, altered gut microbial communities, impaired nutrient assimilation, and organ-level damage, although much of the mechanistic evidence derives from controlled laboratory or livestock-based studies rather than direct wildlife investigations. Behavioural responses remain comparatively underexplored, particularly in large-bodied herbivores, with limited evidence for altered foraging, habitat use, and stress-related behaviours. At the ecosystem level, emerging studies suggest that herbivores may contribute to the landscape-scale redistribution of MPs and NPs through movement and faecal deposition, with potential downstream effects on soil processes, nutrient cycling, and plant–herbivore interactions. However, the current evidence base is constrained by major methodological and conceptual limitations, including the lack of standardized detection and reporting protocols, limited ecological realism in exposure studies, taxonomic and geographic biases, and poor resolution of long-term population-level and food-web consequences. Overall, the available literature indicates that MP and NP pollution represent a multifaceted and emerging risk to wild herbivores and the ecosystems they inhabit. Future research should prioritize standardized contamination-controlled monitoring, non-invasive faecal surveillance, ecologically realistic chronic exposure studies, and integrated conservation frameworks that recognize wild herbivores as sentinel species for terrestrial plastic pollution.

Microplastics doi: 10.3390/microplastics5020077

Authors: Dércia Santos Ana Luzio João Sousa Ana Rita Pinto Edna Cabecinha Simone Varandas Sandra M. Monteiro Maria José Saavedra

Microplastics (MPs) and metals frequently co-occur in aquatic environments, yet their combined effects on gut health and antimicrobial resistance in fish remain poorly understood. This study investigated the chronic effects of polyethylene (PE) and polystyrene (PS) microplastics, alone or combined with copper (Cu), on intestinal integrity, the gut-associated Gram-negative cultivable fraction, and phenotypic antimicrobial resistance in adult zebrafish (Danio rerio). Fish were exposed for 21 days to MPs (1 mg/L), Cu (25 µg/L), or their combinations. Histopathological analysis revealed that Cu-containing treatments induced more severe intestinal alterations, including edema, villus degeneration, and necrosis, whereas MPs-only exposures produced milder and heterogeneous responses. The composition of the Gram-negative cultivable fraction varied among treatments, with Cu, particularly in combination with MPs, associated with a broader occurrence of opportunistic and potentially pathogenic taxa. Antimicrobial susceptibility testing showed a high prevalence of multidrug resistance across treatments, with broader resistance spectra observed in Cu-containing exposures, consistent with metal-driven co-selection. In contrast, MPs alone did not systematically increase resistance and, for some antibiotics, showed resistance levels comparable to or lower than controls. Integrated multivariate analyses indicated that intestinal pathology and antimicrobial resistance co-varied along gradients of overall stress severity and stressor type, with Cu acting as the dominant driver and MPs exerting a modulatory, context-dependent influence. Overall, these findings highlight the importance of integrated assessments of gut pathology, microbial composition, and antimicrobial resistance to better understand the ecological and One Health implications of combined microplastic–metal exposure in aquatic systems.