Detection of Microplastic in Human Placenta and Meconium in a Clinical Setting

Effects of microplastics on the immune system: How much should we worry?

Plastics are everywhere. It is widely recognized that they represent a global problem, the extent of which is yet to be defined. Humans are broadly exposed to plastics, whose effects and consequences are poorly characterized so far. The main route of exposure is via alimentary and respiratory intake. Plastics pollutions may come from both: water and food contamination itself, and their packaging. The smaller sizes (i.e. microplastics <150 µm - MPs) are considered to be the most pervasive of living organisms and, therefore, potentially the most harmful. As humans occupy one of the apex positions of the food chain, we are exposed to bioaccumulation and biomagnification effects of MPs. In fact, MPs are commonly found in human stools and blood. However, there are no data available yet on their ability to accumulate and to produce detrimental consequences on biological systems. Even though the effects of plastics pollution are poorly studied in mammals, including humans, they appear to have inflammatory effects, which is rather concerning as many etiologies of disease are based on a pro-inflammatory status.

Effects of micro- and nanoplastics on blood cells in vitro and cardiovascular parameters in vivo, considering their presence in the human bloodstream and potential impact on blood pressure

The adverse effects of plastics on the environment, wildlife, and human health have been extensively studied, yet their production remains unavoidable due to the lack of viable alternatives. Environmental fragmentation of larger plastic particles generates microplastics (MPs, 0.1-5000 μm) and nanoplastics (NPs, 1-100 nm), which can enter the bloodstream through inhalation or ingestion. This review examines whether MPs and NPs influence blood pressure. To address this question, relevant studies were analyzed based on predefined criteria. Due to anatomical barriers and microcirculatory dynamics, only NPs and small MPs are expected to enter the bloodstream under physiological conditions, although pathological states may alter this. In vitro research indicates that MPs and NPs negatively affect erythrocytes and endothelial cells, while rodent models suggest potential cardiovascular effects. Plastic particles and fibers have been detected in human blood, thrombi, atherosclerotic plaques, and various tissues. However, validated data on plastic particle-related blood pressure changes remain lacking. Despite limitations in their applicability to human physiology, preclinical models suggest that MPs and NPs circulate in the bloodstream, interact with blood cells, and contribute to vascular damage. Mechanisms such as endothelial injury, platelet activation, inflammation, and MPs/NPs accumulation in atherosclerotic plaques may contribute to blood pressure elevation but are unlikely to be the exclusive cause of hypertension. Further research is needed to clarify the role of plastic particles in blood pressure regulation. Standardized detection methods, real-world scenario-related models, and targeted human studies are essential to assessing cardiovascular risks associated with MP and NP exposure.

Exposure of the human placental primary cells to nanoplastics induces cytotoxic effects, an inflammatory response and endocrine disruption

Humans are inevitably exposed to micro- and nanoplastics (MP/NP). These particles are able to cross the biological barriers and enter the bloodstream with levels close to 1.6 µg mL-1; MP/NP have been detected in placentas and meconium of newborns. However, the consequences of this exposure on the integrity, development and functions of the human placenta are not documented. In this study, trophoblasts purified from human placentas at term were exposed for 48 h, to two different sizes of polystyrene nanoparticles (PS-NP) of 20 nm (PS-NP20) and 100 nm (PS-NP100), at environmental and supra-environmental concentrations (0.01-100 µg mL-1). Cell viability, oxidative stress, mitochondrial dynamics, lysosomal degradation processes, autophagy, inflammation/oxidative responses and consequences for placental endocrine and angiogenic functions were assessed. PS-NP size determines their internalization rate and their behavior in trophoblasts. Indeed, PS-NP20 are more rapidly translocated, and accumulated in lysosomes as shown by confocal and TEM imaging. They induce higher cytotoxicity than PS-NP100, as early as 1 µg mL-1 (p < 0.05). In addition, they induce a pro-inflammatory cytokines response: IL-1ß is induced from 0.01 µg mL-1 for the both nanoparticle sizes; IL-6, and TNF-α are overexpressed at 100 µg mL-1 only for PS-NP20 (p < 0.05). For the first time, we report that PS-NP disrupt endocrine function, as observed by a decreased hCG release at concentrations found in human blood. This work, provides an in-depth in vitro assessment of the effects of PS-NP on the human placenta.

Identification and analysis of microplastics in human penile cancer tissues

BACKGROUND

Widespread pollution from microplastics (MPs) has been identified as a significant contributor to adverse health effects in humans. This research aimed to investigate the presence of MPs in human penile cancer.

METHODS

The Laser Infrared Imaging Spectrometer (LDIR) was employed to detect and analyze MPs in the cancerous tissue (CT) and adjacent normal tissue (ANT) of 17 patients diagnosed with penile cancer. Subsequently, the abundance, sizes and types of MPs in CT were compared to those in the corresponding ANT.

RESULTS

Nine types of MPs were identified in 85.3 % of the samples analyzed, with an average abundance of 6.42 particles per gram. The most prevalent types of MPs were polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC), primarily falling within the 20-50 μm size range. MPs exhibited higher abundance and diversity in CT compared to ANT, with comparable size distributions evident in both of two areas.

CONCLUSION

Our study firstly confirm the presence of MPs in tissue samples from patients with penile cancer. Additionally, the abundance and variety of MPs in cancerous tissue are significantly higher than in adjacent normal tissue, although they had similar size distributions.

HIF-1α/HO-1-Mediated Ferroptosis Participates in Polystyrene Nanoplastics-Induced Intergenerational Cardiotoxicity

To explore the intergenerational cardiotoxicity of nanoplastics, maternal mice were exposed to 60 nm polystyrene nanoplastics (PS-NP) during pregnancy and lactation. The results showed that PS-NP can enter the hearts of offspring and induce myocardial fiber arrangement disorder, acidophilic degeneration of cardiomyocytes, and elevated creatine kinase isoenzymes (CK-MB) and lactate dehydrogenase (LDH) levels after maternal exposure to PS-NP at 100 mg/kg during pregnancy and lactation. Mechanistically, KEGG analysis of RNA sequencing showed the participation of hypoxia-inducible factor-1 (HIF-1) and ferroptosis in PS-NP-induced cardiotoxicity. Key features of ferroptosis, including Fe2+ accumulation, mitochondrial injury, oxidative stress, GPX4 downregulation, and FTH1, ACSL4, and SLC7A11 upregulation, were detected. Furthermore, PS-NP treatment upregulated the expressions of HIF-1α and HO-1, and PS-NP-induced ferroptosis can be alleviated by inhibition of HIF-1α using si-HIF-1α. This study provided an insightful reference for the intergenerational cardiotoxicity assessment of PS-NP.

Exposure of Polystyrene Nano- and Microplastics in Increasingly Complex In Vitro Intestinal Cell Models

With the rise in global plastic production and the presence of plastic waste in the environment, microplastics are considered an emerging environmental contaminant. Human exposure and the impact of microplastics on human health are not well studied. Recent studies have observed the presence of microplastics in human tissues and several studies have noted toxicity in in vitro and in vivo mammalian models. We examined the impact of polystyrene nano- and microplastics in increasingly complex intestinal cell models. Using an undifferentiated Caco-2 mono-culture model, we assessed particle association, cytotoxicity, and particle clearance/retention, whereas in differentiated mono- and tri-culture transwell models, we assessed membrane integrity and particle translocation. Only 50 nm and 500 nm particles were internalized in the undifferentiated cells; however, no signs of cellular toxicity were observed at any concentrations tested. Additionally, polystyrene particles had no impact on barrier integrity, but the 50 nm particles were able to cross to the basolateral side, albeit attenuated in the tri-culture model that had a mucus layer. This study reduced some of the variability common to MNPL testing across various in vitro models, but further testing is needed to fully understand the potential effects of human MNPL exposure.

Activation of gut metabolite ACSL4/LPCAT3 by microplastics in drinking water mediates ferroptosis via gut-kidney axis

The environmental pollutant Benzo[a]pyrene (BaP) is commonly found in the environment, with microplastics (MPs) acting as the primary carriers of BaP into living organisms, increasing its availability in the body. However, the specific pathways and mechanisms through which MPs carrying pollutants cause kidney damage are not fully understood. This study aimed to investigate the routes and mechanisms of kidney injury in mice to low concentrations of both MPs and BaP. The combination of polystyrene (PS) and BaP disrupted lipid metabolism in the kidneys, leading to a form of cell death known as ferroptosis. However, this effect was not observed in HK-2 cells in vitro, indicating a cell-specific response. Interestingly, in HIEC-6 cells, both PS and BaP directly induced ferroptosis. These findings confirm that exposure to both PS and BaP can disrupt metabolic homeostasis in the kidneys, contributing to kidney dysfunction and cell death.

Microplastic changes during the development of cervical cancer and its effects on the metabolomic profiles of cancer tissues

Recent studies have detected microplastics (MPs) in reproductive organs and found that they exert toxic effects on the reproductive system. However, the exact mechanism of action remains unclear. This study evaluates changes in MP levels in patients with cervical cancer as the disease progresses and uses untargeted metabolomics to assess the impact of MP exposure on the metabolomic profiles of cervical invasive cancer tissues. A total of 12 MP types were identified in 101 MP particles, with an average abundance of 2.24 ± 1.61 MP particles/g. Of these, polyethylene (PE, 26.73 %) and polypropylene (PP, 19.80 %) were the most frequently detected. Also, some MPs were observed to have sizes smaller than 20 µm. Notably, MP exposure levels increase as cervical cancer progresses (p < 0.05). Metabolomics analysis revealed that, among the 33 biologically significant metabolites screened, D-Mannose and cis,cis-muconic acid showed the most significant differences. Additionally, the aminosugar and nucleotide sugar metabolism pathways were the most significantly enriched in this experiment, potentially acting as pathways through which MPs may contribute to the pathogenesis of cervical cancer. The metabolites and pathways identified in this study may offer new insights and opportunities for disease research in patients with cervical cancer.

Elevated Micro- and Nanoplastics Detected in Preterm Human Placentae

Recent analytical advancements have uncovered increasing micro- and nanoplastics (MNPs) in environmental, dietary, and biological domains, raising concerns about their health impacts. Preterm birth (PTB), a leading cause of maternal and neonatal morbidity and mortality, may be influenced by MNP exposure, yet this relationship remains unexplored. This study quantified 12 MNP polymers in placentae from term (n=87) and preterm (n=71) deliveries using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Cumulative MNP concentrations were 28% higher in PTB placentae (mean ±SD: 224.7 ± 180.7 μg/g vs. 175.5 ± 137.9 μg/g; p=0.038). Polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyurethane (PU), and polycarbonate (PC) were significantly elevated in PTB, and PET, PU, and PC inversely correlated with gestational age and birth weight. Logistic regression identified PVC and PC as independent predictors of PTB. These findings suggest total and specific MNPs are associated with PTB, providing actionable insights and emphasizing the importance of minimizing exposure during pregnancy.

From food-to-human microplastics and nanoplastics exposure and health effects: A review on food, animal and human monitoring data

This review figures out the overall status on the presence of microplastics (MPs) and nanoplastics (NPs) in food and their bioaccumulation in animal and human tissues, providing critical insights into possible human health impacts. Data are discussed on both in-vivo and ex-vivo animal and human studies, and the role of physicochemical properties in determining the biological fate and toxicological effects of MPs and NPs. Particular attention is given to dietary exposure assessments, specifically evaluating daily intake through the consumption of contaminated food items. The current limitations in the body of knowledge and some considerations for future assessments are also reported. Overall, there is a pressing need to establish more robust biomarker research and develop standardized methodologies, for a better understanding of MPs and NPs fate and associated effects in more realistic scenarios for their safe consumption. The review underscores the importance of integrating the human biomonitoring into monitoring programs and interdisciplinary research to ultimately inform on MPs and NPs real burden in the human body.

The microplastic-crisis: Role of bacteria in fighting microplastic-effects in the digestive system

Plastic particles smaller than 5 mm, referred to as Microplastics, pose health risks, like metabolic, immunological, neurological, reproductive, and carcinogenic effects, after being ingested. Smaller plastic particles are more likely to be absorbed by human cells, with nanoplastics showing higher potential for cellular damage, including DNA fragmentation and altered protein functions. Micro- and nanoplastics (MNPs) affect the gastrointestinal tract by altering the microbial composition, they could influence digestive enzymes, and possibly disrupt mucus layers. In the stomach, they potentially interfere with digestion and barrier functions, while in the intestines, they could increase permeability via inflammation and tissue disruption. MNPs can lead to microbial dysbiosis, leading to gastrointestinal symptoms. By activating inflammatory pathways, altering T cell functions and affecting dendritic cells and macrophages, immune system homeostasis could possibly be disrupted. Probiotics offer potential strategies to alleviate plastic effects, by either degrading plastic particles or directly countering health effects. We compared genetic sequences of probiotics to the genome of known plastic degraders and concluded that no probiotic bacteria could serve the role of plastic degradation. However, probiotics could directly mitigate MNP-health effects. They can restore microbial diversity, enhance the gut barrier, regulate bile acid metabolism, reduce inflammation, regulate insulin balance, and counteract metabolic disruptions. Antioxidative properties protect against lipid peroxidation and MNP-related reproductive system damage. Probiotics can also bind and degrade toxins, like heavy metals and bisphenol A. Additionally, bacteria could be used to aggregate MNPs and reduce their impact. Therefore, probiotics offer a variety of strategies to counter MNP-induced health effects.

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

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

Exposure to nano-polystyrene during pregnancy leads to Alzheimer's disease-related pathological changes in adult offspring

Nanoplastics are common environmental pollutants. As of now, research has yet to explore how exposure to nanomaterials during gestation might influence the risk of developing Alzheimer's disease (AD) in offspring. Throughout the research, we assessed the AD pathology in adult offspring of mice prenatal 80 nm polystyrene nanoparticles (PS-NPs) exposure. In contrast with the control group, prenatal PS-NPs exposure obviously decreased brain tissue weight and the organ coefficient (brain weight/body weight) in adult male mice, but it only led to changes in the low-dose group of female mice. Histological examination of the adult offspring brains revealed alterations following exposure to PS-NPs during gestation. Specifically, there was a substantial reduction in neuron cells, significant changes in the number of Nissl bodies, noticeable loss of cell nucleus, and increased presence of neurofibrillary tangles in adult offspring mice exposed to PS-NPs during gestation. Furthermore, the phosphorylation levels of tau proteins at ser396 and ser199 were dramatically enhanced in the PS-NPs exposed group. Furthermore, the expression of Aβ protein was markedly increased, consistent with typical AD pathological features. Our findings suggest that being exposed to PS-NPs during pregnancy substantially raises the risk of AD in offspring.

Exploring Innovative Approaches for the Analysis of Micro- and Nanoplastics: Breakthroughs in (Bio)Sensing Techniques

Plastic pollution, particularly from microplastics (MPs) and nanoplastics (NPs), has become a critical environmental and health concern due to their widespread distribution, persistence, and potential toxicity. MPs and NPs originate from primary sources, such as cosmetic microspheres or synthetic fibers, and secondary fragmentation of larger plastics through environmental degradation. These particles, typically less than 5 mm, are found globally, from deep seabeds to human tissues, and are known to adsorb and release harmful pollutants, exacerbating ecological and health risks. Effective detection and quantification of MPs and NPs are essential for understanding and mitigating their impacts. Current analytical methods include physical and chemical techniques. Physical methods, such as optical and electron microscopy, provide morphological details but often lack specificity and are time-intensive. Chemical analyses, such as Fourier transform infrared (FTIR) and Raman spectroscopy, offer molecular specificity but face challenges with smaller particle sizes and complex matrices. Thermal analytical methods, including pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), provide compositional insights but are destructive and limited in morphological analysis. Emerging (bio)sensing technologies show promise in addressing these challenges. Electrochemical biosensors offer cost-effective, portable, and sensitive platforms, leveraging principles such as voltammetry and impedance to detect MPs and their adsorbed pollutants. Plasmonic techniques, including surface plasmon resonance (SPR) and surface-enhanced Raman spectroscopy (SERS), provide high sensitivity and specificity through nanostructure-enhanced detection. Fluorescent biosensors utilizing microbial or enzymatic elements enable the real-time monitoring of plastic degradation products, such as terephthalic acid from polyethylene terephthalate (PET). Advancements in these innovative approaches pave the way for more accurate, scalable, and environmentally compatible detection solutions, contributing to improved monitoring and remediation strategies. This review highlights the potential of biosensors as advanced analytical methods, including a section on prospects that address the challenges that could lead to significant advancements in environmental monitoring, highlighting the necessity of testing the new sensing developments under real conditions (composition/matrix of the samples), which are often overlooked, as well as the study of peptides as a novel recognition element in microplastic sensing.

Nano-scale dangers: Unravelling the impact of nanoplastics on human trophoblast invasion

Utilizing HTR-8/SVneo cells for in vitro modeling of human trophoblast invasion, we examined how different concentrations of 40 nm and 200 nm carboxylated polystyrene particles affect early-pregnancy trophoblast phenotype and function. We focused on migration and invasion, as critical processes in placental development. Our findings revealed disruptions in extravillous trophoblast mesenchymal phenotype and invasive behavior, following acute exposure to a higher concentration of the smaller sized particles. Specifically, differential uptake of the particles by trophoblast cells was observed, as well as cytotoxicity and concentration-dependent DNA damage after 72 h of exposure. In addition, a 24 h exposure to 100 μg/ml of 40 nm particles correlated with downregulated protein expression of α5 and α1 integrin subunits, N-cadherin, matrix metalloproteinase-2 and macrophage migration inhibitory factor, alongside upregulated protein expression of the epithelial marker E-cadherin. These changes likely contributed to the diminished migration of HTR-8/SVneo cells and the invasive potential of HTR-8/SVneo spheroids. Understanding these interactions is paramount for assessing the broader implications of nanoplastics on reproductive outcomes and maternal-fetal well-being and informing public health measures.

Food packaging solutions in the post-per- and polyfluoroalkyl substances (PFAS) and microplastics era: A review of functions, materials, and bio-based alternatives

Food packaging (FP) is essential for preserving food quality, safety, and extending shelf-life. However, growing concerns about the environmental and health impacts of conventional packaging materials, particularly per- and polyfluoroalkyl substances (PFAS) and microplastics, are driving a major transformation in FP design. PFAS, synthetic compounds with dual hydro- and lipophobicity, have been widely employed in food packaging materials (FPMs) to impart desirable water and grease repellency. However, PFAS bioaccumulate in the human body and have been linked to multiple health effects, including immune system dysfunction, cancer, and developmental problems. The detection of microplastics in various FPMs has raised significant concerns regarding their potential migration into food and subsequent ingestion. This comprehensive review examines the current landscape of FPMs, their functions, and physicochemical properties to put into perspective why there is widespread use of PFAS and microplastics in FPMs. The review then addresses the challenges posed by PFAS and microplastics, emphasizing the urgent need for sustainable and bio-based alternatives. We highlight promising advancements in sustainable and renewable materials, including plant-derived polysaccharides, proteins, and waxes, as well as recycled and upcycled materials. The integration of these sustainable materials into active packaging systems is also examined, indicating innovations in oxygen scavengers, moisture absorbers, and antimicrobial packaging. The review concludes by identifying key research gaps and future directions, including the need for comprehensive life cycle assessments and strategies to improve scalability and cost-effectiveness. As the FP industry evolves, a holistic approach considering environmental impact, functionality, and consumer acceptance will be crucial in developing truly sustainable packaging solutions.

Microplastic and human health with focus on pediatric well-being: a comprehensive review and call for future studies

Although humans are highly dependent on plastics from infancy to adolescence, these materials can degrade into ubiquitous microplastics (MPs) that affect individuals at every stage of life. However, information on the sources, mechanisms, detection techniques, and detrimental effects of MPs on children's health from infancy to adolescence is limited. Hence, here we identified and reviewed original research papers published in 2017-2023 across 11 database categories in PubMed, Google Scholar, Scopus, and Web of Science to improve our understanding of MPs with a focus on pediatric well-being. These studies found that milk and infant formulas are common sources of MP exposure in infants. Infant formula is the dominant source of MPs in babies, while plastic toys are a common source of MPs in toddlers. Adolescents are frequently exposed to MPs through the consumption of food contaminated with MPs and the use of plastics in food packaging. Water and air are sources of MP exposure in children from infancy through adolescence. This study thoroughly summarized how MP exposure in children of all ages causes cell damage and leads to adverse health effects such as cancer. With appropriate authorization from the relevant authorities, small amounts of human biological samples (10 g of feces) were collected from volunteers to assess the amounts of MPs in children with the aim of promoting pediatric well-being. The samples were then treated with Fenton's reagent, stored in glass jars, and filtered through nonplastic filters. Finally, MPs in children were quantified using stereomicroscopy and characterized using micro-Fourier transform infrared spectroscopy.

Examining the hidden dangers: Understanding how microplastics affect pregnancy

Microplastics, a fast-growing environmental concern, play a crucial role in developing the major pollution crisis that affects nearly the entire surface of the planet. Microplastics are tiny particles, measuring less than 5 mm which are ubiquitous, in occurrence, and found in a wide array of products including plastic packaging, synthetic textiles, seafood, fruits, vegetables, salt, sugar, bottled water, and even personal care products. The presence of microplastics in our environment and the potential adverse health effects they may cause have made them a significant perturbation in recent years. Pregnancy is a potentially life-changing experience that entails several apprehensions and new responsibilities for women. For expectant mothers, it is imperative to be aware of the implications of microplastics during pregnancy. One threatened concern is the potential transfer of microplastics across the placenta, which could expose the developing fetus to these particles. Although research on the impact of microplastics on pregnancy is still in its early stages, preliminary findings indicate potential risks that expectant mothers should be aware of. The timing of exposure during pregnancy may play a significant role in the potential risks associated with these tiny particles. In this review, we will delve into the topic, exploring how microplastics enter the body and the potential mechanism by which they pose risks to pregnancy outcomes.

Maternal exposure to polystyrene nanoplastics during gestation and lactation caused fertility decline in female mouse offspring

The impact of micro/nano plastics (MPs/NPs) on human health is a significant area of research. Studies on the effects of maternal exposure to microplastics (MPs) on the fertility in offspring have been conducted, but the damage caused by nanoplastics (NPs) remains ambiguous. In this study, pregnant Kunming mice were exposed to 30 mg/kg/day PS-NPs from 0.5 gestation day (GD) to 21 days postpartum (dpp). Increased rates of miscarriage and premature delivery were observed, as well as reduced litter size, indicating potential permanent reproductive injury in mice of PS-NPs group. Maternal exposure to PS-NPs impaired fertility of the female offsprings. Decreased primordial and increased growing follicles were observed in the ovaries of offspring at 1 dpp and 7 dpp in PS-NPs group, indicating premature activation of primordial follicles. This premature activation is likely due to the PS-NPs'induction of the AKT-FOXO3a signaling pathway by downregulating AMPK phosphorylation level and enhancing mTOR activity. Furthermore, a significant reduction in transzonal projections (TZPs) was noted in the ovaries of adult offspring mice in PS-NPs group. RNA sequencing of the ovaries from adult offspring female mice revealed that the TZPs related genes may be linked to CAMKIIβ, with a corresponding downregulation in expression levels. Overall, maternal exposure to PS-NPs induced profound and enduring effects on the reproductive functions of female offspring, raising critical alarms regarding the multigenerational reproductive toxicity risks associated with nanoplastic exposure in mammals.

Rising Concern About the Carcinogenetic Role of Micro-Nanoplastics

In recent years, awareness regarding micro-nanoplastics' (MNPs) potential effects on human health has progressively increased. Despite a large body of evidence regarding the origin and distribution of MNPs in the environment, their impact on human health remains to be determined. In this context, there is a major need to address their potential carcinogenic risks, since MNPs could hypothetically mediate direct and indirect carcinogenic effects, the latter mediated by particle-linked chemical carcinogens. Currently, evidence in this field is scarce and heterogeneous, but the reported increased incidence of malignant tumors among younger populations, together with the ubiquitous environmental abundance of MNPs, are rising a global concern regarding the possible role of MNPs in the development and progression of cancer. In this review, we provide an overview of the currently available evidence in eco-toxicology, as well as methods for the identification and characterization of environmental MNP particulates and their health-associated risks, with a focus on cancer. In addition, we suggest possible routes for future research in order to unravel the carcinogenetic potential of MNP exposure and to understand prognostic and preventive implications of intratumoral MNPs.

Internal and external microplastic exposure in young adults: A pilot study involving 26 college students in Changsha, China

OBJECTIVE

This study aimed to systematically assess the total environmental exposure to microplastics and determine the internal exposure levels in the human body.

METHODS

A total of 26 young college students were recruited. Exposure scenario estimation methods were used to establish evaluation models. The dietary and water intake behaviors of the participants were documented with questionnaires. The food and water consumed by the participants were sampled using weight and duplicate meal methods. Furthermore, air samples from the activity regions of the participants were collected. Fasting serum, 24-h urine, and fecal samples were also collected. Pyrolysis gas chromatography/mass spectrometry (Py-GCMS) helped identify the types and determine mass concentrations of microplastics across all samples, and the internal and external exposure levels of microplastics among the population were further evaluated.

RESULTS

Microplastics were frequently observed in food samples, with mass concentrations ranging from 2.50 to 91.30 μg/g. Water samples also contained microplastics, with concentrations ranging from 0.02 to 18.41 μg/g. Indoor and outdoor air contained PS, PE, PP, PVC, and PET. The exposure levels of young college students in Changsha to microplastics through dietary intake, water intake, and inhalation were quantified at 346.65 μg/kg bw/d, 41.17 μg/kg bw/d, and 59.57 μg/kg bw/d, respectively. Cumulatively, the total exposure to microplastics from these three sources was 460.20 μg/kg bw/d. Median microplastic levels in serum and feces samples were 20.81 μg/g and 97.36 μg/g, respectively. Additionally, urine samples indicated the presence of seven types of microplastics (PS, PE, PP, PVC, PET, PA66, and PMMA), with a median exposure level of 5.06 μg/g.

CONCLUSION

Among young college students in Changsha, the primary microplastic exposure source was dietary intake, followed by air and drinking water. The internal exposure level in serum was higher than that in urine.

Microplastics are detected in bull epididymal sperm and polystyrene microparticles impair sperm fertilization†

An increase in global infertility has coincided with the accumulation of microplastics (MPs) in the environment. This trend is particularly troubling because only 10% of male infertility cases can be attributed to identifiable causes, leaving a knowledge gap in our understanding of their underlying factors. To bridge this, it is important to explore the connection between the accumulation of MPs and the observed decline in male fertility. We assessed the presence of microplastics in epididymal sperm from bulls and used it as baseline concentrations for sperm exposure. MPs were detected in all epidydimal sperm (ES) samples, with a mean concentration of 0.37 μg mL-1. Next, to investigate the effects of MPs on fertility, bovine sperm was exposed to three different concentrations of a mixture of 1.1, 0.5, and 0.3 μm polystyrene (PS) beads: (1) 0.7 μg mL-1, blood concentration of PS in cows (bPS); (2) 0.37 μg mL-1, based on the concentration of total MPs found in ES (esMP); and (3) 0.026 μg mL-1, based on the concentration of PS found in ES (esPS). All sperm samples incubated with PS exhibited reduced motility compared with the control at 0.5 h. However, PS exposure did not affect acrosome integrity or induced oxidative stress. Embryos produced from sperm exposed to PS had reduced blastocyst rates, in addition to increased ROS formation and apoptosis. By employing physiological exposure, this research provided evidence of MPs in bovine epididymal sperm and demonstrated the detrimental effect of PS on sperm functionality.

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.

From insects to mammals! Tissue accumulation and transgenerational transfer of micro/nano-plastics through the food chain

Despite extensive global attention on microplastic pollution, our understanding of the pathways underlying microplastic translocation, accumulation, and their potential impacts on ecosystems and human health through the food chain remains incomplete. To investigate the translocation and accumulation of microplastics from insects to mammals, we developed a novel oral exposure model that Tenebrio molitor larvae (yellow mealworms, invertebrate terrestrial insects) were firstly orally exposed to both micro and nanometer-sized plastics (M/NPs), and subsequently fed as a food source to mice (mammals). Our results provide clear evidence that micro/nanoplastics (M/NPs) do indeed translocate through the food chain, from lower to higher trophic levels. Fluorescence microscopy and tissue quantification revealed the accumulation of M/NPs in the digestive, somatic, and circulatory systems of the larvae. Specifically, the food chain transferred M/NPs were later detected in the digestive, respiratory, and urinary systems of mice, showcasing strong fluorescent signals in vital organs such as the lungs, liver, intestines, brain, and kidneys, as well as in embryos. These findings highlight the intricate dynamics of M/NPs contamination, emphasizing their ability to traverse biological barriers, accumulate in organisms, and potentially impact embryonic development via food chain transfer.

Is intravenous infusion an unrecognized route for internal microplastic human exposure? A general assessment

As newly recognized environmental pollutants, microplastics (MPs, ≤5 mm in length) have been reported in various human tissues and fluids, including the spleen, liver, heart, blood and blood clots, raising global concerns about their impact on human health. This study investigated the characteristics of MPs in intravenous infusion and the removal of MPs from infusion products by infusion sets fitted with different filters using micro-Fourier Transform Infrared Spectroscopy. MPs were detected in infusion products, with an average abundance of 1.24 ± 1.44 items/unit (2.91 ± 3.91 items/L). The primary types of MPs identified were fragmented particles of polyethene and polypropylene, ranging in size from 15-100 µm. Internal filters in infusion sets played a crucial role in removing MPs, particularly fibrous ones, resulting in a reduction in both abundance and particle size of MPs in the human body. Moreover, this study conducted a general assessment of intravenous microplastic exposure among hospital patients and estimated the global per-person input of MPs via intravenous administration. It is an opportunity for us to gain a deeper understanding of MPs in intravenous infusion and provides guides selecting infusion devices, increasing awareness of associated health risks.

Critical reassessment of microplastic abundances in the marine environment

Microplastics (MPs) pose a growing concern in the marine environment, but their global prevalence remains largely unknown due to the absence of precise and standardized detection methods. This review critically evaluates existing techniques for quantifying MP abundances in marine field studies, addressing inaccuracies resulting from the exclusion of particle sizes, polymer types, or limitations in identification methods. These traced inaccuracies were considered to recalculate MP abundances for particle sizes from 10 to 5000 μm, providing the first corrected global overview of MP distribution that enables quality assessment and reliable comparisons between adjusted data. The recalculations indicate that MP abundances are up to 15 times higher in marine waters (average (1.5 ± 36.2) × 105 items m-3) and up to 11 times higher in the marine sediments (average (2.7 ± 117.9) × 105 items kg-1) than previously reported in the literature. The Australasian Mediterranean Sea (average (1.2 ± 10.6) × 106 items m-3) and the North Atlantic (average (2.1 ± 37.6) × 105 items kg-1) emerged as the most polluted regions in marine waters and sediments, respectively, with primary contributors being the coasts of Southeast Asia and East America. This review demonstrates that previous field studies, global estimates, and models have significantly underestimated MP levels in marine environments in many cases, which could result in misinterpretations of both local and global pollution levels. This work highlights the critical need for precise handling of microplastic samples and urges future researchers to adopt standardized protocols for MP analysis to avoid inaccurate and misleading outcomes.

A Low-Cost Microfluidic Device For the On-Line Counting of Microparticle/Bacteria

On-line counting of the microparticle/bacteria in the liquid medium has great potential in the food safety and biomedical fields. A new low-cost microfluidic device is proposed for the on-line counting of the microparticles/bacteria in the liquid medium. The gradually contracted microchannel and the viscoelastic fluid are combined to achieve the efficient elastic focusing of the particle/bacteria, which significantly improves the counting accuracy by aligning all particles/bacteria in a single position at the center of the microchannel. A simple light resistance-based counting method is designed and integrated with the microchannel, where the low-cost elements including the laser pointer, convex lens, diaphragm, and photodiode, are used to build the optical path of detection. The influence of the flow rate, the particle size, the property of fluid, and the channel structure on the focusing of the particle/bacteria are investigated by the experiment, and the counting ability of the integrated microfluidic device is validated by using different-sized microparticles and the bifidobacterium. With its simple structure, low cost, easy operation, and high efficiency, this microfluidic device is suitable for the commercial applications, such as the on-line counting of the plastic microparticle in water or the colony-forming units (CFU) of bacteria in food.

Effects of polystyrene micro- and nanoplastics on androgen- and estrogen receptor activity and steroidogenesis in vitro

While many plastic additives show endocrine disrupting properties, this has not been studied for micro- and nanoplastics (MNPs) particles despite their ubiquitous presence in humans. The objective of this study was to determine the effects of various sizes and concentrations of polystyrene (PS)-MNPs (50-10,000 nm, 0.01-100 μg/mL) on estrogen- and androgen receptor (ER and AR) activity and steroidogenesis in vitro. Fluorescent (F)PS-MNPs of ≤1000 nm were internalized in VM7 and H295R cells and FPS-MNPs ≤200 nm in AR-ecoscreen cells. H295R cells displayed the highest uptake and particles were closer to the nucleus than other cell types. None of the sizes and concentrations PS-MNPs tested affected ER or AR activity. In H295R cells, PS-MNPs caused some statistically significant changes in hormone levels, though these showed no apparent concentration or size-dependent patterns. Additionally, PS-MNPs caused a decrease in estriol (E3) with a maximum of 37.5 % (100 μg/mL, 50 nm) and an increase in gene expression of oxidative stress markers GPX1 (1.26-fold) and SOD1 (1.23-fold). Taken together, our data show limited endocrine-disrupting properties of PS-MNPs in vitro. Nevertheless the importance of E3 in the placenta warrants further studies in the potential effects of MNPs during pregnancy.

Towards a risk assessment framework for micro- and nanoplastic particles for human health

BACKGROUND

Human exposure to micro- and nanoplastic particles (MNPs) is inevitable but human health risk assessment remains challenging for several reasons. MNPs are complex mixtures of particles derived from different polymer types, which may contain plenty of additives and/or contaminants. MNPs cover broad size distributions and often have irregular shapes and morphologies. Moreover, several of their properties change over time due to aging/ weathering. Case-by-case assessment of each MNP type does not seem feasible, more straightforward methodologies are needed. However, conceptual approaches for human health risk assessment are rare, reliable methods for exposure and hazard assessment are largely missing, and meaningful data is scarce.

METHODS

Here we reviewed the state-of-the-art concerning risk assessment of chemicals with a specific focus on polymers as well as on (nano-)particles and fibres. For this purpose, we broadly screened relevant knowledge including guidance documents, standards, scientific publications, publicly available reports. We identified several suitable concepts such as: (i) polymers of low concern (PLC), (ii) poorly soluble low toxicity particles (PSLT) and (iii) fibre pathogenicity paradigm (FPP). We also aimed to identify promising methods, which may serve as a reasonable starting point for a test strategy.

RESULTS AND CONCLUSION

Here, we propose a state-of-the-art modular risk assessment framework for MNPs, focusing primarily on inhalation as a key exposure route for humans that combines several integrated approaches to testing and assessment (IATAs). The framework starts with basic physicochemical characterisation (step 1), followed by assessing the potential for inhalative exposure (step 2) and includes several modules for toxicological assessment (step 3). We provide guidance on how to apply the framework and suggest suitable methods for characterization of physicochemical properties, exposure and hazard assessment. We put special emphasis on new approach methodologies (NAMs) and included grouping, where adequate. The framework has been improved in several iterative cycles by taking into account expert feedback and is currently being tested in several case studies. Overall, it can be regarded as an important step forward to tackle human health risk assessment.

Microplastic Particles Detected in Fetal Cord Blood, Placenta, and Meconium: A Pilot Study of Nine Mother-Infant Pairs in South China

Microplastics (MPs) are emerging environmental pollutants. Pregnancy and infancy are sensitive windows for environmental exposure. However, few studies have investigated the presence of MPs in mother-infant pairs, or the exposure source. In this study, nine mother-infant pairs were recruited, and samples of placenta, cord blood, and meconium were collected. Information about the living environment and dietary habits were collected to determine the source of exposure during pregnancy. Micro-Raman spectroscopy was applied to identify MPs. In total, 9, 4, and 14 types of MPs were identified in the placenta, cord blood, and meconium samples, with particle counts of 34, 14, and 80, respectively. More than 80.47% of MPs detected in samples had a size of 100-400 μm. The abundance of MPs exhibited the order of meconium > placenta > cord blood (Hc = 14.959, p < 0.01). We found that the abundance of MPs in meconium from women who drank tea ≥ 3 times/week during pregnancy was lower than in those who drank less (p = 0.048). Our study presents evidence of MPs transfer via the placenta-cord blood-meconium pathway. We also found that the habit of drinking tea among pregnant women might be related to the abundance of MPs in meconium.

Microplastics in Cosmetics: Open Questions and Sustainable Opportunities

The cosmetic industry is now changing or rather having an ecological transition in which formulations such as creams, lotions, and powders for make-up, skin and hair care must not contain microplastics, now a taboo word in this field. Nowadays, many companies are intensifying their research and development (R&D) work to align with recent and future legislation that provides for their elimination to safeguard the ecosystem. The production of new eco-sustainable materials is currently a hot topic which finds its place in a market worth above 350 billion dollars which will reach more than 700 billion dollars in a very short time. This review offers an overview of the main advantages and adverse issues relating to the use of microplastics in cosmetics and of their impact, providing an insight into the properties of the polymeric materials that are currently exploited to improve the sensorial characteristics of cosmetic products. In addition, the various regulatory restrictions in the different geographical areas of the world are also described, which is matter for reflection on future direction. Finally, a prospective vision of possible solutions to replace microplastics with sustainable alternatives complete the picture of the next generation personal care products to support decision-making in the cosmetic marketplace.

Polystyrene microplastics exposition on human placental explants induces time-dependent cytotoxicity, oxidative stress and metabolic alterations

Introduction

Microplastics (MPs) are environmental pollutants that pose potential risks to living organisms. MPs have been shown to accumulate in human organs, including the placenta. In this study, we investigated the biochemical impact of 5 μm polystyrene microplastics (PS-MPs) on term placental chorionic villi explants, focusing on cytotoxicity, oxidative stress, metabolic changes, and the potential for MPs to cross the placental barrier.

Methods

Term placental chorionic explants were cultured for 24 hours with varying concentrations of PS-MPs, with MTT assays used to determine the appropriate concentration for further analysis. Cytotoxicity was assessed using the lactate dehydrogenase (LDH) release assay over a period of up to 72 hours. Reactive oxygen species formation and antioxidant activity were evaluated using biochemical assays. Metabolomic profiling was performed using proton nuclear magnetic resonance (1H NMR).

Results

Placental explants exposed to 100 μg/mL of PS-MPs showed a significant increase in cytotoxicity over time (p < 0.01). Levels of mitochondrial and total superoxide anion (p < 0.01 and p < 0.05, respectively) and hydrogen peroxide (p < 0.001) were significantly elevated. PS-MP exposure resulted in a reduction in total sulfhydryl content (p < 0.05) and the activities of antioxidant enzymes superoxide dismutase (p < 0.01) and catalase (p < 0.05), while glutathione peroxidase activity increased (p < 0.05), and the oxidized/reduced glutathione ratio decreased (p < 0.05). Markers of oxidative damage, such as malondialdehyde and carbonylated proteins, also increased significantly (p < 0.001 and p < 0.01, respectively), confirming oxidative stress. Metabolomic analysis revealed significant differences between control and PS-MP-exposed groups, with reduced levels of alanine, formate, glutaric acid, and maltotriose after PS-MP exposure.

Discussion

This study demonstrates that high concentrations of PS-MPs induce time-dependent cytotoxicity, oxidative stress, and alterations in the TCA cycle, as well as in folate, amino acid, and energy metabolism. These findings highlight the need for further research to clarify the full impact of MP contamination on pregnancy and its implications for future generations.

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.

Microplastics in the Human Body: Exposure, Detection, and Risk of Carcinogenesis: A State-of-the-Art Review

Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation.

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.

The estuarine plastics menace: Insights into prevalence, characterization and polymeric risk assessment of microplastics in the Mahi River Estuary, Gujarat, India

Microplastic contamination (MP) has created havoc in all eco-systems especially the estuarine environment. The current investigation focused on assessing MP contamination along the Mahi River Estuary in Gujarat. Thirty sampling sites were selected along the estuary, spanning from Khambhat to Kamboi. Sediment samples were collected, processed, and analyzed for MPs. A total of 1371 MP particles were found, with an average abundance of 0.76 ± 0.25 MPs/g dry weight. The MP abundance was recorded at its highest and lowest at Chokari and Umraya, respectively. The MP abundance varied significantly between study sites. Fibers were reported dominantly, followed by fragments, films, and foam. Size-wise, 1-2 mm and <1 mm-sized MPs were prevalent. Various colours of MPs were also recorded. Polyethylene tetraphene, polyethylene, and polypropylene are the most abundant. Tourism, fishing activities, and a lack of waste management practices can be the possible reasons for MPs input in to estuarine habitats.

Polystyrene nanoplastics mediate skeletal toxicity through oxidative stress and the BMP pathway in zebrafish (Danio rerio)

The widespread presence of micro(nano)plastics (MNPs) has generated public concern. Studies have indicated that MNPs can accumulate in mammalian bones; however, research on the skeletal toxicity and underlying molecular mechanisms of MNPs in aquatic organisms remains limited. We subjected zebrafish embryos to three varying levels (1, 10, 100 μg/mL) of polystyrene nanoplastics (PSNPs) exposure over a period of 7 days in our research. The results revealed that PSNPs significantly reduced the body length and hatching rate of zebrafish, leading to skeletal deformities. mRNA level analysis showed significant upregulation of sp7, sparc, and smad1 genes transcription by PSNPs. Moreover, PSNPs markedly downregulated the mRNA levels associated with runx2a, bmp2a, and bmp4. Further investigations demonstrated that PSNPs dramatically increased ROS levels in zebrafish larvae, with significant downregulation of transcription levels of sod1 and cat genes, resulting in a sharp increase in transcription levels of apoptosis-related regulatory genes bcl-2 and bax. Furthermore, PSNPs led to a marked rise in Caspase 3 activity in zebrafish larvae, suggesting the initiation of apoptosis. PSNPs also notably inhibited alkaline phosphatase (AKP) activity. Compared to a 4-day exposure, a 7-day exposure to PSNPs intensified abnormalities across multiple indicators. In summary, our research indicates that PSNPs cause significant oxidative stress in zebrafish larvae, resulting in apoptosis. Moreover, PSNPs disrupt the transcription of genes related to skeletal development through the bone morphogenetic protein (BMP) pathway, further disrupting skeletal development processes and ultimately resulting in skeletal deformities in zebrafish larvae. This study provides new insights into the skeletal toxicity of MNPs.

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.

Investigating Exposure and Hazards of Micro- and Nanoplastics During Pregnancy and Early Life (AURORA Project): Protocol for an Interdisciplinary Study

BACKGROUND

Micro- and nanoplastics (MNPs) are emerging pollutants of concern with ubiquitous presence in global ecosystems. MNPs pose potential implications for human health; however, the health impacts of MNP exposures are not yet understood. Recent evidence suggests that MNPs can cross the placental barrier, underlying the urgent need to understand their impact on reproductive health and development.

OBJECTIVE

The Actionable eUropean ROadmap for early-life health Risk Assessment of micro- and nanoplastics (AURORA) project will investigate MNP exposures and their biological and health effects during pregnancy and early life, which are critical periods due to heightened vulnerability to environmental stressors. The AURORA project will enhance exposure assessment capabilities for measuring MNPs, MNP-associated chemicals, and plastic additives in human tissues, including placenta and blood.

METHODS

In this interdisciplinary project, we will advance methods for in-depth characterization and scalable chemical analytical strategies, enabling high-resolution and large-scale toxicological, exposure assessment, and epidemiological studies. The AURORA project performs observational studies to investigate determinants and health impacts of MNPs by including 800 mother-child pairs from 2 existing birth cohorts and 110 women of reproductive age from a newly established cohort. This will be complemented by toxicological studies using a tiered-testing approach and epidemiological investigations to evaluate associations between maternal and prenatal MNP exposures and health perturbations, such as placental function, immune-inflammatory responses, oxidative stress, accelerated aging, endocrine disruption, and child growth and development. The ultimate goal of the AURORA project is to create an MNP risk assessment framework and identify the remaining knowledge gaps and priorities needed to comprehensively assess the impact of MNPs on early-life health.

RESULTS

In the first 3 years of this 5-year project (2021-2026), progress was made toward all objectives. This includes completion of recruitment and data collection for new and existing cohorts, development of analytical methodological protocols, and initiation of the toxicological tiered assessments. As of September 2024, data analysis is ongoing and results are expected to be published starting in 2025.

CONCLUSIONS

As plastic pollution increases globally, it is imperative to understand the impact of MNPs on human health, particularly during vulnerable developmental stages such as early life. The contributions of the AURORA project will inform future risk assessment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/63176.

Micro-nanoplastics and cardiovascular diseases: evidence and perspectives

Emerging evidence indicates that chemical exposures in the environment are overlooked drivers of cardiovascular diseases (CVD). Recent evidence suggests that micro- and nanoplastic (MNP) particles derived largely from the chemical or mechanical degradation of plastics might represent a novel CVD risk factor. Experimental data in preclinical models suggest that MNPs can foster oxidative stress, platelet aggregation, cell senescence, and inflammatory responses in endothelial and immune cells while promoting a range of cardiovascular and metabolic alterations that can lead to disease and premature death. In humans, MNPs derived from various plastics, including polyethylene and polyvinylchloride, have been detected in atherosclerotic plaques and other cardiovascular tissues, including pericardia, epicardial adipose tissues, pericardial adipose tissues, myocardia, and left atrial appendages. MNPs have measurable levels within thrombi and seem to accumulate preferentially within areas of vascular lesions. Their presence within carotid plaques is associated with subsequent increased incidence of cardiovascular events. To further investigate the possible causal role of MNPs in CVD, future studies should focus on large, prospective cohorts assessing the exposure of individuals to plastic-related pollution, the possible routes of absorption, the existence of a putative safety limit, the correspondence between exposure and accumulation in tissues, the timing between accumulation and CVD development, and the pathophysiological mechanisms instigated by pertinent concentrations of MNPs. Data from such studies would allow the design of preventive, or even therapeutic, strategies. Meanwhile, existing evidence suggests that reducing plastic production and use will produce benefits for the environment and for human health. This goal could be achieved through the UN Global Plastics Treaty that is currently in negotiation.

Addressing plastic pollution and waste flows: Insights from South Africa's experience

The Pew Charitable Trust's 2020 report 'Breaking the Plastic Wave', indicates that existing technologies could support an 80% reduction in plastic leakage relative to business as usual by 2040. Therefore, South Africa became the first country to work with the Pew Charitable Trust and Oxford University to test and apply 'Pathways', a modelling framework and software tool which stemmed and evolved from the Pew report, at country level. The tool calculates the flows of plastics in the economy and the impact of various strategies to reduce future plastic pollution. The Scenario Builder within the Pathways tool allows the user to optimise flows in the plastics value chain to satisfy a set of defined objectives in order to achieve an optimal solution. Three major findings have emerged from the application of Pathways at country level for South Africa. Firstly, plastic pollution is set to almost double by 2040 if no interventions are implemented. Secondly, meeting the newly legislated extended producer responsibility (EPR) targets set for plastic packaging can avoid 33% of projected total pollution over the period of 2023-2040. Lastly, an optimal system change can avoid 63% of total plastic pollution over the period 2023-2040. Thus, applying Pathways at country level in South Africa has proven to be valuable by setting a baseline against which progress towards reducing plastic pollution can be measured; determining the outcome of meeting the legislated EPR targets over time, and informing policy decisions by allowing users to model different scenarios towards an optimal system change scenario.

Chronic exposure to polystyrene microplastics induced LHR reduction and decreased testosterone levels through NF-κB pathway

The extensive utilization of plastic products in recent years has resulted in a significant contamination of microplastics (MPs). The ingestion of MPs by aquatic and terrestrial organisms facilitates their transmission to mammals through the food chain. Therefore, the toxicity of MPs has attracted widespread attention from researchers. Previous studies have shown a connection between being exposed to polystyrene MPs (PS-MPs) and issues with male reproductive function. Testosterone, a hormone essential for male reproductive function, is produced and secreted by specialized cells known as Leydig cells, which found in the testicular interstitium. In our prior research, we confirmed that exposure to PS-MPs caused a reduction in testosterone levels by interfering with the LH-mediated LHR/cAMP/PKA/StAR pathway, with LHR being pivotal in this mechanism. However, the molecular mechanism underlying PS-MPs-induced reduction of LHR remains unclear. In this study, mice were respectively given drinking water containing 1000 μg/L PS-MPs characterized by diameters of 0.5 μm, 4 μm, and 10 μm for a period of 180 days. Our findings indicated that exposure to PS-MPs resulted in the proliferation of macrophages as well as their polarization towards the M1 phenotype. Additionally, the presence of PS-MPs triggered the release of tumor necrosis factor alpha (TNF-α) from macrophages, thereby activating nuclear factor-κB (NF-κB) signaling pathway within Leydig cells. The translocation of NF-κB into nucleus facilitated its binding to the promoter region of LHR, which consequently led to the repression of LHR transcription. This transcriptional inhibition resulted in a subsequent suppression of testosterone synthesis and secretion. Overall, this study elucidates a theoretical basis for explaining the interference of PS-MPs on the testosterone synthesis and secretion in Leydig cells from the perspective of the interaction between cells in the testicular interstitium.

Raman-guided exploration of placental microplastic exposure: Unraveling the polymeric tapestry and assessing developmental implications

The prevalence of microplastics in human tissues and their potential reproductive toxicity have been increasingly documented, yet their appearance in the placenta and the impact of microplastic exposure on human fertility and pregnancy remains uncertain. Utilizing an inVia™ confocal Raman microspectroscopy by Renishaw equipped with a detection threshold as low as 0.25 µm, our study examined the microplastics in the placentas of 50 women post-delivery and investigated their correlations with gestational age, and neonatal length and weight. We found that 40 microplastic particles were identified across 31 of 50 placentas, averaging 2.35 ± 1.25 µm in size and ranging from 1.03 to 6.84 µm. Seven distinct polymer types were detected, with PTFE, PS, and ABS being the most prevalent. Notably, no significant difference across the normal, PTFE, and PS groups for all demographic variables examined was identified, nor as pathological alterations of placental tissues. In conclusion, our findings demonstrate the presence of seven microplastic polymers in human placentas, with PTFE, PS, and ABS being the most prevalent. However, maternal and neonatal parameters were not affected, and further studies are necessary to elucidate the effects of microplastics on developmental outcomes and fetal health.

Microplastics caused embryonic growth retardation and placental dysfunction in pregnant mice by activating GRP78/IRE1α/JNK axis induced apoptosis and endoplasmic reticulum stress

Microplastics (MPs), a brand-new class of worldwide environmental pollutant, have received a lot of attention. MPs are consumed by both humans and animals through water, food chain and other ways, which may cause potential health risks. However, the effects of MPs on embryonic development, especially placental function, and its related mechanisms still need to be further studied. We investigated the impact on fetal development and placental physiological function of pregnant mice by consecutive gavages of MPs at 0, 25, 50, 100 mg/kg body weight during gestational days (GDs 0-14). The results showed that continuous exposure to high concentrations of MP significantly reduced daily weight gain and impaired reproductive performance of pregnant mice. In addition, MPs could significantly induce oxidative stress and placental dysfunction in pregnant mice. On the other hand, MPs exposure significantly decreased placental barrier function and induced placental inflammation. Specifically, MPs treatment significantly reduced the expression of tight junction proteins in placentas, accompanied by inflammatory cell infiltration and increased mRNA levels of pro-inflammatory cytokines and chemokines in placentas. Finally, we found that MPs induced placental apoptosis and endoplasmic reticulum (ER) stress through the GRP78/IRE1α/JNK axis, leading to placental dysfunction and decreased reproductive performance in pregnant mice. We revealed for the first time that the effects of MPs on placental dysfunction in pregnant animals. Blocking the targets of MPs mediated ER stress will provide potential therapeutic ideas for the toxic effects of MPs on maternal pregnancy.

AJ, Kurian C, Chakraborty P, Paari KA. Food additives and contaminants in infant foods: a critical review of their health risk, trends and recent developments

The infant food market has expanded rapidly over the past two decades. However, the industry faces significant challenges, including concerns over the health effects of infant food additives and issues with food safety. However, new evidences suggest that certain food additives, such as those used to preserve and transport infant formula to keep it fresh for longer, should be avoided. Science into the effects of additives on human behavior makes up a sizable sector of the additives market. Problems such as hypernatremic dehydration, malnutrition, and obesity in infants are directly linked to faulty formula production. The Food and Drug Administration (FDA) has established the toxicity types and chemical tests necessary for evaluating the safety of food additives and GRAS (Generally Recognized as Safe) compounds. These tests are crucial in understanding the food safety aspects of food additives. The health effects of different types of food additives on infants are discussed in this context. The article gives an outline of various national and global agencies that provides recommendations and standards to gauge the quality of baby food. The immunological responses, allergic reaction pathways and other related health hazards among the infants and young children caused by the food additive are discussed in this article.

Graphical Abstract

Developments in the field of intestinal toxicity and signaling pathways associated with rodent exposure to micro(nano)plastics

The broad spread of micro(nano)plastics (MNPs) has garnered significant attention in recent years. MNPs have been detected in numerous human organs, indicating that they may also be hazardous to humans. The toxic effects of MNPs have been demonstrated in marine species and experimental animals. The primary pathway and target organ for MNPs entering the human body is the intestinal system, and increasing research has been done on the harmful effects and subsequent mechanisms of exposure to MNPs. Studies on how MNPs affect gut health in humans are scarce, nevertheless. Since rodents are frequently employed as animal models for human ailments, research on rodents exposed to MNPs can provide a more accurate representation of human circumstances. This study examined the effects of MNPs on intestinal microecology, inflammation, barrier function, and ion transport channels in rodents. It also reviewed the signal pathways involved, such as oxidative stress, nuclear factor (NF)-κB, Toll-like receptor (TLR) 4, inflammatory corpuscles, muscarinic acetylcholine receptors (mAChRs), mitogen-activated protein kinase (MAPK), and cell death. This review will offer a conceptual framework for the management and avoidance of associated illnesses.

A critical review of microplastics in aquatic ecosystems: Degradation mechanisms and removing strategies

Plastic waste discarded into aquatic environments gradually degrades into smaller fragments, known as microplastics (MPs), which range in size from 0.05 to 5 mm. The ubiquity of MPs poses a significant threat to aquatic ecosystems and, by extension, human health, as these particles are ingested by various marine organisms including zooplankton, crustaceans, and fish, eventually entering the human food chain. This contamination threatens the entire ecological balance, encompassing food safety and the health of aquatic systems. Consequently, developing effective MP removal technologies has emerged as a critical area of research. Here, we summarize the mechanisms and recently reported strategies for removing MPs from aquatic ecosystems. Strategies combining physical and chemical pretreatments with microbial degradation have shown promise in decomposing MPs. Microorganisms such as bacteria, fungi, algae, and specific enzymes are being leveraged in MP remediation efforts. Recent advancements have focused on innovative methods such as membrane bioreactors, synthetic biology, organosilane-based techniques, biofilm-mediated remediation, and nanomaterial-enabled strategies, with nano-enabled technologies demonstrating substantial potential to enhance MP removal efficiency. This review aims to stimulate further innovation in effective MP removal methods, promoting environmental and social well-being.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Type-specific inflammatory responses of vascular cells activated by interaction with virgin and aged microplastics

Microplastics (MPs) are recognized as a major environmental problem due to their ubiquitous presence in ecosystems and bioaccumulation in food chains. Not only humans are continuously exposed to these pollutants through ingestion and inhalation, but recent findings suggest they may trigger vascular inflammation and potentially worsen the clinical conditions of cardiovascular patients. Here we combine headspace analysis by needle trap microextraction-gas chromatography-mass spectrometry (HS-NTME-GC-MS) and biological assays to evaluate the effects of polystyrene, high- and low-density polyethylene MPs on phenotype, metabolic activity, and pro-inflammatory status of Vascular Smooth Muscle Cells (VSMCs) the most prominent cells in vascular walls. Virgin and artificially aged MPs (4 weeks at 40 °C and 750 W/m2 simulated solar irradiation) were comparatively tested at 1 mg/mL to simulate a realistic exposure scenario. Our results clearly show the activation of oxidative stress and inflammatory processes when VSMCs were cultured with aged polymers, with significant overexpression of IL-6 and TNF-α. In addition, volatile organic compounds (VOCs), including pentane, acrolein, propanal, and hexanal as the main components, were released by VSMCs into the headspace. Type-specific VOC response profiles were induced on vascular cells from different MPs.