The potential toxicity of microplastics on human health

An integrated evaluation of potentially toxic elements and microplastics in the highland soils of the northeastern Qinghai-Tibetan Plateau

As gateways to the scenic Qinghai-Tibetan Plateau (QTP), some underexplored five grassland (GLs) and three farmland (FLs) soil locations of northeastern counties were investigated. Preliminary detection showed that in the grazing and agricultural soils, elemental concentrations (Fe>Zn>Cr>Cu>Pb>Co>As>Cd) were up to 37 and 10 mg/g, but within the China soil standards, except Cd, while microplastics (MPs) abundances were 200-3640 and 280-973 particles/kg, respectively. Polypropylene (PP: 40-55 %) dominated in GLs mostly as fragments, whereas polyethylene (PE: 72-92 %) in FLs as films. Adsorption results demonstrated that potentially toxic elements (PTEs)-MPs' interaction may chiefly depend on their types and speciation in soils, the physiochemical structure of MPs, and surrounding conditions. The integrated two-dimensional risk assessment categorized three of five GLs under Risk Level VI (high pollution), whereas one of three FLs displayed Risk Level III (moderate pollution). Correlation analysis revealed that altitude, organic matter, soil clay content, and precipitation significantly affected PTEs (p ≤ 0.01), whereas MPs were influenced by altitude, soil clay content, precipitation (p ≤ 0.001), and population density (p ≤ 0.05). Comparison with low-land soils globally designated QTP as a vulnerable region to MPs due to the expanding development. Overall, our study provides a data set to understand the pollution scenario of highlands for its targeted management.

Eco-friendly lily bulb-derived polysaccharide aerogel for efficient microplastics and nanoplastics removal

Microplastics that eventually convert into nanoplastics are emerging global pollutants and the development of efficient adsorbents for their removal is urgently needed. For sustainability and eco-friendliness, in the current study, a polysaccharide aerogel (LPA) was prepared with lily bulbs as the raw material by following water bath extraction, purification and freeze-drying processes. The prepared porous LPA was then applied as a packing material in a mini adsorption column for removing polystyrene (PS) microplastics and nanoplastics. Results revealed that LPA was over 90 kDa in size and consisted mainly of glucomannan and the removal efficiencies for microplastics and nanoplastics were 93.68 % and 96.98 %, respectively, mainly due to hydrogen bonding interactions and porous structure. The adsorption column was robust and maintained a remarkable removal efficiency (over 90 %) for 3 months. In addition, the effects of other extraction methods and pre-freezing conditions before the freeze-drying process were studied. Compared with water bath extraction, ultrasonic-assisted extraction and microwave-assisted extraction transformed the LPA structure, resulting in reduced adsorption ability, while the pre-freezing temperature could be used to adjust the specific surface area. Meanwhile, the effects of temperature and pH of adsorbates were also investigated. The LPA was heat sensitive and not stable under strongly acidic (pH 4) or strongly alkaline (pH 10) conditions, resulting in a sharp decline in removal efficiency. The adsorption behaviour of LPA was further described via adsorption kinetic models, showing that the microplastics and nanoplastics adsorptions could be fitted by pseudo-second-order and pseudo-first-order models, respectively. Moreover, the adsorption performance of LPA was compared with some other aerogels and had a better result. This research provides a promising, sustainable alternative for microplastic and nanoplastic removal that has potential for pollutant adsorption and sample purification as well as a low preparation cost.

Mitigating microplastic-induced organ Damage: Mechanistic insights from the microplastic-macrophage axes

We live in a world increasingly dominated by plastic, leading to the generation of microplastic particles that pose significant global health concerns. Microplastics can enter the body via ingestion, inhalation, and direct contact, accumulating in various tissues and potentially causing harm. Despite this, the specific cellular mechanisms and signaling pathways involved remain poorly understood. Macrophages are essential in absorbing, distributing, and eliminating microplastics, playing a key role in the body's defense mechanisms. Recent evidence highlights oxidative stress signaling as a key pathway in microplastic-induced macrophage dysfunction. The accumulation of microplastics generates reactive oxygen species (ROS), disrupting normal macrophage functions and exacerbating inflammation and organ damage. This review serves as the first comprehensive examination of the interplay between microplastics, macrophages, and oxidative stress. It discusses how oxidative stress mediates macrophage responses to microplastics and explores the interactions with gut microbiota. Additionally, it reviews the organ damage resulting from alterations in macrophage function mediated by microplastics and offers a novel perspective on the defense, assessment, and treatment of microplastic-induced harm from the viewpoint of macrophages.

Microplastic exposure in daily life and the risk of pregnancy-induced hypertension: A study on the association between environmental pollutants and maternal-fetal health outcomes

Pregnancy-induced hypertension (PIH) is a significant threat to maternal and fetal health. Current prevention and treatment strategies for PIH are limited due to inadequate understanding of its etiology and risk factors. This study investigates the link between maternal microplastic (MP) exposure and PIH incidence, using questionnaires, umbilical cord sampling, microplastic detection, and statistical analysis to assess the impact of lifestyle factors on PIH risk. We found higher concentrations of polyethylene (PE) and polycarbonate (PC) in the umbilical cords of PIH patients (*P < 0.05). Total MP levels were 1.46 times higher in the PIH cases. Factors like plastic tableware, seafood intake, and plastic-packaged beverages were potential risk factors, but not independent in multivariate analysis (P > 0.05). MP exposure correlated with plastic containers and takeout meals (*P < 0.05) and was associated with increased neonatal mortality and lower Apgar scores (*P < 0.05). These findings suggest that MPs could be a potential chemical marker for PIH risk. However, the results should be interpreted with caution due to the limitations of sample size and methodology. In conclusion, our preliminary study highlights the link between maternal MP exposure and PIH incidence. Future research should explore MP exposure and long-term health effects to improve pregnancy management and reduce PIH incidence.

Polypropylene surgical mesh induces lipid oxidation in a nonhuman primate model

Polypropylene mesh is widely used in surgery to support weak connective tissue, but pain and exposure complications limit vaginal implantation for pelvic organ prolapse. The increased complication rate with vaginal implantation is incompletely understood. We sought to compare the host response to low vs high polypropylene mesh burden after vaginal or abdominal implantation in rhesus macaques. We hypothesized that in both sites an increased mesh burden would result in increased malondialdehyde (MDA; a marker of lipid oxidative damage), heightened macrophage response, and increased apoptosis. Gynemesh PS and Restorelle implanted on the anterior abdominal wall were compared to a nonhuman primate sacrocolpopexy vaginal implantation model with Restorelle, which was intentionally and successively deformed to produce low, high, and highest mesh burden groups. Abdominal Gynemesh showed more CD68+ macrophages than lower mesh burden vaginal groups but not the highest burden group. In abdominal mesh, apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labeling assay was limited to areas immediately surrounding mesh, while in deformed vaginal mesh, increased apoptosis was seen in the subepithelium. Macrophages and apoptotic cells were correlated at both sites and MDA was correlated with abdominal macrophages and vaginal apoptotic indices. Regardless of implantation site, macrophages, apoptotic indices, and MDA levels were strongly correlated with mesh burden. These data indicate that mesh burden is a main driver in the abdominal and vaginal mesh innate immune response and suggest a possible pathway through which prolonged inflammation contributes to tissue damage in mesh complications, namely through the immune cell production of reactive oxygen species or through stress-shielding. STATEMENT OF SIGNIFICANCE: When implanted on the vagina, polypropylene mesh is associated with a strong negative foreign body response that can result in mesh exposure into the vagina or other organs. The mechanistic pathway for mesh exposure is unknown. Here, we show that polypropylene mesh induced lipid oxidation, as measured by malondialdehyde, in both abdominal and vaginal mesh implants in a nonhuman primate model. Mesh burden was strongly correlated with macrophages, apoptotic indices, and MDA levels. Apoptosis in the subepithelium in deformed mesh samples may be a result of stress shielding or oxidative damage and may contribute to exposure complications. These data suggest a possible pathway through which prolonged inflammation surrounding a biomaterial implant results in tissue damage and implant exposure.

Inorganic Additives Induce More Small-Sized Microplastics Releasing from Medical Face Masks

Although previous studies have extensively explored the release of microplastics from masks, the specific influence of inorganic additives on microplastic emissions has remained unidentified. Herein, we performed a comparative analysis of medical face masks (MFMs) with calcium carbonate (CaCO3) additives against those devoid of CaCO3 to understand their roles in microplastic release. Briefly, our investigation employed surface-enhanced Raman spectroscopy (SERS) to examine micro- and nanoplastic release, while the stereoscopic characterization of mixing states of additives in microplastic was accomplished through a simulated Raman scattering (SRS). We also pioneered a three-dimensional imaging (3D imaging) method for investigating the internal aging of plastic using SRS, which clearly revealed the link between inorganic additives inside polymers and photoaging. We found that inorganic additives substantially accelerate the photoaging of the plastic materials through multiple pathways and induce more small-sized microplastics. Follow-up radical quenching experiments confirmed carbonate radicals as the main cause of this phenomenon. Our research exposes the hazardous potential of inorganic additives in masks to amplify the emission of microplastics.

Toward smart ocean monitoring: Real-time detection of marine litter using YOLOv12 in support of pollution mitigation

Marine litter has emerged as a pressing global environmental and public health crisis, posing severe threats to biodiversity, food security, and coastal economies. Effective large-scale monitoring and early detection are critical for mitigating marine pollution, yet current manual and sensor-based approaches are limited by high costs, low efficiency, and insufficient accuracy across diverse marine environments. This study presents a real-time marine litter detection framework based on the latest YOLOv12 algorithm to address these challenges. We developed a multi-class annotated dataset comprising 15 representative marine litter categories using both aerial and underwater imagery. The proposed model integrates attention-enhanced convolutional modules, multi-scale feature fusion, and Distribution Focal Loss to improve detection performance under complex oceanic conditions. Experimental results demonstrate that YOLOv12 achieves an mAP@50 of 0.8354 and mAP@50-95 of 0.7025, with robust performance in the presence of occlusion, reflections, small-object detection, and multi-object coexistence. Visual and quantitative evaluations confirm the model's potential for real-world deployment in autonomous platforms such as UAVs and underwater robots. This work offers a scalable and high-precision solution for marine litter monitoring, providing critical technical support for pollution mitigation, environmental governance, and sustainable ocean management.

Identification and analysis of microplastics in peritumoral and tumor tissues of colorectal cancer

The widespread occurrence of microplastics (MPs) in the environment has raised significant concerns regarding their potential health impacts, particularly in relation to carcinogenesis. This study aimed to identify and analyze microplastics present in peritumoral and tumor tissues of patients diagnosed with colorectal cancer (CRC). Utilizing advanced scanning electron microscopy (SEM) and laser direct infrared (LDIR) imaging systems, we systematically examined tissue samples to detect and characterize the microplastics. Our findings revealed a diverse array of microplastic types, notably polyvinyl chloride (PVC) and polyethylene (PE), within both peritumoral and tumor regions. Compared to adjacent non-cancerous tissues, tumor tissues exhibited a greater variety and distribution of microplastics. Furthermore, Clathrin-a key protein involved in endocytosis-was found to be highly expressed in colorectal cancer specimens, facilitating the substantial uptake of microplastics. These results suggest a potential association between exposure to microplastics and the pathogenesis of colorectal cancer. This study highlights the urgent need for increased awareness and regulatory measures aimed at mitigating microplastic pollution along with its associated health risks.

PVC nanoplastics impair cardiac function via lysosomal and mitochondrial dysfunction

MICRO: and nanoplastics (MNPs) are emerging environmental pollutants that pose a significant threat to human health, with traces found in cardiac tissues. While previous studies have indicated that MNPs can cantribute to cardiac dysfunction, there is limited systematic investigation into how MNPs exposure affects various organelles. This study focuses on polyvinyl chloride nanoparticles (PVC NPs), one of the most common and persistent plastic pollutants in the environment. Our findings reveal that PVC NPs engage in organelle-specific interactions, predominantly accumulating in the lysosomes and mitochondria of cardiomyocytes. This targeted accumulation results in substantial disruptions to lysosomal autophagic flux and mitochondrial energy metabolism. These results offer new insights into the organelle-specific mechanisms behind PVC NP-induced cardiotoxicity, highlighting the distinct risks associated with this widespread environmental contaminant.

Long-Term Exposure to Microplastics Promotes Early-Stage Hepatocarcinogenesis Induced by Diethylnitrosamine in Rats by Modulation of Their Gut Microbiota

Hepatocarcinogenesis is linked to environmental factors, with microplastics (MPs) emerging as a global environmental concern that may contribute to liver injury. However, the impact of MPs on the early stages of hepatocarcinogenesis has been largely ignored. Here we investigated the impact of long-term MP exposure on the formation of preneoplastic lesions during hepatocarcinogenesis induced by diethylnitrosamine (DEN) in rats. Rats were injected with DEN to induce preneoplastic lesions, and then they were orally administered with 1 µm MPs 0.5 mg/kg body weight per day for 20 weeks. The results revealed that long-term exposure to MPs did not induce the formation of glutathione S-transferase placental form (GST-P)-positive foci as preneoplastic lesions during hepatocarcinogenesis in these animals, thereby indicating non-carcinogenicity. However, MP exposure resulted in a 1-fold increase in both the number and size of GST-P-positive foci in rats initiated with DEN compared to those treated with DEN alone. Accordingly, MP exposure led to a 0.61-fold increase in the index of proliferating cell nuclear antigen (PCNA)-positive cells in DEN-initiated rats when compared to DEN treatment alone. In addition, the composition of the gut microbiota was significantly altered, accompanied by various levels of short-chain fatty acids. Our results suggest that long-term MP exposure can promote pre-neoplastic lesion formation in DEN-induced rats by increased cell proliferation as well as alterations in the gut microbiota and short-chain fatty acid levels. This highlights the potential health risks associated with hepatocarcinogenesis linked to long-term exposure to MPs.

Maternal co-exposure to Cd and PS-NPLs induces offspring ovarian inflammatory aging via promoting M1 macrophage polarization

With the growing crisis of plastic pollution, the severe environmental problem threatens human and ecosystem health. And nanoplastics can carry other environmental contaminants, thereby causing severe toxic effects. Cadmium (Cd), as a metal, has been widely concerned because of its long biological half-life, high toxicity and low excretion rate. Additionally, Cd as an endocrine disrupting chemical also has reproductive toxicity and genotoxicity. Studies have found that co-exposed to Cd and PS-NPLs complexes may lead to more severe adverse effects in aquatic and mammals. And the utilization of other non-essential heavy metals such as cadmium are increased due to iron deficiency anemia in women during pregnancy. Therefore, in our study, 8 week-old female C57BL/6 J mice were co-exposed to Cd and NPLs during pregnancy and lactation, and the offspring are raised to four weeks to explore and predict the potential effect on the development of offspring reproductive system by transcriptomics. The results showed that sex hormone levels were interfered in offspring female mice, and gut microbiota disorder and increased LPS levels originated from the mother, which activating TLR4-related signaling pathways, and promoting ovarian M1 macrophage polarization, thereby increasing the risk of ovarian inflammatory aging in female offspring.

Microplastics as benzo-a-pyrene carriers: genotoxicity assessment simulating human gastric digestion

Microplastic particles (MPs) are ubiquitous environmental pollutants that can remain in ecosystems for prolonged periods. Plastic materials undergo various degradation processes driven by chemical, physical, and biological factors that alter their size, shape, composition, and bioavailability. The gastrointestinal tract is the primary pathway through which MPs are absorbed, raising concerns as they can transport harmful pollutants and microorganisms into the body. Despite their widespread presence, the effects of exposure to MPs that vehicle environmental toxins are still not well understood. In this study, we rigorously simulated the photoaging processes of polystyrene MPs of two distinct sizes (1 µm and 5 µm) and confirmed their capacity to adsorb benzo[a]pyrene, a known carcinogen. Moreover, we explored the transport capabilities of these MPs and analyzed their genotoxic effects on liver cells under simulated gastric digestion conditions. Our findings reveal that MPs enriched with BaP release this toxic compound when ingested and exposed to gastric juices, markedly increasing their toxicity compared to the individual components. This research underscores the alarming potential of MPs to exacerbate risks associated with environmental pollutants in human health.

Comparative Analysis of Metabolic Dysfunctions Associated with Pristine and Aged Polyethylene Microplastic Exposure via the Liver-Gut Axis in Mice

The accumulation of plastic waste in the environment has raised widespread concern about the impact of microplastics (MPs) on human and environmental health, particularly regarding aged MPs. This study investigated the effects of subchronic dietary intake on pristine and aged polyethylene microplastics (PE-MPs) in C57BL/6J mice. Results revealed that both pristine and aged PE-MPs, at doses of 0.01 and 1 mg/day, induced plasma metabolic changes primarily associated with lipid metabolism and digestive processes. These alterations were reflected in the expression changes of proteins involved in unsaturated fatty acid pathways in the liver as well as a reduction in beneficial gut microbiota. Key contributors in the toxicity of aged PE-MPs included ATP-binding cassette transporters, gut bacteria alterations (notably Lactobacillus, Akkermansia, Parasutterella, and Turicibacter), and significantly altered proteins related to fatty acid elongation, such as acyl-CoA thioesterase enzyme family and elongation of very long chain fatty acid protein 5. These disruptions exacerbated lipid metabolism disorders, potentially contributing to metabolic diseases. Additionally, decreased levels of glutathione S-transferase A proteins, along with reduced hepatic glutathione and increased reactive oxygen species in both the small intestine and liver, suggested that aged PE-MPs aggravated hepatic and intestinal damage through oxidative stress. These findings indicated that aged PE-MPs caused more severe hepatic dysfunction and gut microbiota disruption. This effect was likely mediated by the transfer of fatty acids and signaling molecules through the gut-liver axis, ultimately leading to hepatic lipid metabolism disorders and oxidative stress.

Urinary microplastic contaminants in primary school children: Associations with behavioral development

Behavioral problems in children have been increasingly linked to environmental exposures. Microplastics (MPs), prevalent in urban environments, are emerging contaminants with potential neurodevelopmental effects. This study examines the relationship between urinary MPs and behavioral outcomes among primary school children in Shenyang, China. This study was conducted involving 1000 children aged 6-9 years from 40 schools across Shenyang. Urinary MPs, including polyamide (PA), polypropylene (PP), and polyvinyl chloride (PVC), were quantified using optical microscopy. Behavioral outcomes were assessed using the Strengths and Difficulties Questionnaire (SDQ). Mixed-effect negative binomial models evaluated associations between MPs and SDQ scores, adjusting for relevant covariates. The median urinary total microplastic concentration was 9 particles/100 mL. Increased particle counts of urinary MPs were positively associated with higher scores for emotional problems, conduct problems, hyperactivity, and peer problems. Total microplastic levels were linked to increased emotional symptoms (estimate: 0.128, 95 % CI: 0.065-0.198, p < 0.001), conduct problems (estimate: 0.231, 95 % CI: 0.140-0.323, p < 0.001), and hyperactivity (estimate: 0.168, 95 % CI: 0.101-0.235, p < 0.001). Peer relationship issues were also elevated with higher urinary microplastic levels (estimate: 0.206, 95 % CI: 0.133-0.271, p < 0.001). Conversely, prosocial behaviors declined with increased microplastic concentrations (estimate: -0.125, 95 % CI: -0.192 to -0.052, p = 0.001). Stratified analyses indicated no significant differences in these associations between boys and girls. Overall, urinary microplastic concentrations were significantly associated with adverse behavioral outcomes in children, highlighting the potential neurodevelopmental risks of microplastic exposure.

Assessing microplastic and nanoplastic contamination in bird lungs: evidence of ecological risks and bioindicator potential

Microplastics (MPs, 1 µm-5 mm) and nanoplastics (NPs, < 1 µm), collectively termed micro(nano)plastics (MNPs), are pervasive airborne pollutants with significant ecological risks. Birds, recognized as bioindicators, are particularly vulnerable to MNP exposure, yet the extent and risks of MNP pollution in bird lungs remain largely unexplored. This study assessed MP exposure in bird lungs of 51 species and NP exposure in the lungs of five representative species using laser direct infrared (LDIR) and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) techniques, respectively. The LDIR analysis revealed different degrees of MP contamination in bird lungs, with an average abundance of 221.20 items per species and 416.22 MP particles per gram of lung. Among 32 identified MP types, chlorinated polyethylene (CPE) and butadiene rubber (BR) predominated, with particles primarily in film and pellet forms, concentrated in the 20-50 μm size range. The polymer hazard index (PHI) indicated elevated ecological risks (levels Ⅲ or Ⅳ) in most bird lungs. Py-GC-MS detected nylon 66 (PA66), polyvinyl chloride (PVC), and polypropylene (PP) NPs at varying concentrations. Terrestrial, carnivorous, and larger-bodied birds exhibited higher MNP burdens. This study provides the first evidence of MNP contamination in bird lungs, highlighting their potential as bioindicators of airborne MNP pollution.

In vivo and In vitro assessment of the retinal toxicity of polystyrene nanoplastics

Plastic pollution has emerged as a critical global environmental challenge, yet the effects of the ingested plastic particles on ocular health remain largely unexplored. In this study, we investigated the impact of orally ingested polystyrene nanoplastics (PS-NPs) on the mouse retina. The in vivo experimental results showed that PS-NPs could penetrate the mouse retina within 2 h after gavage. Their levels increased at 4 h and remained detectable up to 24 h post-gavage. Prolonged exposure (28 days) to PS-NPs might disrupt the tight junctions of the inner blood-retinal barrier (iBRB). Moreover, PS-NPs induced oxidative stress in the retina by downregulating the expression of Nrf2 and HO-1, and potentially promoted apoptosis via the upregulation of Cleaved caspase 3. Additionally, we used human retinal microvascular endothelial cells (HRMECs) to model the iBRB and employed a human retinal pigment epithelial cell line (ARPE-19) to assess the potential toxicity of PS-NPs on the human retina. Our results indicated that PS-NPs penetrated and disrupted the simulated iBRB, inducing oxidative stress and promoting apoptosis in ARPE-19 cells. This study provides critical insights into the potential risks of ingested PS-NPs to retinal health and offers novel perspectives on the broader implications of plastic pollution for humans.

Ecological and Health Risk Mediated by Micro(nano)plastics Aging Process: Perspectives and Challenges

Aged micro(nano)plastics (MNPs) are normally the ultimate state of plastics in the environment after aging. The changes in the physical and chemical characteristics of aged MNPs significantly influence their environmental behavior by releasing additives, forming byproducts, and adsorbing contaminants. However, a systematic review is lacking on the effects of aged MNPs on ecological and human health regarding the increasing but scattered studies and results. This Review first summarizes the unique characteristics of aged MNPs and methods for quantifying their aging degree. Then we focused on the potential impacts on organisms, ecosystems, and human health, including the "Trojan horse" under real environmental conditions. Through combining meta-analysis and analytic hierarchy process (AHP) model, we demonstrated that, compared to virgin MNPs, aged MNPs would result in biomass decrease and oxidative stress increase on organisms and lead to total N/P decrease and greenhouse gas emissions increase on ecosystems while causing cell apoptosis, antioxidant system reaction, and inflammation in human health. Within the framework of ecological and human health risk assessment, we used the risk quotient (RQ) and physiologically based pharmacokinetic (PBK) models as examples to illustrate the importance of considering aging characteristics and the degree of MNPs in the process of data acquisition, model building, and formula evaluation. Given the ecological and health risks of aged MNPs, our urgent call for more studies of aged MNPs is to understand the potential hazards of MNPs in real-world environments.

Effects of microplastics on chemo-resistance and tumorigenesis of colorectal cancer

Microplastics (MPs) are widely distributed environmental pollutants around the world. Although studies have demonstrated that MPs have adverse effects on human health, the relationship between MPs and tumors remains unclear. The gut is the main site of microplastics absorption, and the function of MPs in the chemoresistance and progression of colorectal cancer (CRC) needs more investigation. Here, we show that MPs exist in human CRC tissues for the first time by using a laser direct infrared chemical imaging system. MPs can cause an increase in CRC incidence in animal models and promote resistance to oxaliplatin. It is illustrated that the uptake of MPs enhances levels of autophagy by activating the mTOR pathway. MPs can also promote the disorder of intestinal flora and intestinal inflammation, serving as an essential component in the onset and advancement of CRC. These results indicated that microplastic pollutants in colorectal cancer could mediate protective autophagy through the mTOR/ULK1 axis, which is one of the new reasons for chemo-resistance in CRC under the background of increasingly serious microplastics pollution. This study identified the adverse effects of MPs on colorectal cancer progression and chemotherapy prognosis, and attempted to block the intake of MPs to propose a novel approach for clinical precision treatment.

Spatial mapping and risk assessment of microplastic contamination in drinking water catchments from north of the Persian Gulf

Microplastics (MPs) are emerging contaminants in drinking water that raise global concerns due to their health risks and long-term environmental persistence. These tiny plastic particles can accumulate within human bodies and ecosystems, making it essential to understand their presence and behavior in water sources, especially in drinking water. In Khuzestan Province, which is of strategic importance in the Gulf region. This study assesses the concentration and types of MPs entering and leaving these 11 treatment plants. In untreated water, particle size analysis revealed that 50% of MPs were measured under 101 µm, with fibers being the most common type (47%), followed by fragments and pellets. Although treatment processes reduced overall MP concentrations, fibers remained the dominant residual type, making up 71% of the MPs in treated water. The main polymers identified were polyethylene (PE) and polypropylene (PP), with PE accounting for up to 75% of MPs in some areas. In terms of color, black/gray MPs were most prevalent (45%), followed by blue, red/pink, yellow/orange, and white/clear particles. While most treatment plants achieved significant reductions in MP levels, some were less effective, likely due to differences in treatment technologies. Notably, the S10 plant in Bandar Mahshahr had especially high inlet MP levels, possibly due to the region's high industrial and human activities. Estimated daily intake (EDI) for adults was approximately 0.00482 MPs per kg of body weight per day, with children having a higher intake of around 0.01866 MPs per kg per day. These findings highlight the need to enhance treatment technologies, control upstream MP sources, and establish routine monitoring to protect water quality in Khuzestan and the wider Gulf region.

Environmental Pollutants, Occupational Exposures, and Liver Disease

Environmental pollutants significantly impact liver disease development, progression, and outcomes. This review examines the complex relationship between environmental exposures and liver pathology, from malignant conditions like hepatocellular carcinoma to steatotic and cholestatic liver diseases. Key environmental factors include air pollutants, volatile organic compounds, persistent organic pollutants, heavy metals, and per- and polyfluoroalkyl substances. These compounds can act through multiple mechanisms, including endocrine disruption, metabolic perturbation, oxidative stress, and direct hepatotoxicity. The impact of these exposures is often modified by factors such as sex, diet, and genetic predisposition. Recent research has revealed that even low-level exposures to certain chemicals can significantly affect liver health, particularly when combined with other risk factors. The emergence of exposomics as a research tool promises to enhance our understanding of how environmental factors influence liver disease. Importantly, exposure effects can vary by demographic and socioeconomic factors, highlighting environmental justice concerns. Implementation of this knowledge in clinical practice requires new diagnostic approaches, healthcare system adaptations, and increased awareness among medical professionals. In conclusion, this review provides a comprehensive examination of current evidence linking environmental exposures to liver disease and discusses implications for clinical practice and public health policy.

Targeted activation of ErbB4 receptor ameliorates neuronal deficits and neuroinflammation in a food-borne polystyrene microplastic exposed mouse model

The impact of polystyrene microplastics (PS-MPs) on the nervous system has been documented in the literature. Numerous studies have demonstrated that the activation of the epidermal growth factor receptor 4 (ErbB4) is crucial in neuronal injury and regeneration processes. This study investigated the role of targeted activation of ErbB4 receptor through a small molecule agonist, 4-bromo-1-hydroxy-2-naphthoic acid (C11H7BrO3, E4A), in mitigating PS-MPs-induced neuronal injury. The findings revealed that targeted activation of ErbB4 receptor significantly ameliorated cognitive behavioral deficits in mice exposed to PS-MPs. Furthermore, E4A treatment upregulated the expression of dedicator of cytokinesis 3 (DOCK3) and Sirtuin 3 (SIRT3) and mitigated mitochondrial and synaptic dysfunction within the hippocampus of PS-MPs-exposed mice. E4A also diminished the activation of the TLR4-NF-κB-NLRP3 signaling pathway, consequently reducing neuroinflammation. In vitro experiments demonstrated that E4A partially alleviated PS-MPs-induced hippocampal neuronal injury and its effects on microglial inflammation. In conclusion, the findings of this study indicate that targeted activation of ErbB4 receptor may mitigate neuronal damage and subsequent neuroinflammation, thereby alleviating hippocampal neuronal injury induced by PS-MPs exposure and ameliorating cognitive dysfunction. These results offer valuable insights for the development of potential therapeutic strategies.

Morphological and chemical analysis of indoor airborne microplastics: implications for human health in Ahvaz, Iran

Airborne microplastics (AMPs) present significant health risks indoors due to prolonged exposure. This study evaluates AMP concentration, types, and health impacts in residential, office, and commercial settings in Ahvaz, Iran, during winter and summer. The annual inhaled AMP dose was calculated based on typical occupancy patterns. AMP particles were collected from 30 locations using active sampling at 5 L/min for 8 h. Raman spectroscopy identified polymers, and SEM-EDX analysis examined surface morphology and elemental composition. The inhaled dose was estimated using MP concentrations and typical indoor exposure times. The highest AMP concentrations were in offices during winter (up to 48 MPs/m3), moderate in residential areas, and lowest in commercial settings. Predominant AMPs were spherules (67.2% in winter, 69.3% in summer), with black/gray particles being most common. Smaller particles (< 250 µm) were more frequent in summer. Identified polymers included polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). The estimated annual inhaled AMP dose was 2,952 MPs/kg/year, mainly from residential, followed by offices and commercial spaces. Results underscore the need for policies to reduce indoor AMP pollution, improve ventilation, and manage exposure risks, especially in high-occupancy areas like offices. Future research should focus on advanced chemical analyses and size-specific dose assessments to better evaluate health risks from inhaled microplastics.

Polydopamine-modified sodium alginate hydrogel for microplastics removal: Adsorption performance, characteristics, and kinetics

The potential health hazards of micro/nanoplastics in food have become a significant concern. This study developed a Polydopamine-modified sodium alginate hydrogel (PMSAH) for removing microplastics in daily drinking water. The hydrogel's performance, characteristics, and kinetics for microplastic removal were systematically evaluated. Results demonstrated that the incorporation of polydopamine reduced the hydrogel's surface zeta potential and increased its adsorption capacity for microplastics. PMSAH5 exhibited the highest removal efficiency, reaching approximately 99.6 %. Additionally, polydopamine-modified sodium alginate hydrogel exhibited higher elasticity and thermal stability. The hydrogel successfully adsorbed microplastics, regardless of their size and surface charge. This adsorption was driven by the combined action of multiple forces, resulting in multilayer adsorption. The unique advantages of polydopamine-mediated multi-molecular interactions present a promising and environmentally friendly approach for effective removal of microplastics in daily drinking water.

Investigation of potential toxic effects of nano- and microplastics on human endometrial stromal cells

Nanoplastics (NPs) and microplastics (MPs) have become a global concern in recent years. Most current research on the impact of plastics on obstetrics has focused on their accumulation in specific tissues in animal models and the disease-causing potential of MPs. However, there is a relative lack of research on the cellular changes caused by the accumulation of MPs. In this study, we aimed to establish a proper in vitro exposure protocol for polystyrene (PS)-NPs and MPs and to investigate possible cytotoxic effects of PS-NPs and MPs on human endometrial stromal cells (ESCs) using different plastic sizes and concentrations. The results showed that smaller plastics, specifically 100 nm PS-NPs and 1 μm PS-MPs, had a higher cellular uptake propensity than larger particles, such as 5 μm PS-MPs, with significant morphological changes and cell death observed at concentrations above 100 μg/mL a 24-h period. In addition, confocal microscopy and real-time imaging confirmed the accumulation of these particles in the nucleus and cytoplasm, with internalization rates correlating with particle size. Also, 100 nm PS-NPs reduced cell proliferation and induced apoptosis. In conclusion, this study demonstrates that exposure to 100 nm PS-NPs and 1 μm PS-MPs leads to dynamic accumulation in ESCs, resulting in cell death or decreased proliferation at specific concentrations, which highlights the potential cellular toxicity of NPs or MPs.

Degradation of floor finishing materials owing to continuous gait: A comprehensive study on the generation and impact of microplastics

With the increasing concern regarding the effects of microplastics (MPs) on human health, it is essential to conduct research on the MPs generated in the atmosphere and on those occurring in indoor environments. One of the causes of particle generation in indoor spaces is the degradation of floor finishing materials, including human gait factor. Therefore, gait simulation experiments were conducted to verify the occurrence of MPs during the gait process. After the experiments, the concentrations of MPs were calculated, and the differences in the concentrations under various gait and floor finishing material conditions were analyzed. Moreover, the morphological analysis of MPs indicates the mechanisms of MPs generation. Additionally, a chemical bond analysis of MPs and surface analysis of floor finishing materials demonstrated the types and sources of MPs generation. Furthermore, the health risk assessment results showed that the health effect of MPs was the lowest in the case of marmoleum flooring, approximately 1.27 and 5.77 times lower than that of laminate flooring and carpet tiles, respectively. Consequently, the study demonstrated that MPs are generated owing to the surface degradation caused by gait and also provided insights into which floor finishing material is least affected by MPs.

Using Insect Larvae and Their Microbiota for Plastic Degradation

Plastic pollution is one of the biggest current global threats to the environment given that petroleum-based plastic is recalcitrant and can stay in the environment for decades, even centuries, depending on the specific plastic type. Since less than 10% of all plastic made is recycled, and the other solutions (such as incineration or landfill storage) are pollutant methods, new, environmentally friendly solutions are needed. In this regard, the latest biotechnological discovery on this topic is the capability of insect larvae to use plastic polymers as carbon feedstock. This present review describes the most relevant information on the insect larvae capable of degrading plastic, mainly Galleria mellonella (Fabricius, 1798), Tenebrio molitor (Linnaeus, 1758), and Zophobas atratus (Fabricius, 1776), and also adds new information about other less commonly studied "plastivore" insects such as termites. This review covers the literature from the very first work describing plastic degradation by larvae published in 2014 all the way to the very latest research available (till June 2024), focusing on the identification of a wide variety of plastic-degrading microorganisms isolated from larvae guts and on the understanding of the potential molecular mechanisms present for degradation to take place. It also describes the latest discoveries, which include the identification of novel enzymes from waxworm saliva.

The Effects of Microplastics on Musculoskeletal Disorder; A Narrative Review

PURPOSE OF REVIEW

The physical health impacts of microplastics have received increasing attention in recent years. However, limited data impedes a full understanding of the internal exposure to microplastics, especially concerning the musculoskeletal system. The purpose of this review is to summarize the recent literature regarding the effects of microplastics on the musculoskeletal system.

RECENT FINDINGS

Microplastics have been shown to cause abnormal endochondral ossification and disrupt the normal function of pre-osteoblasts, osteocyte-like cells, and pre-osteoclasts through gene mutations, endoplasmic reticulum stress induction, and reduced autophagosome formation in bone growth areas. Although there are few reports on their effects on muscle, it has been noted that microplastics inhibit energy and lipid metabolism, decrease type I muscle fiber density, impair muscle angiogenesis, cause muscle atrophy, and increase lipid deposition. Only a few recent studies have shown that microplastics interfere with the normal function of bone growth-related cells and reduce muscle mass and quality. This review underscores the need for further research into other parts of the musculoskeletal system and studies using human tissues at the disease level.

Physicochemical behavior and ecological risk of biofilm-mediated microplastics in aquatic environments

The prevalence of microplastics (MPs) in aquatic environments has become the core of environmental pollution. In recent years, the inevitable biological aging process of MPs in natural environments has attracted researchers' attention. Such biofilm-mediated MPs, colonized by microorganisms, affect the physicochemical behavior and potential ecological risks of MPs. Therefore, it is critical to understand the impact of MPs' biofilm formation on the environmental fate and toxicity of MPs. This review presented a comprehensive discussion of the impact of biofilm formation on unique carrier effects and toxicological effects of MPs in aquatic environments. First, the biofilm formation process on MPs, the compositions of microorganisms in biofilm and the factors influencing biofilm formation were briefly summarized. Second, the sorption of pollutants and enrichment of antibiotic resistance genes onto biofilm-mediated MPs were discussed. Third, the potential effects of biofilm-mediated MPs on gut microbiota were analyzed. Finally, gaps in the field that require further investigations were put forward. This review emphasized that biofilm-mediated MPs have higher environmental risks and ecotoxicity, which is helpful in providing new insights for pollution prevention and control of new pollutant MPs.

Microplastic exposure induces HSP90α secretion and aggravates asthmatic airway remodeling via PI3K-Akt-mTOR pathway

Microplastics pollution has raised a considerable awareness due to their extensive distribution in the environment. It has potential side effects on human health. Microplastics can enter the human respiratory system, then deposit in the lung, destroying the structure of the bronchus and alveoli, and causing pulmonary inflammation, mucus production, and airway hyperresponsiveness, leading to the aggravation of asthma. Nevertheless, the underlying mechanism remains elusive. There are several cytokines involved in the inflammatory response of asthma. Heat shock protein 90α(HSP90α) is one of cytokines involving in inflammation which is a member of the HSPs family. The aim of this study is to explore the mechanism by which microplastics influence the secretion of HSP90α and the progression of asthma. Initially, we found that microplastics were destroyed airway epithelial barrier, resulting in inherent dysfunction in the secretion of HSP90α. Then, microplastics were proved to activate PI3K-Akt-mTOR pathway by prompting airway epithelial cells secrete HSP90α and proliferation of airway smooth muscle cells(ASMCs), leading to airway narrowing and hypersensitivity. 1G6-D7 is a monoclonal antibody to HSP90, which can reverse the pulmonary inflammation infiltration, mucus production, and airway hyperresponsiveness(AHR). Overall, these finding suggested that microplastics elicited inflammation via the PI3K-Akt-mTOR signaling pathway and stimulated the proliferation of ASMCs. Hence, the present study unveils a novel mechanism responsible for microplastic-induced inflammation and airway hyperreactivity, establishing a basis for further research and risk evaluations of microplastics.

Microplastics in human skeletal tissues: Presence, distribution and health implications

Although microplastics have been detected in human blood, placenta and other tissues. In this study, for the first time, we characterized the presence and variation of microplastic deposition patterns in three human skeletal tissues, namely the bone, cartilage, and intervertebral discs. Forty microplastic fragments were observed in 24 samples from the bone, cartilage, and intervertebral disc, ranging from 25.44 to 407.39 μm in diameter. The deposition abundance of microplastics in the human intervertebral disc (61.1 ± 44.2 particles/g) was higher than those in the bone (22.9 ± 15.7 particles/g) and cartilage tissue (26.4 ± 17.6 particles/g). The average sizes of microplastics in intervertebral discs (159.5 ± 103.8 μm) and bone (138.86 ± 105.67 μm) were larger than that in the cartilage tissue (87.5 ± 30.7 μm). The most frequently identified polymers were polypropylene (35 %), ethylene vinyl acetate copolymer (30 %), and polystyrene (20 %). The in vivo experiment suggested that microplastics invaded the bone, cartilage, and intervertebral discs through blood circulation after 4 weeks of exposure. Serum levels of tumor necrosis factor-α (TNF-α), Type Ⅰ procollagen amino-terminal peptide (PINP), and tartrate-resistant acid phosphatase-5b (TRACP-5b) were elevated compared with those in the control group (p < 0.05). Our study suggests that microplastics invade the bone, cartilage, and intervertebral discs through the blood supply, causing distinct patterns of microplastic accumulation in these regions. Microplastic invasion can affect skeletal health by influencing the expression of inflammatory and bone morphogenetic cytokines. These findings provide insights into investigating the impact of microplastics on human skeletal health.

The micro(nano)plastics perspective: exploring cancer development and therapy

Microplastics, as an emerging environmental pollutant, have received widespread attention for their potential impact on ecosystems and human health. Microplastics are defined as plastic particles less than 5 millimeters in diameter and can be categorized as primary and secondary microplastics. Primary microplastics usually originate directly from industrial production, while secondary microplastics are formed by the degradation of larger plastic items. Microplastics are capable of triggering cytotoxicity and chronic inflammation, and may promote cancer through mechanisms such as pro-inflammatory responses, oxidative stress and endocrine disruption. In addition, improved microplastics bring new perspectives to cancer therapy, and studies of microplastics as drug carriers are underway, showing potential for high targeting and bioavailability. Although current studies suggest an association between microplastics and certain cancers (e.g., lung, liver, and breast cancers), the long-term effects and specific mechanisms still need to be studied. This review aimed at exploring the carcinogenicity of microplastics and their promising applications in cancer therapy provides important directions for future research and emphasizes the need for multidisciplinary collaboration to address this global health challenge.

N6-methyladenosine RNA methylation regulates microplastics-induced cell senescence in the rainbow trout liver

Microplastics are prevalent in aquatic ecosystems, impacting various forms of aquatic life, including fish. In this study, Rainbow trout (Oncorhynchus mykiss) were exposed to two concentrations of microplastics (0 and 500 μg/L) over a 14-day period, during which a comprehensive analysis was conducted to assess the liver accumulation of microplastics and their effects on oxidative stress, the liver response, and transcriptomics. Our findings indicated that microplastics significantly accumulated in the liver and activated the antioxidant system in fish by enhancing the activity of antioxidant enzymes. Histological lesions were also observed in the liver of the fish. Furthermore, microplastics induced alterations in the expression of hepatic N6-methyladenosine readers, specifically downregulating IGF2BP1 (encoding insulin like growth factor 2 mRNA binding protein 1) and upregulating YTHDF2 (encoding YTH N6-methyladenosine RNA binding protein F2), which in turn decreased mRNA stability and reduced the expression of C-myc and other regulatory factors involved in the cell cycle and proliferation. This sequence of events resulted in slowed cell proliferation, the induction of cell cycle arrest, and the promotion of cellular senescence. This study offers valuable insights into the toxicological mechanisms of microplastics and enhances our understanding of the threats that plastic pollution poses to freshwater organisms.

Association between microplastics and the functionalities of human gut microbiome

As an integral part of humans, the gut microbiome plays a significant role in the physiological and pathological processes of the host, and dysbiosis of the gut microbiome is linked to various diseases. The impact of microplastics on the diversity and composition of human gut microbiome has been reported previously. However, effects of microplastics on the functionality of the gut microbiome in humans have not been well studied. In the present study, concentrations of microplastics in human blood were detected through pyrolysis-gas chromatography/mass spectrometry in 39 adults. Five types of microplastics were found in human blood, including polyvinyl chloride, polyethylene, polypropylene, polystyrene, and polyamide 66. Shotgun metagenomic sequencing was further employed to analyze the metagenomes of the human stool samples and fecal samples from mice exposed to microplastics. Associations were found between microplastics and microbial species, as well as microbial genes encoding invasion-related virulence factors, quorum sensing, autoinducer and transporter system, and microplastic biodegradation enzymes. The findings are of significance to improve the understanding of functional changes in the gut microbiome associated with microplastic exposure, as well as raising awareness regarding the health risks of microplastics in the human population.

Microplastic in bivalves of an urbanized Brazilian estuary: Human modification, population density and vegetation influence

Microplastics (MPs) global ubiquitously affects particularly coastal regions under significant anthropogenic pressures, where there are limited monitoring efforts. Bivalves are valuable sentinels of MPs contamination. This investigation determined MP contamination in oysters, clams, and mussels at Santos-São Vicente, a heavily urbanized estuary in Brazil, focusing on socio-environmental predictors, spatial distribution, and interspecies variations. Elevated MPs levels were linked to higher human modification (β = 0.5747, p = 0.0223) and reduced population density (β = -8.918e-06, p = 0.0443), regardless of vegetation cover (p > 0.05). Such a negative connection between population density and MP contamination occurred due to the significant presence of industrial and port activities, leading to high MP discharges despite a low population. The simultaneous presence of the three species at specific sites is an intrinsic limitation for broad spatial studies, depending on their environmental availability. Despite higher concentrations in clams, mussels and oysters also exhibited spatial variations in MP concentrations, serving as suitable sentinels. The central and left segments of the estuary displayed elevated MP concentrations, consistent with a well-known contamination gradient. Clams accumulated more MPs (1.97 ± 1.37 [0.00 - 5.55] particles.g-1) than mussels (0.72 ± 1.07 [0.00 - 7.74] particles.g-1) and oysters (0.70 ± 1.03 [0.00 - 7.70] particles.g-1), suggesting higher bioavailability in sediments than the water column. MPs found across all species were predominantly smaller (<1000 µm), fragments or fibers, and colorless. These discoveries lay a groundwork for prospective global investigations by linking MPs concentrations to socio-environmental predictors, contributing to the development of local mitigation measures and global discussions.

Microplastics accumulated in breast cancer patients lead to mitophagy via ANXA2-mediated endocytosis and IL-17 signaling pathway

Breast cancer (BC) is the most common malignancy in women and the leading cause of cancer death. Microplastics (MPs) are plastic fragments with a diameter of less than 5 mm, easily ingested by organisms. Although MPs have been reported to enter the human body through diet, surgery, etc., whether MPs accumulate in BC and their effects have been largely unknown. Our study revealed a significant accumulation of MPs in BC patient samples. MPs pull-down experiments and mass spectrometry (MS) studies showed that MPs bound to annexin A2 (ANXA2) and were endocytosed into cells. This process resulted in mitochondrial damage and subsequent induction of mitophagy. Furthermore, after binding to ANXA2, MPs regulated mitophagy by inhibiting IL-17 exocytosis. These findings revealed the mechanism of toxic effects of MPs in patients with BC, clarified the molecular mechanism of ANXA2-IL-17 signaling pathway causing mitochondrial damage by MPs, and suggested the potential toxic effects and toxicological mechanisms of MPs.

Emission characteristics analysis on microplastics by inorganic sludge discharged from recycling processes of agricultural waste vinyl in Korea

Globally, various policies are being implemented to phase out plastic, and South Korea has set targets to reduce waste and increase recycling rates by 2030. Concerns about managing microplastic pollution are growing. Most advanced research has primarily focused on aquatic ecosystems. This has left a gap in data on residues in sludge generated from agricultural waste recycling processes. Therefore, environmental analysis (leaching tests, heavy metal and microplastics content, etc.) was carried out using the inorganic sludge discharged from the agricultural waste recycling process to establish national data for various environmental analyses in this study. Specifically, inorganic sludge was selected as a sample from the agricultural waste recycling process since it would be recycled as a filling or covering material in agricultural soil. Therefore, this study analyzed and assessed the content of harmful substances and microplastics in the inorganic sludge generated from agricultural waste recycling processes. As a result, it was revealed the detection of unregulated items such as Al (leaching: 1.54 mg/L, content: 23,870 mg/kg), Fe (leaching: 0.48 mg/L, content: 27,453 mg/kg), and Mn (leaching: 0.06 mg/L, content: 649 mg/kg). Among regulated items, Cu (35.96 mg/kg), Ni (8.77 mg/kg), Pb (6.47 mg/kg), and Zn (178.39 mg/kg) were detected within the legal concentration limits. As for microplastics, the number (1814 particles) and mass (446.54 μg/g) were detected. However, the impact of microplastics is not identified clearly yet. Therefore, if the study results and subsequent accumulation of data by expanding the research target waste can be utilized, it is expected that this could serve as fundamental data for establishing policies or legislation for microplastic management systems.

A particle of concern: explored and proposed underlying mechanisms of microplastic-induced lung damage and pulmonary fibrosis

PURPOSE

In the past decade, microplastics (MPs) have drawn significant attention as widespread environmental contaminants, with research increasingly highlighting their harmful effects on respiratory health in aquatic and terrestrial organisms. Findings revealed microplastics in human lung tissues, raising concerns about their potential role in damaging lung tissue integrity and contributing to pulmonary fibrosis-a chronic inflammatory condition characterized by scarring of lung epithelial tissues due to accumulated extracellular matrix, triggered by factors such as alcohol, pathogens, genetic mutations, and environmental pollutants.

OBJECTIVE

In this review, we explore both well-studied and lesser-studied mechanisms and signaling pathways, aiming to shed light on how microplastics might act as mediators that activate distinct, often overlooked signaling cascades.

MATERIALS AND METHODS

This review searched PubMed and Google Scholar using keywords like "plastic," "microplastic," "lung fibrosis," "pulmonary system," "exposure route," and "signaling pathways," combined with "OR" and "AND" in singular and plural forms.

RESULTS

These pathways could not only induce lung damage but also play a significant role in the development of pulmonary fibrosis.

DISCUSSION AND CONCLUSIONS

These signaling pathways could also be targeted to reduce microplastic-induced pulmonary fibrosis, opening new avenues for future treatments.

The Effects of Nanoplastics on the Dopamine System of Cerebrocortical Neurons

Nanoplastics (NPx) can enter living organisms, including humans, through ecosystems, inhalation, and dermal contact and can be found from the intestine to the brain. However, it is unclear whether NPx accumulates and affects the dopamine system. In this study, we investigated the effects of NPx on the dopamine system in cultured murine cerebral cortex neurons. Cultured cerebrocortical neurons were treated with 100 nm NPx at the following concentrations for 24 h: 1.896 × 105, 3.791 × 106, 7.583 × 107, 1.571 × 109, 3.033 × 1010, and 3.033 × 1011 particles/mL. Dopamine-associated proteins were analyzed using immunofluorescence staining. NPx treatment induced its accumulation in neurons in a dose-dependent manner and increased the levels of dopamine receptors D1 and D2 and their co-expression. However, NPx treatment did not affect the levels of other dopamine receptors, dopamine transporters, tyrosine hydroxylase, and microtubule-associated protein 2, or synaptophysin in neuronal structures. This study demonstrated that NPx is a potential modulator of the dopamine system via its receptors rather than its synthesis and reuptake in neurons and may be associated with dopamine-based psychiatric disorders.

Polystyrene nanoplastics promote colitis-associated cancer by disrupting lipid metabolism and inducing DNA damage

Nanoplastics (NPs) have attracted widespread attention owing to their presence in the body. Recent studies highlighted the detrimental effects of NPs on the digestive tract. However, no studies have reported an association between NPs exposure and colitis-associated cancer (CAC). An azoxymethane/dextran sodium sulfate-induced CAC model was used, and polystyrene nanoparticles (PS-NPs) were selected for long-term exposure. Non-targeted metabolomics and 16S rRNA sequencing were used to detect changes in colonic metabolites and gut microbes following PS-NPs exposure. A lipopolysaccharide (LPS)-treated cancer cell model (Caco-2) exposed to PS-NPs was used to investigate the underlying molecular mechanism. Compared to the normal control group, mice in the PS-NPs group exhibited more tumor nodes and reactive oxygen species (ROS), higher expression of pan-CK and Ki-67, and more severe DNA damage. 16S rRNA sequencing revealed that exposure to PS-NPs altered the abundance of Allobaculum and Lactobacillus, whereas metabolic analysis showed that the most significant metabolites were enriched mostly in fatty acid metabolism. Experiments in LPS intervened Caco-2 cells showed that exposure to PS-NPs led to lipid peroxidation, oxidative stress, and DNA damage in Caco-2. Exposure to PS-NPs activated the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway both in the AOM/DSS mouse model and cellular model. Key proteins involved in fatty acid metabolism were downregulated in Caco-2 cells exposed to PS-NPs. The metabolic effects of cancer cells exposed to PS-NPs were significantly inhibited by the activation of the fatty acid metabolism pathway by fenofibrate. PS-NPs exposure disturbed lipid metabolism and induced DNA damage via the activation of PI3K/AKT/mTOR to promote CAC progression. Inhibition of fatty acid metabolism is a therapeutic target for controlling PS-NP-induced CAC. Our study provides an important reference for the prevention and treatment of CAC from the perspective of the environment and enhances awareness of the necessity of plastic control.

Microplastics in different nasal irrigation options

PURPOSE

We aimed to assess the presence of microplastics in nasal irrigation methods commonly used in the treatment of sinusitis and rhinitis, and to evaluate human exposure.

METHODS

A total of 150 samples were included in the study, consisting of nasal wash bottles containing nasal irrigation solution, seawater spray, syringes for nasal irrigation with isotonic solution. The amount of microplastics per millilitre in the samples and patient exposure during single use were assessed separately for each method and product. All samples were filtered using a stainless steel vacuum filter on filter paper with a pore size of 1.2 μm, washed at least three times with distilled water and incubated at 45 °C for 24 h to prevent mould growth. Identification and counting of microplastics was performed using a Leica Flexacam C1 camera connected to an M80 stereomicroscope. The presence of microplastics was confirmed by the hot needle method and Nile red staining.

RESULTS

An average of 6.49 ± 13.08 microplastics/product was detected in all filtered samples. The lowest microplastic count was 0 microplastics/product in syringes and the highest was 92 microplastics/product in nasal wash bottles. Significant differences in the amount of microplastics individuals were exposed to during a single use were found between nasal wash bottles and seawater brands, while no significant differences were found between syringe brands. When nasal wash kits, seawater sprays and isotonic nasal rinses were evaluated separately, significant differences were found in the number of microplastics, the microplastics/ml ratio and the number of microplastics exposed during a single use. The highest microplastic exposure was found in nasal irrigation bottles.

CONCLUSION

The exposure of individuals to microplastics increases with medical support treatments, regardless of intranasal or intravenous administration. Due to the inflammation, oxidative stress and proliferation caused by microplastics, new regulations and inspections of production conditions should be implemented worldwide to reduce exposure.

Penetration of Microplastics and Nanoparticles Through Skin: Effects of Size, Shape, and Surface Chemistry

Skin represents an effective barrier against the penetration of external agents into the human body. Nevertheless, recent research has shown that small particles, especially in the nanosized range, can not only penetrate through the skin but also work as vectors to transport active molecules such as contrast agents or drugs. This knowledge has opened new perspectives on nanomedicine and controlled drug delivery. On the other hand, micro- and nanoplastics represent a form of emerging pollutants, and their concentration in the environment has been reported to drastically increase in the last years. The possible penetration of these particles through the skin has become a major concern for human health. If the actual primary toxicity of these materials is still debated, their possible role in the transport of toxic molecules through the skin, originating as secondary toxicity, is surely alarming. In this review paper, we analyze and critically discuss the most recent scientific publications to underline how these two processes, (i) the controlled delivery of bioactive molecules by micro- and nano-structures and (ii) the unwanted and uncontrolled penetration of toxic species through the skin mediated by micro- and nanoparticles, are deeply related and their efficiency is strongly affected by the nature, size, and shape of the particles.

Medical exposure to micro(nano)plastics: An exposure pathway with potentially significant harm to human health that should not be overlooked

Micro(nano)plastics (MNPs) are an emerging type of contaminants that are widely present in the environments that people live in. MNPs can enter the human body in a variety of pathways, but the three main ones are through dietary intake, air inhalation, and skin contact. However, it has been discovered that medical plastics used in medical activities also pose potential risks to MNPs exposure as exposure pathways are continuously refined and clarified. Unfortunately, there is currently insufficient study on the exposure of medical plastics and MNPs, and exposure risks and potential health problems are frequently overlooked. This study aimed to close this research gap by searching the databases of China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science for relevant literature. It then filtered out publications that contained information relevant to keywords such as micro(nano)plastics, medical plastics, exposure pathways, and human health in order to do analysis and summary. We discovered that medical plastics are a high-risk source of direct MNPs exposure to the human body, and this exposure could pose a potential harm to human health. Because of the potential harm to human health, this work presents the medical exposure of MNPs for the first time and calls for more research and attention on this vital area.

Behaviour of M. aeruginosa-Microplastic composite pollutants in coagulation and sludge storage

Microcystis aeruginosa (M. aeruginosa) blooms and microplastics pollution have been major global water pollution concern in lakes and reservoirs. In this study, the behaviour of M. aeruginosa-microplastic composite pollutants in inorganic coagulant (PACl) and organic coagulant (HTCC) treatment was investigated. Results showed that, in coagulation stage, the dissolved extracellular polymers secreted by M. aeruginosa could promote the adhesion of microplastics to algae, so as to combine them into the algal flocs, thus improving the sedimentation and removal efficiency of microplastics. On the other hand, whilst microplastics increased the size of algal flocs in PACl coagulation and improved algal removal efficiency, they had the opposite effect on HTCC coagulation. And the removal of algal metabolites including microcystins were improved by the presence of microplastics. In sludge storage stage, the oxidative and mechanical damage effects of microplastics promoted the rupture of M. aeruginosa cells in PACl sludge but not in HTCC sludge, which mean more potential risks in recycling of PACl sludge water. Besides, microplastics promoted the proliferation of beneficial bacteria such as Poterioochromonas and Coccomyxa, which contributed to the control of sludge pollution.

Identification and analysis of microplastic aggregation in CAR-T cells

Microplastics (MPs) are increasingly recognized as contaminants present in various environments and are widely acknowledged as potential hazards to the mammalian immune system. In our study of chimeric antigen receptor T cell (CAR-T) therapy, we observed the presence of MP in CAR-T cell products for the first time. It is worth exploring whether MP could enter CAR-T cells and how they might affect CAR-T cells' functionality. Therefore, we analyzed how MP affected CD19 and BCMA-CAR-T cells. Based on flow cytometry, ELISA, and cytotoxicity analysis of in vitro and in vivo experiments, MP suppressed the activity of CAR-T cells. Subsequent investigation revealed that the exposure of CAR-T cells to varying concentrations of MP resulted in a notable increase in apoptosis, ferroptosis, and exhaustion levels. Furthermore, the hyperactivation of the mTOR signaling pathway in MP-treated CAR-T cells was verified. The partial restoration of CAR-T cell function in MP was achieved by inhibiting the mTOR pathway. MP present a threat to CAR-T cell function due to their role in inducing CAR-T cell apoptosis, ferroptosis, and T-cell exhaustion through the hyperactivation of mTOR signaling pathways.

Evaluation of the health impacts and deregulation of signaling pathways in humans induced by microplastics

This review assesses the diverse health risk factors associated with microplastic (MP) exposure and their impact on cellular signaling pathways. MPs induce chronic inflammation, oxidative stress, endocrine disruption, apoptosis, and immune dysregulation. They activate signaling pathways such as NF-κB, MAPK, and Nrf2, exacerbating inflammatory responses, oxidative damage, and hormonal imbalances. Understanding the interplay between MPs and signaling pathways is crucial for elucidating the mechanisms underlying MP-induced health effects. Effective risk assessment and management strategies are essential to mitigate the adverse health impacts of MPs on human populations. This research underscores the urgent need for interdisciplinary collaboration to safeguard human health and environmental sustainability in the face of rising MP pollution. In this paper, we also assess the risk factors caused by the microplastics in the pregnant women and the development of the fetus. This review explores the potential risks and challenges associated with MP exposure in newborn babies. It is quite concerning that microplastic particles were recently found in the placental tissue of newborn children for the first time. Although it is unclear how these tiny particles affect different organs, researchers believe that these tiny particles could potentially carry harmful chemicals or disrupt the developing immune system of the fetus. This review overall focuses on the impact of microplastic disrupting different signaling including reproductive health in humans.

Chronic exposure to polystyrene microplastics induces renal fibrosis via ferroptosis

With the increasing prevalence of microplastics (MPs) in the environment, human health has become a growing concern. After entering the human body, MPs accumulate in the kidneys, indicating that the kidneys are their major target organs. This study investigated nephrotoxicity associated with MPs, with a specific focus on polystyrene (PS) MPs and amino-functionalized polystyrene (PS-NH2) MPs. Although previous studies have documented the nephrotoxic effects associated with short-term exposure to MPs, the mechanisms of kidney toxicity caused by chronic long-term exposure to MPs remain largely unclear. In animal models, mice were exposed to MPs (10 mg/L) at concentrations that are accessible to humans, administered via drinking water over a period of six months. These findings indicate that MPs can induce renal fibrosis by facilitating the onset of inflammation and accumulation of a substantial number of inflammatory cells. Our in vitro study showed that long-term exposure to MPs (60 μg/mL) induced ferroptosis in renal tubular epithelial cells via ferritinophagy and secreted TGF-β1, leading to renal fibroblast activation. Conversely, the application of Fer-1, a ferroptosis inhibitor, prevents ferroptosis in renal epithelial cells and reverses the activation of renal fibroblasts. Our study identified a novel toxicity mechanism for renal fibrosis induced by MPs exposure, offering new insights into the detrimental effects of environmental MPs on human health.

Effect of biosurfactants on the transport of polyethylene microplastics in saturated porous media

Microplastic (MP) pollution has become a significant global environmental issue, and the potential application of biosurfactants in soil remediation has attracted considerable attention. However, the effects of biosurfactants on the transport and environmental risks of MPs are not fully understood. This study investigated the transport of polyethylene (PE) in the presence of two types of biosurfactants: typical anionic biosurfactant (rhamnolipids) and non-ionic biosurfactant (sophorolipids) using column experiments. We explored the potential mechanisms involving PE surface roughness and the influence of dissolved organic matter (DOM) on PE transport in the column under the action of biosurfactants, utilizing the Wenzel equation and fluorescence analysis. The results revealed that both the concentration of biosurfactants and the surface roughness of PE were advantageous for the adhesion of biosurfactants to the PE surface, thereby enhancing the mobility of PE in the column. The proportion of hydrophobic substances in various DOM sources is a critical factor that enhances PE transport in the column. However, the biosurfactant-mediated enhancement of PE transport was inhibited by the biosurfactant-DOM mixture. This was mainly due to DOM occupying the adhesion sites of biosurfactants on PE surfaces. Moreover, the mobility of PE in the presence of sophorolipids is higher than that in the presence of rhamnolipids because the combined hydrophobic and electrostatic forces between PE and sophorolipids create synergistic effects that improve PE stability. Additionally, the mobility of PE increased with rising pH and decreasing ionic strength. These findings provide a more comprehensive understanding of MP transport when using biosurfactants for soil remediation.

Combined effects of polyvinyl chloride or polypropylene microplastics with cadmium on the intestine of zebrafish at environmentally relevant concentrations

Cadmium (Cd) is a common additive in polyvinyl chloride (PVC) and polypropylene (PP) plastics. Aquatic organisms were inevitably co-exposed to PVC/PP microplastics (MPs) and Cd, but their combined toxicity is still unknown. In this study, adult zebrafish were exposed to 200 μg/L MPs (PVC or PP) and 10 μg/L Cd alone or in combination for 28 days to investigate their toxicity and mechanisms. Results showed that combined exposure with PVC/PP enhanced the Cd accumulation in the zebrafish intestine. Subsequently, toxicology analyses showed that both PVC and PP possessed synergistic toxicity with Cd, manifested by the exfoliation and necrosis of intestinal epithelial cells, and increased levels of interleukin-1β (IL-1β), superoxide dismutase (SOD) and malondialdehyde (MDA). PP exhibited a stronger synergistic effect than PVC. Integration of non-targeted metabolomics and 16S rRNA gene sequencing revealed that combined exposure to PVC and Cd induced intestine toxicity mainly through bile acid (BA) biosynthesis, fructose (Fru) and mannose (Man) metabolism, and pentose phosphate pathway (PPP). The combined exposure of PP and Cd induced toxicity through the arginine (Arg) and glutathione (GSH) metabolisms. Meanwhile, combined exposure of PVC/PP and Cd increased the abundance of intestinal Proteobacteria and pathogen Vibrio, and decreased the abundance of Gemmobacter. These changes indrectly promoted the synergistic toxicity of PVC/PP and Cd through metabolites, such as indole-3-pyruvate (IPyA), chenodeoxycholic acid (CDCA), and cholic acid (CA). These findings highlighted that more attention should be paid to the toxicity of chemicals at environmentally relevant concentrations, particularly those co-existing with MPs.

Deciphering the cytotoxicity of micro- and nanoplastics in Caco-2 cells through meta-analysis and machine learning

Plastic pollution, driven by micro- and nanoplastics (MNPs), poses a major environmental threat, exposing humans through various routes. Despite human colorectal adenocarcinoma Caco-2 cells being used as an in vitro model for studying the intestinal epithelium, uncertainties linger about MNPs harming these cells and the factors influencing adverse effects. Addressing this lacuna, our study aimed to elucidate the pivotal MNP parameters influencing cytotoxicity in Caco-2 cells, employing meta-analysis and machine learning techniques for quantitative assessment. Initial scrutiny of 95 publications yielded 17 that met the inclusion criteria, generating a dataset of 320 data points. This dataset underwent meticulous stratification based on polymer type, exposure time, polymer size, MNP concentration, and biological assays utilised. Subsequent dose-response curve analysis revealed moderate correlations for selected subgroups, such as the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) MTT biological assay and exposure time exceeding 24 h, with coefficient of determination (R2) values of 0.50 (p-value: 0.0065) and 0.60 (p-value: 0.0018) respectively. For the aforementioned two subgroups, the MNP concentrations surpassing 10 μg/mL led to diminished viability of Caco-2 cells. Notably, we observed challenges in employing meta-analysis to navigate this multidimensional MNP dataset. Leveraging a random forest model, we achieved improved predictive performance, with R2 values of 0.79 and a root mean square error (RMSE) of 0.14 for the prediction of the Log Response Ratio on the test set. Model interpretation indicated that size and concentration are the principal drivers influencing Caco-2 cell cytotoxicity. Additionally, the partial dependence plot illustrating the relationship between the size of MNPs and predicted cytotoxicity reveals a complex pattern. Our study provides crucial insights into the health impacts of plastic pollution, informing policymakers for targeted interventions, thus contributing to a comprehensive understanding of its human health consequences.