Microplastics

Understanding the toxicity of micro- and nanoplastics (MNPs) in aquatic systems, combined with temperature, is essential in order to assess ecological hazard in a multi-stressor environment. This study investigated the biological responses of marine and freshwater organisms of different trophic levels (including primary producers, decomposers, and consumers) exposed to polystyrene (PS) MNPs, tested at varying concentrations and particle sizes under two temperature conditions (control and +2 °C). Overall, differences were observed between trophic levels: Paracentrotus lividus larvae were more sensitive to higher temperatures, Daphnia magna exhibited a non-linear pattern, and microalgae have generally shown low sensitivity to both MNPs and high temperatures. However, the MNPs’ responses were not generally concentration-dependent, with the exception of Dunaliella tertiolecta. The effects recorded at increased temperature generally varied among species, indicating that even a moderate increase in temperature can modulate responses in different organisms. In the marine system, hazard levels increased with temperature, whereas in freshwater, they were higher but temperature-independent. These results highlight the importance of integrated assessment approaches to accurately evaluate the ecological hazard associated with MNPs pollution in the context of climate change. Full article

Microplastic (MP) pollution has emerged as a significant environmental crisis across the Arabian Gulf, driven by rapid urbanization, industrialization, and infrastructure challenges in waste management. Studies indicate that MPs are ubiquitous in nature and are present in different environmental compartments, including coastal waters, sediments, marine biota, and the atmosphere. The region is characterized by high salinity, high UV index, and frequent dust storms that can affect the physical and chemical behavior of plastic debris. A consistent finding across regional studies highlights the fibrous polyethylene (PE) and polypropylene (PP) polymer types as dominant microplastic particles. This prevalence of fibrous MPs highlights the role of secondary microplastics that are derived from the fragmentation of larger plastic items and textile-derived materials as a major contaminant source. Ecological impacts are increasingly observed, with studies reporting MP ingestion in commercially important fish species and the potential for biomagnification into the human food web. However, there exist key knowledge gaps regarding the long-term toxicological impacts on human health. This review synthesizes existing data to improve the understanding of microplastic distribution in Qatar and the Arabian Gulf while highlighting the need for standardized monitoring approaches and appropriate waste management strategies. Full article

The growing accumulation of microplastics in marine environments demands fast and accurate analytical methods for polymer identification. This study presents a new canonical spectral transformation (CST) strategy designed to extract the most relevant information of Raman spectra and enhance the performance of artificial intelligence (AI) models in the classification of microplastics. Using the Marine Plastic Database (MPDB) as the source of Raman spectra, five supervised models—k-Nearest Neighbor (KNN), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Multilayer Perceptron (MLP), and a one-dimensional Convolutional Neural Network (CNN-1D)—were trained and evaluated under both typical (conventional methodology) and CST workflows using 500 noisy samples per category. The CST consists of representing a Raman spectra in a vector where only the magnitude peaks of the most relevant frequency bands of the spectra are retained and the remaining values are null. This CST minimizes the inclusion of non-target data reaching the AI models. All models achieved higher accuracy with CST, where CNN-1D achieved the most significant performance, increasing accuracy to 0.90. In addition, CNN-1D identified Polystyrene (PS) and Poly(methyl methacrylate) (PMMA) with a score of 100% and 99%, respectively. The results demonstrate that CST effectively enhances spectral feature extraction and can be generalized to other spectroscopic techniques, providing a scalable framework for AI-assisted microplastic identification in seawater samples. Full article

The presence of microplastics (<5 mm) has become a major threat to marine ecosystems and the organisms inhabiting them. This issue affects a wide range of animals, including commercially important marine fish, whose ingestion of microplastics can cause mechanical and metabolic damage. This study aimed to characterize the main types of microplastic-like particles ingested by Centropomus viridis, Cynoscion othonopterus, Pomadasys macracanthus, Diapterus peruvianus, Lutjanus colorado, and Scomberomorus sierra, important commercial fish species in northwestern Mexico. Four sampling events were conducted over an annual cycle (November to August) in the lagoon and insular systems of Navachiste and Ohuira, Sinaloa, Mexico (RAMSAR sites 1826 and 2025). A total of 556 individuals were captured, and their stomach contents were analyzed using stereoscopic microscopy. Systematic sediment sampling was also performed at each capture site (El Coloradito, El Caracol, El Huitussi, El Aparecido, El Cerro Cabezón, Topolobampo, El Cerro Partido, and El Tortugo) by examining the upper 30 cm of sediment to ensure representativeness of the particle inventory. Four of the six analyzed species (C. viridis, C. othonopterus, P. macracanthus, and D. peruvianus) contained microplastic-like particles (MP-p), totaling 163 items, with an average ingestion rate of 0.29 items individual⁻¹. The omnivorous species D. peruvianus showed the highest ingestion (0.52 items individual⁻¹; 0.0029 items g⁻¹ wet weight). Five categories of MP-p were distinguished based on morphology and fluorescence; however, their polymeric identity cannot be confirmed without spectroscopic analyses. Sediment results showed that most microplastic-like fragments occurred at site 2025 during autumn, spring, and summer, while levels at site 1826 did not differ significantly. This study provides the first evidence of microplastic contamination in these fish species and in this region of northwestern Mexico. Full article

The study of river basins is key to understanding the dynamics of microplastic (MPs) generation, transport, and accumulation in regions where various productive activities converge and waste management is limited. The objective of this study was to characterize economic activities in the Tecolutla River basin, Mexico, to identify risk factors associated with MPs generation and release throughout the production chain. A descriptive applied research study was conducted using a structured questionnaire administered to 19 economic units distributed across seven municipalities in the Tecolutla River basin, Veracruz, Mexico. The instrument allowed for the evaluation of the use of plastic materials in inputs, production processes, final products, and waste management practices. Among the economic units analyzed (n = 19), 94.7% reported the use of polymeric materials, with a predominance of thermoplastics such as polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polypropylene (PP), which have a high potential for secondary fragmentation. Within the tertiary sector, accommodation and food preparation services account for the highest proportion of units with limited separation and recycling practices. Activities in the secondary sector, especially the textile and construction industries, showed a high potential for releasing this pollutant due to the use of synthetic fibers, composite materials, and the absence of retention systems. The results provide a basis for the design of mitigation strategies targeting priority productive sectors at the watershed scale. Full article

Microplastic (MP) contamination in freshwater systems has emerged as a growing environmental concern. This study investigated the occurrence and seasonal variability of MPs in surface water, the water column, and sediments at selected sites in Lake Alhajuela, Panama. Lake Alhajuela is an artificial reservoir that supplies water to the Panama Canal lock system and to the cities of Panama and Colón, serving more than 50% of the country’s population. MPs were isolated using two digestion protocols followed by density separation, and fragments and films larger than 1 mm were chemically characterized using FTIR–ATR spectroscopy. Mean MP concentrations were 759 ± 536 MPs L⁻¹ in surface water, 328 ± 140 MPs L⁻¹ in the water column, and 109 ± 87 MPs g⁻¹ in sediments. Statistical analyses revealed no significant differences among sampling sites; however, significant seasonal differences were observed (p < 0.01). Smaller MPs (63–249 µm) were more abundant compared to larger MPs (>250 µm). Fragments and fibers were the most predominant type of MP reported. Our results confirm the presence of MPs in the surface and water column, as well as sediments of the Alhajuela Lake. Further studies are needed to elucidate the fate, sources, transport, and distribution of MPs across Lago Alhajuela as well as to assess the lake’s potential contribution of MPs to Gatun Lake and the Panama Canal system. Full article

Terrestrial environments function as major sinks and dynamic sources of microplastics. Land use strongly influences inputs, accumulation, and transport pathways of these contaminants in the environment. Despite the extensive literature, few reviews have compared contamination levels and the potential impacting factors across land uses. To fill this gap, this review synthesizes current knowledge on the origins, occurrence, pathways, and ecological effects of microplastics across diverse land uses. The review revealed multiple interconnected pathways that drive microplastic contamination in terrestrial systems. Abundances are consistently higher in intensively managed croplands, urban areas and industrial vicinities. However, their detection in remote environments underscores the critical role of diffuse inputs and long-range atmospheric transport. Vertically, microplastics are enriched in topsoils, and their concentrations declines with depth. Horizontally, concentration declines with increasing distance from major hotspots like agricultural fields, industrial facilities, and road networks. Ecologically, microplastics alter soil physical properties, modify chemical conditions, and shift microbial community composition and enzyme activities. Furthermore, they stress soil fauna and plants through ingestion, toxicity, and physical blockage, with impacts contingent on polymer type, particle morphology, and concentration. Collectively, this review reveals consistent spatial patterns and widespread adverse ecological impacts, highlighting the clear need for integrated management strategies to mitigate terrestrial microplastic pollution. Full article

Microplastics represent an emerging threat to aquatic ecosystems, human health, and coastal aesthetics, with increasing concern about their accumulation on beaches due to ocean currents, wave action, and accidental spills. Despite their environmental impact, current methods for detecting and quantifying microplastics remain largely manual, time-consuming, and spatially limited. In this study, we propose a deep learning-based approach for the semantic segmentation of microplastics on sandy beaches, enabling pixel-level localization of small particles under real-world conditions. Twelve segmentation models were evaluated, including U-Net and its variants (Attention U-Net, ResUNet), as well as state-of-the-art architectures such as LinkNet, PAN, PSPNet, and YOLOv11 with segmentation heads. Models were trained and tested on augmented data patches, and their performance was assessed using Intersection over Union (IoU) and Dice coefficient metrics. LinkNet achieved the best performance with a Dice coefficient of 80% and an IoU of 72.6% on the test set, showing superior capability in segmenting microplastics even in the presence of visual clutter such as debris or sand variation. Qualitative results support the quantitative findings, highlighting the robustness of the model in complex scenes. Full article

Analyzing microplastics in marine organisms is essential for understanding the ecological and toxicological impacts of marine microplastic pollution in coastal food webs. This study investigated microplastic ingestion in three edible invertebrate species commonly found on Vietnamese sandy beaches, wedge clam Donax sp., hermit crabs Pagurus sp., and horn-eyed ghost crabs Ocypode ceratophthalmus, which differ in feeding modes and mobility, using micro-Fourier Transform Infrared spectroscopy (µ-FTIR) with a detection limit of 20 µm. Results showed that all three species ingested microplastics, with ingestion patterns varying according to species-specific traits and habitat-related feeding behaviors. The highly mobile crabs Ocypode ceratophthalmus (omnivore) and Pagurus sp. (scavenger) were found to partially reflect the polymer pollution in their ambient environment. The higher ingestion rate and diversity of polymer types observed in sedentary Donax sp. suggest that this species could serve as a potential bioindicator for microplastic pollution, given its mixed suspension and deposit feeding habits that integrate pollution from both the water column and beach sediments. Overall, these results reveal widespread microplastic ingestion among edible beach fauna, highlighting potential ecological and human health concerns, and emphasizing the need for targeted pollution management and increased public awareness. Advancing our understanding will require larger datasets and controlled experiments to more robustly assess species-specific responses and the likelihood of trophic transfer. Full article

Microplastics (MPs) are prevalent in coastal habitats, but their occurrence in highly vulnerable coastal zones and human exposure risk are poorly understood, especially in developing nations like Bangladesh. This inquiry focused on the prevalence and potential hazards of MPs in surface sediment and shallow groundwater samples collected from 12 sites in Cox’s Bazar, Bangladesh, from August to October 2023. Using stereomicroscopy and FTIR, MPs were quantified, with concentrations ranging from 60 to 813.33 MPs/kg in surficial sediment and 3.34 to 36.66 MPs/L in shallow groundwater, with mean values of 294.38 ± 26.61 MPs/kg and 18.91 ± 4.75 MPs/L. The dominant MPs were composed of transparent and white fibers, ranging in size from 0 to 0.5 mm, with HDPE (High-Density Polyethylene) and PP (Polypropylene) identified as the most commonly found polymers. To assess MP exposure in humans and the environment, this investigation used three indices: the polymer hazard index (PHI), the pollutant load index (PLI), and the estimated daily intake (EDI). The findings indicate that children exhibit greater exposure than adults, with observed low contamination levels, alongside a spectrum of toxicity from moderate to extreme. This study enhances understanding of MP contamination in the surficial sediments and shallow groundwater of Bangladesh, highlighting the need for further investigation into ecotoxicology, human health risks, legislation, and related issues. Full article

Heterogeneous photocatalysis increasingly requires rapid polymer degradation tests relevant to aqueous conditions. In this study, a multi-technique approach was developed to monitor the early-stage photo-oxidation of polyethylene (PE) and polystyrene (PS) microplastics in an aqueous ZnO–TiO₂ suspension under combined ultraviolet A and ultraviolet B (UV-A/B) irradiation. The changes were analyzed by ATR-FTIR and Raman spectroscopy, DSC, and gravimetric measurements. For PE, the carbonyl index increased from 0.0189 to 0.1350 after 12 h, mass loss reached 16.98%, and crystallinity decreased from 32.05% to 25.36% after 8 h. The Raman spectra of PE showed band broadening and intensity redistribution, indicating increasing structural disorder. In contrast, PS showed weaker Raman changes, while FTIR revealed a non-monotonic carbonyl-index response, and DSC showed a 2.2 °C increase in Tg after 12 h. Gravimetric analysis also showed measurable mass loss in PS, reaching 18.62% after 12 h. The results demonstrate that the combined use of ATR-FTIR, Raman, DSC, and gravimetry enables reliable distinction between early oxidation, surface modification, and material erosion in photocatalytically treated microplastics. Full article

In an accelerated aging experiment involving a wide range of cumulative UV-B radiant exposures (up to approximately 9.46 × 10³ J cm⁻²), the degradation state of microplastics was assessed using SEM, FTIR, Raman spectroscopy, and DSC, and correlated with the cumulative UV-B dose. Sunlight-induced photooxidation is a significant weathering mechanism for microplastics. In this study, high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC), nylon, and polystyrene (PS) were exposed to UV-B radiation under controlled dry conditions at two irradiance levels (0.06 and 0.6 mW cm⁻²), covering cumulative UV-B radiant exposures of up to approximately 9.47 × 10³ J cm⁻². Degradation was evaluated using SEM, FTIR, Raman spectroscopy, and DSC, and was related to the cumulative UV-B dose (H). The extent and progression of degradation varied significantly among the polymers. Overall, FTIR provided the most sensitive assessment of photooxidative surface changes for HDPE, LDPE, PP, and PS, Raman spectroscopy was most diagnostic for PVC (particularly for dechlorination-related changes), and DSC-derived crystallinity was most informative for nylon. These dose-resolved datasets establish a reproducible reference framework (“degradation library”) to facilitate the comparative assessment of the relative photooxidative aging stage of microplastics under comparable surface UV-driven conditions. Outdoor “sunlight-equivalent” times are reported solely as order-of-magnitude contextualization due to environmental variability. Full article

The escalating use of plastic medical products has made medical microplastics (MMPs) contamination an important health concern for specific populations (e.g., patients undergoing medical interventions) and has rendered it a growing focus in global environmental health research. This review systematically summarizes the release characteristics of MMPs throughout their life cycle from device manufacturing and clinical use to waste disposal, and elucidates human exposure pathways. For the general population, environmental exposure and dietary intake are the dominant exposure sources. In patients, however, invasive procedures and intravenous infusions serve as direct, high-concentration routes, enabling MMPs to enter the bloodstream directly. The article focuses on analyzing the molecular mechanisms underlying multisystem pathological effects induced by MMPs, including cardiovascular injury, respiratory dysfunction, digestive disorders, and reproductive toxicity, which involve key pathways such as oxidative stress, inflammatory responses, apoptosis, and dysregulated autophagy. Regarding existing detection technologies, we compare and evaluate the advantages and limitations of microscopic observation, spectral analysis, and chromatography–mass spectrometry in terms of sensitivity, specificity, and applicability, proposing that integrated technical strategies can significantly improve detection reliability. Finally, the review discusses current challenges and future research directions, including the establishment of standardized risk assessment frameworks, the development of highly sensitive in situ detection technologies, and the exploration of targeted intervention strategies. This work provides a theoretical basis for understanding the health risks of MMPs and offers valuable insights for formulating safety management policies for medical plastics. Full article

Marine-related activities contribute significantly to plastic pollution in oceans worldwide, particularly in regions located along international maritime routes such as Türkiye. The Dardanelles serves as a major maritime gateway connecting the Aegean Sea with both the Sea of Marmara and the Black Sea, enabling heavy vessel traffic that subsequently disperses plastic pollutants across large areas of the Mediterranean and beyond. Therefore, for the first time, this study applied material flow analysis to estimate potential sources and pathways of macro- and microplastics from 12 vessel categories, including fishing fleets, merchant ships, cruise liners, and military vessels in the Northern Aegean Sea. This approach provides insight into the range of sources and pathways, highlights priority areas for mitigation, and identifies additional knowledge gaps. Through material flow analysis–based estimations, general macro- and microplastic waste is found to be the largest contributor to marine plastic pollution, with an average of 14,965 tons/year, followed by antifouling particles at 5848.5 tons/year. Overall, this study presents a comprehensive evaluation of vessel-derived plastic pollution in a strategically significant maritime corridor and emphasizes its potential implications for the broader marine eco-system. Full article

Microplastics impact coral reefs due to their presence in the water column. This is the case of Ingeniero Reef, which borders the Veracruz-Boca del Rio metropolitan area. The objective of this study was to determine the presence of microplastics in the feeding zone adjacent to the corals located on Ingeniero Reef. Two sampling periods were conducted (dry and rainy seasons, 2023), obtaining water samples from the area adjacent to the corals and from the water column, with 20 per sampling period. In the laboratory, the microplastics were separated and classified by type, size, and color. A one-way ANOVA was performed to compare microplastic concentration between the two seasons and average size in corals and the water column, and the Bray–Curtis index was applied. A new technique for obtaining microplastics from coral reefs was developed. The concentration of microplastics varies according to the climatic season, with fibers being the dominant type. The size of microplastics can be a determining factor for corals. The development and application of standardized protocols for studying microplastics will allow for more reliable monitoring programs, yielding comparable results that will enable the assessment of the impact of this emerging pollutant. Full article

Accumulation of microplastics (MPs) in aqueous environments poses a serious ecological problem nowadays. MP particles are able to adsorb pollutants of different kinds and to transport them to living organisms, leading to biotoxicity. Hence, investigation of the adsorption of pollutants of different molecular weights onto MP particles is an important task. We employed the numerical Scheutjens–Fleer self-consistent field method to study (i) the formation of MP particles consisting of homopolymer macromolecules and (ii) the adsorption of pollutant homopolymer chains onto the MP particles. Under poor solvent conditions, the polymer macromolecules were shown to form MPs with a constant density inside the particle and with an interfacial layer at its periphery. The size of the MP particles and the thickness of the interfacial layer were controlled by the solvent quality. MP particles were shown to adsorb pollutant polymer chains from the surrounding liquid due to higher compatibility of the MP particle with the pollutant polymer chains as compared to the solvent. The amount of adsorbed polymer pollutant increased with the increase of its concentration in solution. Softer MP particles were shown to adsorb larger amounts of pollutants due to a broader interfacial layer. The conformational characteristics of the adsorbed polymer chains (trains, loops, and tails) were studied in detail. Full article

Plastic and microplastic (MP) pollution, along with alien species invasion, are of great concern for natural habitat preservation and human health, and are two important and concomitant likely causes for global biodiversity loss. In the present study, a Seabin, a device for buoyant waste collection in calm waters, was used to also characterize the waste collected in northernmost side of Lake Garda (Italy) in a period of very low anthropogenic pressure, the Winter season of 2024–2025. During the survey, 92.6 g of plastic was collected, i.e., a total of 540 pieces. About 6.9 mg of plastic per m³ of water was found, corresponding to about 0.04 plastic items per m³ and approximately 13 pieces of microplastics per day. Fourier-transform Infrared (FTIR) spectroscopy identification showed that the plastic was composed mainly of polyethylene (PE), polypropylene (PP), and polystyrene (PS). Microorganisms (Diatoms, Bacillariophyta) and microcrack formation with deposits of inorganic matter (mainly Si, Al, O, Ca) were also evidenced by SEM/EDX in all the observed aged MP. Qualitative evaluation of the captured biota highlighted the presence of at least five alien species, including invasive Dikerogammarus villosus. This study describes an easy and cost-effective novel methodology for simultaneously monitoring plastic waste and alien species presence in calm waters, which acts also as a mitigation tool for plastic pollution. The results could be of interest not only to policymakers and scientists, but also for public health and for environmental monitoring. Full article

Microplastics (MPs) are pervasive in marine ecosystems, yet the molecular mechanisms underlying their sublethal effects on zooplankton remain poorly understood. Here, we integrated transcriptomic screening with sequence homology analysis, structural modeling, and molecular dynamics (MD) simulations to examine protein–polymer interaction behavior in the tropical euphausiid Euphausia distinguenda. Transcriptomic analysis identified three MP-responsive proteins; two isoforms (P1, P2) were consistently downregulated following exposure to polyethylene microspheres, while a third candidate (P3) was upregulated but excluded from modeling due to insufficient homology. Structural models of P1 and P2 were generated using AlphaFold2 (ColabFold implementation) and evaluated through comparative structural analyses. MD simulations (100 ns) were conducted using representative polymer oligomers LDPE used as a polyethylene analog and PET and PC included as contrast polymers, which revealed pronounced protein-specific differences and polymer-dependent modulation of interaction stability. Nonbonded Lennard–Jones and Coulomb interaction energies indicated substantially greater intermolecular contact stabilization for P2 than for P1 across all polymers, with LDPE yielding the lowest mean polymer RMSD for P2, and PET for P1. Together, these results indicate that MP–protein interactions in E. distinguenda are consistent with a dominant role of protein structural coherence and dynamic surface compatibility rather than by static structural complementarity or specific binding affinity and provide a reproducible basis for exploring molecular-scale responses to MP exposure in ecologically relevant zooplankton. Full article

The environmental persistence of post-consumer plastics remains a critical challenge due to their chemical stability, the presence of additives, and prior environmental weathering. This study evaluates the partial biodegradation and chemical transformation of post-consumer low-density polyethylene (LDPE) and expanded polystyrene (EPS) by Tenebrio molitor larvae under uncontrolled environmental conditions. Four diets were tested, including LDPE+S and EPS+S (polymers supplemented with wheat bran), to assess the influence of a co-substrate on larval performance and polymer transformation. Fourier-transform infrared spectroscopy (FTIR) revealed the emergence of oxygen-containing functional groups (–OH and C=O) in the frass, which were absent or negligible in pristine materials, indicating oxidative modification of the polymer matrix. Gel permeation chromatography (GPC) revealed pronounced reductions in number-average molecular weight (Mn) and increased polydispersity for EPS-derived fractions, consistent with heterogeneous chain scission and partial depolymerization. For LDPE, GPC evidenced the formation of THF-soluble, low-molecular-weight polymer-derived fragments, indicating fragmentation despite the inability to quantify pristine LDPE due to its insolubility in the mobile phase. Gas chromatography–mass spectrometry (GC–MS) identified aromatic hydrocarbons, phthalate esters, organosiloxanes, and fatty acid derivatives, reflecting both degradation intermediates and migrated additives from post-consumer plastics. Together, these results provide integrated evidence that Tenebrio molitor can induce chemical transformation of post-consumer LDPE and EPS under non-controlled environmental conditions, offering mechanistic insight into a biologically mediated degradation pathway that is directly relevant to realistic plastic waste scenarios. Full article