Search Results (105)

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. Full article

Plastics and microplastics are widespread in the environment, yet knowledge about their impact on agricultural soils, including their microbiological properties, remains limited. Therefore, this study addressed the research question regarding the impact of secondary microplastics, biodegradable poly(lactic acid) (PLA) mulch film, and low-density polyethylene (LDPE) film on the abundance, structure, and functions of soil bacteria, with particular emphasis on the presence of bacterial pathogens. PLA and LDPE were applied to the soil at a dose of 4 g kg⁻¹ d.m. of soil. The aim of the experiment was to evaluate and compare the effectiveness of soil bioaugmentation with the Pseudomonas umsongensis strain and its biostimulation with humic acids in mitigating the negative effects of microplastics. The response of culturable bacteria revealed high sensitivity of organotrophic bacteria to both microplastics, with a stronger inhibitory effect from PLA, as well as stimulation of actinomycetes. 16S rRNA gene amplicon sequencing indicated that the materials differentially influenced the bacterial response. PLA most strongly stimulated Actinobacteriota and favored the dominance of Bacillus and Limnochorda, whereas LDPE promoted the growth of Actinobacteriota and Chloroflexota as well as genera KD4-96 and 1921-2. Both microplastics were colonized by potential pathogens, including Bacillus, Mycobacterium, Ralstonia, and Cupriavidus. PLA additionally stimulated the proliferation of Leifsonia sp. and Curtobacterium sp., while both PLA and LDPE reduced the abundance of Enterobacter sp. and Herbaspirillum sp. Bioaugmentation using the Pseudomonas umsongensis strain was more effective in restoring the balance of the soil microbiome than biostimulation with humic acids. The results indicate that microbial preparations based on Pseudomonas umsongensis may serve as an important tool in restoring the balance of soil exposed to microplastics. Full article

Polyethylene microplastics (PE-MPs) are ubiquitous constituents of waste activated sludge (WAS), acting as a major land-based source threatening coastal environmental integrity. However, how particle size and dose govern the methanogenic outcome during WAS digestion remains poorly defined. This study evaluated two particle sizes (50 vs. 300 µm) and doses (100 vs. 200 particles/gTS) to elucidate the differential effects of PE-MPs on methane yield and the underlying biological mechanisms. The results show that, while low-dose treatments either slightly inhibited methane yield (RS1) or had no significant effect (RL1), high-dose treatments (RS2 and RL2) achieved a net positive effect, with significant increases of 10.2% (p < 0.05) and 9.0% (p < 0.05) relative to the control, respectively. Nevertheless, RS2 and RL2 achieved methanogenic enhancement via distinctly different biological pathways. RS2 harnessed the stress of reactive oxygen species (ROS) (110.5% of the control) to drive community restructuring and biomass accrual (positive correlation between ROS intensity and total VS, Pearson’s r = 0.99). Key syntrophic and electrogenic taxa (e.g., Syntrophales, Bacteroidetes vadinHA17) exhibited a fully interconnected, decentralized network, thereby achieving tight coupling between hydrolysis and methanogenesis. RL2 leveraged the physical carrier effect to promote granulation and biomass growth, enriching Syntrophobacter to enhance propionate degradation. This culminated in a highly modular, sparse network characterized by localized competitive interactions. Together, dosage governs the net methanogenic effect of PE MPs, whereas particle size dictates the mechanistic routes of action. This work offers a mechanistic framework to optimize energy recovery from PE-MP-contaminated sludge while mitigating secondary environmental risks, providing a science-based strategy for the sustainable management of plastic-laden sludge that reconciles renewable energy recovery with pollution control. Full article

Microplastics (MPs) are increasingly recognized as pervasive co-contaminants in aquatic environments, yet their impacts on advanced oxidation processes remain poorly understood. Herein, we systematically investigate the role of representative MPs in diclofenac (DCF) degradation within a permanganate–manganese dioxide (PM-MnO₂) catalytic system. Results show that PM alone exhibits limited reactivity toward DCF, while MnO₂ significantly enhances DCF degradation. In the absence of MnO₂, MPs increase PM consumption but do not influence DCF degradation, indicating that MPs primarily act as competing oxidant sinks. In contrast, under MnO₂ catalytic conditions, the effect of MPs strongly depends on their interaction with MnO₂. Pre-adhesion of MPs onto MnO₂ suppresses DCF degradation by blocking active sites and inhibiting interfacial electron transfer. However, when MPs are introduced without pre-adhesion, no inhibition is observed; instead, a slight enhancement in DCF removal occurs. This promotion is attributed to in situ oxidation of MPs, which consumes PM and simultaneously generates secondary MnO₂ colloids that provide additional reactive interfaces. Further analysis reveals that PM consumption is decoupled from DCF degradation due to multi-pathway oxidant partitioning, including DCF oxidation, MP oxidation, and Mn redox cycling. These findings demonstrate that MPs can act as both inhibitors and promoters depending on their interaction mode with catalysts, highlighting the importance of catalyst accessibility and reaction sequence. This study provides new insights into the complex roles of MPs in catalytic oxidation systems and offers guidance for applying PM-based technologies in realistic water matrices. Full article

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. Full article

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 $60\pm 35$ μm to $3\pm 1$ 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. Full article

Cadmium (Cd) and polystyrene (PS) microplastic co-contamination in agricultural soils poses a potential threat to food security. Some functional microorganisms in soil can alleviate the dual stress of Cd and PS on crops. In this study, a biofilm-forming bacterium, Enterobacter sp. W5, was isolated from heavy metal-contaminated rhizosphere soil. Strain W5 exhibited Cd removal efficiency (46.3%) and strong biofilm-forming capacity (OD₅₇₀ = 5.05), and it effectively colonized PS microplastic surfaces. XPS analysis detected bacterial functional groups (C–O–C, C=O) and PS-associated signals (O–C=O), which may act synergistically in Cd²⁺ adsorption. Furthermore, XPS and XRD analyses revealed the presence of Cd-containing precipitates (including CdS, CdO, and Cd₃(PO₄)₂). In hydroponic wheat experiments, W5 inoculation alleviated Cd-PS combined stress, thus significantly promoting plant growth and reducing Cd accumulation by 22.6% in roots and by 34.2% in aboveground tissues. Subcellular distribution analysis revealed that W5 enhanced Cd retention in root cell walls, thereby limiting its translocation to active cellular compartments. Proteomic analysis identified a set of 11 consistently downregulated proteins, including A0A3B6HQ68 and A0A3B6KJV9, which were enriched in secondary metabolite biosynthesis pathways. Bioinformatic analysis suggests that these proteins may be associated with Cd stress responses, though their exact roles remain to be verified. Collectively, this study provides a valuable microbial resource and mechanistic insights into the application of biofilm-forming bacteria for mitigating combined heavy metal–microplastic pollution in agricultural systems. Full article

The interaction between airborne allergens and environmental microplastics is an emerging concern in the context of increasing plastic pollution and allergic disease prevalence. In this study, we investigated the molecular interaction between Cry j 1, the major allergen of Japanese cedar (Cryptomeria japonica) pollen, and polyethylene terephthalate (PET) microplastic surfaces using all-atom molecular dynamics simulations integrated with computational epitope selection analyses. The simulations showed that Cry j 1 adsorbs onto PET primarily through hydrophobic and van der Waals interactions, with residues Pro165, Ala227, Tyr228, and Val163 contributing prominently to surface association. Mapping of selected epitope regions indicated that several linear B-cell epitopes remained solvent exposed following adsorption, whereas two CD4⁺ T-cell epitope regions (T5 and T6) contributed more directly to PET interaction. PET adsorption was accompanied by moderate changes in conformational dynamics, including reduced residue-level flexibility and localized secondary-structure adjustments, while the overall protein fold remained structurally stable throughout the simulation. Small decreases in radius of gyration and solvent-accessible surface area suggested mild adsorption-associated compaction rather than major unfolding. These findings indicate that PET association can influence the structural dynamics and interfacial behavior of Cry j 1 without extensive disruption of its global architecture. Because the study is entirely computational, the immunological implications remain hypothetical and require experimental validation. Nevertheless, this work provides a molecular-level framework for understanding how airborne microplastics may influence allergen behavior and protein-surface interactions in polluted atmospheric environments. Full article

Urban trees are increasingly exposed to persistent anthropogenic drivers that extend beyond climatic forcing and fundamentally alter the conditions of secondary growth. While climatic controls of cambial phenology and xylogenesis are well established, the mechanisms by which non-climatic drivers regulate cambial activity and wood formation remain fragmented and are often inferred only indirectly. Here, we develop a cambium-centred framework to synthesise current evidence on how anthropogenic drivers shape wood formation in urban and peri-urban trees. To our knowledge, this is among the first syntheses explicitly linking anthropogenic drivers to distinct stages of xylogenesis. Anthropogenic drivers are typically chronic, spatially heterogeneous, and temporally decoupled from seasonal climatic rhythms, and may alter cambial kinetics and generate anatomical signatures not captured by ring width alone. We evaluate major driver domains, including root-zone constraints, altered hydrology, urban microclimate, pollution, salinity, and mechanical disturbance, while also considering emerging drivers such as artificial light at night and microplastics. Evidence is stratified into three levels: direct observations, indirect physiological evidence, and mechanistic plausibility. Across driver classes, three recurrent anatomical patterns emerge: reduced conduit size under hydraulic or osmotic stress; anomalies in wall deposition under carbon limitation or oxidative stress; and pronounced circumferential heterogeneity under spatially localised forcing. Integrative approaches combining xylogenesis monitoring, quantitative wood anatomy, dendrometer observations and spatially explicit sampling are essential to disentangle anthropogenic from climatic effects and improve assessment of tree resilience. Full article

The textile industry has contributed significantly to global microplastic pollution, generating both primary and secondary microplastics. Primary microplastics, released during the manufacturing process of textiles, are the main concern due to their long-chain structure and persistence, while secondary microplastics are generated from the degradation of synthetic or blended textile products, which have already been in service or use. This review provides a comprehensive overview of methods for investigating fibrous primary microplastics generated throughout the major stages of the textile value chain, including yarn production, fabric manufacturing, garment processing, finishing, and packaging. In fact, there is an urgent need to deal with fibrous primary microplastics, as they are particularly hazardous due to their form (thin, long and often needle-like) and long-lasting life (can sustain in the environment over hundreds of years). Each manufacturing stage produces measurable microfiber losses. For example, pre-consumer production emits approximately 0.12 million metric tons of microplastics per year. High-speed yarn spinning releases additional MP (microplastics); rotor-spun polyester yarns shed 2000–8000 MFPs/g (microplastic fibers/g). The mechanical stresses such as friction, abrasion, and yarn breakage during weaving and knitting operations contribute significantly up to 10⁴–10⁶ microfibers per m² of fabric during production. Wet processing (dyeing, printing, and finishing) is another major hotspot for primary microplastic generation, with dye house effluents reporting up to 54,100 microfibers per liter. Moreover, during mechanical and chemical finishing operations, the generated nanoplastics (NPs) rose significantly, exceeding 10¹¹ particles per gram of material. Subsequently, the garments manufacturing units are estimated to produce 10,000 garments per day (5 tons of fabric), which equates to 5–25 kg/day of microplastic fiber waste. Targeted schemes for the study of primary microplastics at the earliest stages of textile production could significantly reduce environmental release and strengthen progress toward a more circular and sustainable textile economy. Full article

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. Full article

The use of bio-based and biodegradable plastic products (BBpPs) ensures the mitigation of environmental effects of fossil-based plastics, especially in humanitarian crises where waste management is challenging. Polyhydroxyalkanoates (PHAs) are promising biodegradable biopolymers that are biocompatible and do not cause microplastic pollution. However, experimental assessment of PHA biodegradation is challenged by its time- and resource-intensiveness. In this study, a comprehensive computational Quantitative Structure–Activity Relationship (QSAR)-based approach was developed to predict biodegradability of short chain length (scl)-PHA-based formulations consisting of various additives and building blocks. A novel curated dataset for the (scl)-PHA poly(-3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), with literature-reported environmental and biodegradation parameters from lab-scale experiments in soil, marine, freshwater and compost systems, was constructed and used to develop and validate the introduced approach. Random forest (RF) and Extreme Gradient Boosting (XGBoost) machine learning (ML) models were optimized and validated with cross-validation and test set predictions. The optimal models reported high accuracy values of the coefficient of determination R², indicating excellent relationships between structure and biodegradation metrics. Further analysis of descriptor variable importance confirmed that biopolymer biodegradability was favorably affected by biodegradation time, while mechanisms, environmental conditions, and additives contributed secondary yet physically consistent effects. The proposed QSAR framework demonstrated a robust and interpretable web-based tool for predicting the environmental fate of PHBV in natural environments and supported the sustainable safe-by-design (SSbD) approach of next-generation biodegradable polymers. Full article

Microplastics may pose health risks, particularly for chronic lung diseases. Clarifying the link between circulating microplastics and pulmonary disease is vital for shaping research and interventions. The objective of this study was to evaluate whether microplastics in peripheral blood are associated with COPD or IPF vs. no lung disease. In this pilot prospective case-control study, participants were grouped as control (n = 10), COPD (n = 9), or IPF (n = 10). Relevant comorbidities and exposures were obtained from records and questionnaires. All underwent standardized blood collection (PlasticTox©). Samples were analyzed for total microplastic concentration, stratified by size (<10 µm, 10–30 µm, 30–70 µm). The primary outcome was to show a difference in total microplastic burden between lung disease and controls. Secondary measures were to determine size-specific concentrations and associations with demographic variables and smoking history. Among 29 participants (median age 70 (IQR 64–80); 14 women (48.3%)), COPD/IPF groups had significantly higher total microplastic concentrations vs. controls (median 26.0 vs. 3.5 particles/100 µL; p < 0.01). Particle burdens <10 µm and 10–30 µm were particularly elevated (both p < 0.01). After adjusting for smoking, only the <10 µm fraction remained independently associated with lung disease (adjusted odds ratio 1.94 (95% CI, 1.23–7.04)). In this pilot exploratory study, individuals with COPD or IPF showed greater circulating microplastic levels than controls. These findings should be interpreted as hypothesis-generating, and larger analytically validated studies are needed to clarify directionality, causal mechanisms, contamination control, and the clinical relevance of circulating microplastic burden. 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 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