Open research questions in Microplastics and Plastic Pollution

What the literature leaves open

• Although evidence remains preliminary, MPs have been detected in several upper airway specimens, and their biologi- cal significance remains incompletely understood. Current evidence is insufficient to establish causal relationships be- tween MP exposure and rhinologic diseases.

  Microplastics in the Human Nasal Cavity and Upper Airway: Emerging Evidence and Rhinologic Implications · 2026 · DOI

• Future investigations should establish standardized protocols for collecting, processing, and analyzing upper airway specimens in MP research. Reproducible nasal sampling techniques and contamination-control strategies will be essential for improving interstudy comparability and analytical reliability. Longitudinal clinical studies are also needed to evaluate the relationship between chronic MP exposure and the development or progression of rhinologic diseases. In particular, future research should examine whether persistent exposure contributes to epithelial dysfunction, impaired mucociliary clearance, or chronic sinonasal inflammation in susceptible individuals. Pediatric populations also warrant attention because children may be more vulnerable to inhaled environmental contaminants owing to developmental and behavioral factors. In addition, possible olfactory pathway-mediated translocation into the central nervous system warrants further investigation, particularly with respect to potential neurotoxicity associated with chronic exposure. The clinical significance of medical device-associated exposure also requires clarification. Because nasal irrigation bottles and CPAP devices are widely used in rhinologic and sleep medicine practice, quantitative assessment of device-derived MP exposure may become increasingly important. Multidisciplinary collaboration among rhinologists, toxicologists, environmental scientists, and analytical chemists will be needed to clarify the clinical implications of upper airway MP exposure.

  Microplastics in the Human Nasal Cavity and Upper Airway: Emerging Evidence and Rhinologic Implications · 2026 · DOI

• However, quantitative estimates, such as the apparent highest value of 637 MPs g−1, and the observation that the majority of particles detected are released during the first 8 min, remain tentative, given the limited range of products offered and the lack of replication across different brands, formulations, chewing schedules, and analytical tools.

  Chewing Gum to Microplastic: Hidden Pollution and Its Scalable Circular Upcycling Pathways · 2026 · DOI

• The quantity of polymers contained within both the mineral matrix and the floating fraction > 100 μm of contemporary sediments remains unknown; it is evident that the total is higher.

  Methodology for assessing microplastic quantity in contemporary urban surface deposited sediments · 2026 · DOI

• More than 60% of studies were conducted in western Indonesia, with a strong concentration on Java Island, whereas large parts of eastern Indonesia remain poorly documented.

  Bridging the gap for advancing microplastic research and monitoring in the Indonesian marine and coastal environments · 2026 · DOI

• While direct quantitative data on microplastic release from urinary catheters are currently lacking, coronary catheters have been shown to release microplastics during simulated use 43, and PVC infusion tubes release microplastics in the 0. While recent studies have confirmed that medically derived MPs can enter the human body through direct exposure routes, their potential role in modulating pathogenic bacteria and involvement in the pathogen’s infection process is poorly understood.

  PVC microplastics facilitate uropathogenic Escherichia coli pathogenicity by enhancing host cell invasion and mitochondrial-dependent pyroptosis · 2026 · DOI

• BACKGROUND AND OBJECTIVES: Landfill leachate has been identified as a pathway for microplastic release into aquatic environments; however, its role as a dynamic transformation system remains poorly understood.

  Dynamics of microplastics along landfill leachate pathways and treatment processes · 2026 · DOI

• Although definitive causal relationships between nanoplastic exposure and human kidney disease have not yet been established, the evidence reviewed demonstrates consistent biological plausibility, widespread environmental occurrence, and multiple mechanisms capable of producing tissue injury. While definitive causal relationships have not yet been established, the widespread occurrence of nanoplastics, the consistency of reported toxicological mechanisms, and the growing evidence of internal human exposure support the need for continued investigation. Most available studies focus on environmental detection and toxicological mechanisms, whereas human epidemiological investigations remain scarce. Although epidemiological evidence remains insufficient to establish direct clinical consequences, the biological consistency observed across studies raises important questions regarding long-term cardiovascular risks associated with chronic nanoplastic exposure. Current evidence is largely derived from laboratory studies and environmental monitoring investigations, while long-term human epidemiological studies remain scarce.

  Nanoplastics in Drinking Water: Emerging Evidence on Renal Toxicity, Systemic Health Effects, and Public Health Implications · 2026 · DOI

• RESEARCH subjected availability identified particles was A limitation of this study is that only a subset of visually to spectroscopic confirmation due to analytical time and instrument constraints. Although stringent quality assurance and quality control measures were implemented, the inability to verify all suspected particles using FTIR may introduce a degree of uncertainty into the overall microplastic abundance estimates. the Another important limitation is the absence of direct spectroscopic analysis of the packaging materials sampled water products. associated with Consequently, while the identified polymer types suggest that packaging materials may be a major source of contamination, definitive source attribution could not be established through direct spectral comparison between recovered microplastics and the corresponding packaging components.

  Assessment of Storage-Induced Microplastic Generation, Polymer Characteristics, and Human Exposure Risks in Bottled and Sachet Drinking Water Under Different Environmental Conditions in Port Harcourt, Nigeria · 2026 · DOI

• or spectroscopic methods were excluded from further analysis. The FTIR protocol followed internationally recognized established methodologies for microplastic characterization in accuracy, drinking water, reproducibility, and comparability with previous studies. analytical ensuring and Human Exposure Assessment: Human exposure to microplastics through drinking water consumption was estimated using the Estimated Daily Intake (EDI) model: EDI = Where: EDI = Estimated Daily Intake (particles/kg/day) C = Microplastic concentration (particles/L) IR = Daily water Consumption rate (L/day) BW = Average body weight (kg) The following assumptions were adopted: Adult water consumption rate: 2 L/day, Child water consumption rate: 1 L/day, adult body weight: 70 kg and Child body weight: 15 kg. Annual microplastic intake estimates were also calculated based on the daily intake values. full For statistical analysis, the experimental unit was defined as an individual 1 L packaged drinking water sample subjected to a specified combination of storage condition and storage duration. The study adopted a factorial experimental design comprising four storage conditions (Indoor Control, Ambient Market Storage, Direct Sunlight Exposure, and Elevated Temperature Storage) and four storage durations (0, 30, 60, and 90 days). Five bottled-water brands and five sachet-water brands were included in the experimental treatment combination replicated three times. For the one-way ANOVA, microplastic concentrations measured at Day 90 were aggregated based on storage condition, irrespective of water type. This resulted in four treatment groups (one per storage condition). Each group consisted of observations drawn from the ten water brands, each with replicate measurements, yielding a total of 60 observations (15 observations per storage condition). The analysis was used to setup, with each IRE 1718899 ICONIC RESEARCH AND ENGINEERING JOURNALS 2367 © JUN 2026 | IRE Journals | Volume 9 Issue 12 | ISSN: 2456-8880 DOI: https://doi.org/10.64388/IREV9I12-1718899 the treated as concentrations determine whether microplastic differed significantly among storage conditions after prolonged exposure. For the two-way ANOVA, all observations obtained across four storage conditions and four storage durations were included the analysis. Storage condition and storage in fixed factors, while duration were the dependent microplastic concentration was variable. The model assessed the main effects of storage condition and storage duration, as well as their interaction effect. The error term was estimated from within-group variability across all replicate for each measurements treatment combination. Overall, factorial design generated 240 the observations for the two-way ANOVA, while the subset used for the one-way ANOVA at Day 90 comprised 60 observations. Data Analysis: Data were analyzed using Statistical Package for the Social Sciences (SPSS) Version 27 and Microsoft Excel. Descriptive statistics included: Mean, and deviation, Percentage.

  Assessment of Storage-Induced Microplastic Generation, Polymer Characteristics, and Human Exposure Risks in Bottled and Sachet Drinking Water Under Different Environmental Conditions in Port Harcourt, Nigeria · 2026 · DOI

• This study is limited by its regional dataset, relatively small number of images, and reliance on controlled imag- ing conditions, which may not fully reflect field com- plexity such as degraded plastics, heterogeneous debris, and variable illumination and may constrain scalability to environmental contexts. The reliance on IoU as the sole performance metric may also overlook perceptual accuracy in cases of partial segmentation. Finally, back- ground and mixed plastic categories exposed systematic weaknesses in both models, indicating unresolved issues in distinguishing plastics from organic matter. Potential biases in image segmentation, particularly in bound- ary detection, and the restricted set of models explored (manually annotated, Cellpose, and SAM) may also affect generalizability. In addition, manual polygon-based annotation in Roboflow was highly time-consuming, pos- ing challenges for scaling to larger datasets.

  Advancing marine microplastic monitoring through deep learning-based image segmentation · 2026 · DOI

• Future work should focus on hybrid frameworks that integrate segmentation with spectral or textural features to overcome the limitations of edge-based detection. Incorporating multi-modal imaging (e.g., hyperspectral, polarized light) could improve discrimination of translu- cent and flexible plastics. Integration with spectroscopy or physics-based reflectance models may help resolve ambiguities between plastics and organic matter, as has been suggested in recent cross-disciplinary approaches [4, 16]. Expanding training datasets with field-collected, degraded plastics, including samples from diverse envi- ronmental matrices incorporating in-situ variability and mixed samples will be critical for improving generaliz- ability. Finally, combining SAM with complementary AI models (e.g., YOLO for object detection, spectroscopy for chemical classification) may yield more scalable and ecologically meaningful monitoring pipelines under the One Health framework. Linking detection outputs with ecological risk and human health assessments will fur- ther enhance the model’s robustness and applicability for standardized monitoring and targeted mitigation strate- gies across broader environmental contexts; including freshwater systems, terrestrial soils, and atmospheric deposition pathways in addition to marine environments.

  Advancing marine microplastic monitoring through deep learning-based image segmentation · 2026 · DOI

• Plastic pollution is a widespread stressor in aquatic ecosystems. As summarized in Table 1 and Figure 1, plastics affect multiple components of energy balance in aquatic ectothermic vertebrates, including feeding, digestion, metabolism, and growth. Evidence is strongest for fish, whereas amphibians remain less studied and data for reptiles are largely limited to observational reports. Across taxa, plastic exposure often alters feeding processes, most often resulting in reduced food intake. This reduction is primarily linked to false satiety, gastrointestinal obstruction, and behavioral disruption. In fish, decreased feeding is associated not only with physical factors such as gut filling, but also with changes in neuroendocrine appetite regulation and sensory function, indi- cating centrally mediated responses. Amphibians show similar reductions in food intake, although current evidence is largely descriptive and does not address behavioral, sensory, or endocrine mechanisms. In reptiles, reduced feeding has mainly been linked with physical blockage of the gastrointestinal tract. Plastics also impair digestive function through structural and functional changes in the gastrointestinal system. In fish, exposure is associated with epithelial damage, inflammation, altered mucus production, and disruption of digestive enzyme activity and nutri- ent transport, indicating impaired gastrointestinal function that likely reduces nutrient absorption efficiency. Amphibians exhibit comparable histological alterations, suggesting reduced digestive capacity, although direct links to digestive function remain limited. In reptiles, available data are largely restricted to physical damage and obstruction, with little information on digestive physiology or nutrient processing. Disruption of the gut microbiota also occurs across groups. In fish, plastic exposure often reduces microbial diversity, alters community composition, and increases opportunistic pathogens while reducing beneficial taxa. In amphibians, responses are more TABLE 1 Summary of major effects of plastic in aquatic ectothermic vertebrates.

  Plastics as disruptors of feeding, digestive physiology, metabolism, and growth in fish and other aquatic ectothermic vertebrates · 2026 · DOI

• It is well known that the stacking of thylakoids and the lateral macro-organization of the pigment–protein complexes in the membrane are interrelated (reviewed by Musta´rdy and Garab 2003; Dekker and Boekema 2005) but dgd1 is poorly characterized in this respect.

  Microplastics in farmed and wild prawn (Macrobrachium rosenbergii) from aquatic environments in Bangladesh · 2026 · DOI

• This study advances understanding of MP contamination in commercial species and understudied environ- ments, providing an essential basis for future moni- toring programs, source identification, and integrated coastal management strategies aimed at mitigating ecological impacts and human health risks.

  Influence of biological, ecological, and anthropogenic factors on microplastic contamination in coastal fishes from Southeastern Brazil · 2026 · DOI

• Among reptiles, sea turtles display near-universal MP ingestion with documented maternal transfer to eggs; freshwater turtles, terrestrial squamates, and crocodilians remain critically understudied.

  Microplastic Contamination in Amphibians and Reptiles: An Ecotoxicological Synthesis of Exposure, Mechanisms, and Risk Implications · 2026 · DOI

• Chronic inhalation exposure to nanoplastics, specifically polyethylene terephthalate (PET) nanoplastics (PET-NPLs) is an emerging health concern, yet the long-term consequences for genomic stability and DNA damage response (DDR) capacity in bronchial epithelial cells remain poorly characterized.

  Long-Term PET-Nanoplastic Exposure Alters DNA Damage Response Capacity in BEAS-2B Human Bronchial Epithelial Cells · 2026 · DOI

• There is a growing consensus that MP identification should involve multiple measurement techniques, but statistically robust methods to relate multiple database matching scores are lacking.

  Improved Microplastic Identification from Simultaneously Collected Photothermal Infrared and Raman Spectra Using Multiview Conformal Prediction · 2026 · DOI

• Plastic pollution is ubiquitous in the environment, with microplastics (particles < 5 mm) a worldwide emergent contaminant of concern; however, no studies have explored historical patterns in freshwater macroinvertebrates in connection to species traits and changes in land use.

  Archived Historical Aquatic Macroinvertebrate Specimens Suggest Connections Between Microplastic Abundance Patterns, Trophic Traits, and Land Use · 2026 · DOI

• This study has several limitations which should be made explicit in interpreting the policy blueprint matrix. First, the matrix is grounded primarily in a single structured participatory policy co-creation workshop conducted in Accra, Ghana, in October 2024. Although the workshop brought together 57 participants from government, industry, civil society, research institutions, and the informal sector, the evidence base remains anchored in one national setting. The framework should therefore be understood as a Ghana-grounded policy prototype and organising framework rather than as a fully validated model applicable uniformly across all Global South contexts. Secondly, while the co-creation design sought to reduce bias through purposive cross-sector sampling, mixed-group deliberation, common discussion prompts, repeated comparison across groups, and plenary validation, the workshop-derived outputs may still reflect stakeholder positionalities, institutional priorities, and the practical constraints of a time- ARTICLE IN PRESS ARTICLE IN PRESS ACCEPTED MANUSCRIPT bounded participatory exercise. As such, the synthesis should not be read as a structured and policy-oriented consolidation of the priorities which surfaced through this particular co-creation process. Thirdly, the study does not provide longitudinal validation of implementation outcomes. Although the blueprint has since progressed to national-level acceptance in Ghana, this article does not evaluate implementation over time and does not yet test whether the proposed pillars generate measurable effects in practice across sectors or jurisdictions. The policy blueprint is therefore proposed rather than empirically validated through longitudinal policy tracking. These limitations do not negate the value of the blueprint, rather they define its present scope. They also point directly to priorities for future research, including comparative replication in additional Global South settings, further participatory refinement across different governance contexts, and longitudinal evaluation of implementation, feasibility, equity impacts, and reductions in dependence on single-use plastics.

  A policy blueprint for scaling plastic alternatives in Global South contexts · 2026 · DOI

• Within the scope of the study, an assessment was conducted to determine water quality and microplastic levels in the Balıkesir drinking water distribution network. The results obtained Research Article / Araştırma Makalesi Jeoloji Mühendisliği Dergisi 50 (1) 2026Journal of Geological Engineering 50 (1) 2026 70 indicate that there are no water quality issues at the sampled locations. Except for sampling point 1, various types of microplastics were detected at the other sampling points (2–3–4–5–6). In this context, it is recommended to enhance recycling practices that prevent plastics from entering water resources and to review measures about reducing the use of single-use plastics in order to mitigate the increase in microplastic pollution in water sources. Additionally, considering the growing pressure on water resources due to drought, it is advised to promote practices such as rainwater harvesting and to evaluate alternatives for the treatment, recovery, and reuse of wastewater.

  Sustainable Management of Water Resources in the Context of Water Quality: Balıkesir City Center Case Study · 2026 · DOI

• This study is subject to several limitations that should be considered when interpreting the results. First, although the Susurluk Basin extends over a large geographical area, the analysis was restricted to seven sampling points. These locations were selected because they are representative sites that are consistently used by the Balıkesir Metropolitan Municipality and the General Directorate of Balıkesir Water and Sewerage Administration (BASKİ) for routine water quality monitoring. Second, the assessment was based on a single sampling campaign conducted to evaluate the instantaneous condition of the water resources during the study period. As a result, temporal and seasonal variations in water quality were not examined. This limitation may constrain generalization of the findings with respect to long-term hydrological and hydrochemical dynamics in the basin.

  Sustainable Management of Water Resources in the Context of Water Quality: Balıkesir City Center Case Study · 2026 · DOI

• microbial influencing This review highlights the complex interactions among heavy metals, microplastics, and pesticides in soil environments. Microplastics play dual roles as both carriers and regulators of pollutant behavior, the migration, transformation, and bioavailability of coexisting remediation contaminants. Meanwhile, technologies offer promising solutions for mitigating composite pollution due to their versatility and sustainability. However, current research mainly focuses on single or binary pollutant systems, and studies on multi-pollutant interactions remain limited. Future research should prioritize: (i) elucidating the mechanisms of multi-pollutant interactions at molecular and microbial community levels; (ii) developing robust microbial consortia capable of functioning under complex environmental stress; and (iii) integrating microbial technologies with other remediation strategies for field-scale applications. Overall, advancing our understanding of composite pollution and developing efficient remediation strategies are 3 essential for ensuring soil health and sustainable agricultural development.

  Interactions among Heavy Metals, Microplastics and Pesticides in Soil and Advances in Microbial Remediation · 2026 · DOI

• This technical note represents preliminary exploratory observations and not formal analytical validation. Limitations include small donor count, decentralized uncontrolled storage conditions, absence of formal stability controls, qualitative morphology interpretation, and exploratory interaction-state analysis. Additional controlled longitudinal studies remain necessary.

  Optical Interaction Patterns in a Microplastics and Nanoplastics Urine Test: Cross-Donor Consistency of Aged Decentralized Human Urine Samples · 2026 · DOI

• While convective ultrafiltration could theoretically enhance the removal of selected low–molecular weight plastic- associated additives, the impact of dialysis modality on circulating MNP burden remains unknown.

  Micro- and nanoplastics and the kidney: human evidence, clinical vulnerabilities, dialysis-related exposure, and CKD · 2026 · DOI

Most-cited papers in Microplastics and Plastic Pollution

• Predicted growth in plastic waste exceeds efforts to mitigate plastic pollution · Science · 2020 · 2,752 citations
• The global threat from plastic pollution · Science · 2021 · 2,607 citations
• Pathways for degradation of plastic polymers floating in the marine environment · Environmental Science Processes & Impacts · 2015 · 1,553 citations
• Microplastics and Nanoplastics in Atheromas and Cardiovascular Events · New England Journal of Medicine · 2024 · 992 citations
• A theoretical assessment of microplastic transport in river catchments and their retention by soils and river sediments · Environmental Science Processes & Impacts · 2016 · 578 citations
• Designing a circular carbon and plastics economy for a sustainable future · Nature · 2024 · 432 citations
• The potential effects of microplastics on human health: What is known and what is unknown · AMBIO · 2021 · 396 citations
• The potential impact of nano- and microplastics on human health: Understanding human health risks. · Environmental Research · 2024 · 373 citations
• The Kidney-Related Effects of Polystyrene Microplastics on Human Kidney Proximal Tubular Epithelial Cells HK-2 and Male C57BL/6 Mice · Environmental Health Perspectives · 2021 · 326 citations
• Global projections of plastic use, end-of-life fate and potential changes in consumption, reduction, recycling and replacement with bioplastics to 2050 · Sustainable Production and Consumption · 2024 · 297 citations

Most recent work

• Low and steady: Minimal change in plastic exposure in Kermadec Petrels in the remote South Pacific · Marine Pollution Bulletin · 2026
• Nanoplastic Aggregation Driven by Environmental Components Reshapes Hormone Signaling and Energy Metabolism in <i>Lactuca sativa</i> · Journal of Agricultural and Food Chemistry · 2026
• Quorum Sensing-Based Long-Term Biodegradation of Polyethylene Terephthalate in Contaminated Soil by Engineered <i>Escherichia coli</i> and <i>Pseudomonas putida</i> · ACS Synthetic Biology · 2026
• Residential indoor airborne microplastics profiles: Levels, characterization, composition, and inhalation exposure assessment · Atmospheric Pollution Research · 2026
• Atmospheric warming contributions from airborne microplastics and nanoplastics · Nature Climate Change · 2026
• Different Weathering Strategies Result in Different Surface Properties and Adsorption Behavior in Aged Microplastics · Environmental Science & Technology · 2026
• Evolutionarily conserved mucus-mediated nanoplastic bioflocculation in Tetrahymena · Science China Life Sciences · 2026
• Trophic exposure to environmentally relevant concentrations of nanoplastics induces slight modulation of the antioxidant system in the estuarine bivalve Scrobicularia plana · Ecotoxicology and Environmental Safety · 2026
• Rapid quantification of fluorescent micro- and nanoplastics (≤2 μm) in soil · 2026
• Dark side of biodegradable microplastics in mangrove ecosystem: Plastisphere as an overlooked hotspot of sulfate-reducing metabolism · Water Research · 2026

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