Prospects on the nano-plastic particles internalization and induction of cellular response in human keratinocytes

Microplastics in the human body: A comprehensive review of exposure, distribution, migration mechanisms, and toxicity

Microplastics (MPs) are pervasive across ecosystems, presenting substantial risks to human health. Developing a comprehensive review of MPs is crucial due to the growing evidence of their widespread presence and potential harmful effects. Despite the growth in research, considerable uncertainties persist regarding their transport dynamics, prevalence, toxicological impacts, and the potential long-term health effects they may cause. This review thoroughly evaluates recent advancements in research on MPs and their implications for human health, including estimations of human exposure through ingestion, inhalation, and skin contact. It also quantifies the distribution and accumulation of MPs in various organs and tissues. The review discusses the mechanisms enabling MPs to cross biological barriers and the role of particle size in their translocation. To ensure methodological rigor, this review adheres to the PRISMA guidelines, explicitly detailing the literature search strategy, inclusion criteria, and the quality assessment of selected studies. The review concludes that MPs pose significant toxicological risks, identifies critical gaps in current knowledge, and recommends future research directions to elucidate the prolonged effects of MPs on human health. This work aims to offer a scientific framework for mitigating MP-related hazards and establishes a foundation for ongoing investigation.

Beyond microbeads: Examining the role of cosmetics in microplastic pollution and spotlighting unanswered questions

The presence of microplastics in cosmetics and personal care products (C&PCPs) has been increasingly in the public eye since the early 2010s. Despite increasing research into the potential environmental and health effects of microplastics, most research to date on microplastics in C&PCPs has investigated "rinse-off" products, while the potential impacts of "leave-on" C&PCPs have been largely neglected, despite these products being purchased in greater volumes and often having two or more microplastic ingredients in their formulations(CosmeticsEurope, 2018b). This review aims to synthesize the current knowledge of microplastic in C&PCPs, assessing the potential environmental and human health impacts of C&PCPs and discussing the regulatory implications. The lack of studies on leave-on C&PCPs is significant, suggesting a severe knowledge gap regarding microplastic presence in, and emissions from, C&PCPs. There is a noticeable lack of studies on the (eco)toxicological consequences of microplastic exposure from C&PCPs. As a result, significant aspects of microplastic contamination may be overlooked in the microplastic legislations emerging globally (including from the European Commission), which intend to restrict microplastic use in C&PCPs but focus on rinse-off C&PCPs only. This review highlights the potential consequences of microplastics in leave-on C&PCPs for regulatory decision-making, particularly as alternatives to microplastics are considered during the phase-out periods and spotlights the need for sufficient monitoring and research on these alternatives, to avoid unforeseen consequences.

A systematic review on the impact of micro-nanoplastics on human health: Potential modulation of epigenetic mechanisms and identification of biomarkers

Epigenetic-mediated modifications, induced by adverse environmental conditions, significantly alter an organism's physiological mechanisms. Even after elimination of the stimulus, these epigenetic modifications can be inherited through mitosis, thereby triggering transgenerational epigenetics. Plastics, with their versatile properties, are indispensable in various aspects of daily life. However, due to mismanagement, plastics have become so ubiquitous in the environment that no ecosystem on Earth is free from micro-nanoplastics (MNPs). This situation has raised profound concerns regarding their potential impact on human health. Recently, both in vivo animal and in vitro human cellular models have shown the potential to identify the harmful effects of MNPs at the genome level. The emerging epigenetic impact of MNP exposure is characterized by short-term alterations in chromatin remodelling and miRNA modulation. However, to understand long-term epigenetic changes and potential transgenerational effects, substantial and more environmentally realistic exposure studies are needed. In the current review, the intricate epigenetic responses, including the NHL-2-EKL-1, NDK-1-KSR1/2, and WRT-3-ASP-2 cascades, wnt-signalling, and TGF- β signalling, established in model organisms such as C. elegans, mice, and human cell lines upon exposure to MNPs, were systematically examined. This comprehensive analysis aimed to predict human pathways by identifying human homologs using databases and algorithms. We are confident that various parallel miRNA pathways, specifically the KSR-ERK-MAPK pathway, FOXO-Insulin cascade, and GPX3-HIF-α in humans, may be influenced by MNP exposure. This influence may lead to disruptions in key metabolic and immune pathways, including glucose balance, apoptosis, cell proliferation, and angiogenesis. Therefore, we believe that these genes and pathways could serve as potential biomarkers for future studies. Additionally, this review emphasizes the origin, dispersion, and distribution of plastics, providing valuable insights into the complex relationship between plastics and human health while elaborating on the epigenetic impacts.

Internalization of nano- and micro-plastics in human erythrocytes leads to oxidative stress and estrogen receptor-mediated cellular responses

Plastic material versatility has resulted in a substantial increase in its use in several sectors of our everyday lives. Consequently, concern regarding human exposure to nano-plastics (NPs) and micro-plastics (MPs) has recently increased. It has been shown that plastic particles entering the bloodstream may adhere to the erythrocyte surface and exert adverse effects following erythrocyte aggregation and adhesion to blood vessels. Here, we explored the effects of polystyrene nano-plastics (PS-NPs) and micro-plastics (PS-MPs) on human erythrocytes. Cellular morphology, binding/internalization of PS-NPs and PS-MPs, oxidative stress parameters, as well as the distribution and anion exchange capability of band 3 (anion exchanger 1; SLC4A1) have been analyzed in human erythrocytes exposed to 1 μg/mL PS-NPs or PS-MPs for 3 and 24 h, respectively. The data obtained showed significant modifications of the cellular shape after exposure to PS-NPs or PS-MPs. In particular, a significantly increased number of acanthocytes, echinocytes and leptocytes were detected. However, the percentage of eryptotic cells (<1 %) was comparable to physiological conditions. Analytical cytology and confocal microscopy showed that PS-NPs and PS-MPs bound to the erythrocyte plasma membrane, co-localized with estrogen receptors (Erα/ERβ), and were internalized. An increased trafficking from the cytosol to the erythrocyte plasma membrane and abnormal distribution of ERs were also observed, consistent with ERα-mediated binding and internalization of PS-NPs. An increased phosphorylation of ERK1/2 and AKT kinases indicated that an activation of the ER-modulated non-genomic pathway occurred following exposure to PS-NPs and PS-MPs. Interestingly, PS-NPs or PS-MPs caused a significant production of reactive oxygen species, resulting in an increased lipid peroxidation and protein sulfhydryl group oxidation. Oxidative stress was also associated with an altered band 3 ion transport activity and increased oxidized haemoglobin, which led to abnormal clustering of band 3 on the plasma membrane. Taken together, these findings identify cellular events following the internalization of PS-NPs or PS-MPs in human erythrocytes and contribute to elucidating potential oxidative stress-related harmful effects, which may affect erythrocyte and systemic homeostasis.

Kinetics and toxicity of nanoplastics in ex vivo exposed human whole blood as a model to understand their impact on human health

The ubiquitous presence of nanoplastics (NPLs) in the environment is considered of great health concern. Due to their size, NPLs can cross both the intestinal and pulmonary barriers and, consequently, their presence in the blood compartment is expected. Understanding the interactions between NPLs and human blood components is required. In this study, to simulate more adequate real exposure conditions, the whole blood of healthy donors was exposed to five different NPLs: three polystyrene NPLs of approximately 50 nm (aminated PS-NH2, carboxylated PS-COOH, and pristine PS- forms), together with two true-to-life NPLs from polyethylene terephthalate (PET) and polylactic acid (PLA) of about 150 nm. Internalization was determined in white blood cells (WBCs) by confocal microscopy, once the different main cell subtypes (monocytes, polymorphonucleated cells, and lymphocytes) were sorted by flow cytometry. Intracellular reactive oxygen species (iROS) induction was determined in WBCs and cytokine release in plasma. In addition, hemolysis, coagulation, and platelet activation were also determined. Results showed a differential uptake between WBC subtypes, with monocytes showing a higher internalization. Regarding iROS, lymphocytes were those with higher levels, which was observed for different NPLs. Changes in cytokine release were also detected, with higher effects observed after PLA- and PS-NH2-NPL exposure. Hemolysis induction was observed after PS- and PS-COOH-NPL exposure, but no effects on platelet functionality were observed after any of the treatments. To our knowledge, this is the first study comprehensively evaluating the bloodstream kinetics and toxicity of NPL from different polymeric types on human whole blood, considering the role played by the cell subtype and the NPLs physicochemical characteristics in the effects observed after the exposures.

Research Progress on Micro(nano)plastic-Induced Programmed Cell Death Associated with Disease Risks

Due to their robust migration capabilities, slow degradation, and propensity for adsorbing environmental pollutants, micro(nano)plastics (MNPs) are pervasive across diverse ecosystems. They infiltrate various organisms within different food chains through multiple pathways including inhalation and dermal contact, and pose a significant environmental challenge in the 21st century. Research indicates that MNPs pose health threats to a broad range of organisms, including humans. Currently, extensive detection data and studies using experimental animals and in vitro cell culture indicate that MNPs can trigger various forms of programmed cell death (PCD) and can induce various diseases. This review provides a comprehensive and systematic analysis of different MNP-induced PCD processes, including pyroptosis, ferroptosis, autophagy, necroptosis, and apoptosis, based on recent research findings and focuses on elucidating the links between PCD and diseases. Additionally, targeted therapeutic interventions for these diseases are described. This review provides original insights into the opportunities and challenges posed by current research findings. This review evaluates ways to mitigate various diseases resulting from cell death patterns. Moreover, this paper enhances the understanding of the biohazards associated with MNPs by providing a systematic reference for subsequent toxicological research and health risk mitigation efforts.

Synergy under the Sun? Nanoplastics Enhance Estrogenicity of Common UV-Blocker

Human cells and zebrafish coexposed to nanoplastics and the sunscreen ingredient homosalate showed more plastics in tissues, estrogenic activity, and relevant gene expression changes than they showed after either exposure alone.

Sonicated polyethylene terephthalate nano- and micro-plastic-induced inflammation, oxidative stress, and autophagy in vitro

The environmental presence of nano- and micro-plastic particles (NMPs) is suspected to have a negative impact on human health. Environmental NMPs are difficult to sample and use in life science research, while commercially available plastic particles are too morphologically uniform. Additionally, this NMPs exposure exhibited biological effects, including cell internalization, oxidative stress, inflammation, cellular adaptation, and genotoxicity. Therefore, developing new methods for producing heterogenous NMPs as observed in the environment is important as reference materials for research. Thus, we aimed to generate and characterize NMPs suspensions using a modified ultrasonic protocol and to investigate their biological effects after exposure to different human cell lines. To this end, we produced polyethylene terephthalate (PET) NMPs suspensions and characterized the particles by dynamic light scattering and scanning electron microscopy. Ultrasound treatment induced polymer degradation into smaller and heterogeneous PET NMPs shape fragments with similar surface chemistry before and after treatment. A polydisperse suspension of PET NMPs with 781 nm in average size and negative surface charge was generated. Then, the PET NMPs were cultured with two human cell lines, A549 (lung) and HaCaT (skin), addressing inhalation and topical exposure routes. Both cell lines interacted with and have taken up PET NMPs as quantified via cellular granularity assay. A549 but not HaCaT cell metabolism, viability, and cell death were affected by PET NMPs. In HaCaT keratinocytes, large PET NMPs provoked genotoxic effects. In both cell lines, PET NMPs exposure affected oxidative stress, cytokine release, and cell morphology, independently of concentration, which we could relate mechanistically to Nrf2 and autophagy activation. Collectively, we present a new PET NMP generation model suitable for studying the environmental and biological consequences of exposure to this polymer.

Micro(nano)-plastics exposure induced programmed cell death and corresponding influence factors

Plastic products have played an indispensable role in our daily lives for several decades, primarily due to their cost-effectiveness and unmatched convenience. Nevertheless, recent developments in nanotechnology have propelled our attention toward a distinct category of plastic fine particulates known as micro(nano)-plastics (MPs/NPs). The investigation of the cytotoxic effects of MPs/NPs has emerged as a central and burgeoning area of research in environmental toxicology and cell biology. In the scope of this comprehensive review, we have meticulously synthesized recent scientific inquiries to delve into the intricate interplay between MPs/NPs and programmed cell death mechanisms, which encompass a range of highly regulated processes. First, the signaling pathways and molecular mechanisms of different programmed death modalities induced by MPs/NPs were elaborated, including apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. The causes of different programmed deaths induced by MPs/NPs, such as size, surface potential, functional group modification, aging, biological crown, and co-exposure of MPs/NPs are further analyzed. In contrast, the various cellular programmed death modes induced by MPs/NPs are not alone most of the time, and lastly, the connections between different cellular programmed death modes induced by MPs/NPs, such as interconversion, mutual promotion, and mutual inhibition, are explained. Our primary objective is to unveil the multifaceted toxicological implications of MPs/NPs on the intricate web of cellular fate and biological homeostasis. This endeavor not only broadens our understanding of the potential risks associated with MPs/NPs exposure but also underscores the urgent need for comprehensive risk assessments and regulatory measures in the context of environmental health.

Microplastics in dermatology: Potential effects on skin homeostasis

BACKGROUND

Microplastics (MPs) and nanoplastics (NPs) have become a growing concern in dermatology due to their widespread presence in cosmetic formulations and the environment. These minuscule synthetic polymer particles prompt an essential exploration of their potential impact on dermatological homeostasis.

AIMS

This study aims to investigate the effects of MPs and NPs on the integumentary system. Specifically, it seeks to understand the potential cutaneous alterations, inflammatory responses, and disruptions to the skin's physiological functions caused by these synthetic particles.

PATIENTS/METHODS

The investigation involves a comprehensive analysis of emerging research on MPs and NPs. This includes their presence in cosmetic formulations and environmental pervasiveness. The study delves into their capacity to breach the cutaneous barrier, raising concerns about the implications of prolonged exposure.

RESULTS

Evidence suggests that MPs and NPs may indeed incite cutaneous alterations, provoke inflammatory responses, and disturb the homeostasis of the skin's physiological functions. Their small dimensions enhance their capability to breach the cutaneous barrier, further emphasizing the apprehensions associated with prolonged exposure.

CONCLUSIONS

While a precise understanding of the implications of MPs and NPs on dermatological health remains an ongoing scientific endeavor, this study underscores the growing significance of these synthetic particles. The findings emphasize the need for proactive measures to safeguard both individual well-being and environmental preservation in the context of dermatological health.

Combined Effects of Polystyrene Nanosphere and Homosolate Exposures on Estrogenic End Points in MCF-7 Cells and Zebrafish

BACKGROUND

Micro- and nanoplastics (MNPs) and homosalate (HMS) are ubiquitous emerging environmental contaminants detected in human samples. Despite the well-established endocrine-disrupting effects (EDEs) of HMS, the interaction between MNPs and HMS and its impact on HMS-induced EDEs remain unclear.

OBJECTIVES

This study aimed to investigate the influence of MNPs on HMS-induced estrogenic effects and elucidate the underlying mechanisms in vitro and in vivo.

METHODS

We assessed the impact of polystyrene nanospheres (PNSs; 50  nm , 1.0 mg / L ) on HMS-induced MCF-7 cell proliferation (HMS: 0.01 - 1 μ M , equivalent to 2.62 - 262 μ g / L ) using the E-SCREEN assay and explored potential mechanisms through transcriptomics. Adult zebrafish were exposed to HMS (0.0262 - 262 μ g / L ) with or without PNSs (50  nm , 1.0 mg / L ) for 21 d. EDEs were evaluated through gonadal histopathology, fertility tests, steroid hormone synthesis, and gene expression changes in the hypothalamus-pituitary-gonad-liver (HPGL) axis.

RESULTS

Coexposure of HMS and PNSs resulted in higher expression of estrogen receptor α (ESR1) and the mRNAs of target genes (pS2, AREG, and PGR), a greater estrogen-responsive element transactivation activity, and synergistic stimulation on MCF-7 cell proliferation. Knockdown of serum and glucocorticoid-regulated kinase 1 (SGK1) rescued the MCF-7 cell proliferation induced by PNSs alone or in combination with HMS. In zebrafish, coexposure showed higher expression of SGK1 and promoted ovary development but inhibited spermatogenesis. In addition, coexposure led to lower egg hatchability, higher embryonic mortality, and greater larval malformation. Coexposure also modulated steroid hormone synthesis genes (cyp17a2, hsd17[Formula: see text]1, esr2b, vtg1, and vtg2), and resulted in higher 17 β -estradiol (E 2 ) release in females. Conversely, males showed lower testosterone, E 2 , and gene expressions of cyp11a1, cyp11a2, cyp17a1, cyp17a2, and hsd17[Formula: see text]1.

DISCUSSION

PNS exposure exacerbated HMS-induced estrogenic effects via SGK1 up-regulation in MCF-7 cells and disrupting the HPGL axis in zebrafish, with gender-specific patterns. This offers new mechanistic insights and health implications of MNP and contaminant coexposure. https://doi.org/10.1289/EHP13696.

Effects of nanomaterial exposure on telomere dysfunction, hallmarks of mammalian and zebrafish cell senescence, and zebrafish mortality

Environmental and occupational exposure to hazardous substances accelerates biological aging. However, the toxic effects of nanomaterials on telomere and cellular senescence (major hallmarks of the biological aging) remained controversial. This study was to synthesize all published evidence to explore the effects of nanomaterial exposure on the telomere change, cellular senescence and mortality of model animals. Thirty-five studies were included by searching electronic databases (PubMed, Embase and Web of Science). The pooled analysis by Stata 15.0 software showed that compared with the control, nanomaterial exposure could significantly shorten the telomere length [measured as kbp: standardized mean difference (SMD) = -1.88; 95% confidence interval (CI) = -3.13 - - 0.64; % of control: SMD = -1.26; 95%CI = -2.11- - 0.42; < 3 kbp %: SMD = 5.76; 95%CI = 2.92 - 8.60), increase the telomerase activity (SMD = -1.00; 95%CI = -1.74 to -0.26), senescence-associated β-galactosidase levels in cells (SMD = 8.20; 95%CI = 6.05 - 10.34) and zebrafish embryos (SMD = 7.32; 95%CI = 4.70 - 9.94) as well as the mortality of zebrafish (SMD = 3.83; 95%CI = 2.94 - 4.72)]. The expression levels of telomerase TERT, shelterin components (TRF1, TRF2 and POT1) and senescence biomarkers (p21, p16) were respectively identified to be decreased or increased in subgroup analyses. In conclusion, this meta-analysis demonstrates that nanomaterial exposure is associated with telomere attrition, cell senescence and organismal death.

Adverse Effects of Micro- and Nanoplastics on Humans and the Environment

The pervasive pollution caused by nano- and microplastics (N/MPLs) is a pressing concern, and was exacerbated during the COVID-19 pandemic due to the substantial release of disposable Personal Protective Equipment (PPE) into the environment [...].

Micro- and nanoplastics (MNPs) and their potential toxicological outcomes: State of science, knowledge gaps and research needs

Plastic waste has been produced at a rapidly growing rate over the past several decades. The environmental impacts of plastic waste on marine and terrestrial ecosystems have been recognized for years. Recently, researchers found that micro- and nanoplastics (MNPs), micron (100 nm - 5 mm) and nanometer (1 - 100 nm) scale particles and fibers produced by degradation and fragmentation of plastic waste in the environment, have become an important emerging environmental and food chain contaminant with uncertain consequences for human health. This review provides a comprehensive summary of recent findings from studies of potential toxicity and adverse health impacts of MNPs in terrestrial mammals, including studies in both in vitro cellular and in vivo mammalian models. Also reviewed here are recently released biomonitoring studies that have characterized the bioaccumulation, biodistribution, and excretion of MNPs in humans. The majority MNPs in the environment to which humans are most likely to be exposed, are of irregular shapes, varied sizes, and mixed compositions, and are defined as secondary MNPs. However, the MNPs used in most toxicity studies to date were commercially available primary MNPs of polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and other polymers. The emerging in vitro and in vivo evidence reviewed here suggests that MNP toxicity and bioactivity are largely determined by MNP particle physico-chemical characteristics, including size, shape, polymer type, and surface properties. For human exposure, MNPs have been identified in human blood, urine, feces, and placenta, which pose potential health risks. The evidence to date suggests that the mechanisms underlying MNP toxicity at the cellular level are primarily driven by oxidative stress. Nonetheless, large knowledge gaps in our understanding of MNP toxicity and the potential health impacts of MNP exposures still exist and much further study is needed to bridge those gaps. This includes human population exposure studies to determine the environmentally relevant MNP polymers and exposure concentrations and durations for toxicity studies, as well as toxicity studies employing environmentally relevant MNPs, with surface chemistries and other physico-chemical properties consistent with MNP particles in the environment. It is especially important to obtain comprehensive toxicological data for these MNPs to understand the range and extent of potential adverse impacts of microplastic pollutants on humans and other organisms.

Assessing the Impact of Polyethylene Nano/Microplastic Exposure on Human Vaginal Keratinocytes

The global rise of single-use throw-away plastic products has elicited a massive increase in the nano/microplastics (N/MPLs) exposure burden in humans. Recently, it has been demonstrated that disposable period products may release N/MPLs with usage, which represents a potential threat to women's health which has not been scientifically addressed yet. By using polyethyl ene (PE) particles (200 nm to 9 μm), we showed that acute exposure to a high concentration of N/MPLs induced cell toxicity in vaginal keratinocytes after effective cellular uptake, as viability and apoptosis data suggest, along with transmission electron microscopy (TEM) observations. The internalised N/MPLs altered the expression of junctional and adherence proteins and the organisation of the actin cortex, influencing the level of genes involved in oxidative stress signalling pathways and that of miRNAs related to epithelial barrier function. When the exposure to PE N/MPLs was discontinued or became chronic, cells were able to recover from the negative effects on viability and differentiation/proliferation gene expression in a few days. However, in all cases, PE N/MPL exposure prompted a sustained alteration of DNA methyltransferase and DNA demethylase expression, which might impact epigenetic regulation processes, leading to accelerated cell ageing and inflammation, or the occurrence of malignant transformation.

SKN-1/Nrf2-dependent regulation of mitochondrial homeostasis modulates transgenerational toxicity induced by nanoplastics with different surface charges in Caenorhabditis elegans

The toxic effects of nanoplastics on transgenerational toxicity in environmental organisms and the involved mechanisms remain poorly comprehended. This study aimed to identify the role of SKN-1/Nrf2-dependent regulation of mitochondrial homeostasis in response to transgenerational toxicity caused by changes in nanoplastic surface charges in Caenorhabditis elegans (C. elegans). Our results revealed that compared with the wild-type control and PS exposed groups, exposure to PS-NH₂ or PS-SOOOH at environmentally relevant concentrations (ERC) of ≥ 1 μg/L caused transgenerational reproductive toxicity, inhibited mitochondrial unfolded protein responses (UPR) by downregulating the transcription levels of hsp-6, ubl-5, dve-1, atfs-1, haf-1, and clpp-1, membrane potential by downregulating phb-1 and phb-2, and promoted mitochondrial apoptosis by downregulating ced-4 and ced-3 and upregulating ced-9, DNA damage by upregulating hus-1, cep-1, egl-1, reactive oxygen species (ROS) by upregulating nduf-7 and nuo-6, ultimately resulting in mitochondrial homeostasis. Additionally, further study indicated that SKN-1/Nrf2 mediated antioxidant response to alleviate PS-induced toxicity in the P0 generation and dysregulated mitochondrial homeostasis to enhance PS-NH₂ or PS-SOOOH-induced transgenerational toxicity. Our study highlights the momentous role of SKN-1/Nrf2 mediated mitochondrial homeostasis in the response to nanoplastics caused transgenerational toxicity in environmental organisms.

In Vitro Approaches to Determine the Potential Carcinogenic Risk of Environmental Pollutants

One important environmental/health challenge is to determine, in a feasible way, the potential carcinogenic risk associated with environmental agents/exposures. Since a significant proportion of tumors have an environmental origin, detecting the potential carcinogenic risk of environmental agents is mandatory, as regulated by national and international agencies. The challenge mainly implies finding a way of how to overcome the inefficiencies of long-term trials with rodents when thousands of agents/exposures need to be tested. To such an end, the use of in vitro cell transformation assays (CTAs) was proposed, but the existing prevalidated CTAs do not cover the complexity associated with carcinogenesis processes and present serious limitations. To overcome such limitations, we propose to use a battery of assays covering most of the hallmarks of the carcinogenesis process. For the first time, we grouped such assays as early, intermediate, or advanced biomarkers which allow for the identification of the cells in the initiation, promotion or aggressive stages of tumorigenesis. Our proposal, as a novelty, points out that using a battery containing assays from all three groups can identify if a certain agent/exposure can pose a carcinogenic risk; furthermore, it can gather mechanistic insights into the mode of the action of a specific carcinogen. This structured battery could be very useful for any type of in vitro study, containing human cell lines aiming to detect the potential carcinogenic risks of environmental agents/exposures. In fact, here, we include examples in which these approaches were successfully applied. Finally, we provide a series of advantages that, we believe, contribute to the suitability of our proposed approach for the evaluation of exposure-induced carcinogenic effects and for the development of an alternative strategy for conducting an exposure risk assessment.

Exposure to nanoplastics induces mitochondrial impairment and cytomembrane destruction in Leydig cells

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 μg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17β-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.

Isolation and characterization of microplastics from skin care products; interactions with albumin proteins and in-vivo toxicity studies on Artemia salina

Skincare products are a significant source of primary microplastics (MPs). This study isolates and characterizes microplastic from two skin care products: face wash (FW-MPs) and face scrub (FS-MPs). Microplastics extracted were around 660 µm in size. The extracted MPs, designated as unground MPs (UG-MPs), were smooth surface and spherical. Ground ones were denoted as the ground MPs (G-MPs) that varied in size and surface shape. G-MPs interacted with bovine serum albumin (BSA) and human serum albumin (HSA). BSA adsorption on FW-MPs was 29%, whereas HSA adsorption was 47%. Contrarily, FS-MPs displayed 17% and 31%. Fluorescence spectroscopy and FE-SEM images showed HSA adsorption on G-MPs was greater than BSA. G-MP interaction changed the life cycle of Artemia salina. UV-Vis and fluorescence spectroscopy were used to study protein adsorption and desorption on G-MPs. A. salina treated to 2.5 mg/mL G-MPs delayed hatching and development and internalized microplastics in the gut at 144 h exposure.

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

Polystyrene nanoplastics affect transcriptomic and epigenomic signatures of human fibroblasts and derived induced pluripotent stem cells: Implications for human health

Plastic pollution is increasing at an alarming rate yet the impact of this pollution on human health is poorly understood. Because human induced pluripotent stem cells (hiPSC) are frequently derived from dermal fibroblasts, these cells offer a powerful platform for the identification of molecular biomarkers of environmental pollution in human cells. Here, we describe a novel proof-of-concept for deriving hiPSC from human dermal fibroblasts deliberately exposed to polystyrene (PS) nanoplastic particles; unexposed hiPSC served as controls. In parallel, unexposed hiPSC were exposed to low and high concentrations of PS nanoparticles. Transcriptomic and epigenomic signatures of all fibroblasts and hiPSCs were defined using RNA-seq and whole genome methyl-seq, respectively. Both PS-treated fibroblasts and derived hiPSC showed alterations in expression of ESRRB and HNF1A genes and circuits involved in the pluripotency of stem cells, as well as in pathways involved in cancer, inflammatory disorders, gluconeogenesis, carbohydrate metabolism, innate immunity, and dopaminergic synapse. Similarly, the expression levels of identified key transcriptional and DNA methylation changes (DNMT3A, ESSRB, FAM133CP, HNF1A, SEPTIN7P8, and TTC34) were significantly affected in both PS-exposed fibroblasts and hiPSC. This study illustrates the power of human cellular models of environmental pollution to narrow down and prioritize the list of candidate molecular biomarkers of environmental pollution. This knowledge will facilitate the deciphering of the origins of environmental diseases.

Investigating nanoplastics toxicity using advanced stem cell-based intestinal and lung in vitro models

Plastic particles in the nanometer range-called nanoplastics-are environmental contaminants with growing public health concern. As plastic particles are present in water, soil, air and food, human exposure via intestine and lung is unavoidable, but possible health effects are still to be elucidated. To better understand the Mode of Action of plastic particles, it is key to use experimental models that best reflect human physiology. Novel assessment methods like advanced cell models and several alternative approaches are currently used and developed in the scientific community. So far, the use of cancer cell line-based models is the standard approach regarding in vitro nanotoxicology. However, among the many advantages of the use of cancer cell lines, there are also disadvantages that might favor other approaches. In this review, we compare cell line-based models with stem cell-based in vitro models of the human intestine and lung. In the context of nanoplastics research, we highlight the advantages that come with the use of stem cells. Further, the specific challenges of testing nanoplastics in vitro are discussed. Although the use of stem cell-based models can be demanding, we conclude that, depending on the research question, stem cells in combination with advanced exposure strategies might be a more suitable approach than cancer cell lines when it comes to toxicological investigation of nanoplastics.

Particulate plastics in drinking water and potential human health effects: Current knowledge for management of freshwater plastic materials in Africa

Plastic materials have contributed to the release of environmentally relevant particulate plastics which can be found almost everywhere and may be present in drinking water. Human exposure to these materials is diverse and our understanding of their internalization in the human body is incipient. This review discusses the state of knowledge of particulate plastics exposure in drinking water and the potential risks of adverse health in the human body. Particulate plastics have problematized water systems worldwide, and about 4,000,000 fine plastics may be ingested from drinking water annually by an individual. Testing methods for these materials in environmental media are presently inconsistent and standard protocols do not exist. Their potential ecotoxicological consequences are recognised to be linked to their physicochemical diversity, biological transpositions, and cytological tolerance in living organisms. It is observed that toxicological endpoints are varied and lack properly defined modes of action. In particular, fine particulate plastics have been observed to translocate into body tissues and cells where they are capable of provoking endocrine disruption, genetic mutations, and cancer responses. We propose a reclassification of particulate plastics to cater for their biological deposition and attributable risks of adverse health. Environmental management of particulate plastics in many developing countries is weak and their potential releases into drinking water have received limited research. Given that large populations are exposed to fresh surface water and plastic packaged drinking water worldwide, and that the risk assessment pathways are unvalidated at the moment, we argue for developing countries to increase their capacity for the environmental monitoring and circular management of plastic materials. Large-scale epidemiological cohort studies and surrogate assessment pathways are also recommended to provide a better understanding of the hazard characterization of particulate plastics exposure.

Multispectroscopy analysis of polystyrene nanoplastic interaction with diastase α-amylase

The digestive enzyme of plant are generally α-amylase. They functions enzyme that breakdown starch into maltose and sugars. This happens in the endosperm of the seed. Due to pollutants, this process get happened one of emergent xenobiotics are micro and nano plastics. This study involves the interaction 100 nm size of polystyrene nano plastic (PSNPs) on α-amylase. The hyperchromism of α-amylase - PSNPs conjugate's revealed that ground-state complex in a microenvironment. Fluorescence quenching happened when the concentration of PSNPs was increased. The Stern Volmer plot revealed binding constant (K_a) was 1.904 × 1019 M^-1. S^-1 while the quenching constant (K_q) was 1.036 × 1011 M^-1, the blue shift of the peak showed static quenching. The binding constant was K_A = 4.2 × 1012, the number of binding site on PSNPs for α-amylase was n = 1.12. The synchronous result showed a gradual reduction in the intensity of Trp residues because when the α-amylase interacts with PSNPs short-range π-π interaction happens around the Trp163 residues. The enzyme activity of α-amylase by 44 % and its IC₅₀ value was found to be 100 µg/mL. The enzyme kinetics (Vmax) analysis showed the type of inhibition with and without PSNPs Vmax 769 and Vmax 303 µg/mL/min, uncompetitive inhibition respectively. The effect of PSNPs on the enzymatic activity of α-amylase showed structural alterations of the protein. Therefore the in vitro and in silico studies were shown evidence of interaction between α-amylase and PSNPs leads to conformational structural changes in α-amylase.

A review on the impacts of nanomaterials on neuromodulation and neurological dysfunction using a zebrafish animal model

Nanomaterials have been widely employed from industrial to medical fields due to their small sizes and versatile characteristics. However, nanomaterials can also induce unexpected adverse effects on health. In particular, exposure of the nervous system to nanomaterials can cause serious neurological dysfunctions and neurodegenerative diseases. A number of studies have adopted various animal models to evaluate the neurotoxic effects of nanomaterials. Among them, zebrafish has become an attractive animal model for neurotoxicological studies due to several advantages, including the well-characterized nervous system, efficient genome editing, convenient generation of transgenic lines, high-resolution in vivo imaging, and an array of behavioral assays. In this review, we summarize recent studies on the neurotoxicological effects of nanomaterials, particularly engineered nanomaterials and nanoplastics, using zebrafish and discuss key findings with advantages and limitations of the zebrafish model in neurotoxicological studies.

Different effecting mechanisms of two sized polystyrene microplastics on microalgal oxidative stress and photosynthetic responses

Increasing marine microplastics (MPs) pollution potentially threatens the stability of phytoplankton community structures in marine environments. MPs toxicities to microalgae are largely determined by particle size, while the size-dependent mechanisms are still not fully understood. In this study, two sizes (0.1 µm and 1 µm) of polystyrene (PS) MPs were used as experimental targets to systemically compare their different effecting mechanisms on the marine model diatom Thalassiosira pseudonana with respect to oxidative stress and photosynthesis. The results indicated the toxicity of 1 µm sized MPs was higher than 0.1 µm sized MPs regarding to population growth. In condition of similar microalgal population inhibition rates, we found more enhanced cellular oxidative stress and cell death happened in the 1 µm MPs treatments, which could be linked to higher zeta potential of 1 µm MPs and more severe cell surface damage; microalgal surface light shading and cellular pigments decline were more obvious in the 0.1 µm MPs treatment, which could be linked to high aggregation abilities of 0.1 µm MPs. Gene expressions supported the morphological and physiological findings on the transcriptional level. Environmental related MPs concentrations (5 μg L^-1) also aroused gene expression changes of T. pseudonana while more changing genes were found under 0.1 µm MPs than 1 µm MPs. These results provide novel insights into the size-dependent mechanisms of MPs toxicity on marine microalgae, as well as their potential influence on the marine environment.

Exposure to nanopolystyrene and its 4 chemically modified derivatives at predicted environmental concentrations causes differently regulatory mechanisms in nematode Caenorhabditis elegans

Nanoplastics represented by nanopolystyrene (NPS) and its chemically modified derivatives are environmentally ecotoxicological hotpots in recent years, but their toxicity and underlying mechanisms have not been fully identified. Here we employed Caenorhabditis elegans as an animal model to systematically compare the toxicity between nanopolystyrene and its 4 chemically modified derivatives (PS-PEG, PS-COOH, PS-SOOOH and PS-NH₂) at predicted environmental concentrations. Our study demonstrated that compared with PS exposed group, PS-NH₂ exposure (15 μg/L) caused a significant decline in lifespan by suppressed DAF-16/insulin signaling and shortened body length by inhibiting DBL-1/TGF β signaling. Different from PS-NH₂ exposed group, PS-SOOOH exposure (15 μg/L) could not cause changes in lifespan, but shortened body length by inhibiting DBL-1/TGF β signaling. In addition, PS-COOH, PS-SOOOH or PS-NH₂ exposure (1 μg/L or 15 μg/L) caused more serious toxicity in reducing locomotion behavior and causing gut barrier deficit. Hence the rank order in toxicity of PS-NH₂＞PS-SOOOH＞PS-COOH＞PS＞PS-PEG was identified. Furthermore, we also presented evidence to support the contention that the observed toxic effects on nematodes were linked to oxide stress and activation of anti-oxidative molecules for reversing the adverse effects induced by nanopolystyrene and its 4 chemically modified derivatives. Our data highlighted nanoplastics may be charge-dependently toxic to environmental organisms, and the screened low toxic modification may support polystyrene nanoparticles continued application for daily consumer goods and biomedicine.

Long-term exposure to nanoplastics alters molecular and functional traits related to the carcinogenic process

Micro/nanoplastics (MNPLs) are considered emergent pollutants widely spread over all environmental compartments. Although their potential biological effects are being intensively evaluated, many doubts remain about their potential health effects in humans. One of the most underdeveloped fields is the determination of the potential tumorigenic risk of MNPLs exposure. To shed light on this topic, we have designed a wide battery of different hallmarks of cancer applied to prone-to-transformed progress MEF cells exposed to polystyrene nanoplastics (PSNPLs) in the long term (6 months). Interestingly, most of the evaluated hallmarks of cancer are exacerbated after exposure, independently if they are associated with an early tumoral phenotype (changes in stress-related genes, or microRNA deregulation), advanced tumoral phenotype (growing independently of anchorage ability, and migration capacity), or an aggressive tumoral phenotype (invasion potential, changes in pluripotency markers, and ability to grow to form tumorspheres). This set of obtained data constitutes a relevant warning on the potential carcinogenic risk associated with long-term exposures to MNPLs, specifically that induced by the PSNPLs evaluated in this study.

The interaction of micro/nano plastics and the environment: Effects of ecological corona on the toxicity to aquatic organisms

Concerns about the micro/nano plastics (MNPs) exposure risks have risen in recent years. The ecological corona (EC), which is generated by the interaction between MNPs and environmental substances, has a significant impact on their environmental fate and ecological risks. As the largest sink of MNPs, the aquatic environment is of great significance for understanding the environmental behaviour of MNPs. Transmission Electron Microscope (TME), Fourier Transform Infra-Red (FTIR), Scanning Electron Microscope (SEM), Dynamic Light Scattering (DLS) and other analytical methods have been used as effective methods to analyse the formation process of EC and detect the existing EC directly or indirectly on the surface of MNPs. The physicochemical properties of MNPs, complex aquatic environments and ageing time have been identified as the key factors affecting EC formation in aquatic environments. Moreover, the EC absorbed on MNPs significantly changed their environmental behaviour and toxicity to aquatic organisms. This review gives a full understanding of the EC formation progress on the surface of MNPs and different analytical methods for EC have been summarised which can further assist the ecological risk assessment of MNPs in the aquatic environment.

Deeply in Plasticenta: Presence of Microplastics in the Intracellular Compartment of Human Placentas

Microplastics (MPs) are defined as plastic particles smaller than 5 mm. They have been found almost everywhere they have been searched for and recent discoveries have also demonstrated their presence in human placenta, blood, meconium, and breastmilk, but their location and toxicity to humans have not been reported to date. The aim of this study was twofold: 1. To locate MPs within the intra/extracellular compartment in human placenta. 2. To understand whether their presence and location are associated with possible structural changes of cell organelles. Using variable pressure scanning electron microscopy and transmission electron microscopy, MPs have been localized in ten human placentas. In this study, we demonstrated for the first time the presence and localization in the cellular compartment of fragments compatible with MPs in the human placenta and we hypothesized a possible correlation between their presence and important ultrastructural alterations of some intracytoplasmic organelles (mitochondria and endoplasmic reticulum). These alterations have never been reported in normal healthy term pregnancies until today. They could be the result of a prolonged attempt to remove and destroy the plastic particles inside the placental tissue. The presence of virtually indestructible particles in term human placenta could contribute to the activation of pathological traits, such as oxidative stress, apoptosis, and inflammation, characteristic of metabolic disorders underlying obesity, diabetes, and metabolic syndrome and partially accounting for the recent epidemic of non-communicable diseases.

Plastic particles in medicine: A systematic review of exposure and effects to human health

Single-use plastics (SUPs) have become an essential constituent of our daily life. It is being exploited in numerous pharmaceutical and healthcare applications. Despite their advantages and widespread use in the pharma and medical sectors, the potential clinical problems of plastics, especially the release of micro-nanoplastics (MNPs) and additives from medical plastics (e.g. bags, containers, and administrative sets) and sorption of drugs remain understudied. Certainly, the MNPs are multifaceted stressors that cause detrimental effects to the ecosystem and human health. The origin and persistence of MNPs in pharmaceutical products, their administration to humans, endurance and possible health implication, translocation, and excretion have not been reviewed in detail. The prime focus of this article is to conduct a systematic review on the leaching of MNPs and additives from pharmaceutical containers/administrative sets and their interaction with the pharmaceutical constituents. This review also explores the primary and secondary routes of MNPs entry from healthcare plastic products and their potential health hazards to humans. Furthermore, the fate of plastic waste generated in hospitals, their disposal, and associated MNPs release to the environment, along with preventive, and alternative measures are discussed herein.

Female mosquito-a potential vector for transporting plastic residues to humans

With the prodigious use of plastics in the industrial sector and daily life, plastic has become one of the fastest-growing sources of pollution in the aquatic environment. Therefore, ingestion of micro/nanoplastics (MP/NPs) by aquatic organisms is inevitable. But the knowledge on the definite effect, ontogenetic transfer, and translocation of NPs remains incipient. Thus, this study examines the abundance of MPs in mosquito larvae collected from the sewage pit. Additionally, this study demonstrates the MPs-mediated biochemical alterations and effects on development of mosquito, and then ontogenetic transfer and translocation of NPs in Aedes aegypti. Totally 1241 MPs belonging to polyethylene, polycarbonate, polypropylene, polystyrene, polyvinyl chloride and nylon with sizes ranging from 0.5 μm to 80 μm in diameter were isolated from the mosquito larvae. Indeed all the four stages of mosquito larvae feed on NPs and subsequently transfer them to non-feeding pupa and then to flying adult mosquitoes, further to the offspring. However, the NPs exposure and accumulation did not affect the survival of mosquitoes, but altered the biochemical constituents, thereby delaying the development of mosquitoes. Notably the female mosquitoes that emerged from the NPs treatment group showed increased blood-feeding activity and increased starvation resistance capacity. The puzzling accumulation of NPs/residues in different organs, especially in the salivary gland signifies that female mosquitoes could potentially inject polymer residues into humans and animals. At the outset, these observations emphasize that the mosquitoes act as a vector of NPs in the aqueous environment and transport them to terrestrial animals.

Influence of protein configuration on aggregation kinetics of nanoplastics in aquatic environment

Aggregation kinetics of nanoplastics in aquatic environment are influenced by their interactions with proteins having different structures and properties. This study employed time-resolved dynamic light scattering (TR-DLS) to investigate the effects of 5 proteins (bovine hemoglobin (BHb), bovine (BSA) and human serum albumin (HSA), collagen type I (Col I), and bovine casein (CS)) on aggregation kinetics of polystyrene nanoplastics (PSNPs) under natural water conditions, which were simulated using various ionic strength (1-1000 mM NaCl and 0.01-100 mM CaCl₂), pH (3-9), and protein concentration (1-5 mg/L of total organic carbon). The results indicated that the interactions between proteins and PSNPs strongly depended on electrostatic properties, protein structures, and solution chemistries, which induced distinct aggregation behaviors in NaCl and CaCl₂ solutions. Electrostatic repulsion and steric hindrance dominated their interactions in NaCl solution by stabilizing PSNPs with the order of spherical BSA and disordered CS > heart-shaped HSA > fibrillar Col I; whereas positively charged BHb destabilized PSNPs with aggregation rate of 1.71 nm/s at 300 mM NaCl. In contrast, at CaCl₂ concentration below 20 mM, proteins destabilized PSNPs following the sequence of HSA > BHb > Col I > BSA depending on counterbalance among double layer compression, cation bridging, and steric hindrance; whereas CS stabilized PSNPs by precipitating Ca²⁺ that inhibited charge screening effect. Both protein concentration and solution pH affected protein corona formation, surface charge, and protein structure that altered stability of PSNPs. Characterizations using fluorescence spectroscopy, circular dichroism, and two-dimensional correlation analysis spectroscopy showed fluorescence quenching and ellipticity reduction of proteins, indicating strong adsorption affinity between PSNPs and proteins. The study provides insight to how protein configuration and water chemistry affect fate and transport of nanoplastics in aquatic environment.

Exposure to polystyrene nanoplastics impairs lipid metabolism in human and murine macrophages in vitro

The use of polystyrene micro and nanoplastics in cosmetics and personal care products continues to grow every day. The harmful effects of their biological accumulation in organisms of all trophic levels including humans have been reported by several studies. While we have accumulating evidence on the impact of nanoplastics on different organ systems in humans, only a handful of reports on the impact of polystyrene nanoplastics upon direct contact with the immune system at the cellular level are avialable. The present study offers significant evidence on the cell-specific harmful impact of sulfate-modified nanoplastics (S-NPs) on human macrophages. Here we report that exposure of human macrophages to S-NPs (100 µg/mL) stimulated the accumulation of lipids droplets (LDs) in the cytoplasm resulting in the differentiation of macrophages into foam cells. The observed effect was specific for human and murine macrophages but not for other cell types, especially human keratinocytes, liver, and lung cell models. Furthermore, we found that S-NPs mediated LDs accumulation in human macrophages was accompanied by acute mitochondrial oxidative stress. The accumulated LDs were further delivered and accumulated into lysosomes leading to impaired lysosomal clearance. In conclusion, our study reveals that exposure to polystyrene nanoplastics stabilized with anionic surfactants can be a potent stimulus for dysregulation of lipid metabolism and macrophage foam cell formation, a characteristic feature observed during atherosclerosis posing a serious threat to human health.