A review on microplastics and nanoplastics in the environment: Their occurrence, exposure routes, toxic studies, and potential effects on human health

Recent advances on transport and transformation mechanism of nanoplastics in lung cells

Microplastics (MPs) are solid plastic particles less than or equal to 5 mm in size that are insoluble in water, and when the diameter is further reduced to <1 micrometer (μm), we call them nanoplastics (NPs). MPs and NPs are widely present in the atmosphere, and plastic particles have also been detected in the sputum of patients with respiratory diseases. This warns us that these tiny plastic particles are a potential threat to human respiratory health. The lungs, as the main organs of the respiratory system, are more likely to be adversely affected by inhaled NPs. However, the mechanism of transport and transformation of NPs in the lung is not clear, so our review mainly focuses on a series of effects and mechanisms of NPs on lung cells through absorption, distribution, metabolism, excretion (ADME) after inhalation into the human body. The most commonly used models in these experimental studies we focus on are A549 and BEAS-2B cells, which are used to model the lung cell response to plastic particles. In addition, we also summarize some shortcomings of these experiments and prospects for future studies, hoping to provide further clues for future studies and contribute to the prevention of related hazards and diseases.

Assessment of microplastics in human stool: A pilot study investigating the potential impact of diet-associated scenarios on oral microplastics exposure

As emerging contaminants microplastic particles have become of particular relevance as they are widely present in the environment and of potential concern to human health. Humans are exposed through different routes, with oral intake and inhalation being the most significant. Dietary intake substantially contributes to oral exposure, although data is still lacking. This first-of-its-kind pilot study investigates the influence of different plastic use and food consumption scenarios (normal, low, high) on microplastic content in stool reflecting oral intake by performing an intervention study with fifteen volunteers. Stool samples were analyzed for ten different plastic types in three size fractions including 5-50 μm (qualitative), 50-500 μm and 500-5000 μm (quantitative). In all samples, microplastic particles were detected with median concentrations up to 3.5 particles/g stool in the size fraction 50-500 μm. Polyethylene was the most frequently detected polymer type. The different scenarios did not result in a consistent pattern of microplastics, however, the use of plastics for food packaging and preparation, and the consumption of highly processed food were statistically significantly associated with microplastics content in stool. These results provide initial findings that contribute to filling current knowledge gaps and pave the way for further research.

Unveiling the impacts of microplastic pollution on soil health: A comprehensive review

Soil contamination by microplastics (MPs) has emerged as a significant global concern. Although traditionally associated with crop production, contemporary understanding of soil health has expanded to include a broader range of factors, including animal safety, microbial diversity, ecological functions, and human health protection. This paradigm shifts underscores the imperative need for a comprehensive assessment of the effects of MPs on soil health. Through an investigation of various soil health indicators, this review endeavors to fill existing knowledge gaps, drawing insights from recent studies conducted between 2021 and 2024, to elucidate how MPs may disrupt soil ecosystems and compromise their crucial functions. This review provides a thorough analysis of the processes leading to MP contamination in soil environments and highlights film residues as major contributors to agricultural soils. MPs entering the soil detrimentally affect crop productivity by hindering growth and other physiological processes. Moreover, MPs hinder the survival, growth, and reproductive rates of the soil fauna, posing potential health risks. Additionally, a systematic evaluation of the impact of MPs on soil microbes and nutrient cycling highlights the diverse repercussions of MP contamination. Moreover, within soil-plant systems, MPs interact with other pollutants, resulting in combined pollution. For example, MPs contain oxygen-containing functional groups on their surfaces that form high-affinity hydrogen bonds with other pollutants, leading to prolonged persistence in the soil environment thereby increasing the risk to soil health. In conclusion, we succinctly summarize the current research challenges related to the mediating effects of MPs on soil health and suggest promising directions for future studies. Addressing these challenges and adopting interdisciplinary approaches will advance our understanding of the intricate interplay between MPs and soil ecosystems, thereby providing evidence-based strategies for mitigating their adverse effects.

Amino-modified nanoplastics at predicted environmental concentrations cause transgenerational toxicity through activating germline EGF signal in Caenorhabditis elegans

In the real environment, some chemical functional groups are unavoidably combined on the nanoplastic surface. Reportedly, amino-modified polystyrene nanoparticles (PS-A NPs) exposure in parents can induce severe transgenerational toxicity, but the underlying molecular mechanisms remain largely unclear. Using Caenorhabditis elegans as the animal model, this study was performed to investigate the role of germline epidermal growth factor (EGF) signal on modulating PS-A NPs' transgenerational toxicity. As a result, 1-10 μg/L PS-A NPs exposure transgenerationally enhanced germline EGF ligand/LIN-3 and NSH-1 levels. Germline RNAi of lin-3 and nsh-1 was resistant against PS-A NPs' transgenerational toxicity, implying the involvement of EGF ligand activation in inducing PS-A NPs' transgenerational toxicity. Furthermore, LIN-3 overexpression transgenerationally enhanced EGF receptor/LET-23 expression in the progeny, and let-23 RNAi in F1-generation notably suppressed PS-A NPs' transgenerational toxicity in the exposed worms overexpressing germline LIN-3 at P0 generation. Finally, LET-23 functioned in neurons and intestine for regulating PS-A NPs' transgenerational toxicity. LET-23 acted at the upstream DAF-16/FOXO within the intestine in response to PS-A NPs' transgenerational toxicity. In neurons, LET-23 functioned at the upstream of DAF-7/DBL-1, ligands of TGF-β signals, to mediate PS-A NPs' transgenerational toxicity. Briefly, this work revealed the exposure risk of PS-A NPs' transgenerational toxicity, which was regulated through activating germline EGF signal in organisms.

A comprehensive review of urban microplastic pollution sources, environment and human health impacts, and regulatory efforts

Microplastic (MP) pollution in urban environments is a pervasive and complex problem with significant environmental and human health implications. Although studies have been conducted on MP pollution in urban environments, there are still research gaps in understanding the exact sources, regulation, and impact of urban MP on the environment and public health. Therefore, the goal of this study is to provide a comprehensive overview of the complex pathways, harmful effects, and regulatory efforts of urban MP pollution. It discusses the research challenges and suggests future directions for addressing MPs related to environmental issues in urban settings. In this study, original research papers published from 2010 to 2024 across ten database categories, including PubMed, Google Scholar, Scopus, and Web of Science, were selected and reviewed to improve our understanding of urban MP pollution. The analysis revealed multifaceted sources of MPs, including surface runoff, wastewater discharge, atmospheric deposition, and biological interactions, which contribute to the contamination of aquatic and terrestrial ecosystems. MPs pose a threat to marine and terrestrial life, freshwater organisms, soil health, plant communities, and human health through ingestion, inhalation, and dermal exposure. Current regulatory measures for MP pollution include improved waste management, upgraded wastewater treatment, stormwater management, product innovation, public awareness campaigns, and community engagement. Despite these regulatory measures, several challenges such as; the absence of standardized MPs testing methods, MPs enter into the environment through a multitude of sources and pathways, countries struggle in balancing trade interests with environmental concerns have hindered effective policy implementation and enforcement. Addressing MP pollution in urban environments is essential for preserving ecosystems, safeguarding public health, and advancing sustainable development. Interdisciplinary collaboration, innovative research, stringent regulations, and public participation are vital for mitigating this critical issue and ensuring a cleaner and healthier future for urban environments and the planet.

Polyethylene terephthalate nanoparticles induce oxidative damage in Chlorella vulgaris

Polyethylene Terephthalate (PET) is a type of plastic largely used for packing food and beverages. Unfortunately, it includes a major portion of the plastic distributed through aquatic systems wherever systematic collection and recycling are lacking. Although PET is known to be non-toxic, it is not obvious whether the nanoparticles (NPs) formed due to their degradation have any direct/indirect effect on aquatic organisms. In order to study the effects on aquatic environment, fresh water algae Chlorella vulgaris was subjected to incremental concentrations of the NPs. We observed a concentration and duration of exposure dependent decrease in algal growth rate along with reduced total chlorophyll content. Scanning electron microscopy revealed deformities in cell shape and the uptake of Propidium Iodide suggested membrane damage in response to NP exposure. Intracellular Reactive Oxygen Species level was also found significantly higher, evidenced by Dichlorodihydrofluorescein diacetate staining. Activity of antioxidant enzymes Superoxide dismutase (SOD), Peroxidase (POD) and Catalase (CAT) were significantly higher in the NP exposed groups suggesting the cellular response to regain homeostasis. Further, expression levels of the genes psaB, psbC, and rbcL associated with photosynthesis increased above two fold with respect to the control inferring the possibility of damage to photosynthesis and the initial molecular responses to circumvent the situation. In short, our studies provide evidence for oxidative stress mediated cellular damages in Chlorella vulgaris exposed to NPs of PET.

Topic modeling discovers trending topics in global research on the ecosystem impacts of microplastics

The ecological threats of microplastics (MPs) have sparked research worldwide. However, changes in the topics of MP research over time and space have not been evaluated quantitatively, making it difficult to identify the next frontiers. Here, we apply topic modeling to assess global spatiotemporal dynamics of MP research. We identified nine leading topics in current MP research. Over time, MP research topics have switched from aquatic to terrestrial ecosystems, from distribution to fate, from ingestion to toxicology, and from physiological toxicity to cytotoxicity and genotoxicity. In most of the nine leading topics, a disproportionate amount of independent and collaborative research activity was conducted in and between a few developed countries which is detrimental to understanding the environmental fates of MPs in a global context. This review recognizes the urgent need for more attention to emerging topics in MP research, particularly in regions that are heavily impacted but currently overlooked.

Elaborating more realistic model microplastics by simulating polypropylene's environmental ageing

In this work, we propose a new protocol for producing model microplastics from an industrial polymer and compare it to a conventional method, cryomilling. Polypropylene industrial pellets were chosen due to their widespread production and frequent presence in the environment, making them a notable source of microplastics. Both protocols start with aging under Ultra-Violet light of the pellets but differ in the subsequent mechanical stress applied-strong vs. soft-to break down the photodegraded pellets into microplastics. All generated particles were fully characterized in terms of size, shape, oxidation rate, and stability in aqueous media. Microplastics produced via cryomilling exhibited significant size and oxidation heterogeneity and tended to aggregate in water. Although the new protocol involving soft mechanical stress required a longer preparation time, it simulated more accurately the environmental degradation of raw plastic. This method successfully produced oxidized microplastics with a controlled size distribution centered around 50 µm which remained stable in water without stabilizers.

Efficacy of DHA-enriched phosphatidylserine and its underlying mechanism in alleviating polystyrene nanoplastics-induced hepatotoxicity in mice

OBJECTIVE

Plastic pollution has become a global pollution problem that cannot be ignored. As the main destination of human oral intake, the toxic effects of plastic on the digestive system represented by the intestine and liver are the focus of current research. Marine-derived DHA-PS has a variety of biological activities, mainly focusing on improving brain function and regulating lipid metabolism. However, whether it has an improvement effect on PS-NPs-induced hepato-intestinal injury and the underlying mechanism remain unclear.

METHODS

A murine liver injury model was established by gavage of PS-NPs for six weeks. By integrating approaches from lipidomics, transcriptomics, and gut microbiota analysis, the molecular mechanism by which DHA-PS alleviates PS-NPs-induced murine hepatotoxicity was explored through the "gut-liver axis".

RESULTS

Our findings reveal that prolonged exposure to PS-NPs results in significant murine liver damage and dysfunction, characterized by increased oxidative stress and inflammation, along with exacerbated hepatic lipid accumulation. Mechanistically, PS-NPs disrupt the hepatic SIRT1-AMPK pathway by suppressing the expression of SIRT1, AMPKα, and PPARα, while enhancing the expression of SREBP-1c, ultimately leading to disordered hepatic lipid metabolism. The sphingolipid and glycerophospholipid metabolic pathways were particularly affected. Additionally, in agreement with transcriptomic analyses, PS-NPs activate the hepatic TLR4/NF-κB pathway. At the same time, exposure to PS-NPs decreases the expression of ZO-1, occludin, and claudin-1, diminishes the relative abundance of beneficial gut bacteria (norank_f_Muribaculaceae, Akkermansia, and norank_f_norank_o_Clostridia_UCG-014), and increases the prevalence of pathogenic gut bacteria (Coriobacteriaceae_UCG-002 and Desulfovibrio), exacerbating liver injury through the gut-liver axis. However, administering DHA-PS (50 mg/kg) effectively alleviated these injuries.

CONCLUSION

This study was the first to employ multi-omics techniques to elucidate the potential mechanisms underlying hepatotoxicity induced by PS-NPs, thereby supporting the use of DHA-PS as a dietary supplement to mitigate the effects of nanoplastic pollutants.

Orally Ingested Micro- and Nano-Plastics: A Hidden Driver of Inflammatory Bowel Disease and Colorectal Cancer

Micro- and nano-plastics (MNPLs) can move along the food chain to higher-level organisms including humans. Three significant routes for MNPLs have been reported: ingestion, inhalation, and dermal contact. Accumulating evidence supports the intestinal toxicity of ingested MNPLs and their role as drivers for increased incidence of colorectal cancer (CRC) in high-risk populations such as inflammatory bowel disease (IBD) patients. However, the mechanisms are largely unknown. In this review, by using the leading scientific publication databases (Web of Science, Google Scholar, Scopus, PubMed, and ScienceDirect), we explored the possible effects and related mechanisms of MNPL exposure on the gut epithelium in healthy conditions and IBD patients. The summarized evidence supports the idea that oral MNPL exposure may contribute to intestinal epithelial damage, thus promoting and sustaining the chronic development of intestinal inflammation, mainly in high-risk populations such as IBD patients. Colonic mucus layer disruption may further facilitate MNPL passage into the bloodstream, thus contributing to the toxic effects of MNPLs on different organ systems and platelet activation, which may, in turn, contribute to the chronic development of inflammation and CRC development. Further exploration of this threat to human health is warranted to reduce potential adverse effects and CRC risk.

Long-Term Exposure to Polystyrene Microspheres and High-Fat Diet-Induced Obesity in Mice: Evaluating a Role for Microbiota Dysbiosis

BACKGROUND

Microplastics (MPs) have become a global environmental problem, emerging as contaminants with potentially alarming consequences. However, long-term exposure to polystyrene microspheres (PS-MS) and its effects on diet-induced obesity are not yet fully understood.

OBJECTIVES

We aimed to investigate the effect of PS-MS exposure on high-fat diet (HFD)-induced obesity and underlying mechanisms.

METHODS

In the present study, C57BL/6J mice were fed a normal diet (ND) or a HFD in the absence or presence of PS-MS via oral administration for 8 wk. Antibiotic depletion of the microbiota and fecal microbiota transplantation (FMT) were performed to assess the influence of PS-MS on intestinal microbial ecology. We performed 16S rRNA sequencing to dissect microbial discrepancies and investigated the dysbiosis-associated intestinal integrity and inflammation in serum.

RESULTS

Compared with HFD mice, mice fed the HFD with PS-MS exhibited higher body weight, liver weight, metabolic dysfunction-associated steatotic liver disease (MASLD) activity scores, and mass of white adipose tissue, as well as higher blood glucose and serum lipid concentrations. Furthermore, 16S rRNA sequencing of the fecal microbiota revealed that mice fed the HFD with PS-MS had greater α -diversity and greater relative abundances of Lachnospiraceae, Oscillospiraceae, Bacteroidaceae, Akkermansiaceae, Marinifilaceae, Deferribacteres, and Desulfovibrio, but lower relative abundances of Atopobiaceae, Bifidobacterium, and Parabacteroides. Mice fed the HFD with PS-MS exhibited lower expression of MUC2 mucin and higher levels of lipopolysaccharide and inflammatory cytokines [tumor necrosis factor-α (TNF-α ), interleukin-6 (IL-6), IL-1β , and IL-17A] in serum. Correlation analyses revealed that differences in the microbial flora of mice exposed to PS-MS were associated with obesity. Interestingly, microbiota-depleted mice did not show the same PS-MS-associated differences in Muc2 and Tjp1 expression in the distal colon, expression of inflammatory cytokines in serum, or obesity outcomes between HFD and HFD + PS-MS. Importantly, transplantation of feces from HFD + PS-MS mice to microbiota-depleted HFD-fed mice resulted in a lower expression of mucus proteins, higher expression of inflammatory cytokines, and obesity outcomes, similar to the findings in HFD + PS-MS mice.

CONCLUSIONS

Our findings provide a new gut microbiota-driven mechanism for PS-MS-induced obesity in HFD-fed mice, suggesting the need to reevaluate the adverse health effects of MPs commonly found in daily life, particularly in susceptible populations. https://doi.org/10.1289/EHP13913.

Unveiling the ecotoxicological impact of microplastics on organisms - the persistent organic pollutant (POP): A comprehensive review

Microplastics have been ubiquitous in our environment for decades, and numerous studies have revealed their extensive dispersion, reaching far beyond the surface of the land, soil, aquatic ecosystems. They have infiltrated the food-chain, the food web, even the air we breathe, as well as the water we drink. Microplastics have been detected in the food we consume, acting as vectors for hazardous chemicals that adhere to their hydrophobic surfaces. This can result in the transfer of these chemicals to the aquatic life, posing a threat to their well-being. The release of microplastics into different environmental settings can give rise to various eco-toxicological implications. The substantial body of literature has led scientists to the consensus that microplastic pollution is a global problem with the potential to impact virtually any type of ecosystem. This paper aims to discuss crucial information regarding the occurrence, accumulation, and ecological effects of microplastics on organisms. It also highlights the new and emerging disease named "Plasticosis" that is directly linked to microplastics and its toxicological effects like permanent scarring and long-term inflammation in the digestive system of the seabirds. By comprehending the behaviour of these microplastic pollutants in diverse habitats and evaluating their ecological consequences, it becomes possible to facilitate a better understanding of this toxicological issue.

Beyond the food on your plate: Investigating sources of microplastic contamination in home kitchens

Given that a substantial amount of time is spent in kitchens preparing food, the kitchen equipment used may be relevant in determining the composition and amount of microplastics ending up on our dinner plate. While previous research has predominantly focused on foodstuffs as a source of microplastics, we emphasise that micro- and nanoplastics are ubiquitous and likely originate from diverse sources. To address the existing knowledge gap regarding additional sources contributing to microplastics on our dinner plates, this review investigates various kitchen processes, utensils and equipment (excluding single-use items and foodstuffs) to get a better understanding of potential microplastic sources within a home kitchen. Conducting a narrative literature review using terms related to kitchenware and kitchen-affiliated equipment and processes, this study underscores that the selection of preparation tools, storage, serving, cooking, and cleaning procedures in our kitchens may have a significant impact on microplastic exposure. Mechanical, physical, and chemical processes occurring during food preparation contribute to the release of microplastic particles, challenging the assumption that exposure to microplastics in food is solely tied to food products or packaging. This review highlights diverse sources of microplastics in home kitchens, posing concerns for food safety and human health.

Environmentally persistent free radicals on photoaging microplastics shortens longevity via inducing oxidative stress in Caenorhabditis elegans

Microplastics (MPs) are ubiquitous environmental contaminants that exert multiple toxicological effects. Current studies have mainly focused on modeled or unaged MPs, which lack environmental relevance. The generation and toxicity of environmentally persistent free radicals (EPFRs) on photoaging polystyrene (PS) have not been well studied, and the role of EPFRs on the toxic effects of photoaged PS is easily ignored. Photoaging primarily produces EPFRs, followed by an increase in reactive oxygen species (ROS) content and oxidative potential, which alter the physicochemical properties of photoaged PS. The mean lifespan and lipofuscin content were significantly altered after acute exposure to photoaged PS for 45 d (PS-45) and 60 d (PS-60) in Caenorhabditis elegans. Intestinal ROS and gst-4::GFP expression were enhanced, concomitant with the upregulation of associated genes. Treatment with N-acetyl-l-cysteine by radical quenching test significantly decreased EPFRs levels on the aged PS and inhibited the acceleration of the aging and oxidative stress response in nematodes. Pearson's correlation analysis also indicated that the EPFRs levels were significantly associated with these factors. Thus, the EPFRs generated on photoaged PS contribute to the acceleration of aging by oxidative stress. This study provides new insights into the potential toxicity and highlights the need to consider the role of EPFRs in the toxicity assessment of photoaged PS.

Effects of polystyrene microspheres on the swimming behavior and metabolism of grass carp (Ctenopharyngodon idella)

Microplastics (MPs) are a heterogeneous class of pollutants fouling aquatic environments and they are hazardous to aquatic organisms. This study investigated the size-dependent effects of polystyrene microspheres (PSMPs) on the swimming ability, metabolism, and oxidative stress of juvenile grass carp (Ctenopharyngodon idella). Test fish were exposed to four sizes of PSMPs (0.07, 0.5, 5, and 20-μm), and swimming ability was tested after different exposure times (2, 7, and 15 days). To measure the effect on swimming ability, critical swimming speed (Ucrit) was determined, and to assess metabolic effects, oxygen consumption (MO2), routine metabolic rate (RMR), maximum oxygen consumption (MMR), and excess post-exercise oxygen consumption (EPOC) were determined. To assess the effects on oxidative stress, the activities of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) were determined in the liver and gills of test fish. After exposure to 20 μm PSMPs, there was a significant drop in Ucrit compared to the control group (P<0.05), with decreases of 22 % on Day 2 and Day 7, and 21 % on Day 15. The RMR and MMR increased significantly (P<0.05), the RMR by 23.9 % on Day 2 and the MMR by 17.2 % on Day 2 and on Day 15, 44.7 % and 20.0 % respectively. The EPOC decreased with exposure time, by 31 % (0.07-μm), 45 %-(0.5-μm), 49 % (5-μm), and 57 % (20-μm) after 15 days. Exposure to the larger PSMPs increased CAT and SOD activity more than the smaller PSMPs and the increases began with SOD activity in the gills. The larger PSMPs were consistently more harmful to juvenile grass carp than the smaller PSMPs. Our results clearly show that PSMPs have detrimental effects on juvenile grass carp and provide additional scientific evidence that environmental monitoring and regulation of microplastic pollution is necessary.

A novel and simple method for measuring nano/microplastic concentrations in soil using UV-Vis spectroscopy with optimal wavelength selection

A simple method for measuring the concentration of nano/microplastics (N/MPs) in soil, which is difficult owing to the size of the filter mesh and the resolution of the measuring instrument, was investigated. A spectrophotometer was used for the measurements and polystyrene particles were used as the N/MP samples. When measuring N/MP concentrations in soil suspensions, absorbance was measured at two wavelengths, and the best combination of wavelengths for measurement was extracted because soil particles and leached components interfere with N/MP absorbance. A wavelength combination of 220-260 nm and 280-340 nm was found to be suitable for a variety of soils. As N/MPs are adsorbed on the surface of soil particles and precipitate with soil particles in suspension, a calibration curve was created between the concentration of N/MPs in the soil suspension and the N/MP content in the soil. The calibration curve showed a linear relationship, allowing for the estimation of the concentration of N/MPs in the soil. Although other N/MP materials, such as polyethylene and polyethylene terephthalate, must also still be considered and tested, this simple method has the potential to measure N/MPs in various types of soil.

In vitro digestion of microplastics in human digestive system: Insights into particle morphological changes and chemical leaching

Despite the well-reported occurrences and established pathways for microplastics (MPs) ingestion by humans, the eventual fate of these particles in the human gastrointestinal system is poorly understood. The present study tries to gain a better understanding of the fate of four common food-borne MPs, i.e. Polystyrene (PS), Polypropylene (PP), Low-density Polyethylene (LDPE), and Nylon, in a simulated in vitro human digestive system. Firstly, the changes in the physicochemical properties of 20-210 μm sized MPs as well as the leaching of chemicals were monitored using fluorescence microscopy, FTIR, and LC-QTOF-MS. Thereafter, the mass loss and morphological alterations in 3-4 mm sized MPs were observed after removing the organic matter. The interaction of PS and PP MPs with duodenal and bile juices manifested in a corona formation. The increase in surface roughness in PP MPs aligned with MP-enzyme dehydrogenation reactions and the addition of NO groups. A few fragments ranging from 30 to 250 μm, with negligible mass loss, were released during the MP digestion process. In addition, the leaching of compounds, e.g. capsi-amide, butanamide, and other plasticizers and monomers was also observed from MPs during digestion, and which may have the potential to accumulate and get absorbed by the digestive organs, and to subsequently impart toxic effects.

Reproductive toxicity and related mechanisms of micro(nano)plastics in terrestrial mammals: Review of current evidence

Micro(nano)plastics (MNPs) have been detected in various ecological environments and are widely used due to their stable properties, raising widespread concern about their potential human reproductive toxicity. Currently, infertility affects approximately 10-30% of couples of reproductive age globally. MNPs, as environmental pollutants, have been shown to exhibit reproductive toxicity through intrinsic mechanisms or as carriers of other hazardous substances. Numerous studies have established that MNPs of varying sizes and types can penetrate biological barriers, and enter tissues and even organelles of organisms through four main routes: dietary ingestion, inhalation, dermal contact, and medical interventions. However, historical research on the toxic effects of MNPs on reproduction mainly focused on lower and aquatic species. We conducted an inclusive review of studies involving terrestrial mammals, revealing that MNPs can induce reproductive toxicity via various mechanisms such as oxidative stress, inflammation, fibrosis, apoptosis, autophagy, disruption of intestinal flora, endocrine disruption, endoplasmic reticulum stress, and DNA damage. In terrestrial mammals, reproductive toxicity predominantly manifests as disruption in the blood-testis barrier (BTB), impaired spermatogenesis, sperm malformation, sperm DNA damage, reduced sperm fertilizing capacity, compromised oocyte maturation, impaired follicular growth, granulosa cell apoptosis, diminished ovarian reserve function, uterine and ovarian fibrosis, and endocrine disruption, among other effects. Furthermore, MNPs can traverse the maternal-fetal interface, potentially impacting offspring reproductive health. To gain a comprehensive understanding of the potential reproductive toxicity and underlying mechanisms of MNPs with different sizes, polymer types, shapes, and carried toxins, as well as to explore effective protective interventions for mitigating reproductive damage, further in-depth animal studies, clinical trials, and large-scale epidemiological studies are urgently required.

Environmental impact of microplastics and potential health hazards

Microscopic plastic (microplastic) pollutants threaten the earth's biodiversity and ecosystems. As a result of the progressive fragmentation of oversized plastic containers and products or manufacturing in small sizes, microplastics (particles of a diameter of 5 mm with no lower limit) are used in medicines, personal care products, and industry. The incidence of microplastics is found everywhere in the air, marine waters, land, and even food that humans and animals consume. One of the greatest concerns is the permanent damage that is created by plastic waste to our fragile ecosystem. The impossibility of the complete removal of all microplastic contamination from the oceans is one of the principal tasks of our governing body, research scientists, and individuals. Implementing the necessary measures to reduce the levels of plastic consumption is the only way to protect our environment. Cutting off the plastic flow is the key remedy to reducing waste and pollution, and such an approach could show immense significance. This review offers a comprehensive exploration of the various aspects of microplastics, encompassing their composition, types, properties, origins, health risks, and environmental impacts. Furthermore, it delves into strategies for comprehending the dynamics of microplastics within oceanic ecosystems, with a focus on averting their integration into every tier of the food chain.

Negligible adsorption and toxicity of microplastic fibers in disinfected secondary effluents

Wastewater treatment plants play a crucial role in controlling the transport of pollutants to the environment and often discharge persistent contaminants such as synthetic microplastic fibers (MFs) to the ecosystem. In this study, we examined the fate and toxicity of polyethylene terephthalate (PET) MFs fabricated from commercial cloth in post-disinfection secondary effluents by employing conditions that closely mimic disinfection processes applied in wastewater treatment plants. Challenging conventional assumptions, this study illustrated that oxidative treatment by chlorination and ozonation incurred no significant modification to the surface morphology of the MFs. Additionally, experimental results demonstrated that both pristine and oxidized MFs have minimal adsorption potential towards contaminants of emerging concern in both effluents and alkaline water. The limited adsorption was attributed to the inert nature of MFs and low surface area to volume ratio. Slight adsorption was observed for sotalol, sulfamethoxazole, and thiabendazole in alkaline water, where the governing adsorption interactions were suggested to be hydrogen bonding and electrostatic forces. Acute exposure experiments on human cells revealed no immediate toxicity; however, the chronic and long-term consequences of the exposure should be further investigated. Overall, despite the concern associated with MFs pollution, this work demonstrates the overall indifference of MFs in WWTP (i.e., minor effects of disinfection on MFs surface properties and limited adsorption potential toward a mix of trace organic pollutants), which does not change their acute toxicity toward living forms.

Toxicological review of micro- and nano-plastics in aquatic environments: Risks to ecosystems, food web dynamics and human health

The increase of micro- and nano-plastics (MNPs) in aquatic environments has become a significant concern due to their potential toxicological effects on ecosystems, food web dynamics, and human health. These plastic particles emerge from a range of sources, such as the breakdown of larger plastic waste, consumer products, and industrial outputs. This review provides a detailed report of the transmission and dangers of MNPs in aquatic ecosystems, environmental behavior, and interactions within aquatic food webs, emphasizing their toxic impact on marine life. It explores the relationship between particle size and toxicity, their distribution in different tissues, and the process of trophic transfer through the food web. MNPs, once consumed, can be found in various organs, including the digestive system, gills, and liver. Their consumption by lower trophic level organisms facilitates their progression up the food chain, potentially leading to bioaccumulation and biomagnification, thereby posing substantial risks to the health, reproduction, and behavior of aquatic species. This work also explores how MNPs, through their persistence and bioaccumulation, pose risks to aquatic biodiversity and disrupt trophic relationships. The review also addresses the implications of MNPs for human health, particularly through the consumption of contaminated seafood, highlighting the direct and indirect pathways through which humans are exposed to these pollutants. Furthermore, the review highlights the recommendations for future research directions, emphasizing the integration of ecological, toxicological, and human health studies to inform risk assessments and develop mitigation strategies to address the global challenge of plastic pollution in aquatic environments.

Abundance, characterization, and health risk evaluation of microplastics in borehole water in Birnin Kebbi, Nigeria

Microplastic pollution has become a global menace, and water, being a major "sink" for pollutants, represents a significant source of human exposure. This study aimed to assess the safety of borehole water in Birnin Kebbi, Nigeria, specifically concerning microplastic pollution. Water samples were collected from boreholes in selected areas, including Bayan Kara, Malali, Rafin Atiku, Aliero Quarters, GwadanGaji, FUBK Takeoff Site, Kalgo Market, and Tarasa. Microplastics were extracted from the water samples through filtration using glass fiber filter papers, and were subsequently subjected to spectroscopy and microscopy to determine concentrations, shapes, and polymer types. Health risks associated with the microplastics were also calculated. The results revealed that the samples from Tarasa exhibited the highest concentrations of microplastics (96.967 particles/L), followed by Bayan Kara (92.70 particles/L), Rafin Atiku (92.33 particles/L), GwadanGwaji (92.30 particles/L), FUBK Takeoff Site (91.07 particles/L), Aliero Quarters (90.43 particles/L), Kalgo Market (88.00 particles/L), and Malali (86.40 particles/L). The most dominant shape was fibers (73 %), followed by fragments (16 %), foams (6 %), and filaments (5 %). Polyethylene and polyamide, in that order, were the most dominant polymers, while polystyrene was the least common. The majority of risk scores were classified as III. It can be inferred from the results that microplastic pollution in borehole water poses a health hazard in the city. Consumers of borehole water in the studied areas are advised to treat the water before consumption to mitigate potential health risks.

Transcriptomic and metabolomic analysis unveils nanoplastic-induced gut barrier dysfunction via STAT1/6 and ERK pathways

The widespread prevalence of micro and nanoplastics in the environment raises concerns about their potential impact on human health. Recent evidence demonstrates the presence of nanoplastics in human blood and tissues following ingestion and inhalation, yet the specific risks and mechanisms of nanoplastic toxicity remain inadequately understood. In this study, we aimed to explore the molecular mechanisms underlying the toxicity of nanoplastics at both systemic and molecular levels by analyzing the transcriptomic/metabolomic responses and signaling pathways in the intestines of mice after oral administration of nanoplastics. Transcriptome analysis in nanoplastic-administered mice revealed a notable upregulation of genes involved in pro-inflammatory immune responses. In addition, nanoplastics substantially reduced the expression of tight junction proteins, including occludin, zonula occluden-1, and tricellulin, which are crucial for maintaining gut barrier integrity and function. Importantly, nanoplastic administration increased gut permeability and exacerbated dextran sulfate sodium-induced colitis. Further investigation into the underlying molecular mechanisms highlighted significant activation of signaling transsducer and activator of transcription (STAT)1 and STAT6 by nanoplastic administration, which was in line with the elevation of interferon and JAK-STAT pathway signatures identified through transcriptome enrichment analysis. Additionally, the consumption of nanoplastics specifically induced nuclear factor kappa-B (NF-κB) and extracellular signal-regulated kinase (ERK)1/2 signaling pathways in the intestines. Collectively, this study identifies molecular mechanisms contributing to adverse effects mediated by nanoplastics in the intestine, providing novel insights into the pathophysiological consequences of nanoplastic exposure.

The biodistribution of polystyrene nanoparticles administered intravenously in the chicken embryo

Nanoplastics can cause severe malformations in chicken embryos. To improve our understanding of the toxicity of nanoplastics to embryos, we have studied their biodistribution in living chicken embryos. We injected the embryos in the vitelline vein at stages 18-19. We injected polystyrene nanoparticles (PS-NPs) tagged with europium- or fluorescence. Their biodistribution was tracked using inductively-coupled plasma mass spectrometry on tissue lysates, paraffin histology, and vibratome sections analysed by machine learning algorithms. PS-NPs were found at high levels in the heart, liver and kidneys. Furthermore, PS-NPs crossed the endocardium of the heart at sites of epithelial-mesenchymal transformation; they also crossed the liver endothelium. Finally, we detected PS-NPs in the allantoic fluid, consistent with their being excreted by the kidneys. Our study shows the power of the chicken embryo model for analysing the biodistribution of nanoplastics in embryos. Such experiments are difficult or impossible in mammalian embryos. These findings are a major advance in our understanding of the biodistribution and tissue-specific accumulation of PS-NPs in developing animals.

Effects of micro/nanoplastics on oxidative damage and serum biochemical parameters in rats and mice: a meta-analysis

Micro/nanoplastics (MNPs) are emerging as environmental pollutants with potential threats to human health. The accumulation of MNPs in the body can cause oxidative stress and increase the risk of cardiovascular disease (CVD). With the aim to systematically evaluate the extent of MNPs-induced oxidative damage and serum biochemical parameters in rats and mice, a total of 36 eligible articles were included in this meta-analysis study. The results reported that MNPs can significantly increase the levels of oxidants such as reactive oxygen species (ROS) and malondialdehyde (MDA) (P < 0.05), and resulted in notable increase in serum biochemical parameters including aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (P < 0.05). Conversely, MNPs significantly reduced levels of antioxidants such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT) (P < 0.05). Subgroup analysis revealed that smaller MNPs with oral administration and prolonged treatment, were associated with more pronounced oxidative stress and enhanced serum biochemical parameters alteration. In addition, after affected by MNPs, the levels of ALT and AST in liver group (SMD = 2.26, 95% CI = [1.59, 2.94] and SMD = 3.10, 95% CI = [1.25, 4.94]) were higher than those in other organs. These comprehensive results provide a scientific foundation for devising strategies to prevent MNPs-induced damage, contributing to solution of this environmental and health challenge.

Physiological and transcriptomic responses of seawater halobios to micro/nano-scale polystyrene-cadmium exposure in a marine food web

Micro/nano-plastics (MPs/NPs) represent an emerging contaminant, posing a significant threat to oceanic halobios. While the adverse effects of joint pollutants on marine organisms are well-documented, the potential biological impacts on the food chain transmission resulting from combinations of MPs/NPs and heavy metals (HMs) remain largely unexplored. This study exposed the microbial loop to combined contaminants (MPs/NPs + HMs) for 48h, bacteria and contaminants are washed away before feeding to the traditional food chain, employing microscopic observation, biochemical detection, and transcriptome analysis to elucidate the toxicological mechanisms of the top predator. The findings revealed that MPs/NPs combined with Cd2+ could traverse both the microbial loop and classical food chain. Acute exposure significantly affected the carbon biomass of the top predator Tigriopus japonicus (75.8% lower). Elevated antioxidant enzyme activity led to lipid peroxidation, manifesting in increased malondialdehyde levels. Transcriptome sequencing showed substantial differential gene expression levels in T. japonicus under various treatments. The upregulation of genes associated with apoptosis and inflammatory responses, highlighting the impact of co-exposure on oxidative damage and necroptosis within cells. Notably, NPs-Cd exhibited stronger toxicity than MPs-Cd. NPs-Cd led to a greater decrease in the biomass of top predators, accompanied by lower activities of GSH, SOD, CAT, and GSH-PX, resulting in increased production of lipid peroxidation product MDA and higher oxidative stress levels. This investigation provides novel insights into the potential threats of MPs/NPs combined with Cd2+ on the microbial loop across traditional food chain, contributing to a more comprehensive assessment of the ecological risks associated with micro/nano-plastics and heavy metals.

Generation of Eroded Nanoplastics from Domestic Wastes and Their Impact on Macrophage Cell Viability and Gene Expression

This study reports an innovative approach for producing nanoplastics (NP) from various types of domestic waste plastics without the use of chemicals. The plastic materials used included water bottles, styrofoam plates, milk bottles, centrifuge tubes, to-go food boxes, and plastic bags, comprising polyethylene terephthalate (PET), polystyrene (PS), polypropylene (PP), high-density polyethylene (HDPE), and Poly (Ethylene-co-Methacrylic Acid) (PEMA). The chemical composition of these plastics was confirmed using Raman and FTIR spectroscopy, and they were found to have irregular shapes. The resulting NP particles ranged from 50 to 400 nm in size and demonstrated relative stability when suspended in water. To assess their impact, the study investigated the effects of these NP particulates on cell viability and the expression of genes involved in inflammation and oxidative stress using a macrophage cell line. The findings revealed that all types of NP reduced cell viability in a concentration-dependent manner. Notably, PS, HDPE, and PP induced significant reductions in cell viability at lower concentrations, compared to PEMA and PET. Moreover, exposure to NP led to differential alterations in the expression of inflammatory genes in the macrophage cell line. Overall, this study presents a viable method for producing NP from waste materials that closely resemble real-world NP. Furthermore, the toxicity studies demonstrated distinct cellular responses based on the composition of the NP, shedding light on the potential environmental and health impacts of these particles.

Wearing face masks as a potential source for inhalation and oral uptake of inanimate toxins - A scoping review

BACKGROUND

From 2020 to 2023 many people around the world were forced to wear masks for large proportions of the day based on mandates and laws. We aimed to study the potential of face masks for the content and release of inanimate toxins.

METHODS

A scoping review of 1003 studies was performed (database search in PubMed/MEDLINE, qualitative and quantitative evaluation).

RESULTS

24 studies were included (experimental time 17 min to 15 days) evaluating content and/or release in 631 masks (273 surgical, 228 textile and 130 N95 masks). Most studies (63%) showed alarming results with high micro- and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkyl substances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate, DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.

DISCUSSION

Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.

CONCLUSION

Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.

Microplastic contamination in salt-cured fish and commercial sea salts: an emerging food safety threat in relation to UN Sustainable Development Goals (SDGs)

Microplastic (MP) contamination in seafood, particularly processed varieties like dried and salt-cured fish, poses a significant threat to human health. This study investigated MP levels in 22 salt-cured fish species and commercial sea salts along the Indian east coast. Results showed substantially higher MP concentrations compared to global averages, with fragments and fibres (< 250 µm) composing 70% of identified MPs, primarily PVC and PS polymers (> 55%). Station 2 exhibited high pollution levels, with salt-cured fish averaging 54.06 ± 14.48 MP items/g and salt containing 23.53 ± 4.2 MP items/g, indicating a high hazard risk index. A modest correlation was observed between MP abundance, morphotypes, polymer composition in the salt, and their impact on fish products. Given the critical link between food safety, security, and public health, further research is imperative to mitigate MP contamination, aligning with UN Sustainable Development Goals (Goal 2, Goal 3, Goal 14, and Goal 15) for enhanced food safety and security.

Cost-effectiveness Analysis of Single-Use Duodenoscope Applied to Endoscopic Retrograde Cholangiopancreatography

OBJECTIVES

Secondary infections due to transmission via the duodenoscope have been reported in up to 3% of endoscopic retrograde cholangiopancreatographies. The use of single-use duodenoscopes has been suggested. We investigate the cost-effectiveness of these duodenoscopes use in cholangiopancreatography.

MATERIALS AND METHODS

A cost-effectiveness analysis was implemented to compare the performance of cholangiopancreatographies with reusable duodenoscopes versus single-use duodenoscopes. Effectiveness was analyzed by calculating quality-adjusted life years (QALY) from the perspective of the National Health System. Possibility of crossover from single-use to reusable duodenoscopes was considered. A willingness-to-pay of €25,000/QALY was set, the incremental cost-effectiveness ratio (ICER) was calculated, and deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Considering cholangiopancreatographies with single-use and reusable duodenoscopes at a cost of €2900 and €1333, respectively, and a 10% rate of single-use duodenoscopes, ICER was greater than €3,000,000/QALY. A lower single-use duodenoscope cost of €1211 resulted in an ICER of €23,583/QALY. When the unit cost of the single-use duodenoscope was €1211, a crossover rate of more than 9.5% made the use of the single-use duodenoscope inefficient.

CONCLUSIONS

Single-use duodenoscopes are cost-effective in a proportion of cholangiopancreatographies if its cost is reduced. Increased crossover rate makes single-use duodenoscope use not cost-effective.

Effects of different concentrations and particle sizes of nanoplastics on gut microbiology, metabolism, and immunity in Chiromantes dehaani

This study investigated the effects of nanoplastics (NPs) of varying particle sizes (75, 500, and 1000 nm) and concentrations (2.5 and 10 mg/L) on the gut health of Chiromantes dehaani. The experimental groups included a control (Cg0), and varying combinations of particle size and concentration. Our results showed that 75 nm NPs were more likely to enhance pathogenic bacterial growth than other sized NPs. Compared with CK, Low NPs concentrations (2.5 mg/L) raised total cholesterol (T-CHO) levels in the gut, while high concentrations significantly decreased both triglyceride (TG) and T-CHO levels (p < 0.05). The enzymatic activities of intestinal lipase and amylase were inhibited by NPs exposure, with greater inhibition at higher NPs concentrations. The 500 nm NPs exhibited a notably higher inhibitory effect than the 75 and 1000 nm NPs (P < 0.05). In terms of apoptosis, NPs exposure led to reduced mRNA expression of Bcl2 and increased expression of Caspase-3, Caspase-8, and Caspase-9, indicating an induction of apoptosis. This effect was more pronounced at higher NPs concentrations, with 75 nm NPs more likely to induce apoptosis in intestinal cells than 500 nm and 1000 nm NPs. Moreover, NPs triggered intestinal inflammatory responses, evidenced by the increased mRNA expression of TNF-β, TNF-α, IL1β, IL6, and IL8, and the decreased expression of IL10. High NPs concentrations were more likely to induce intestinal inflammation, with 500 nm NPs imparting the strongest effect. In summary, the study demonstrated that NPs, and particularly those at higher concentrations, disrupted the gut environment of C. dehaani by altering the microflora, reducing microbial diversity, inhibiting digestion and metabolism, inducing apoptosis, and triggering inflammation. Among the sizes of NPs tested, 500 nm NPs had the most significant adverse impact on digestion, metabolism, and inflammation, while 75 nm NPs most strongly induced apoptosis in C. dehaani's intestinal cells.

Differences in toxicity induced by the various polymer types of nanoplastics on HepG2 cells

The problem of microplastics (MPs) contamination in food has gradually come to the fore. MPs can be transmitted through the food chain and accumulate within various organisms, ultimately posing a threat to human health. The concentration of nanoplastics (NPs) exposed to humans may be higher than that of MPs. For the first time, we studied the differences in toxicity, and potential toxic effects of different polymer types of NPs, namely, polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polystyrene (PS) on HepG2 cells. In this study, PET-NPs, PVC-NPs, and PS-NPs, which had similar particle size, surface charge, and shape, were prepared using nanoprecipitation and emulsion polymerization. The results of the CCK-8 assay showed that the PET-NPs and PVC-NPs induced a decrease in cell viability in a concentration-dependent manner, and their lowest concentrations causing significant cytotoxicity were 100 and 150 μg/mL, respectively. Moreover, the major cytotoxic effects of PET-NPs and PVC-NPs at high concentrations may be to induce an increase in intracellular ROS, which in turn induces cellular damage and other toxic effects. Notably, our study suggested that PET-NPs and PVC-NPs may induce apoptosis in HepG2 cells through the mitochondrial apoptotic pathway. However, no relevant cytotoxicity, oxidative damage, and apoptotic toxic effects were detected in HepG2 cells with exposure to PS-NPs. Furthermore, the analysis of transcriptomics data suggested that PET-NPs and PVC-NPs could significantly inhibit the expression of DNA repair-related genes in the p53 signaling pathway. Compared to PS-NPs, the expression levels of lipid metabolism-related genes were down-regulated to a greater extent by PET-NPs and PVC-NPs. In conclusion, PET-NPs and PVC-NPs were able to induce higher cytotoxic effects than PS-NPs, in which the density and chemical structure of NPs of different polymer types may be the key factors causing the differences in toxicity.

Science-based evidence on pathways and effects of human exposure to micro- and nanoplastics

Human exposure to plastic particles has raised great concern among all relevant stakeholders involved in the protection of human health due to the contamination of the food chain, surface waters, and even drinking water as well as due to their persistence and bioaccumulation. Now more than ever, it is critical that we understand the biological fate of plastics and their interaction with different biological systems. Because of the ubiquity of plastic materials in the environment and their toxic potential, it is imperative to gain reliable, regulatory-relevant, science-based data on the effects of plastic micro- and nanoparticles (PMNPs) on human health in order to implement reliable risk assessment and management strategies in the circular economy of plastics. This review presents current knowledge of human-relevant PMNP exposure doses, pathways, and toxic effects. It addresses difficulties in properly assessing plastic exposure and current knowledge gaps and proposes steps that can be taken to underpin health risk perception, assessment, and mitigation through rigorous science-based evidence. Based on the existing scientific data on PMNP adverse health effects, this review brings recommendations on the development of PMNP-specific adverse outcome pathways (AOPs) following the AOP Users' Handbook of the Organisation for Economic Cooperation and Development (OECD).

The weakened physiological functions of human serum albumin in presence of polystyrene nanoplastics

Due to the widespread presence of nanoplastics (NPs) in daily essentials and drinking water, the potential adverse effects of NPs on human health have become a global concern. Human serum albumin (HSA), the most abundant and multi-functional protein in plasma, has been chosen to understand the biological effects of NPs after entering the blood. The esterase activity and the transport of bisphenol A in the presence of polystyrene nanoplastics (PSNPs) under physiological conditions (pH 4.0 and 7.4) have been investigated to evaluate the possible biological effects. The interactions between PSNPs and HSA have also been systematically studied by multispectral methods and dynamic light scattering techniques. The esterase activity of HSA presented a decreased trend with increasing PSNPs; conversely, higher permeabilities are accompanied by higher amounts of PSNPs. Compared with the unchanged hydrodynamic diameter and weaker interactions at pH 7.4, stronger binding between HSA and PSNPs at pH 4.0 led to a significant increase in the particle size of the PSNPs-HSA complex. The quenching mechanism belonged to the static quenching type. The electrostatic force is proposed to be the dominant factor for PSNPs binding to HSA. The work provides some information about the toxicity of NPs when exposed to humans.

A comprehensive review on the source, ingestion route, attachment and toxicity of microplastics/nanoplastics in human systems

Microplastics (MPs)/nanoplastics (NPs) are widely found in the natural environment, including soil, water and the atmosphere, which are essential for human survival. In the recent years, there has been a growing concern about the potential impact of MPs/NPs on human health. Due to the increasing interest in this research and the limited number of studies related to the health effects of MPs/NPs on humans, it is necessary to conduct a systematic assessment and review of their potentially toxic effects on human organs and tissues. Humans can be exposed to microplastics through ingestion, inhalation and dermal contact, however, ingestion and inhalation are considered as the primary routes. The ingested MPs/NPs mainly consist of plastic particles with a particle size ranging from 0.1 to 1 μm, that distribute across various tissues and organs within the body, which in turn have a certain impact on the nine major systems of the human body, especially the digestive system and respiratory system, which are closely related to the intake pathway of MPs/NPs. The harmful effects caused by MPs/NPs primarily occur through potential toxic mechanisms such as induction of oxidative stress, generation of inflammatory responses, alteration of lipid metabolism or energy metabolism or expression of related functional factors. This review can help people to systematically understand the hazards of MPs/NPs and related toxicity mechanisms from the level of nine biological systems. It allows MPs/NPs pollution to be emphasized, and it is also hoped that research on their toxic effects will be strengthened in the future.

A Latest Review on Micro- and Nanoplastics in the Aquatic Environment: The Comparative Impact of Size on Environmental Behavior and Toxic Effect

Micro and nanoplastics (MNPs) have attracted growing global research attention due to their distinct environmental impacts, addressing escalating concerns. The diverse materials, sizes, and shapes of MNPs result in a range of environmental impacts. Size, a crucial characteristic of MNPs, influences their environmental behavior, affecting processes like migration, sedimentation, aggregation, and adsorption. Moreover, size modulates the biodistribution and toxicity of MNPs in aquatic organisms. This review delves into the comprehensive impacts of plastic size, with a primary focus on environmental behavior and toxic effects. Ultimately, this review emphasizes the ecological implications of MNP size, laying a foundation for future research in this field.

Smart carbon-based sensors for the detection of non-coding RNAs associated with exposure to micro(nano)plastics: an artificial intelligence perspective

Micro(nano)plastics (MNPs) are pervasive environmental pollutants that individuals eventually consume. Despite this, little is known about MNP's impact on public health. In this article, we assess the evidence for potentially harmful consequences of MNPs in the human body, concentrating on molecular toxicity and exposure routes. Since MNPs are present in various consumer products, foodstuffs, and the air we breathe, exposure can occur through ingestion, inhalation, and skin contact. MNPs exposure can cause mitochondrial oxidative stress, inflammatory lesions, and epigenetic modifications, releasing specific non-coding RNAs in circulation, which can be detected to diagnose non-communicable diseases. This article examines the most fascinating smart carbon-based nanobiosensors for detecting circulating non-coding RNAs (lncRNAs and microRNAs). Carbon-based smart nanomaterials offer many advantages over traditional methods, such as ease of use, sensitivity, specificity, and efficiency, for capturing non-coding RNAs. In particular, the synthetic methods, conjugation chemistries, doping, and in silico approach for the characterization of synthesized carbon nanodots and their adaptability to identify and measure non-coding RNAs associated with MNPs exposure is discussed. Furthermore, the article provides insights into the use of artificial intelligence tools for designing smart carbon nanomaterials.

Mechanistic Insights into Cellular and Molecular Basis of Protein-Nanoplastic Interactions

Plastic waste is ubiquitously present across the world, and its nano/sub-micron analogues (plastic nanoparticles, PNPs), raise severe environmental concerns affecting organisms' health. Considering the direct and indirect toxic implications of PNPs, their biological impacts are actively being studied; lately, with special emphasis on cellular and molecular mechanistic intricacies. Combinatorial OMICS studies identified proteins as major regulators of PNP mediated cellular toxicity via activation of oxidative enzymes and generation of ROS. Alteration of protein function by PNPs results in DNA damage, organellar dysfunction, and autophagy, thus resulting in inflammation/cell death. The molecular mechanistic basis of these cellular toxic endeavors is fine-tuned at the level of structural alterations in proteins of physiological relevance. Detailed biophysical studies on such protein-PNP interactions evidenced prominent modifications in their structural architecture and conformational energy landscape. Another essential aspect of the protein-PNP interactions includes bioenzymatic plastic degradation perspective, as the interactive units of plastics are essentially nano-sized. Combining all these attributes of protein-PNP interactions, the current review comprehensively documented the contemporary understanding of the concerned interactions in the light of cellular, molecular, kinetic/thermodynamic details. Additionally, the applicatory, economical facet of these interactions, PNP biogeochemical cycle and enzymatic advances pertaining to plastic degradation has also been discussed.

Effect of polypropylene microplastics on virus resistance in spotted sea bass (Lateolabrax maculatus)

Microplastics (MPs) pollution is a hot issue of global concern. Polypropylene microplastics (PP-MPs) age quickly in the marine environment and break down into smaller particles because of their relatively low temperature resistance, poor ultraviolet resistance, and poor antioxidant capacity, making them one of the major pollutants in the ocean. We assessed whether long-term exposure to micron-sized PP-MPs influences fish susceptibility to viral diseases. We found that exposure to PP-MPs (1-6 μm and 10-30 μm) at concentrations of 500 and 5000 μg/L resulted in uptake into spleen and kidney tissues of Lateolabrax maculatus. Increased activation of melanomacrophage centers was visible in histopathological sections of spleen from fish exposed to PP-MPs, and greater deterioration was observed in the spleen of fish infected by largemouth bass ulcerative syndrome virus after PP-MPs exposure. Additionally, exposure to PP-MPs led to significant cytotoxicity and a negative impact on the antiviral ability of cells. PP-MPs exposure had inhibitory or toxic effects on the immune system in spotted sea bass, which accelerated virus replication in vivo and decreased the expression of the innate immune- and acquired immune related genes in spleen and kidney tissues, thus increasing fish susceptibility to viral diseases. These results indicate that the long-term presence of micron-sized PP-MPs might impact fish resistance to disease, thereby posing a far-reaching problem for marine organisms.

Microplastics in Ecuador: A review of environmental and health-risk assessment challenges

Pollution from plastic debris and microplastics (MPs) is a worldwide issue. Classified as emerging contaminants, MPs have become widespread and have been found not only in terrestrial and aquatic ecosystems but also within the food chain, which affects both the environment and human health. Since the outbreak of COVID-19, the consumption of single-use plastics has drastically increased, intensifying mismanaged plastic waste in countries such as Ecuador. Therefore, the aim of this review is to 1) summarize the state of MP-related knowledge, focusing on studies conducted with environmental matrices, biota, and food, and 2) analyze the efforts by different national authorities and entities in Ecuador to control MP contamination. Results showed a limited number of studies have been done in Ecuador, which have mainly focused on the surface water of coastal areas, followed by studies on sediment and food. MPs were identified in all samples, indicating the lack of wastewater management policies, deficient management of solid wastes, and the contribution of anthropogenic activities such as artisanal fishing and aquaculture to water ecosystem pollution, which affects food webs. Moreover, studies have shown that food contamination can occur through atmospheric deposition of MPs; however, ingredients and inputs from food production, processing, and packaging, as well as food containers, contribute to MP occurrence in food. Further research is needed to develop more sensitive, precise, and reliable detection methods and assess MPs' impact on terrestrial and aquatic ecosystems, biota, and human health. In Ecuador specifically, implementing wastewater treatment plants in major cities, continuously monitoring MP coastal contamination, and establishing environmental and food safety regulations are crucial. Additionally, national authorities need to develop programs to raise public awareness of plastic use and its environmental effects, as well as MP exposure's effects on human health.

Noxious ramifications of cosmetic pollutants on gastrointestinal microbiome: A pathway to neurological disorders

On exposure to cosmetic pollutants, gastrointestinal dysbiosis, which is characterised by a disturbance in the gut microbiota, has come into focus as a possible contributor to the occurrence of neurotoxic consequences. It is normal practice to use personal care products that include parabens, phthalates, sulphates, triclosans/triclocarbans and micro/nano plastics. These substances have been found in a variety of bodily fluids and tissues, demonstrating their systemic dispersion. Being exposed to these cosmetic pollutants has been linked in recent research to neurotoxicity, including cognitive decline and neurodevelopmental problems. A vital part of sustaining gut health and general well-being is the gut flora. Increased intestinal permeability, persistent inflammation, and impaired metabolism may result from disruption of the gut microbial environment, which may in turn contribute to neurotoxicity. The link between gastrointestinal dysbiosis and the neurotoxic effects brought on by cosmetic pollutants may be explained by a number of processes, primarily the gut-brain axis. For the purpose of creating preventative and therapeutic measures, it is crucial to comprehend the intricate interactions involving cosmetic pollutants, gastrointestinal dysbiosis, and neurotoxicity. This review provides an in-depth understanding of the various hazardous cosmetic pollutants and its potential role in the occurrence of neurological disorders via gastrointestinal dysbiosis, providing insights into various described and hypothetical mechanisms regarding the complex toxic effects of these industrial pollutants.

PLASTAMINATION: Outcomes on the Central Nervous System and Reproduction

BACKGROUND

Environmental exposures to non-biodegradable and biodegradable plastics are unavoidable. Microplastics (MPs) and nanoplastics (NPs) from the manufacturing of plastics (primary sources) and the degradation of plastic waste (secondary sources) can enter the food chain directly or indirectly and, passing biological barriers, could target both the brain and the gonads. Hence, the worldwide diffusion of environmental plastic contamination (PLASTAMINATION) in daily life may represent a possible and potentially serious risk to human health.

OBJECTIVE

This review provides an overview of the effects of non-biodegradable and the more recently introduced biodegradable MPs and NPs on the brain and brain-dependent reproductive functions, summarizing the molecular mechanisms and outcomes on nervous and reproductive organs. Data from in vitro, ex vivo, non-mammalian and mammalian animal models and epidemiological studies have been reviewed and discussed.

RESULTS

MPs and NPs from non-biodegradable plastics affect organs, tissues and cells from sensitive systems such as the brain and reproductive organs. Both MPs and NPs induce oxidative stress, chronic inflammation, energy metabolism disorders, mitochondrial dysfunction and cytotoxicity, which in turn are responsible for neuroinflammation, dysregulation of synaptic functions, metabolic dysbiosis, poor gamete quality, and neuronal and reproductive toxicity. In spite of this mechanistic knowledge gained from studies of non-biodegradable plastics, relatively little is known about the adverse effects or molecular mechanisms of MPs and NPs from biodegradable plastics.

CONCLUSION

The neurological and reproductive health risks of MPs/NPs exposure warrant serious consideration, and further studies on biodegradable plastics are recommended.

Surface interaction of vancomycin with polystyrene microplastics and its effect on human serum albumin

Microplastics have a well-documented ability to adsorb various chemicals and contaminants found in the environment. By similar mechanisms, when medicines are stored in plastic packaging, the leaching of plastics into the contents poses the risk of possible toxicity and decreased drug efficacy. The work thus examines the presence of two categories of anthropogenic materials - microplastics (MPs) and medications - with their possible combined effects and fate in biological systems. A study on the kinetics and isotherm of the adsorption of vancomycin hydrochloride on the surface of polystyrene microspheres is performed, and the best-fitting models are obtained respectively as the pseudo-second-order model and the Temkin isotherm. Further, the interaction of each of, the drug, MPs and drug-adsorbed MPs with human serum albumin (HSA), the model protein chosen to validate the potential toxicity in humans, is determined by fluorescence spectroscopy. A thermodynamic analysis of this protein-ligand interaction shows that the process is spontaneous, endothermic and entropically favoured, and that hydrophobic forces operate between the interacting species. An unfolding of HSA is observed, disrupting its functions like the esterase activity. Competitive binding experiments with Warfarin and Ibuprofen as specific site markers on HSA reveal that all the studied ligands bind non-specifically to HSA.

The invisible Threat: Assessing the reproductive and transgenerational impacts of micro- and nanoplastics on fish

Micro- and nanoplastics (MNPs), emerging as pervasive environmental pollutants, present multifaceted threats to diverse ecosystems. This review critically examines the ability of MNPs to traverse biological barriers in fish, leading to their accumulation in gonadal tissues and subsequent reproductive toxicity. A focal concern is the potential transgenerational harm, where offspring not directly exposed to MNPs exhibit toxic effects. Characterized by extensive specific surface areas and marked surface hydrophobicity, MNPs readily adsorb and concentrate other environmental contaminants, potentially intensifying reproductive and transgenerational toxicity. This comprehensive analysis aims to provide profound insights into the repercussions of MNPs on fish reproductive health and progeny, highlighting the intricate interplay between MNPs and other pollutants. We delve into the mechanisms of MNPs-induced reproductive toxicity, including gonadal histopathologic alterations, oxidative stress, and disruptions in the hypothalamic-pituitary-gonadal axis. The review also underscores the urgency for future research to explore the size-specific toxic dynamics of MNPs and the long-term implications of chronic exposure. Understanding these aspects is crucial for assessing the ecological risks posed by MNPs and formulating strategies to safeguard aquatic life.

Polystyrene Microplastics Exacerbate Candida albicans Infection Ability In Vitro and In Vivo

Plastic pollution is an important environmental problem, and microplastics have been shown to have harmful effects on human and animal health, affecting immune and metabolic physiological functions. Further, microplastics can interfere with commensal microorganisms and exert deleterious effects on exposure to pathogens. Here, we compared the effects of 1 µm diameter polystyrene microplastic (PSMPs) on Candida albicans infection in both in vitro and in vivo models by using HT29 cells and Galleria mellonella larvae, respectively. The results demonstrated that PSMPs could promote Candida infection in HT29 cells and larvae of G. mellonella, which show immune responses similar to vertebrates. In this study, we provide new experimental evidence for the risk to human health posed by PSMPs in conjunction with Candida infections.

Microplastics in marine mussels, biological effects and human risk of intake: A case study in a multi-stressor environment

This study documented seasonal levels of microplastics (MPs) and biomarkers (condition index, neurotoxicity, energy, oxidative stress) in mussels (Mytilus galloprovincialis), and water physico-chemical parameters in the Douro estuary (NE Atlantic coast), and estimated the human risk of MP intake (HRI) through mussels. Mussel stress was determined through the Integrated Biomarker Response (IBR). HRI was estimated from mussel MP concentrations and consumer habits. MPs were mainly micro-fibres (72 %) with varied chemical composition. Seasonal MP means (±SEM) in mussels ranged from 0.111 ± 0.044 (spring) to 0.312 ± 0.092 MPs/g (summer). Seasonal variations of mussel stress (IBR: 1.4 spring to 9.7 summer) and MP concentrations were not related. MeO-BDEs, PBDEs, temperature, salinity and other factors likely contributed to mussel stress variation. HRI ranged from 2438 to 2650 MPs/year. Compared to the literature, MP contamination in mussels is low, as well as the human risk of MP intake through their consumption.

Combined exposure to polyvinyl chloride and polystyrene microplastics induces liver injury and perturbs gut microbial and serum metabolic homeostasis in mice

A variety of microplastics (MPs) have become ubiquitous environmental pollutants, leading to inevitable human contact and health impacts. Most previous research has explored the toxic effects of a single type of MPs exposure. However, the effects of co-exposure to both common types of MPs, polyvinyl chloride (PVC) and polystyrene (PS) MPs on mammals have not been explored. Here, adult mice were exposed to PS-PVC (1.0 µm PS and 2.0 µm PVC both at the concentration of 0.5 mg/day) for 60 days. The results showed that PS-PVC co-exposure-induced hepatotoxicity was evidenced by liver histopathological changes, the release of inflammatory cytokines, and the activation of oxidative stress. Moreover, the intestinal mucosal barrier was damaged after PS-PVC treatment. The results of 16S rRNA gene sequencing reported there was a marked shift in the gut microbial structure accompanied by decreased relative abundances of probiotics, such as Clostridium, Lachnospiraceae_UCG-006, Desulfovibrio, Clostridiales_unclassified and Ruminococcaceae_unclassified and increased the conditional pathogen abundances, such as Erysipelatoclostridium. Furthermore, the triglyceride (TG) and total cholesterol (TCH) expression levels in the serum and liver were increased after PS-PVC co-exposure. Serum metabolomics analysis showed that there were 717 differential expression metabolites found in the positive- and negative-ion modes, including 476 up-regulated and 241 down-regulated, mainly enriched in butyrate metabolism, thiamine metabolism, and phenylacetate metabolism. In addition, remarked changes in the gut microbiota and serum metabolic profiles were closely related to hepatic and intestinal injuries after PS-PVC co-exposure. These results have provided new insights into the toxic effects of PS and PVC MPs co-exposure through the gut-liver axis and the health risks of PS and PVC MPs should be paid more attention to humans.

Human biomonitoring of microplastics and health implications: A review

BACKGROUND

Microplastics (MPs) are plastic particles (<5 mm) ubiquitous in water, soil, and air, indicating that humans can be exposed to MPs through ingestion of water and food, and inhalation.

OBJECTIVE

This review provides an overview of the current human biomonitoring data available to evaluate human exposure and health impact of MPs.

METHOD

We compiled 91 relevant studies on MPs in human matrices and MPs toxicological endpoints to provide evidence on MPs distribution in the different tissues and the implications this can have from a health perspective.

RESULTS

Human exposure to MPs has been corroborated by the detection of MPs in different human biological samples including blood, urine, stool, lung tissue, breast milk, semen and placenta. Although humans have clearance mechanisms protecting them from potentially harmful substances, health risks associated to MPs exposure include the onset of inflammation, oxidative stress, and DNA damage, potentially leading to cardiovascular and respiratory diseases, as well as cancer, as suggested by in vitro and in vivo studies.

CONCLUSION

Based on compiled data, MPs have been recurrently identified in different human tissues and fluids, suggesting that humans are exposed to MPs through inhalation and ingestion. Despite differences in MPs concentrations appear in exposed and non-exposed people, accumulation and distribution pathways and potential human health hazards is still at an infant stage. Human biomonitoring data enables the assessment of human exposure to MPs and associated risks, and this information can contribute to draw management actions and guidelines to minimize MP release to the environment, and thus, reduce human uptake.

The male reproductive toxicity after nanoplastics and microplastics exposure: Sperm quality and changes of different cells in testis

Nanoplastics (NPs) and Microplastics (MPs) pollution has become a severe threat to the planet and is a growing concern. However, their effects on male reproductive toxicity remain poorly understood. In this study, a series of morphological analyses were completed to explore the influence of NPs and MPs exposure on the testis in mice. After 12-weeks exposure, although both NPs and MPs exposure can lead to reproductive toxicity, compared with NPs exposure, exposure to MPs leads to a more significant increase in reproductive toxicity dependent on some particle size. Moreover, increased reproductive toxicities, including increased spermatogenesis disorders, and sperm physiological abnormality, oxidative stress, testis inflammation was more associated with MPs group than NPs group. Ultra-pathological structure observed by transmission electron microscopy indicated that both NPs and MPs have different effects on spermatogonia, spermatocytes and Sertoli cells. Exposure to MPs resulted in decreased Sertoli cell numbers and reduced Leydig cell area, and showed no effects on differentiation of Leydig cells by the expression level of the Insulin-Like factor 3 (INSL3) in Leydig cells. Transcriptomic sequencing analysis provided valuable insights into the differential effects of NPs and MPs on cellular processes. Specifically, our findings demonstrated that NPs were predominantly involved in the regulation of steroid biosynthesis, whereas MPs primarily influenced amino acid metabolism. This study demonstrates the effect of adult-stage reproductive toxicity in mice after exposure to NPs and MPs, which will deep the understanding of the NPs and MPs induced toxicity.