Discovery and quantification of plastic particle pollution in human blood

NiO/AgNPs nanowell enhanced SERS sensor for efficient detection of micro/nanoplastics in beverages

The ubiquity of plastic products has led to an increased exposure to micro and nano plastics across diverse environments, presenting a novel class of pollutants with substantial health implications. Emerging research indicates their capacity to infiltrate human organs, posing risks of tissue damage and carcinogenesis. Given the prevalent consumption of beverages as a primary vector for these plastics' entry into the human system, there is an imperative need for the advancement of precise detection methodologies in liquids. In this study, we introduce a substrate comprising a Nickel Oxide (NiO) nanosheet array decorated with Silver Nanoparticles (AgNPs) for the Surface-Enhanced Raman Spectroscopy (SERS) analysis of micro//nano plastics. This configuration, leveraging a unique nanowell architecture alongside silver plasmonic enhancement, demonstrates unparalleled sensitivity and repeatability in signal, facilitating the accurate quantification of these contaminants. Through the application of a portable Raman apparatus, this study successfully identifies prevalent micro/nano plastics including polystyrene (PS), polyethylene (PE), and polypropylene (PP), achieving detection sensitivities of 5 μg/mL, 25 μg/mL, and 25 μg/mL, respectively. Moreover, the substrate's efficacy extends to the detection of PS within commonly consumed beverages such as water, milk, and liquor with sensitivities of 25 μg/mL, 50 μg/mL, and 50 μg/mL, respectively. These findings highlight the substrate's potential as an expedient and effective sensor for the real-time monitoring of micro/nano plastic pollutants.

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.

Long-term exposure of human U87 glioblastoma cells to polyethylene microplastics: Investigating the potential cancer progression

Precancerous cells are present in all human bodies. Various environmental triggers can promote the development of cancer. Microplastics, an emerging concern, may potentially act as one such trigger, contributing to cancer initiation or progression. Studies have confirmed the presence of microplastics within the human body. This raises concerns about their potential toxicity and health risks. In the present study, we aimed to investigate the impact of polyethylene microplastics (PE-MPs) within the size range of 37-75 microns on glioblastoma cancer cells. Initially, we assessed the short-term effects of six different concentrations of PE-MPs (20 mg/mL, 10 mg/mL, 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, and 0.62 mg/mL) on the U87 glioblastoma cell line. The results demonstrated that PE-MPs exposure led to an increase in cell proliferation compared to the untreated control group. Based on these findings, we decided to further explore the long-term effects of PE-MPs on U87 cancer cells. To evaluate the long-term effects, U87 glioblastoma cells were continuously exposed to 0.005 g of PE-MPs over an extended period of 26 days. Chronic exposure to PE-MPs significantly increased the proliferative and migratory capacities of U87 cells compared to the unexposed control group. Furthermore, continuous PE-MPs exposure altered the behavior and morphological characteristics of U87 cells. These cells exhibited a propensity to aggregate and form colonies within the culture flask. The formation of spheroid structures was also observed in the PE-MPs-exposed cell population. The results of this research indicate that polyethylene microplastics can promote the progression of glioblastoma cancer.

Integrin A5B1-mediated endocytosis of polystyrene nanoplastics: Implications for human lung disease and therapeutic targets

The extensive use of plastic products has exacerbated micro/nanoplastic (MPs/NPs) pollution in the atmosphere, increasing the incidence of respiratory diseases and lung cancer. This study investigates the uptake and cytotoxicity mechanisms of polystyrene (PS) NPs in human lung epithelial cells. Transcriptional analysis revealed significant changes in cell adhesion pathways following PS-NPs exposure. Integrin α5β1-mediated endocytosis was identified as a key promoter of PS-NPs entry into lung epithelial cells. Overexpression of integrin α5β1 enhanced PS-NPs internalization, exacerbating mitochondrial Ca2+ dysfunction and depolarization, which induced reactive oxygen species (ROS) production. Mitochondrial dysfunction triggered by PS-NPs led to oxidative damage, inflammation, DNA damage, and necrosis, contributing to lung diseases. This study elucidates the molecular mechanism by which integrin α5β1 facilitates PS-NPs internalization and enhances its cytotoxicity, offering new insights into potential therapeutic targets for microplastic-induced lung diseases.

Impact of Fenton aging on the incipient motion of microplastic particles in open-channel flow

Upon entering the environment, Microplastics (MPs) experience aging processes that modify their properties and integrity. Previous methods for predicting the incipient motion of MPs have been validated using pristine plastics, which do not account for the effects of aging. This can lead to uncertainties in both quantification and characterization. This study investigates the effect of aging on the incipient motion of MPs with different bed roughness (smooth and rough beds) and MP properties (e.g., grain sizes and densities) in an open-channel flow. Five types of MPs were subjected to four different degrees of aging using the Fenton reagent, and their incipient velocities were tested on beds with two distinct roughness. The results suggest that the incipient velocity of MPs increases linearly with aging. However, this increase is not uniform across different particles and bed roughness. Upon comparing various commonly employed sediment incipient velocity equations, experimental results are in agreement with Ruijin Zhang's equation as the most precise. The parameters in Ruijin Zhang's equation are modified to enhance its applicability for predicting the incipient velocity of aged MPs. This study provides novel insights into the incipient motion of aged MPs in an open-channel flow, highlighting the intricate interaction between aged MP characteristics and bed roughness.

Links between fecal microplastics and parameters related to metabolic dysfunction-associated steatotic liver disease (MASLD) in humans: An exploratory study

Microplastics (MPs) can persist in the environment and human body. Murine studies showed that exposure to MPs could cause metabolic dysregulation, contributing metabolic dysfunction-associated steatotic liver disease (MASLD) or steatohepatitis (MASH). However, research on the role of MPs in humans is limited. Thus, we aimed to assess links between human fecal MPs and liver histology, gene expression, immune cells and intestinal microbiota (IM). We included 6 lean healthy liver donors and 6 normal liver (obese) and 11 MASH patients. Overall, pre-BSx, we observed no significant differences in fecal MPs between groups. However, fecal MP fibers and total MPs positively correlated with portal and total macrophages and total killer T cells while total fecal MPs were positively correlated with natural killer cells. Additionally, 19 genes related to immune system and apoptosis correlated with fecal MPs at baseline. Fecal MP fibers correlated positively with fecal Bifidobacterium and negatively with Lachnospiraceae. Patients with MASH (n = 11) were re-assessed 12-months post-bariatric surgery (BSx) and we found that those with persistent disease (n = 4) had higher fecal MP fragments than those with normalized liver histology (n = 7). At 12-month post-BSx, MP fragments positively correlated with helper T cells and total MPs positively correlated with natural killer T cells and B cells. Our study is the first to look at 1) the role of MPs in MASH and its association with IM, immune cells and hepatic gene expression and 2) look at the role of MPs longitudinally in MASH persistence following BSx. Future research should further explore this relationship.

Exposure to polystyrene microplastics during lactational period alters immune status in both male mice and their offspring

The widespread use of microplastics and their harmful effects on the environment have emerged as serious concerns. However, the effect of microplastics on the immune system of mammals, particularly their offspring, has received little attention. In this study, polystyrene microplastics (PS-MPs) were orally administered to male mice during lactation. Flow cytometry was used to assess the immune cells in the spleens of both adult male mice and their offspring. The results showed that mice exposed to PS-MPs exhibited an increase in spleen weight and an elevated number of B and regulatory T cells (Tregs), irrespective of dosage. Furthermore, the F1 male offspring of the PS-MPs-exposed group had enlarged spleens; an increased number of B cells, T helper cells (Th cells), and Tregs; and an elevated ratio of T helper cells 17 (Th17 cells) to Tregs and T helper cells 1 (Th1 cells) to T helper cells 2 (Th2 cells). These results suggested a pro-inflammatory state in the spleen. In contrast, in the F1 female offspring exposed to PS-MPs, the changes in splenic immune cells were less pronounced. In the F2 generation of mice with exposed to PS-MPs, minimal alterations were observed in spleen immune cells and morphology. In conclusion, our study demonstrated that exposure to real human doses of PS-MPs during lactation in male mice altered the immune status, which can be passed on to F1 offspring but is not inherited across generations.

Are microplastics a new cardiac threat? A pilot study with wild fish from the North East Atlantic Ocean

Global environmental contamination by microplastics (MPs) is a growing problem with potential One Health impacts. The presence of MPs in vital organs, such as the heart, is of particular concern, but the knowledge is still limited. The goal of the present pilot study was to investigate the potential presence of MPs in the heart of wild specimens of three commercial fish species (Merluccius merluccius, Sardina pilchardus, and Trisopterus luscus) from the North East Atlantic Ocean. Heart samples from 154 fish were analysed for MP content (one heart sample per fish). A total of 44 MPs were recovered from heart samples from the three species. MPs had varied chemical composition (5 polymers), shapes (4) and colours (5). Differences in the profile of the MPs among species was observed (p ≤ 0.05). Thirty fish (19%) had MPs in their hearts, with a total mean (±SD) concentration of 0.286 ± 0.644 MPs/fish. S. pilchardus had the highest heart contamination (p ≤ 0.05). There were no significant (p > 0.05) differences between M. merluccius and T. luscus. These findings in fish with different biological and ecological traits together with literature data suggest that heart contamination likely is a disseminated phenomenon. Therefore, further research on the presence of MPs in the cardiovascular system and its potential health effects is very much needed.

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.

Identification of micro- and nanoplastic particles in postnatal sprague-dawley rat offspring after maternal inhalation exposure throughout gestation

Micro-nanoplastic particulates (MNPs) have been identified in both indoor and outdoor environments. From these real-world exposures, MNPs have been identified in human fluids and organ tissues, including the placenta and breastmilk. Laboratory studies have identified MNPs are capable of crossing the placental barrier and depositing in fetal tissues; however, it remained unclear if MNPs persist in offspring tissues after birth. Six pregnant Sprague-Dawley rats were divided equally into two groups: control and exposed to polyamide-12 (PA-12) MNP aerosols (11.46 ± 3.78 mg/m3) over an average of 4.35 h ± 0.39 for 10 non-consecutive days between gestational day (GD) 6 - GD 19, in our custom rodent exposure chamber, allowing for whole-body inhalation. Two-weeks after delivery in-house, offspring tissues (i.e. lung, liver, kidney, heart, brain) from 1 male and 1 female pup per litter were fixed in 4 % paraformaldehyde, sectioned, stained with hematoxylin and eosin, and assessed using hyperspectral dark-field microscopy. PA-12 MNPs were identified in all offspring tissues of the exposed dams. No MNPs were visualized in control tissues. These findings have important implications for human MNPs translocation, deposition, maternal/fetal health, and the developmental origins of health and disease. Further research is warranted to quantify MNPs mass deposition, biological accumulation, and systemic toxicity.

New molecular mechanism of nanoplastics affecting cadmium protein toxicity: Conformational response and differential binding of human serum albumin

The significant health risks of nanoplastics (NPs) and cadmium (Cd) are currently attracting a great deal of attention and research. At present, the effects and mechanisms of NPs and Cd on human serum albumin (HSA), a key functional protein in the organism on transportation, remain unknown. Here, the differences in the effects and mechanisms of action of Cd alone and composite systems (NPsCd) were explored by enzyme activity assay, multi-spectroscopy analysis and molecular docking. The results showed that HSA activity was inhibited and decreased to 80 % and 69.55 % (Cd = 30 mg/L) by Cd alone and NPs-Cd exposure, respectively. Exposure to Cd induced backbone disruption and protein defolding of HSA, and secondary structure disruption was manifested by the reduction of α-helix. Cd exposure also induces fluorescence sensitization of HSA. Notably, the addition of NPs further exacerbated the effects associated with Cd exposure, which was consistent with the changes in HSA activity. Thus, the above conformational changes may be responsible for inducing the loss of enzyme activity. Moreover, it was determined by RLS spectroscopy that NPs-Cd bound to HSA in the form of protein crowns. Molecular docking has further shown that Cd binds to the surface of Sudlow site II of HSA, suggesting that Cd impairs the function of HSA by affecting the protein structure. More importantly, the addition of NPs further exacerbated the disruption of the protein structure by the adherent binding of HSA on the surface of the plastic particles, which induced a greater change in the enzyme activity. This study provides useful perspectives for investigating the impact of composite pollution on HSA of human functional proteins.

Rapid, sensitive, and non-destructive on-site quantitative detection of nanoplastics in aquatic environments using laser-backscattered fiber-embedded optofluidic chip

A definitive link between the micro- and nano-plastics (NPLs) and human health has been firmly established, emphasizing the higher risks posed by NPLs. The urgent need for a rapid, non-destructive, and reliable method to quantify NPLs remains unmet with current detection techniques. To address this gap, a novel laser-backscattered fiber-embedded optofluidic chip (LFOC) was constructed for the rapid, sensitive, and non-destructive on-site quantitation of NPLs based on 180º laser-backscattered mechanism. Our theoretical and experimental findings reveal that the 180º laser-backscattered intensities of NPLs were directly proportional to their mass and particle number concentration. Using the LFOC, we have successfully detected polystyrene (PS) NPLSs of varying sizes, with a minimum detection limit of 0.23 μg/mL (equivalent to 5.23 ×107 particles/mL). Moreover, PS NPLs of different sizes can be readily differentiated through a simple membrane-filtering method. The LFOC also demonstrates high sensitivity in detecting other NPLs, such as polyethylene, polyethylene terephthalate, polypropylene, and polymethylmethacrylate. To validate its practical application, the LFOC was used to detect PS NPLs in various aquatic environments, exhibiting excellent accuracy, reproducibility, and reliability. The LFOC provides a simple, versatile, and efficient tool for direct, on-site, quantitative detection of NPLs in aquatic environments.

Microplastics exposure disrupts nephrogenesis and induces renal toxicity in human iPSC-derived kidney organoids

Microplastics (MPs) have emerged as a pervasive environmental pollutant of global concern. Their detection within the human placenta and fetal organs has prompted apprehension regarding the potential hazards of MPs during early organogenesis. The kidney, a vital multifunctional organ, is susceptible to damage from MPs in adulthood. However, the precise adverse effects of MP exposure on human nephrogenesis remain ambiguous due to the absence of a suitable model. Here, we explore the potential impact of MPs on early kidney development utilizing human kidney organoids in vitro. Human kidney organoids were subjected to polystyrene-MPs (PS-MPs, 1 μm) during the nephron progenitor cell (NPC) stage, a critical phase in early kidney development and patterning. We delineate the effects of PS-MPs on various stages of nephrogenesis, including NPC, renal vesicle, and comma-shaped body, through sequential examination of kidney organoids. PS-MPs were observed to adhere to the surface of cells during the NPC stage and accumulate within glomerulus-like structures within kidney organoids. Moreover, both short- and long-term exposure to PS-MPs resulted in diminished organoid size and aberrant nephron structure. PS-MP exposure heightened reactive oxygen species (ROS) production, leading to NPC apoptosis during early kidney development. Increased apoptosis, diminished cell viability, and NPC reduction likely contribute to the observed organoid size reduction under PS-MP treatment. Transcriptomic analysis at both NPC and endpoint stages revealed downregulation of Notch signaling, resulting in compromised proximal and distal tubular structures, thereby disrupting normal nephron patterning following PS-MP exposure. Our findings highlight the significant disruptive impact of PS-MPs on human kidney development, offering new insights into the mechanisms underlying PS-MP-induced nephron toxicity.

Genotoxic and neurotoxic potential of intracellular nanoplastics: A review

Plastic waste comprises polymers of different chemicals that disintegrate into nanoplastic particles (NPLs) of 1-100-nm size, thereby littering the environment and posing a threat to wildlife and human health. Research on NPL contamination has up to now focused on the ecotoxicology effects of the pollution rather than the health risks. This review aimed to speculate about the possible properties of carcinogenic and neurotoxic NPL as pollutants. Given their low-dimensional size and high surface size ratio, NPLs can easily penetrate biological membranes to cause functional and structural damage in cells. Once inside the cell, NPLs can interrupt the autophagy flux of cellular debris, alter proteostasis, provoke mitochondrial dysfunctions, and induce endoplasmic reticulum stress. Harmful metabolic and biological processes induced by NPLs include oxidative stress (OS), ROS generation, and pro-inflammatory reactions. Depending on the cell cycle status, NPLs may direct DNA damage, tumorigenesis, and lately carcinogenesis in tissues with high self-renewal capabilities like epithelia. In cells able to live the longest like neurons, NPLs could trigger neurodegeneration by promoting toxic proteinaceous aggregates, OS, and chronic inflammation. NPL genotoxicity and neurotoxicity are discussed based on the gathered evidence, when available, within the context of the intracellular uptake of these newcomer nanoparticles. In summary, this review explains how the risk evaluation of NPL pollution for human health may benefit from accurately monitoring NPL toxicokinetics and toxicodynamics at the intracellular resolution level.

Microplastics meet micropollutants in a central european river stream: Adsorption of pollutants to microplastics under environmentally relevant conditions

Microplastics have emerged as pervasive pollutants in aquatic environments, and their interaction with organic contaminants poses a significant environmental challenge. This study aimed to explore the adsorption of micropollutants onto microplastics in a river, examining different plastic materials and the effect of aging on adsorption capacity. Microplastics (low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC)) were introduced into a river stream, and a comprehensive analysis involving 297 organic pollutants was conducted. Passive samplers were deployed to monitor micropollutant presence in the river. Sixty-four analytes were identified in the river flow, with telmisartan being the most prevalent. Nonaged PVC showed the highest telmisartan concentration at 279 ng/g (168 ng/m2 regarding the microplastic surface), while aged PVC exhibited a fourfold decrease. Conversely, aged LDPE preferentially adsorbed metoprolol and tramadol, with concentrations increasing 12- and 3-fold, respectively, compared to nonaged LDPE. Azithromycin and clarithromycin, positively charged compounds, exhibited higher sorption to PET microplastics, regardless of aging. Diclofenac showed higher concentrations on nonaged PVC compared to aged PVC. Aging induced structural changes in microplastics, including color alterations, smaller particle production, and increased specific surface area. These changes influenced micropollutant adsorption, with hydrophobicity, dissociation constants, and the ionic form of pollutants being key factors. Aged microplastics generally showed different sorption properties. A comparison of microplastics and control sand particles indicated preferential micropollutant sorption to microplastics, underscoring their role as vectors for contaminant transport in aquatic ecosystems. Analysis of river sediment emphasized the significance of contact time in pollutant accumulation. Overall, this study provides insights into the complex interactions between microplastics and organic pollutants under environmental conditions and contributes to a better understanding of the fate and behavior of these two types of contaminants in aquatic ecosystems.

Characteristics of microplastics and their abundance impacts on microbial structure and function in agricultural soils of remote areas in west China

As an emergent pollutant, microplastics (MPs) are becoming prevalent in the soil environment. However, the characteristics of MPs and the response of microbial communities to the abundance of MPs in agricultural soils in West China still need to be elucidated in detail. This study utilized the Agilent 8700 Laser Direct Infrared (LDIR) to analyze the characteristics of small-sized MPs (20-1000 μm) in soils from un-mulched and mulched agricultural fields in West China, and illustrated their correlation with microbial diversity. The results revealed a higher abundance of MPs in mulched soil ((4.12 ± 2.13) × 105 items kg-1) than that in un-mulched soil ((1.04 ± 0.26) × 105 items kg-1). The detected MPs were dominated by fragments, 20-50 μm and Polyamide (PA). High-throughput sequencing analysis indicated that alpha diversity (Chao1 and Shannon indices) in the plastisphere was lower compared to that in soil, and varied significantly with MPs abundance in soil. As the abundance of MPs increased, the proportion of soil about the degradation of organic matte and photoautotrophic taxa increased, which showed enrichment in the plastisphere. Functional predictions further indicated that MPs abundance affected potential soil functions, such as metabolic pathways associated with the C and N cycling. The plastisphere showed higher functional abundance associated with organic matter degradation, indicating higher potential health risks compared to soil environments. Based on the RDA analyses, it was determined that environmental physicochemical properties and MPs abundance had a greater impact on fungal communities than on bacterial communities. In general, the abundance of MPs affected the microbial diversity composition and potentially influenced the overall performance of soil ecosystems. This study offers empirical data on the abundance of MPs in long-term mulched agricultural fields and new insights for exploring the ecological risk issues associated with MPs.

Hepatic and metabolic outcomes induced by sub-chronic exposure to polystyrene microplastics in mice

Microplastics (MPs) have attracted significant attention due to their global distribution in living environments. Although some studies have reported MP-induced hepatotoxicity in mouse models, a systematic approach to MP-mediated liver toxicity was still lacking. Therefore, we used a mouse model to study the sub-chronic effects of MP exposure on the liver. Female C57BL/6 mice, aged 6 weeks, received an oral administration of 0.3 mg of Nile Red-labeled polystyrene (PS) microplastics, with particle sizes of 0.5 µm (submicron) and 5 µm (micron), via gavage, while control mice received vehicle only. Each mouse was exposed to MPs twice a week for 12 weeks. After sacrifice, the levels of MP accumulation, oxidative stress, inflammation, and pathological changes were measured in the mouse liver, and blood samples were collected for serum biochemistry analysis. Our results demonstrated that 0.5 µm PS-MPs were accumulated in mouse livers post-MP exposure, but not in the 5 µm MP exposure group. Simultaneously, increased levels of glucose, triglyceride, alanine transaminase (ALT), aspartate transaminase (AST), superoxide dismutase, 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), interleukin-6, and lipid droplets were found in the 0.5 µm MP exposure group, while the fewer responses, including elevated liver weight index, glucose, high-density lipoprotein, AST, and decreased HNE-MA were observed in 5 µm MP exposure group. These results indicate that sub-chronic exposure to submicron MPs causes MP deposition in mouse livers, which further induces oxidative stress, increases inflammatory cytokines and perturbs glucose and lipid homeostasis, which might trigger more severe metabolic dysfunction or non-alcoholic steatohepatitis-like hepatotoxicity.

Are we eating plastic? Science mapping of microplastic pollution in the aquatic food chain

This study evaluates the knowledge structure of microplastic pollution and its effects on the aquatic food chain. The presence of microplastics has seriously harmed the ecosystem. Through bibliometric analysis, 216 journal publications were retrieved from the Web of Science (WoS) from 2008 to 2023 (April), with no restriction in the time frame. Applying bibliographic coupling and co-word analysis, the emerging, current, and future themes of microplastic pollution are presented. Three research streams are derived from bibliographic coupling, centralized on the source of microplastic pollution and its impact. At the same time, research streams from co-word analysis are associated with overcoming the issue of microplastics in the ecosystem. This study's implications suggest three main principles to mitigate microplastic issues: (1) educating the public on the impact of microplastic pollution, (2) implementing holistic regulations and policies, and (3) developing treatment strategies through conventional, innovative, and hybrid approaches. Microplastic pollution is a global concern, requiring a holistic and comprehensive approach to overcome it. This review is the first to present a scientific mapping of the microplastics literature, which is a fundamental basis for future research on microplastic pollution and its impact on the ecosystem. Integr Environ Assess Manag 2024;20:1800-1811. © 2024 SETAC.

The time for ambitious action is now: Science-based recommendations for plastic chemicals to inform an effective global plastic treaty

The ubiquitous and global ecological footprint arising from the rapidly increasing rates of plastic production, use, and release into the environment is an important modern environmental issue. Of increasing concern are the risks associated with at least 16,000 chemicals present in plastics, some of which are known to be toxic, and which may leach out both during use and once exposed to environmental conditions, leading to environmental and human exposure. In response, the United Nations member states agreed to establish an international legally binding instrument on plastic pollution, the global plastics treaty. The resolution acknowledges that the treaty should prevent plastic pollution and its related impacts, that effective prevention requires consideration of the transboundary nature of plastic production, use and pollution, and that the full life cycle of plastics must be addressed. As a group of scientific experts and members of the Scientists' Coalition for an Effective Plastics Treaty, we concur that there are six essential "pillars" necessary to truly reduce plastic pollution and allow for chemical detoxification across the full life cycle of plastics. These include a plastic chemical reduction and simplification, safe and sustainable design of plastic chemicals, incentives for change, holistic approaches for alternatives, just transition and equitable interventions, and centering human rights. There is a critical need for scientifically informed and globally harmonized information, transparency, and traceability criteria to protect the environment and public health. The right to a clean, healthy, and sustainable environment must be upheld, and thus it is crucial that scientists, industry, and policy makers work in concert to create a future free from hazardous plastic contamination.

Microplastics pollution in sediments of the Thames and Medway estuaries, UK: Organic matter associations and predominance of polyethylene

Microplastics at 10 sites along a 77 km transect of the river Thames estuary (UK) and 5 sites along 29 km of the Medway estuary were separated from sediment and analysed by ATR-FTIR spectroscopy. Microplastics were observed at all sites. Highest Thames concentrations were in urban London between Chelsea and West Thurrock (average 170.80 particles kg-1 ± 46.64, 3.36 mg kg-1 ± 1.79 by mass), mid-outer estuary sites were two to three times lower. Microplastics were slightly dominated by particles (54 %) over fibres (45 %), including polymer types ranked: polyethylene > PET > polypropylene > polyamide. Medway microplastics decreased seaward, with one urban-municipal site impacted by a combined-sewer-overflow containing a high proportion of fibres (Rochester, 484 particles kg-1, 7.39 mg kg-1 by mass). Microplastic abundance was correlated to organic carbon (TOC %) (R2 of 0.71 Thames and 0.96 Medway), but not sediment particle size. Sedimentary microplastics accumulation in the Thames was controlled by urbanisation-distance, and site hydrodynamics.

Effects of polystyrene nano- and microplastics on human breast epithelial cells and human breast cancer cells

The continuous littering of the environment with plastic and the resulting nano- and microplastics produced from various processes are ever-increasing problems. These materials also affect humans, as the absorption and accumulation of nano- and microplastics and their effects on health have thus far been rarely researched, which also applies to cancer. In the present study, the absorption of different sizes of polystyrene (PS) nano- and microplastics (PS particles) into human breast epithelial cells and human breast cancer cells was investigated. Subsequently, how the proliferation, colony and mammosphere formation abilities, cell fusion and migration of the cells were influenced by the PS particles were investigated. Our data revealed granularity-, dose- and cell line-dependent absorption of the PS particles, with the highest absorption observed in the MDA-MB-231-DSP1-7 cells and the lowest in the M13SV1_Syn1-DSP8-11 cells. Neither the colony-forming ability nor the cell fusion activity increased with the addition of PS particles. In contrast, slight, partially significant stimulatory effects on both proliferation and cell migration were observed, although these effects depended on the particle quantity and size and the cell line used. In summary, PS particles are absorbed by human breast epithelial and human breast cancer cells and influence cells that may be associated with cancer progression.

The adsorption of drugs on nanoplastics has severe biological impact

Micro- and nanoplastics can interact with various biologically active compounds forming aggregates of which the effects have yet to be understood. To this end, it is vital to characterize these aggregates of key compounds and micro- and nanoplastics. In this study, we examined the adsorption of the antibiotic tetracycline on four different nanoplastics, made of polyethylene (PE), polypropylene (PP), polystyrene (PS), and nylon 6,6 (N66) through chemical computation. Two separate approaches were employed to generate relevant conformations of the tetracycline-plastic complexes. In the first approach, we folded the plastic particle from individual polymer chains in the presence of the drug through multiple separate simulated annealing setups. In the second, more biased, approach, the neat plastic was pre-folded through simulated annealing, and the drug was placed at its surface in multiple orientations. The former approach was clearly superior to the other, obtaining lower energy conformations even with the antibiotic buried inside the plastic particle. Quantum chemical calculations on the structures revealed that the adsorption energies show a trend of decreasing affinity to the drug in the order of N66> PS> PP> PE. In vitro experiments on tetracycline-sensitive cell lines demonstrated that, in qualitative agreement with the calculations, the biological activity of tetracycline drops significantly in the presence of PS particles. Preliminary molecular dynamics simulations on two selected aggregates with each plastic served as first stability test of the aggregates under influence of temperature and in water. We found that all the selected cases persisted in water indicating that the aggregates may be stable also in more realistic environments. In summary, our data show that the interaction of micro- and nanoplastics with drugs can alter drug absorption, facilitate drug transport to new locations, and increase local antibiotic concentrations, potentially attenuating antibiotic effect and at the same time promoting antibiotic resistance.

Twenty years of microplastic pollution research-what have we learned?

Twenty years after the first publication that used the term microplastic, we review current understanding, refine definitions, and consider future prospects. Microplastics arise from multiple sources, including tires, textiles, cosmetics, paint, and the fragmentation of larger items. They are widely distributed throughout the natural environment, with evidence of harm at multiple levels of biological organization. They are pervasive in food and drink and have been detected throughout the human body, with emerging evidence of negative effects. Environmental contamination could double by 2040, and wide-scale harm has been predicted. Public concern is increasing, and diverse measures to address microplastic pollution are being considered in international negotiations. Clear evidence on the efficacy of potential solutions is now needed to address the issue and to minimize the risks of unintended consequences.

A toxic relationship: ultra-processed foods & plastics

BACKGROUND

Among the crises engulfing the world is the symbiotic rise of ultra-processed foods (UPFs) and plastics. Together, this co-dependent duo generates substantial profits for agri-food and petrochemical industries at high costs for people and planet. Cheap, lightweight and highly functional, plastics have ideal properties that enable business models to create demand for low-cost, mass-produced and hyper-palatable UPFs among populations worldwide, hungry, or not. Evidence linking UPF consumption to deterioration in diet quality and higher risk of chronic diseases is well-established and growing rapidly. At the same time, the issue of plastic food contact chemicals (FCCs) is receiving increasing attention among the human health community, as is the generation and dispersion of micro- and nanoplastics.

MAIN BODY

In this commentary, we explore how the lifecycles and shared economic benefits of UPFs and plastics interact to co-produce a range of direct and indirect harms. We caution that the chemical dimension of these harms is underappreciated, with thousands of plastic FCCs known to migrate into foodstuffs. Some of these are hazardous and have been detected in humans and the broader environment, while many are yet to be adequately tested. We question whether policies on both UPF and plastic chemicals are fit for purpose when production and consumption of these products is adding to the chronic chemical exposures that plausibly contribute to the increasing global burden of non-communicable diseases.

CONCLUSIONS

In the context of ongoing negotiations for a legally binding global treaty to end plastics pollution, and rapidly growing concern about the burgeoning share of UPFs in diets worldwide, we ask: What steps are needed to call time on this toxic relationship?

Nanoplastics: Immune Impact, Detection, and Internalization after Human Blood Exposure by Single-Cell Mass Cytometry

The increasing exposure to nanoplastics (NPs) raises significant concerns for human health, primarily due to their potential bioaccumulative properties. While NPs have recently been detected in human blood, their interactions with specific immune cell subtypes and their impact on immune regulation remain unclear. In this proof-of-concept study, model palladium-doped polystyrene NPs (PS-Pd NPs) are utilized to enable single-cell mass cytometry (CyTOF) detection. The size-dependent impact of carboxylate polystyrene NPs (50-200 nm) is investigated across 15 primary immune cell subpopulations using CyTOF. By taking advantage of Pd-doping for detecting PS-Pd NPs, this work evaluates their impact on human immune-cells at the single-cell level following blood exposure. This work traces PS-Pd NPs in 37 primary immune-cell subpopulations from human blood, quantifying the palladium atom count per cell by CyTOF while simultaneously assessing the impact of PS-Pd NPs on cell viability, functionality, and uptake. These results demonstrate that NPs can interact with, interfere with, and translocate into several immune cell subpopulations after exposure. In vivo distribution experiments in mice further confirmed their accumulation in immune cells within the liver, blood, and spleen, particularly in monocytes, macrophages, and dendritic cells. These findings provide valuable insights into the impact of NPs on human health.

Exploring the Interaction of Human α-Synuclein with Polyethylene Nanoplastics: Insights from Computational Modeling and Experimental Corroboration

Plastics, particularly microplastics (MPs) and nanoplastics (NP), have become major environmental and health concerns due to their high chemical stability. The highly hydrophobic plastics enter living organisms through reversible interactions with biomolecules, forming biocoronas. Following recent reports on plastics breaching the blood-brain barrier, the binding behavior of human α-synuclein (hαSn) with polyethylene-based (PE) plastics was evaluated by using molecular dynamics simulations and experimental methods. The results provided three important findings: (i) hαSn transitions from an open helical to a compact conformation, enhancing intramolecular interactions, (ii) nonoxidized PE NPs (NPnonox) rapidly adsorb hαSn, as supported by experimental data from dynamic light scattering and adsorption isotherms, altering its structure, and (iii) the oxidized NP (NPox) failed to capture hαSn. These interactions were dominated by the N-terminal domain of hαSn, with major contributions from hydrophobic amino acids. These findings raise concerns about the potential pharmacological effects of NP-protein interactions on human health.

Maternal exposure to nanopolystyrene induces neurotoxicity in offspring through P53-mediated ferritinophagy and ferroptosis in the rat hippocampus

There are increasing concerns regarding the rapid expansion of polystyrene nanoplastics (PS-NPs), which could impact human health. Previous studies have shown that nanoplastics can be transferred from mothers to offspring through the placenta and breast milk, resulting in cognitive deficits in offspring. However, the neurotoxic effects of maternal exposure on offspring and its mechanisms remain unclear. In this study, PS-NPs (50 nm) were gavaged to female rats throughout gestation and lactation to establish an offspring exposure model to study the neurotoxicity and behavioral changes caused by PS-NPs on offspring. Neonatal rat hippocampal neuronal cells were used to investigate the pathways through which NPs induce neurodevelopmental toxicity in offspring rats, using iron inhibitors, autophagy inhibitors, reactive oxygen species (ROS) scroungers, P53 inhibitors, and NCOA4 inhibitors. We found that low PS-NPs dosages can cause ferroptosis in the hippocampus of the offspring, resulting in a decline in the cognitive, learning, and memory abilities of the offspring. PS-NPs induced NOCA4-mediated ferritinophagy and promoted ferroptosis by inciting ROS production to activate P53-mediated ferritinophagy. Furthermore, the levels of the antioxidant factors glutathione peroxidase 4 (GPX4) and glutathione (GSH), responsible for ferroptosis, were reduced. In summary, this study revealed that consumption of PS-NPs during gestation and lactation can cause ferroptosis and damage the hippocampus of offspring. Our results can serve as a basis for further research into the neurodevelopmental effects of nanoplastics in offspring.

Microplastics: an often-overlooked issue in the transition from chronic inflammation to cancer

The presence of microplastics within the human body has raised significant concerns about their potential health implications. Numerous studies have supported the hypothesis that the accumulation of microplastics can trigger inflammatory responses, disrupt the microbiome, and provoke immune reactions due to their physicochemical properties. Chronic inflammation, characterized by tissue damage, angiogenesis, and fibrosis, plays a crucial role in cancer development. It influences cancer progression by altering the tumor microenvironment and impairing immune surveillance, thus promoting tumorigenesis and metastasis. This review explores the fundamental properties and bioaccumulation of microplastics, as well as their potential role in the transition from chronic inflammation to carcinogenesis. Additionally, it provides a comprehensive overview of the associated alterations in signaling pathways, microbiota disturbances, and immune responses. Despite this, the current understanding of the toxicity and biological impacts of microplastics remains limited. To mitigate their harmful effects on human health, there is an urgent need to improve the detection and removal methods for microplastics, necessitating further research and elucidation.

Microplastics exacerbate tissue damage and promote carcinogenesis following liver infection in mice

Cancer is a leading cause of death worldwide, posing a substantial threat to human well-being. Microplastics (MPs) exposure can harm human health and the carcinogenicity of MP remains uncertain. In this study, we investigated carcinogenesis by MPs exposure. We observed MP significantly exacerbated hepatic injury in infectious conditions. In addition, cancer-related p53 and p21 signals are activated by MPs. Analysis of the liver transcriptomic landscape uncovered a noteworthy intensification of the carcinogenesis pathway by MPs compared with pre-infection. The transcription factor SALL2 could act as an oncogenic promoter in the promotion of cancer regulated by MPs. Further, big data analysis presents the correlation between MPs pollution and human hepatocellular carcinoma. This work revealed a toxic amplification effect of the non-bioactive MPs on the bioactive pathogens. This finding provides new insight into understanding the potential toxicity of the MPs.

Micro(nano)plastic and Related Chemicals: Emerging Contaminants in Environment, Food and Health Impacts

Microplastic pollution is a problem of increasing concern in food, and while food safety issues around the world are serious, an increasing number of food safety issues related to microplastics have become the focus of people's attention. The presence of microplastics in food is a worldwide problem, and they are present in all kinds of foods, foods of both animal and plant origin, food additives, drinks, plastic food packaging, and agricultural practices. This can cause problems for both humans and the environment. Microplastics have already been detected in human blood, heart, placenta, and breastmilk, but their effects in humans are not well understood. Studies with mammals and human cells or organoids have given perspective about the potential impact of micro(nano)plastics on human health, which affect the lungs, kidneys, heart, neurological system, and DNA. Additionally, as plastics often contain additives or other substances, the potentially harmful effects of exposure to these substances must also be carefully studied before any conclusions can be drawn. The study of microplastics is very complex as there are many factors to account for, such as differences in particle sizes, constituents, shapes, additives, contaminants, concentrations, etc. This review summarizes the more recent research on the presence of microplastic and other plastic-related chemical pollutants in food and their potential impacts on human health.

Association between blood microplastic levels and severity of extracranial artery stenosis

Microplastics (MPs) contamination raises concerns about their impact on human health, particularly cardiovascular diseases. This study investigated the blood MPs levels in patients with extracranial artery stenosis (ECAS) and their possible link to disease severity. 20 ECAS and 10 control patients were recruited. Blood samples, collected before the digital subtract angiography (DSA) procedure, were analyzed by pyrolysis-gas chromatography mass spectrometry (Py-GC/MS), laser direct infrared (LDIR) spectroscopy, and scanning electron microscopy (SEM). Demographic and clinical information was also examined. Strict quality controls were implemented to prevent contamination. MPs were detected by Py-GC/MS in all blood samples, with concentrations significantly higher in ECAS group compared to control (174.89 ± 24.95 vs 79.82 ± 31.73 μg/g, p < 0.001), and polyvinyl chloride (PVC) and polyamide 66 (PA66) were the most abundant among the detected polymers. Further analyses suggested that higher concentrations of MPs may be associated with more severe artery stenosis (p < 0.001). Compared with the normal group, ECAS group had a higher level of D-dimer (0.61 ± 0.6 μg/L vs 0.28 ± 0.09 μg/L, p < 0.05) and longer Thrombin Time (sec) (18.30 ± 3.43 μg/L vs 16.25 ± 1.74 μg/L, p < 0.05). Additionally, LDIR and SEM detected the shape and physical properties of the MPs. In this study, we revealed significant higher blood MPs levels in ECAS patients, with a notable correlation between MPs concentrations and arterial stenosis severity.

Assessment of the cytotoxicity micro- and nano-plastic on human intestinal Caco-2 cells and the protective effects of catechin

Micro- and nano-plastics (M/NPs) potentially leach from plastic wrapping into food and beverages. However, the risks of ingested M/NPs to human intestinal health remain unclear. This study aimed to determine the potential risks and mechanisms of PS-M/NPs using a human intestinal epithelial in vitro model and to explore protective measures to reduce these risks. The results showed that polystyrene (PS) M/NPs exhibited size-dependent cytotoxicity (3 μm < 0.3 μm < 80 nm < 20 nm). Additionally, by measuring intracellular reactive oxygen species (ROS) production after exposure to PS-M/NPs and the elimination of ROS by N-acetyl-L-cysteine, we identified oxidative stress as a mechanism of PS-M/NP-induced cytotoxicity. Hazard quotients calculated from the study indicated that the risks of M/NPs derived from plastic teabags exceeded the margin of safety, suggesting that ingested M/NPs potentially pose a risk to human intestinal health. Furthermore, this study found that catechins can reduce the adverse effects of M/NPs, so we propose that drinking tea may offer a protective effect against the harm of M/NPs on the intestinal system.

Erosion of rigid plastics in turbid (sandy) water: quantitative assessment for marine environments and formation of microplastics

Mechanical degradation (erosion) of plastics in the marine environment has been reported in many literature studies but without quantitative information. This type of degradation is crucial as it accounts for most of the initial microplastic products, in marine environments (e.g., rivers and oceans). Here, we quantify the erosion of plastics by water-borne sediments under typical perpendicular water velocities and sand loads of turbid rivers and coastal oceans. Polypropylene (PP) shows the highest response to water-borne erosion, with a surface degradation rate of 5160 μm per year (4.44 mg per mm2 per year), compared with high-density polyethylene (HDPE) with a degradation rate of 1874 μm per year (1.79 mg per mm2 per year), resulting in the formation of microplastics (MPs). The rate of formation of such microplastic particles (>10 μm), as characterised by a laser direct infrared (LDIR) chemical imaging system, amounts to 669 particles per mm2 per year for PP and 187 particles per mm2 per year for HDPE, exhibiting average particle sizes of 60 μm and 23 μm in the same order. Furthermore, surface microscopy provided valuable insights into the dominant erosion mechanisms, revealing three distinct zones and the surface features reveal the brittle erosion behaviours. These results will enable a better assessment of degradation and lifetime prediction of plastics in turbid rivers and coastal oceans, allowing precise estimation of the rate of formation of MPs.

Bioaccumulation Rate of Non-Biodegradable Polystyrene Microplastics in Human Epithelial Cell Lines

Environment plastic accumulation has been attracting the attention of both political and scientific communities, who wish to reduce global pollution. Plastic items have been detected everywhere, from oceans to the air, raising concerns about the fate of plastics within organisms. Leaked plastics are ingested by animals, entering the food chain and eventually reaching humans. Although a lot of studies focused on the evaluation of plastic particles in the environment and living organisms have already been published, the behavior of plastic at the cellular level is still missing. Here, we analyzed the bioaccumulation and extrusion trend of two differently sized plastic particles (1 and 2 µm), testing them on three human epithelial cell lines (liver, lung, and gut) that represent epithelial sites mainly exposed to plastic. A different behavior was detected, and the major plastic uptake was shown by liver cells, where the 1 µm beads accumulated with a dose-dependent profile. Moreover, a 60% reduction in the content of 1 µm particles in cells was evaluated after plastic removal. Finally, the viability and proliferation of the three human cell lines were not significantly affected by both the 1 and 2 µm beads, suggesting that cells might have a defense mechanism against plastic exposure risk.

Optimization of sample preparation, fluorescence- and Raman techniques for environmental microplastics

Microspectroscopic imaging techniques based on spontaneous Raman scattering, Stimulated Raman Scattering (SRS), or fluorescence (with a selective dye) can be used to detect environmental microplastics (MPs) and determine their chemical as well as physical properties. The present study first focuses on optimizing the sample preparation, including a new design for a density separation apparatus and optimization of the Nile Red staining procedure. Tests were carried out with both white and colored reference materials, as well as environmental MPs in a suspended matter sample from the Rhine river. The new 'MESSY' system has a mean recovery of 95 ± 5.5 % (three polymer materials, in duplicate). The optimized Nile Red staining allows coarse categorization of MPs into "polar" vs. "non-polar" materials based on their Fluorescence Index (emission wavelength), but fluorescent additives in the polymer can cause misclassification. For unambiguous identification of the polymer type, Raman spectroscopy can be used. Even colored polymers, with or without Nile Red staining, were readily identified by Raman spectroscopy using a red laser (785 nm), except for particles containing carbon black. A Deep-UV Raman microscope (ex = 248.6 nm) was constructed, which allowed identification of all colored plastics, even those pigmented with carbon black. Since unsupervised mapping with spontaneous Raman is very slow, point measurements are preferably used after preselection of particles of interest based on fluorescence imaging. SRS is several orders of magnitude faster than spontaneous Raman mapping but requires multiple scans at different z-heights and at multiple wavenumber settings to detect and identify all particles. The results are expected to contribute to the development of suitable methodologies for the detection and identification of environmental microplastics.

Integrated transcriptomics and proteomics analyses reveal the ameliorative effect of hepatic damage in tilapia caused by polystyrene microplastics with chlorella addition

Fish exhibit varying responses to polystyrene microplastics (MPs) depending on particle size. Previous studies suggested that microorganisms adhering to the surface of MPs can induce toxic effects. In this study, Tilapia were exposed to MPs of control (group A), 75 nm (B), 7.5 μm (C), 750 μm (D), as well as combinations of all sizes (E) and 75 nm MPs with Chlorella vulgaris addition (F) for 7, 10 and 14 days. Histopathological changes in liver of tilapia were assessed using enzyme activities, transcriptomics and proteomics. The results showed that in groups combined MPs of different particle sizes and those supplemented with chlorella, MPs were localized on the surface of goblet cells, leading to vacuoles, constricted hepatic sinuses and nuclei displacement. Exposure to 7.5 and 750 μm MPs significantly increased the contents of fatty acid synthase (FAS), adenosine triphosphate (ATP), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), total cholesterol (TC), total triglyceride (TG) contents at 7 and 10 days. In particular, cytochrome p450 1a1 (EROD), reactive oxygen species (ROS) and superoxide dismutase (SOD) were markedly elevated following exposure to MPs. Apoptotic markers caspase-3, and inflammatory markers, including tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β), had a similar upward trend in comparisons of group C vs A at 7 d, group D vs A at 14 d. The peroxisome proliferator activated receptor (PPAR) signaling pathway, spliceosome, was highly enriched during the 7-day exposure of medium sized MPs, while largest MPs in the comparison of group D vs A at 14 d activated pathways such as phagosome, apoptosis, salmonella infection. Transcriptomic analysis revealed that after 14 days, the kyoto encyclopedia of genes and genomes (KEGG) pathways associated with protein processing in endoplasmic reticulum and the PPAR signaling has been significantly enriched in the Chlorella-supplemented group, which was further confirmed via the proteomic analysis. Overall, the findings highlight the size-dependent effects of MPs on histopathological changes, gene and protein expression in the liver of tilapia, and C. vulgaris effectively attenuated liver damages, likely through modulation of endoplasmic reticulum protein processing and PPAR signaling pathways.

Detection and analysis of microplastics in tissues and blood of human cervical cancer patients

Microplastics (MPs) can enter the reproductive system and can be potentially harmful to human reproductive health. In this study, 13 types of microplastics (MPs) were identified in patient blood, cancer samples, and paracarcinoma samples using Raman spectroscopy, with polyethylene, polypropylene and polyethylene-co-polypropylene being the most abundant polymer types. Futher, cotton was also found in our study. The diversity and abundance of MPs were higher in blood samples than in cancerous tissues, and there was a significant positive correlation between diversity (p < 0.05). Furthermore, the diversity and abundance of MPs in cancerous tissues were higher than in paracancerous tissues. The dimensional sizes of MPs in these samples were also very similar, with the majority of detected MPs being smaller in size. Correlation analysis showed that patient's age correlated with the abundance of MPs in blood samples, body mass index (BMI) correlated with the abundance of MPs in cancerous tissues. Notably, the frequency with which patients consume bottled water and beverages may also increase the abundance of MPs. This study identifies for the first time the presence of MPs and cotton in cancerous and paracancerous tissues of human cervical cancer patients. This provides new ideas and basic data to study the risk relationship between MP exposure and human health.

Microplastics detected in three types of female reproductive organs using micro-Raman spectroscopy

Microplastics (MPs) are synthetic solid particles or polymer matrices that range in size from 1 μm to 5 mm. MPs are widely present in the global biosphere, leading to increasing concerns about their impact on human health. In this study, micro-Raman spectroscopy was used to evaluate the presence and characteristic of MPs in adenomyosis, ovarian ectopic cysts, and uterine tube tissue samples from 60 females. MPs were detected in all human samples at an average level of 1.5 ± 1.2 particles per g of tissue (Average 1.40 ± 1.11 particles per g of tissue after blank correction.). Among these MPs, a total of 11 polymer types were identified. MPs are mainly composed of polyethylene (PE, 31 %), polypropylene (PP, 22 %) and PE-co-PP (11 %). These MPs had an average length of 15.15 ± 6.45 μm and an average width of 12.56 ± 6.65 μm, with the majority (70 %) measuring less than 20 μm in size. Most MPs were fibers (38.9 %) and fragments (24.4 %). A significant correlation (p <0.05) was found between the sizes of MPs detected across the three disease samples, with PE and PP being the most frequently identified types. This study demonstrates the presence of MPs in diseased tissues from patients with adenomyosis, ovarian ectopic cysts, and uterine tubes, providing evidence for the presence of MPs in reproductive system tissues.

Nanoplastics exposure-induced mitochondrial dysfunction contributes to disrupted stem cell differentiation in human cerebral organoids

Nanoplastics are ubiquitous in our daily lives, raising concerns about their potential impact on the human brain. Many studies reported that nanoplastics permeate the blood-brain barrier and influence cellular processes in mouse models. However, the neurotoxic effects of ingesting nanoplastics on human brain remain poorly understood. Here, we treated cerebral organoids with polystyrene nanoplastics to model the effects of nanoplastic exposure on human brain. Importantly, we found that mitochondria might be the significant organelles affected by polystyrene nanoplastics using immunostaing and RNA-seq analysis. Subsequently, we observed the increased cell death and decreased cell differentiation in our cerebral organoids. In conclusion, our findings shed insights on the mechanisms underlying the toxicity of nanoplastics on human brain organoids, providing an evaluation system in detection potential environmental toxicity on human brain.

The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of various chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensue tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

Polystyrene nanoplastics enhance thrombosis through adsorption of plasma proteins

Plastic products offer remarkable convenience for modern life. However, growing concerns are emerging regarding the potential health hazards posed by nanoplastics, which formed as plastics break down. Currently, the biological effects and mechanisms induced by nanoplastics are largely underexplored. In this study, we report that polystyrene nanoplastics can enter the bloodstream and enhance thrombus formation. Our findings show that polystyrene nanoplastics adsorb plasma proteins, particularly coagulation factor XII and plasminogen activator inhibitor-1, play a key role in this process, as demonstrated by proteomics, bioinformatic analyses, and molecular dynamics simulations. The adsorption of these proteins by nanoplastics is an essential factor in thrombosis enhancement. This newly uncovered pathway of protein adsorption leading to enhanced thrombosis provides new insights into the biological effects of nanoplastics, which may inform future safety and environmental risk assessment of plastics.

Treatment of polyethylene microplastics degraded by ultraviolet light irradiation causes lysosome-deregulated cell death

BACKGROUND

Microplastics (MPs), plastic particles < 5 mm in size, are prevalent in the environment, and human exposure to them is inevitable. To assess the potential risk of MPs on human health, it is essential to consider the physicochemical properties of environmental MPs, including polymer types, size, shape, and surface chemical modifications. Notably, environmental MPs undergo degradation due to external factors such as ultraviolet (UV) rays and waves, leading to changes in their surface characteristics. However, limited knowledge exists regarding the health effects of MPs, with a specific focus on their surface degradation. This study concentrates on cytotoxic MPs with surface degradation through UV irradiation, aiming to identify the mechanisms underlying their cell toxicity.

RESULTS

Polyethylene (PE) and surface-degraded PE achieved through UV light irradiation were employed as model MPs in this study. We explored the impact of PE and degraded PE on cell death in murine macrophage cell line RAW264.7 cells and human monocyte cell line THP-1 cells. Flow cytometric analysis revealed that degraded PE induced programmed cell death without activating caspase 3, while non-degraded PE did not trigger programmed cell death. These findings suggest that degraded PE might induce programmed cell death through mechanisms other than caspase-driven apoptosis. To understand the mechanisms of cell death, we investigated how cells responded to degraded PE-induced cellular stress. Immunofluorescence and western blotting analyses demonstrated that degraded PE induced autophagosome formation and increased p62 expression, indicating inhibited autophagy flux after exposure to degraded PE. Furthermore, degraded PE exposure led to a decrease in acidic lysosomes, indicating lysosomal dysregulation. These results imply that degraded PE induces lysosomal dysfunction, subsequently causing autophagy dysregulation and cell death.

CONCLUSIONS

This study unveils that UV-induced degradation of PE results in cell death attributed to lysosomal dysfunction. The findings presented herein provide novel insights into the effects of surface-degraded MPs on biological responses.

Toxicity of parental co-exposure of microplastic and bisphenol compounds on adult zebrafish: Multi-omics investigations on offspring

In recent years, the widespread use of bisphenol compounds and microplastics (MP) have attracted attention due to their harmful effects. Here, individual and combined effects of MP and bisphenol compounds, were assessed on adult zebrafish after co-exposure of bisphenol A (BPA) or bisphenol S (BPS) and 25 μm polyethylene MP. Impacts on their offspring (the F1 generation) were also investigated. The reproductive toxicity in adult zebrafish impacted exerted by bisphenol compounds were aggravated by the co-presence of MP. Transcriptomics and metabolomics further showed single or co-exposure of bisphenol compounds and MP could together regulate apoptosis, calcium signaling pathway and glycerophospholipid signaling pathways. Our results also showed the different toxicity mechanisms on transcriptional and metabolic profiles in the combination effects of bisphenol compounds and MP. The co-exposure of BPA and MP predominantly influenced neurotoxicity via the MAPK signaling pathway and voltage-dependent calcium channels, whereas the co-exposure of BPS and MP principally affected visual development through phototransduction and retinol metabolism. The co-exposure of BPA and MP, as well as BPS and MP, specifically regulate lipid metabolism and carbohydrate metabolism in zebrafish offspring, respectively. Overall, this study provided a deep understanding of the toxicity differences between co-exposure and single exposure of bisphenol compound and MP in zebrafish, as well as the transgenerational effects and potential molecular mechanisms of bisphenol compounds and MP in zebrafish offspring.

Early-life exposure to polystyrene micro- and nanoplastics disrupts metabolic homeostasis and gut microbiota in juvenile mice with a size-dependent manner

Early-life exposure to different sizes of micro- and nanoplastics (MNPs) affects biotoxicity, which is related not only to the dose but also directly to particle size. In this study, pregnant ICR mice received drinking water containing 5 μm polystyrene microplastics (5 μm PS-MPs) or 0.05 μm polystyrene nanoplastics (0.05 μm PS-NPs) from pregnancy to the end of lactation. Histopathological and molecular biological detection, 16s rRNA sequencing for intestinal flora analysis, and targeted metabolomics analysis were used to look into how early-life exposure to MNPs of various sizes affects young mice's growth and development, gut flora, and metabolism. The outcomes showed that 0.05 μm and 5 μm PS-MNPs can pass through the placental and mammary barriers, and MNPs accumulating in various organs were size-dependent: the greater the accumulation in organs, the smaller the particle size. Further studies found that the larger 5 μm PS-MPs caused only small accumulation in organs, with the main health hazard being the disruption of intestinal barrier and liver function, indirectly causing gut dysbiosis and metabolic disorders. In contrast, the smaller 0.05 μm PS-NPs caused excessive accumulation in organs, not only impaired the function of the intestine and liver, but also caused direct mechanical damage to physical tissues, and ultimately resulted in more severe intestinal and metabolic disorders. Our findings underline the size-dependent risks associated with micro- and nanoplastics exposure early in life and highlight the necessity for tailored approaches to address health damages from early MNPs exposure.

Biotechnology for the degradation and upcycling of traditional plastics

Traditional plastics, predominantly derived from petrochemicals, are extensively utilized in modern industry and daily life. However, inadequate management and disposal practices have resulted in widespread environmental contamination, with polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene being the most prevalent pollutants. Biological methods for plastic degradation have garnered significant attention due to their cost-effectiveness and potential for resource recovery, positioning them as promising strategies for sustainable plastic waste management. While polyethylene terephthalate, characterized by its relatively less stable C-O bonds, has been extensively studied and demonstrates significant potential for biodegradation. In contrast, the biodegradation of other plastics remains a significant challenge due to the inherent stability of their C-C backbone structures. This review comprehensively examines the state-of-the-art biotechnology for treating these traditional plastics, focusing on: (1) the roles of specific microorganisms and enzymes, their taxonomic classifications, and the metabolic pathways involved in plastic biodegradation; and (2) a proposed two-stage hybrid approach integrating physicochemical and biological processes to enhance the biodegradation or upcycling of these traditional plastics. Additionally, the review highlights the critical role of multi-omics approaches and tailored strategies in enhancing the efficiency of plastic biodegradation while examining the impact of plastic molecular structures and additives on their degradation potential. It also addresses key challenges and delineates future research directions to foster the development of innovative biological methods for the effective and sustainable management of plastic waste.

A new filtration system for extraction and accurate quantification of microplastics

The analysis of microplastics is crucial due to their widespread occurrence and significant impact as environmental pollutants. Appropriate extraction and analytical techniques are necessary to evaluate the abundance, dispersal, and effects of microplastics. In this context, the filtration step to extract microplastics from solution media is indispensable for quantifying microplastics accurately. Usually, a pretreatment procedure such as density separation or solvent extraction is employed before filtration. Nevertheless, the adsorption of microplastic particles onto the glassware surface is known to occur and careful rinsing is inevitable for a suitable recovery rate. The study presents a novel filtration device developed for easy use to increase microplastic recovery from liquid samples. Fluorescent polyethylene (PE) particles were used to examine recovery by optical microscopy and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The conventional filtration system (CFS) exhibited lower microplastic recovery (45.1 ± 7.9%, n = 10) due to the adsorption of microplastics onto the inner surface and the bottom edge of the upper glass funnel. In contrast, the newly developed modified filtration system (MFS) enables fast suction of liquid samples by removing the glass frit with the upper glass funnel and filter being spatially separated. The significantly improved recovery rates using MFS for PE particles were 100% (n = 5) and 93.4 ± 3.4% (n = 10), respectively, confirming the feasibility of the newly developed filtration system to analyze microplastics using Py-GC/MS. The study highlights the importance of filtration processing in establishing analytical standards for assessing and managing microplastics by suggesting MFS as an advanced filtration system.

Mechanisms of exacerbation of Th2-mediated eosinophilic allergic asthma induced by plastic pollution derivatives (PPD): A molecular toxicological study involving lung cell ferroptosis and metabolomics

Polystyrene microplastics (PS-MP) and dibutyl phthalate (DBP) are plastic pollution derivatives (PPDs) commonly found in the natural environment. To investigate the effects of PPD exposure on the risk of allergic asthma, we established a PPD exposure group in a mouse model. The dose administered for PS-MP was 0.1 mg/d and for DBP was 30 mg/kg/d, with a 5-week oral administration period. The pathological changes of airway tissue and the increase of oxidative stress and inflammatory response confirmed that PPD aggravated eosinophilic allergic asthma in mice. The mitochondrial morphological changes and metabolomics of mice confirmed that ferrotosis and oxidative stress played key roles in this process. Treatment with 100 mg/Kg deferoxamine (DFO) provided significant relief, and metabolomic analysis of lung tissue supported the molecular toxicological. Our findings suggest that the increased levels of reactive oxygen species (ROS) in the lungs lead to Th2-mediated eosinophilic inflammation, characterized by elevated IL-4, IL-5, and eosinophils, and reduced INF-γ levels. This inflammatory response is mediated by the NFκB pathway and exacerbates type I hypersensitivity through increased IL-4 production. In this study, the molecular mechanism by which PPD aggravates asthma in mice was elucidated, which helps to improve the understanding of the health effects of PPD and lays a theoretical foundation for addressing the health risks posed by PPD.

Microplastics in the soil-water-food nexus: Inclusive insight into global research findings

Nuisance imposed by biotic and abiotic stressors on diverse agroecosystems remains an area of focus for the scientific fraternity. However, emerging contaminants such as microplastics (MP) have imposed additional dimension (alone or in combinations with other stressors) in agroecosystems and keep escalating the challenges to achieve sustainability. MP are recognized as persistent anthropogenic contaminants, fetch global attention due to their unique chemical features that keeps themselves unresponsive to the decaying process. This review has been theorized to assess the current research trends (along with possible gap areas), widespread use of MP, enhancement of the harshness of heavy metals (HMs), complex interactions with physico-chemical constituents of arable soil, accumulation in the edible parts of field crops, dairy products, and other sources to penetrate the food web. So far, the available review articles are oriented to a certain aspect of MP and lack a totality when considered from in soil-water-food perspective. In short, a comprehensive perspective of the adverse effects of MP on human health has been assessed. Moreover, an agro-techno-socio-health prospective-oriented critical assessment of policies and remedial measures linked with MP has provided an extra edge over other similar articles in influential future courses of research.

Quantitative tracking of nanoplastics along the food chain from lettuce (Lactuca sativa) to snails (Cantareus aspersus)

Terrestrial systems are a significant sink for plastic contamination, including nano- and microplastics (NMPs). To date, limited information is available about the transfer of NMPs up the food web via trophic transfer, however, concerns about this exposure pathway for invertebrates and higher-level organisms have been raised. We aim to examine and quantify the trophic transfer of europium doped polystyrene nanoplastics (Eu-PS; NPs) within a terrestrial food chain. The uptake of 100 nm spherical Eu-PS particles from water through the roots of the plants to the leaves and finally to garden snails (Cantareus aspersus) was assessed. Lettuce (Lactuca sativa) was cultivated in Hoagland solution spiked with different concentrations of Eu-PS (15, 150 and 1500 μg/L) for three weeks. Then, lettuce shoots were used as food for snails for 19 days at a rate of 1 g of shoots per day. The Eu-PS primarily accumulated in the lettuce roots for all treatments, with a limited transfer to the shoots (only quantifiable in the highest treatment; translocation factor: TF < 1). No detectable levels of Eu-PS were found in the snails' digestive gland; however, the Eu-PS particles were detected in their feces (trophic transfer factor: TFF > 1). Moreover, only limited effects were observed on lettuce biomass by NPs treatments. No effects of the Eu-PS particles on snails were observed, with the exception of a consistent decrease in the shell diameter. Overall, our research illustrates that NPs can be absorbed by plants through their roots, subsequently transported to the shoots. However, our findings show limited transfer of NPs into snail tissues, but direct excretion into their feces. We provide an important insight into the potential transfer within the human food chain.