Microplastics in take-out food containers

Human intake assessment of triclosan associated with the daily use of polypropylene-made antimicrobial food packaging

In this work, we aimed to evaluate human intake of triclosan (TCS) associated with real-life use of different brands of Microban™ microwave-safe food packaging. Calculations were based on: TCS migration data (under the worst-case foreseeable conditions), MPs abundance and TCS bioaccessibility from microplastics (MPs), leached from containers under microwave heating. Bioaccessibility studies were performed with in vitro digestion of MPs, followed by liquid-liquid extraction of TCS from digestive fluids and LC-QqQ-MS analysis yielding values of 46 ± 9%. The estimated weekly intake (EWI) of TCS ranged between 11 and 42 μg/kg body weight/week, with migration being the largest contribution (0.6-2.3 mg/week), compared to leaching of MPs (75-300 μg/week). These values represent a significant source of human exposure to TCS, emphasizing the need to harmonize the ban of TCS in food contact materials worldwide and improve compliance testing of food contact articles, particularly those marketed through online sales platforms.

Plastic takeaway food containers may cause human intestinal damage in routine life usage: Microplastics formation and cytotoxic effect

The microplastics and organic additives formed in routine use of plastic takeaway food containers may pose significant health risks. Thus, we collected plastic containers made of polystyrene, polypropylene, polyethylene terephthalate, polylactic acid and simulated two thermal usages, including hot water (I) and microwave treatments (M). Nile Red fluorescence staining was developed to improve accurate counting of microplastics with the aid of TEM and DLS analysis. The quantity of MPs released from thermal treatments was determined ranging from 285.7 thousand items/cm2 to 681.5 thousand items/cm2 in containers loaded with hot water with the following order: IPS>IPP>IPET>IPLA, while microwave treatment showed lower values ranging from 171.9 thousand items/cm2 to 301.6 thousand items/cm2. In vitro toxicity test using human intestinal epithelial Caco-2 cells indicated decrease of cell viability in raw leachate, resuspended MPs and supernatants, which might further lead to cell membrane rupture, ROS production, and decreased mitochondrial membrane potential. Moreover, the leachate inhibited the expression of key genes in the electron transport chain (ETC) process, disrupted energy metabolism. For the first time, we isolate the actually released microplastics and organic substances for in vitro toxicity testing, and demonstrate their potential impacts to human intestine. SYNOPSIS: Plastic take-out containers may release microplastics and organic substances during daily usage, both of which can cause individual and combined cytotoxic effects on human colon adenocarcinoma cells Caco-2.

A review on micro- and nanoplastics in humans: Implication for their translocation of barriers and potential health effects

As emerging contaminants, micro- and nanoplastics (MNPs) can absorb and leach various toxic chemicals and ultimately endanger the health of the ecological environment and humans. With extensive research on MNPs, knowledge about MNPs in humans, especially their translocation of barriers and potential health effects, is of utmost importance. In this review, we collected literature published from 2000 to 2023, focusing on MNPs on their occurrence in humans, penetrating characteristics in the placental, blood-brain, and blood-testis barriers, and exposure effects on mammalian health. The characteristics and distributions of MNPs in human samples were analyzed, and the results demonstrated that MNPs were ubiquitous in most human samples, except for kidneys and cerebrospinal fluid. In addition, the phenomenon of MNPs crossing barriers and their underlying mechanisms were discussed. We also summarized the potential factors that may affect the barrier crossing and health effects of MNPs, including characteristics of MNPs, exposure doses, administration routes, exposure durations, co-exposure to other pollutants, and genetic predisposition. Exposure to MNPs may cause cytotoxicity, neurotoxicity, and developmental and reproductive toxicity in mammals. People are encouraged to reduce their exposure to MNPs to prevent these adverse health effects. Finally, we discussed the shortcomings of current research on MNPs in humans, providing a valuable reference for understanding and evaluating the potential health risks from MNP exposure in mammals, including humans.

Microplastics in seafood: Consumer preferences and valuation for mitigation technologies

Microplastics, an emerging pollutant, have garnered widespread attention due to potential repercussions on human health and the environment. Given the critical role of seafood in food security, growing concerns about microplastics might be detrimental to meeting future global food demand. This study employed a discrete choice experiment to investigate Chilean consumers' preferences for technology aimed at mitigating microplastic levels in mussels. Using a between-subjects design with information treatments, we examined the impact of informing consumers about potential human health and environmental effects linked to microplastics pollution on their valuation for the technology. We found that the information treatments increased consumers' willingness to pay for mussels. Specifically, consumers were willing to pay a premium of around US$ 4 for 250 g of mussel meat with a 90 % depuration efficiency certification. The provision of health impact information increased the price premium by 56 %, while the provision of environmental information increased it by 21 %. Furthermore, combined health and environmental information significantly increased the probability of non-purchasing behavior by 22.8 % and the risk perception of microplastics for human health by 5.8 %. These results emphasized the critical role of information in shaping consumer preferences and provided evidence for validating investment in research and development related to microplastic pollution mitigation measures.

Reducing microplastics in tea infusions released from filter bags by pre-washing method: Quantitative evidences based on Raman imaging and Py-GC/MS

Microplastics released from plastic-based filter bags during tea brewing have attracted widespread attention. Laser confocal micro-Raman and direct classical least squares were used to identify and estimate micron-sized microplastics. Characteristic peaks from pyrolysis-gas chromatography/mass spectrometry of polyethylene terephthalate, polypropylene, and nylon 6 were selected to construct curves for quantification submicron-sized microplastics. The results showed that microplastics released from tea bags in the tea infusions ranged from 80 to 1288 pieces (micron-sized) and 0 to 63.755 μg (submicron-sized) per filter bag. Nylon 6 woven tea bags released far fewer microplastics than nonwoven filter bags. In particular, a simple strategy of three pre-washes with room temperature water significantly reduced microplastic residues with removal rates of 76 %-94 % (micron-sized) and 80 %-87 % (submicron-sized), respectively. The developed assay can be used for the quantitative evaluation of microplastics in tea infusions, and the pre-washing reduced the risk of human exposure to microplastics during tea consumption.

Environmental impact of microplastics and potential health hazards

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

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

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

Microplastic and PTFE contamination of food from cookware

Microplastics are a prolific environmental contaminant that have been evidenced in human tissues. Human uptake of microplastic occurs via inhalation of airborne fibres and ingestion of microplastic-contaminated foods and beverages. Plastic and PTFE-coated cookware and food contact materials may release micro- and nanoplastics into food during food preparation. In this study, the extent to which non-plastic, new plastic and old plastic cookware releases microplastics into prepared food is investigated. Jelly is used as a food simulant, undergoing a series of processing steps including heating, cooling, mixing, slicing and storage to replicate food preparation steps undertaken in home kitchens. Using non-plastic cookware did not introduce microplastics to the food simulant. Conversely, using new and old plastic cookware resulted in significant increases in microplastic contamination. Microplastics comprised PTFE, polyethylene and polypropylene particulates and fibrous particles, ranging 13-318 μm. Assuming a meal was prepared daily per the prescribed methodology, new and old plastic cookware may be contributing 2409-4964 microplastics per annum into homecooked food. The health implications of ingesting microplastics remains unclear.

A systematic review of microplastics emissions in kitchens: Understanding the links with diseases in daily life

The intensification of microplastics (MPs) pollution has emerged as a formidable environmental challenge, with profound global implications. The pervasive presence of MPs across a multitude of environmental mediums, such as the atmosphere, soil, and oceans, extends to commonplace items, culminating in widespread human ingestion and accumulation via channels like food, water, and air. In the domestic realm, kitchens have become significant epicenters for MPs pollution. A plethora of kitchen utensils, encompassing coated non-stick pans, plastic cutting boards, and disposable utensils, are known to release substantial quantities of MPs particles in everyday use, which can then be ingested alongside food. This paper conducts a thorough examination of contemporary research addressing the release of MPs from kitchen utensils during usage and focuses on the health risks associated with MPs ingestion, as well as the myriad factors influencing the release of MPs in kitchen utensils. Leveraging the insights derived from this analysis, this paper proposes a series of strategic recommendations and measures targeted at mitigating the production of MPs in kitchen settings. These initiatives are designed not solely to diminish the release of MPs but also to enhance public awareness regarding this pressing environmental concern. By adopting more informed practices in kitchens, we can significantly contribute to the reduction of the environmental burden of MPs pollution, thus safeguarding both human health and the ecological system.

Microplastic Release from Single-Use Plastic Beverage Cups

Microplastics (MPs) have attracted considerable attention as one of the most remarkable food and drink pollutants in recent years. Disposable cups, which are widely used as single-use containers, have been suspected as the primary sources of MPs found in cold and hot beverages. In this study, the effect of different exposure times (0, 5, 10 and 20 min) and temperatures (4 °C, 50 °C and 80 °C) on MP release from the single-use cups made of four different materials [polypropylene (PP), polystyrene (PS), polyethylene (PE) coated paper cups and expanded polystyrene (EPS)] into the water was investigated. The number of MPs ranged from 126 p/L to 1420 p/L, while the highest and lowest counts were observed in the PP (50 °C for 20 min) and PE-coated paper cups (4 °C 0 min), respectively. Washing the cups with ultrapure water prior to use reduced the MP release by 52-65%. SEM images demonstrated the abrasion on the surface of the disposable cups as a result of hot water exposure. Intensities of FTIR absorbance levels at some wavelengths were decreased by the water treatment, which could be evidence of surface abrasion. The annual MP exposure of consumers was calculated as 18,720-73,840 by the consumption of hot and cold beverages in disposable cups. In conclusion, as the level and potential toxicity of MP exposure in humans are not yet fully known, this study sheds light on the number of MPs transferred to cold and hot beverages from single-use disposable cups.

Tracing the entry process of submicrometre plastics in soybean sprouts by leaf-derived fluorescent carbon dots

As a global emerging contaminant, microplastics (MPs) in water or soil can accumulate in vegetables, making them easily ingested through the diet. With excellent and tunable optical properties, carbon dots (CDs) are highly advantageous for tracing the entry process of MPs. Originally, long-wavelength CDs were synthesized from leaf-derived extracts, and fluorescent submicrometer plastics (CDs-MPs) with clean surfaces and concentrated particle sizes were obtained by soap-free microemulsion polymerization. The concentration of CDs-MPs exhibits a significant linear relationship with long-wavelength fluorescence intensity (λEx/λEm: 415/676 nm). Soybean sprouts (SBS), as an important type of food, are susceptible to contamination of MPs due to their soft epidermis and rapidly growing biomass. The results showed that CDs-MPs could be embedded into the cortex of SBS and enter the plant with cell division and elongation, leading to an increase in pore size on the cell wall surface. After entering the root system, CDs-MPs will pass through the Casparian strip and migrate in the vessels. Then, CDs-MPs enter the leaves through vascular bundles, and the distribution and size of epicuticular wax on leaves have changed. Furthermore, SBS showed resistant growth and increased levels of oxidative response when exposed to MPs/CDs-MPs. It is the first study to demonstrate the application of leaf-derived CDs in the prevention of MPs pollution by revealing the migration behavior of submicrometre plastics in SBS.

Isolation and identification of microplastics in infant formulas - A potential health risk for children

Microplastics (MPs) are plastic particles between 0.1 and 5,000 µm in size that can contaminate food. Unfortunately, to date, little attention has been paid to analyzing the presence of such particles in baby foods. The present study aimed to determine the degree of contamination of infant formula with MPs. A total of thirty products were subjected to analysis. The research methodology used included the isolation of plastic particles, identification and characterization of MPs using advanced microscopic and spectroscopic techniques. Microplastics were detected in all tested samples. The most frequently identified polymers were polyamide, polyethylene, polypropylene, and poly(ethylene terephthalate). The particles exhibited diverse forms, including fibers, fragments, and films, displaying a range of colors such as colorless, black, and brown particles. Furthermore, the daily intake of MPs by children fed exclusively infant formula was estimated to be approximately 49 ± 32 MPs. This poses a potential health risk for the youngest.

Potential health risks of microplastic fibres release from disposable surgical masks: Impact of repeated wearing and handling

Disposable surgical masks undeniably provide important personal protection in daily life, but the potential health risks by the release of microplastic fibres from masks should command greater attention. In this study, we conducted a microplastic fibre release simulation experiment by carrying masks in a pocket and reusing them, to reveal the number and morphological changes of microfibres released. Fourier transform infrared spectrometry, scanning electron microscopy, and optical microscopy were employed to analyse the physical and chemical characteristics of the mask fibres. The results indicated that the reuse of disposable masks led to a significant release of microplastic fibres, potentially leading to their migration into the respiratory system. Furthermore, the release of microplastic fibres increased with prolonged external friction, particularly when masks were stored in pockets. The large-scale release of microplastic fibres due to mask reuse raises concerns about potential health risks to the human respiratory system. The reuse of disposable masks should be also strictly avoided in daily life in the future. Furthermore, the current study also established a robust foundation for future research endeavours on health risks associated with microplastic fibres entering the respiratory system through improper mask usage.

Characterization of the intestinal transport mechanism of polystyrene microplastics (MPs) and the potential inhibitory effect of green tea extracts on MPs intestinal absorption

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 μm, of amine-modified MPs compared to either larger size (1 μm diameter, or carboxylate-MPs (0.2 and 1 μm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.

Nrf2-mediated ferroptosis of spermatogenic cells involved in male reproductive toxicity induced by polystyrene nanoplastics in mice

Microplastics (MPs) and nanoplastics (NPs) have become hazardous materials due to the massive amount of plastic waste and disposable masks, but their specific health effects remain uncertain. In this study, fluorescence-labeled polystyrene NPs (PS-NPs) were injected into the circulatory systems of mice to determine the distribution and potential toxic effects of NPs in vivo. Interestingly, whole-body imaging found that PS-NPs accumulated in the testes of mice. Therefore, the toxic effects of PS-NPs on the reproduction systems and the spermatocytes cell line of male mice, and their mechanisms, were investigated. After oral exposure to PS-NPs, their spermatogenesis was affected and the spermatogenic cells were damaged. The spermatocyte cell line GC-2 was exposed to PS-NPs and analyzed using RNA sequencing (RNA-seq) to determine the toxic mechanisms; a ferroptosis pathway was found after PS-NP exposure. The phenomena and indicators of ferroptosis were then determined and verified by ferroptosis inhibitor ferrostatin-1 (Fer-1), and it was also found that nuclear factor erythroid 2-related factor 2 (Nrf2) played an important role in spermatogenic cell ferroptosis induced by PS-NPs. Finally, it was confirmed in vivo that this mechanism of Nrf2 played a protective role in PS-NPs-induced male reproductive toxicity. This study demonstrated that PS-NPs induce male reproductive dysfunction in mice by causing spermatogenic cell ferroptosis dependent on Nrf2.

Detection of nanoplastics released from consumer plastic food containers by electromagnetic heating pyrolysis mass spectrometry

Nanoplastics released from consumer plastic food containers are emerging environmental pollutants and directly ingested as part of the diet. However, quantification methods for nanoplastics are still lacking. Herein, a rapid identification and mass quantification approach was developed for nanoplastics analysis by combining electromagnetic heating with pyrolysis mass spectrometry (Eh-Py-MS). The pyrolysis products directly entered into the MS, which omits the gas phase separation process and shortens the detection time. A compact pyrolysis chamber was used and this increased the sample transfer efficiency and lowered power requirement. The operational parameters were systematically examined. The influence of nanoplastic size, additive, humic acid, and aging on detection was investigated, and it was concluded that environmental factors (humic acid, aging) and plastic properties (size, additives) did not influence the detection. The developed chamber showed that the limit of detection of polystyrene (PS) nanoplastics was 15.72 ng. Several typical food packages were demonstrated with satisfactory recovery rates (87.5-110%) and precision (RSD ≤11.36%). These results suggested that the consumer plastic food containers are a significant source of direct exposure to nanoplastics in humans from the environment.

Everything falls apart: How solids degrade and release nanomaterials, composite fragments, and microplastics

To ensure the safe use of materials, one must assess the identity and quantity of exposure. Solid materials, such as plastics, metals, coatings and cements, degrade to some extent during their life cycle, and releases can occur during manufacturing, use and end-of-life. Releases (e.g., what is released, how does release happen, and how much material is released) depend on the composition and internal (nano)structures of the material as well as the applied stresses during the lifecycle. We consider, in some depth, releases from mechanical, weathering and thermal stresses and specifically address the use cases of fused-filament 3D printing, dermal contact, food contact and textile washing. Solid materials can release embedded nanomaterials, composite fragments, or micro- and nanoplastics, as well as volatile organics, ions and dissolved organics. The identity of the release is often a heterogenous mixture and requires adapted strategies for sampling and analysis, with suitable quality control measures. Control materials enhance robustness by enabling comparative testing, but reference materials are not always available as yet. The quantity of releases is typically described by time-dependent rates that are modulated by the nature and intensity of the applied stress, the chemical identity of the polymer or other solid matrix, and the chemical identity and compatibility of embedded engineered nanomaterials (ENMs) or other additives. Standardization of methods and the documentation of metadata, including all the above descriptors of the tested material, applied stresses, sampling and analytics, are identified as important needs to advance the field and to generate robust, comparable assessments. In this regard, there are strong methodological synergies between the study of all solid materials, including the study of micro- and nanoplastics. From an outlook perspective, we review the hazard of the released entities, and show how this informs risk assessment. We also address the transfer of methods to related issues such as tyre wear, advanced materials and advanced manufacturing, biodegradable polymers, and non-solid matrices. As the consideration of released entities will become more routine in industry via lifecycle assessment in Safe-and-Sustainable-by-Design practices, release assessments will require careful design of the study with quality controls, the use of agreed-on test materials and standardized methods where these exist and the adoption of clearly defined data reporting practices that enable data reuse, meta-analyses, and comparative studies.

Bacterial screening in Indian coastal regions for efficient polypropylene microplastics biodegradation

Polypropylene based medical devices significantly increased production and usage in COVID-19 pandemic states, and this material is very resilient in the environment. Thus, more than ever, rapid action is needed to reduce this pollution. This study focuses on the degradation of polypropylene microplastics (PP MPs) by unique marine bacterial strains obtained from the Thoundi (Bacillus tropicus, Bacillus cereus, Stenotrophomonas acidaminiphila, and Brucella pseudintermedia) and Rameshwaram coasts (Bacillus cereus). Those above five bacterial strains were chosen after preliminary screening of their hydrophobicity, biofilm-forming capabilities, and responsiveness to the zone of clearance technique. During the biodegradation process (28 days), the growth, metabolic activity, and viability of these five isolates were all raised. After the post-biodegradation process, the weight loss percentages of the mentioned bacterial strains treated with PP MPs gradually decreased, with values of 51.5 ± 0.5 %, 47.5 ± 0.5 %, 33 ± 1 %, 28.5 ± 0.5 and 35.5 ± 0.5 %, respectively. UV-Vis DRS and SEM analysis confirmed that bacterial strains adhering to MPs cause cracks and cavities on their surface. The degradation of PP MPs can be inferred from alterations in the FT-IR spectrum, specifically in the carbonyl group range of 1100-1700 cm-1, as well as changes in the 1H NMR spectrum, including chemical shift and proton peak pattern alterations. Bacterial strains facilitated the degradation of PP MPs through the secretion of hydrolase-categorized enzymes of protease, lipase, and esterase. The findings of this study indicate that marine bacteria may possess distinctive characteristics that facilitate the degradation of plastic waste and contribute to environmental conservation.

Unraveling the micro- and nanoplastic predicament: A human-centric insight

Micro- and nanoplastics are vast anthropogenic pollutants in our direct surroundings with a robust environmental stability and a potential for a long-lasting and increasing global circulation. This has raised concerns among the public and policy makers for human health upon exposure to these particles. The micro- and nanoplastic burden on humans is currently under debate, along with criticism on the experimental approaches used in hazard assessment. The present review presents an overview of the human-relevant aspects associated with the current micro-and nanoplastic burden. We focus on environmental circulation and the estimation of exposure quantities to humans, along with a state-of-the-art overview of particle accumulation in over 15 human organs and other specimen. Additionally, data regarding particle characteristics used in toxicity testing was extracted from 91 studies and discussed considering their environmental and human relevance.

Assessing the inconsistency of microplastic measurements in foods and beverages

The widespread occurrence of microplastics (MPs) in the food chain has gained substantial recognition as a pressing concern, highlighting the inevitability of human exposure through ingestion of foodborne MPs, coupled with the release of MPs from plastic packaging. However, there are notable disparities in the reported numbers of MPs in foods and beverages, warranting a thorough investigation into the factors contributing to these discrepancies. Table salt is one of the major sources of MPs, and there was an approximately hundred-fold difference between the reviewed studies that reported the highest and lowest number of MPs. In addition, more noticeable discrepancies were discovered between studies on MPs released from teabags. One study reported that approximately 15 billion MPs were released into a cup of tea from a single teabag, whereas another research paper found only approximately 106.3 ± 14.6 MP/teabag after brewing. This comprehensive review focuses on the inconsistencies observed across studies examining MPs, shedding light on the plausible factors underlying these variations. Furthermore, the review outlines areas in analytical procedures that require enhancement and offers recommendations to promote accuracy and standardization in future research efforts, such as employing analytical methods capable of confirming the presence of MPs, using appropriate filter sizes, considering representative sample sizes when extrapolation is involved, and so on. By pinpointing the detection processes leading to the inconsistent results observed in MP studies, this comparative analysis will contribute to the development of reliable analytic methods for understanding the extent of microplastic contamination in the human food chain.

Size-dependent toxicity of polystyrene microplastics on the gastrointestinal tract: Oxidative stress related-DNA damage and potential carcinogenicity

Microplastics (MPs) and nanoplastics (NPs) have been generally regarded as emerging pollutants and received worldwide attention in recent years. Water and food consumption are the primary pathways for human exposure to MPs/NPs, thus gastrointestinal tracts may be susceptible to their toxicity. Although the recent report has indicated the presence of MPs/NPs in multiple human organs, little is known about their gastric effects. Therefore, this study focused on the adverse effects of polystyrene microplastics (PS-MPs) on gastric epithelium in vivo and in vitro. Surface-enhanced Raman spectroscopy (SERS) revealed the distribution of PS-MPs was associated with their particle sizes, and predominantly concentrated in gastric tissues. Gastric barrier injury and mitochondrial damage were observed in rats after exposure to PS-MPs. Compared with the larger ones, polystyrene nanoplastics (PS-NPs) more significantly reduced the activity of antioxidant enzymes while enhancing the level of MDA, 8-OhdG and γ-H2AX. Meanwhile, PS-MPs caused upregulation of β-catenin/YAP through redox-dependent regulation of nucleoredoxin (NXN) and dishevelled (Dvl). These findings supported the size-dependent effects of PS-MPs on oxidative stress and DNA damage. Moreover, the redox-dependent activation of the β-catenin/YAP cascade suggested a novel toxic mechanism for PS-MPs and implied the potential carcinogenic effects.

Exposure of U.S. adults to microplastics from commonly-consumed proteins

We investigated microplastic (MP) contamination in 16 commonly-consumed protein products (seafoods, terrestrial meats, and plant-based proteins) purchased in the United States (U.S.) with different levels of processing (unprocessed, minimally-processed, and highly-processed), brands (1 - 4 per product type, depending on availability) and store types (conventional supermarket and grocer featuring mostly natural/organic products). Mean (±stdev) MP contamination per serving among the products was 74 ± 220 particles (ranging from 2 ± 2 particles in chicken breast to 370 ± 580 in breaded shrimp). Concentrations (MPs/g tissue) differed between processing levels, with highly-processed products containing significantly more MPs than minimally-processed products (p = 0.0049). There were no significant differences among the same product from different brands or store types. Integrating these results with protein consumption data from the American public, we estimate that the mean annual exposure of adults to MPs in these proteins is 11,000 ± 29,000 particles, with a maximum estimated exposure of 3.8 million MPs/year. These findings further inform estimations of human exposure to MPs, particularly from proteins which are important dietary staples in the U.S. Subsequent research should investigate additional drivers of MPs in the human diet, including other understudied food groups sourced from both within and outside the U.S.

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

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

Isolating micro/nanoplastics from organic-rich wastewater: Co/PMS outweighs Fenton system

Rapid isolation of microplastics is the prerequisite for correct and in-depth understanding of their environmental impacts and human health threats. And Fenton's reagent (Fe/H2O2 system, FHS) has been proven to be a viable way to isolate microplastics from wastewater, but it is limited because of harsh reaction conditions, long reaction time and low efficiency. Herein, it's proven that the Fenton-like system, which is using Cobalt (II) salts to decompose potassium peroxymonosulfate (Co/PMS system, CPS) with generation of 1O2, can offer shorter time (within 30 min) in complex sample isolation. The experimental results showed that the isolation time of micro/nanoplastics from pollutants with CPS in only 30 min, while it was at least more than 5 h with FHS. Via a serious of experiments of comparison and characterization between FHS and CPS, whether from the point of view of reaction time or isolation effect, CPS is superior to FHS. On this basis, we validate the applicability of this system (CPS) in different reaction conditions (concentration, pH), different sizes (from microns to nanometers) and types of plastic (PS, PA, PE, PP, PVC). In addition, the CPS can also preserve the integrity of the plastic itself and reduce the impact on the quality of samples evidenced by a variety of characterization of physicochemical structure like UV-vis, TEM, AFM, FTIR and XPS. CPS is proved to be faster, higher, stronger for enhancing the isolation of micro/nanoplastics from complex matrix. In a word, this study provides a promising solution for the efficient isolation of microplastics from wastewater without causing additional harm to the plastics.

Micro(nano)plastics in the Human Body: Sources, Occurrences, Fates, and Health Risks

The increasing global attention on micro(nano)plastics (MNPs) is a result of their ubiquity in the water, air, soil, and biosphere, exposing humans to MNPs on a daily basis and threatening human health. However, crucial data on MNPs in the human body, including the sources, occurrences, behaviors, and health risks, are limited, which greatly impedes any systematic assessment of their impact on the human body. To further understand the effects of MNPs on the human body, we must identify existing knowledge gaps that need to be immediately addressed and provide potential solutions to these issues. Herein, we examined the current literature on the sources, occurrences, and behaviors of MNPs in the human body as well as their potential health risks. Furthermore, we identified key knowledge gaps that must be resolved to comprehensively assess the effects of MNPs on human health. Additionally, we addressed that the complexity of MNPs and the lack of efficient analytical methods are the main barriers impeding current investigations on MNPs in the human body, necessitating the development of a standard and unified analytical method. Finally, we highlighted the need for interdisciplinary studies from environmental, biological, medical, chemical, computer, and material scientists to fill these knowledge gaps and drive further research. Considering the inevitability and daily occurrence of human exposure to MNPs, more studies are urgently required to enhance our understanding of their potential negative effects on human health.

Recognition and detection technology for microplastic, its source and health effects

Microplastic (MP) is ubiquitous in the environment which appeared as an immense intimidation to human and animal health. The plastic fragments significantly polluted the ocean, fresh water, food chain, and other food items. Inadequate maintenance, less knowledge of adverse influence along with inappropriate usage in addition throwing away of plastics items revolves present planet in to plastics planet. The present study aims to focus on the recognition and advance detection technologies for MPs and the adverse effects of micro- and nanoplastics on human health. MPs have rigorous adverse effect on human health that leads to condensed growth rates, lessened reproductive capability, ulcer, scrape, and oxidative nervous anxiety, in addition, also disturb circulatory and respiratory mechanism. The detection of MP particles has also placed emphasis on identification technologies such as scanning electron microscopy, Raman spectroscopy, optical detection, Fourier transform infrared spectroscopy, thermo-analytical techniques, flow cytometry, holography, and hyperspectral imaging. It suggests that further research should be explored to understand the source, distribution, and health impacts and evaluate numerous detection methodologies for the MPs along with purification techniques.

Suspected sources of microplastics and nanoplastics: Contamination from experimental reagents and solvents

There is an increasing concern about the potential effects of microplastics (MPs) and nanoplastics on human health and other organisms. For the separation and detection of MPs, there are various approaches, and the distinct procedures led to different results. However, the presence of MPs in the reagents was not addressed, which could cause false and/or inaccurate results during MPs detection. In this study, the chemical reagents commonly used for the separation and detection of MPs were selected to ascertain whether these reagents introduce MPs. It was shown that a large number of MPs were detected in the reagent and solvent samples. The largest number of MPs (>1 μm) was detected in the KOH reagent, with the abundance of 3070 items/g. The order of MPs abundance in the selected reagents was: KOH > NaCl > CaCl2 > SDS > NaI > H2O2. The types of MPs were the same as the body and stopper of the reagent packaging bottles. MPs size detected in reagent bottles was primarily smaller than 10 μm. The abundance of MPs in the reagents were independent of their purity, however, there was a certain difference in MPs abundance in reagents from different manufacturers. Furthermore, the presence of nanoplastics (< 1 μm) was verified in the reagents through Py-GCMS, with the abundance (39.47-43.01 mg/kg) higher than that of MPs. The obtained results in this study raised specific requirements and cautions for MPs and nanoplastics related research in terms of quality control. Also, this work can facilitate a more accurate assessment of MPs concentrations in the environment.

Potential Migration and Health Risks of Heavy Metals and Metalloids in Take-Out Food Containers in South Korea

The consumption of take-out food has increased worldwide; consequently, people are increasingly being exposed to chemicals from food containers. However, research on the migration of metals from containers to food is limited, and therefore, information required to determine the health risks is lacking. Herein, the amount of transfer of nine metals and metalloids (Pb, Sb, Cd, Ge, Co, Mn, Sn, As, and Hg) from food containers to food in South Korea was assessed from take-out food containers classified into paper and plastic container groups. The sample containers were eluted over time by either warming with 4% acetic acid at 70 °C or cooling with 4% acetic acid at 100 °C /deionized water at 25 °C. It was analyzed using an inductively coupled plasma mass spectrometer and a direct mercury analyzer. The reliability of the quantitative results was verified by calculating the linearity, limit of detection, and limit of quantification. We found that the amount of metals and metalloids (Pb, Sb, Cd, and Co) eluting over time was highly significant in the plastic group. Regardless of the food simulant and elution time, the amount of Sb transferred from the food containers to food was substantially higher in the plastic (average concentration: 0.488-1.194 μg/L) than in the paper group (average concentration: 0.001-0.03 μg/L). Fortunately, all food containers were distributed at levels safe for human health (hazard index: 0.000-64.756%). However, caution is needed when warm food is added to food containers. Overall, our results provide baseline data for the management and use of take-out containers.

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

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

Microplastic contamination of packaged spirulina products

Microplastic (MP) contamination in commercially sold spirulina products has not been previously investigated. In this study, 29 spirulina samples in various packaging types were purchased from different brands and origins to assess the presence of MPs. Microplastic analysis was conducted using microscopic and μ-Raman techniques. To ascertain whether the content is indeed spirulina and make a comparison with the MP level, C-Phycocyanin levels were also analyzed. A total of 251 MP-like particles were observed. Out of the 29 examined packaged spirulina brands, 26 showed potential MPs upon visual inspection, with 35 particles confirmed as MPs (73% of the analyzed particles). The mean abundance of MPs was estimated at 13.77 ± 2.45 MPs/100 g dw. Powdered spirulina had a higher but not statistically significant MP abundance (17.34 ± 4.22 MPs/100 g dw) compared to capsule/tablet forms (10.43 ± 2.45 MPs/100 g dw). Fragments accounted for 38.3% while fibers constituted 61.7% of the identified MPs, with sizes ranging from 0.07 to 2.15 mm for fragments and 0.19 to 5.691 mm for fibers. The color distribution of MPs in spirulina samples was predominantly blue (52.8%), followed by black (25.4%), white (10.9%), and others (10.9%). Ten synthetic polymers and cellulose were identified through μ-Raman analysis, with polypropylene (31.6%) and polystyrene (8.3%) being the most prevalent. The correlation between C-Phycocyanin and MPs concentrations, was not found statistically significant. The abundance and composition of MPs were found to be influenced by packaging and processing stages. Identifying potential sources of MPs in spirulina products and evaluating their risks to human health is crucial.

The iron matters: Aged microplastics disrupted the iron homeostasis in the liver organoids

Plastic products undergo artificial and unintentional aging during daily use, causing the presence of aged microplastics (aMP). Humans are inevitably exposed to aMP. Liver is one of the critical target organs of MP through oral intake, however, limited research has focused on the hepatic toxicity of aMP compared to pristine MP (pMP). We utilized the human pluripotent stem cells-derived liver organoids (LOs) to compare the cytotoxicity of pristine polystyrene microplastics (pPS) (1 μm, carbonyl index 0.08) and aged polystyrene microplastics (aPS) (1 μm, carbonyl index 0.20) ranged from 20 to 200 ng/mL. Our findings indicate that aPS was more cytotoxic than pPS. We explored the disrupted iron homeostasis in terms of the [Fe2+] and [Fe3+] levels, iron storage and transport. A "vector-like effect" induced by aPS has been preliminarily suggested by the correlated change in total iron level and co-localization of PS and ferritin light chain (FTL) in the LOs following exposure to aPS and ferric ammonium citrate (FAC) individually and combinedly. In addition, we observed abnormal mitochondrial morphology, elevated lipid peroxidation, and declined GSH peroxidase activity, together with the declined expression of transferrin receptor (TFRC) and elevated expressions of SLC7A11, FTL. The gene handled iron transport and iron use were disrupted by aPS. Moreover, we employed FAC to introduce iron overload and Nacetylcysteine (NAC) to protect the lipid peroxidation. In aPS + FAC group, aggravated effects could be observed in aspects of [Fe2+] level, lipid peroxidation, and compromised expression levels of iron homeostasis-related markers, in contrast, in aPS + NAC group, most of changes recovered but the hepatocytoxicity remained. Specifically, a dimorphic change in elevated FTL and decreased ferritin heavy chain (FTH1) caused by 50 ng/mL aMP (57.33 ± 3.57 items/mL, equivalent to human intake level), indicated a specific response to low-dose aMP.

A review on takeaway packaging waste: Types, ecological impact, and disposal route

Rapid economic growth and urbanization have led to significant changes in the world's consumption patterns. Accelerated urbanization, the spread of the mobile Internet, and the increasing pace of work globally have all contributed to the demand for the food takeaway industry. The rapid development of the takeaway industry inevitably brings convenience to life, and with it comes great environmental pressure from waste packaging materials. While maintaining the convenience of people's lives, further reducing the environmental pollution caused by takeaway packaging materials and promoting the recycling and reuse of takeaway packaging waste need to attract the attention and concern of the whole society. This review systematically and comprehensively introduces common takeaway food types and commonly used packaging materials, analyzes the impacts of discarded takeaway packaging materials on human health and the ecological environment, summarizes the formulation and implementation of relevant policies and regulations, proposes treatment methods and resourceful reuse pathways for discarded takeaway packaging, and also provides an outlook on the development of green takeaway packaging. Currently, only 20% of waste packaging materials are recycled worldwide, and there is still a need to develop more green takeaway packaging materials and continuously improve relevant policies and regulations to promote the sustainable development of the takeaway industry. The review is conducive to further optimizing the takeaway packaging management system, alleviating the environmental pollution problem, and providing feasible solutions and technical guidance for further optimizing takeaway food packaging materials and comprehensive utilization of resources.

Exposure sources and pathways of micro- and nanoplastics in the environment, with emphasis on potential effects in humans: A systematic review

Microplastics (MPs) are emerging pollutants that are ubiquitous in the environment, and may be a potential threat to human health. This review describes the MP exposure sources and pathways through drinking water, food intake, and air inhalation. The unregulated discharge of MPs in water sources and the absence of required MP filter technology in water treatment plants are important routes of MP exposure through drinking water. The presence of MPs in food may lead to the accumulation of MPs in the body. Exposure to MPs can occur through airborne fallout and dust inhalation in both indoor and outdoor environments. This review summarizes the MP exposure sources and possible pathways in the human body, and illustrates that the intake of drinking water, food consumption, and air inhalation should be assessed in during routine activities. Integr Environ Assess Manag 2023;19:1422-1432. © 2023 SETAC.

Microplastics in environment: a comprehension on sources, analytical detection, health concerns, and remediation

Contamination of ecosystems by microplastics (MPs) has been reported intensively worldwide in the recent decade. A trend of reports indicated their presence in the atmosphere; food items and soil ecosystems are rising continuously. Literature evidenced that MPs are abundant in seawater, beach sand, drinking water, agricultural soils, wastewater treatment plant (WWTP) effluent, and the atmosphere. The greater abundance of MPs in the environment has led to their invasion of seafood, human-consumed food items such as table salts, beverages, takeout food containers, and disposable cups, marine biological lives, and creating serious health hazards in humans. Moreover, the absence of guidelines and specifications for controlling MPs in the environment makes the situation alarming, and the human toxicity data of MPs is scarce. Thereby, the toxicity assessment of MPs in humans is of greater concern. This review compiles the updated information on the potential sources of MPs in different components of the environment (viz. soil, water, and air), their analysis methods, effects on human health, and remediation methods.

Vertical distribution and transport of microplastics in the urban atmosphere: New insights from field observations

The distribution and transport of atmospheric microplastics (AMPs) have raised concerns regarding their potential effects on the environment and human health. Although previous studies have reported the presence of AMPs at ground level, there is a lack of comprehensive understanding of their vertical distribution in urban environments. To gain insight into the vertical profile of AMPs, field observations were conducted at four different heights (ground level, 118 m, 168 m and 488 m) of the Canton Tower in Guangzhou, China. Results showed that the profiles of AMPs and other air pollutants had similar layer distribution patterns, although their concentrations differed. The majority of AMPs were composed of polyethylene terephthalate and rayon fibers ranging from 30 to 50 μm. As a result of atmospheric thermodynamics, AMPs generated at ground level were only partially transported upward, leading to a decrease in their abundance with increasing altitude. The study found that the stable atmospheric stability and lower wind speed between 118 m and 168 m resulted in the formation of a fine layer where AMPs tended to accumulate instead of being transported upward. This study for the first time delineated the vertical profile of AMPs within the atmospheric boundary layer, providing valuable data for understanding the environmental fate of AMPs.

Synergistic analysis of performance, microbial community, and metabolism in aerobic granular sludge under polyacrylonitrile microplastics stress

Aerobic granular sludge (AGS) has proved to be a promising biotechnology for microplastics wastewater treatment. However, polyacrylonitrile microplastics (PAN MPs), the most widely used plastic in textile materials, have not been investigated. Therefore, the effect of the neglected PAN MPs on AGS at different concentrations (1, 10, and 100 mg/L) was evaluated. The results indicated that PAN MPs with 1 and 10 mg/L concentrations had no obvious effect on granular stability and nutrient removal performance, but greatly promoted the secretion of EPS. Remarkably, the granule structure was severely damaged under 100 mg/L PAN MPs. Moreover, microbial community analysis showed that phylum Proteobacteria played a dominant role in resistance to PAN MPs. Metabolic analysis further revealed that genes related to denitrification pathway (nasA, nirK, nirS and norB) and membrane transport were significantly inhibited under PAN MPs stress. This study may provide additional information on the treatment of microplastics wastewater using AGS.

Toxicity assessment of microplastic (MPs); a threat to the ecosystem

Plastic is now considered part and parcel of daily life due to its extensive usage. Microplastic (MP) pollution is becoming a growing worry and has been ranked as the second most critical scientific problem in the realm of ecology and the environment. Microplastics are smaller in size than the plastic and are more harmful to biotic and as well as abiotic environments. The toxicity of microplastic depends upon its shape and size and increases with an increase in its adsorption capacity and their toxicity. The reason behind their harmful nature is their small size and their large surface area-to-volume ratio. Microplastic can get inside fruits, vegetables, seeds, roots, culms, and leaves. Hence microplastic enters into the food chain. There are different entry points for microplastic to enter into the food chain. Such sources can include polluted food, beverages, spices, plastic toys, and household (packing, cooking, etc.). The concentration of microplastic in terrestrial environments is increasing day by day. Microplastic causes the destruction of soil structure; destroys soil microbiota, cause depletion of nutrients in the soil, and their absorption by plants decreases plant growth. Apart from other environmental problems caused by microplastic, human health is also badly affected by microplastic pollution present in the terrestrial environment. The presence of microplastics in the human body has been confirmed. Microplastic enters into the body of humans in different possible ways. According to their way of entering the body, microplastics cause different diseases in humans. MPs also cause negative effects on the human endocrine system. At the ecosystem level, the impacts of microplastic are interconnected and can disrupt ecological processes. Although recently different papers have been published on several aspects of the microplastic present in the terrestrial environment but there is no complete overview that focus on the interrelationship of MPs in plants, and soil and their effect on higher animals like a human. This review provides a completely detailed overview of existing knowledge about sources, occurrences, transport, and effects of microplastic on the food chain and soil quality and their ecotoxicological effects on plants and humans.

Source apportionment of microplastics in indoor dust: Two strategies based on shape and composition

Microplastic (MP) pollution is widely distributed in the environment. However, methods for source apportionment of MPs are still lacking. In this study, the shape and size of 102,860 MPs in indoor dust from 39 cities of China were analyzed by laser direct infrared, and accordingly, a shape index (fshape) based on MP's aspect ratio was developed to assess the contribution of textiles release. In addition, a composition index (fcomp) based on the ratio of the mass concentration of polyethylene terephthalate (PET) to polyamide (PA), which were detected by liquid chromatography-tandem mass spectrometry, was proposed. The contribution of textile source and non-textile source to the indoor MPs were also estimated based on fcomp. It is estimated by fshape that 43% of MPs in indoor dust was released from textiles. Among the most abundant MPs in indoor dust, 98% of polyurethane, 94% of PA and 92% of PET come from the textile source, 76% of polypropylene and almost all of polyethylene come from the non-textile source. fcomp indicates that 83% of PET MPs comes from textile source, i.e., polyester. Considering the application proportion of PET in textile and non-textile industry, it is estimated that 59% of MPs in indoor dust comes from textile source, which is similar to the result obtained by fshape.

Large polystyrene microplastics results in hepatic lipotoxicity in mice

Like small microplastics (MPs), recent studies reveal that large MPs could cause health risks in mice, even if they are not enriched in tissues. However, potential hepatoxicity following large MPs exposure and the underlying mechanisms have not been thoroughly investigated. In the present study, we explored the disruption of hepatic lipid metabolism and potential underlying toxic mechanisms in mice caused by long-term exposure to large polystyrene MPs (40-100 μm) based on a multi-omic approach. After 21 weeks of feeding foods containing MPs (50 and 500 mg/kg food), lipidomic revealed that environmentally relevant and higher doses MP exposures resulted in significant changes in a total of 20 lipid classes. Ceramide (Cer) and dihydroceramide (dhCer) were significantly reduced, while cholesteryl ester (CE), lysoalkylphosphatidylcholine (LPCO), lysophosphatidylethanolamine (LPE) and total glyceride (TG) were all elevated by MPs. The transcriptomic and other physiological data suggested that the potential toxic mechanisms may be related to disorders of fatty acid and cholesterol synthesis and metabolism disorders, and transporting of TG. Our findings demonstrate the hepatic lipotoxicity following exposure to environmentally relevant and higher doses of large MPs, calling for future research and management of the environmental risks of MPs with relatively large particle sizes.

Probiotics improve polystyrene microplastics-induced male reproductive toxicity in mice by alleviating inflammatory response

As a new type of environmental pollutant, microplastics have been garnered increasing attention, especially in regard to their effects on the reproductive system. However, researchers have yet to report whether prevention and treatment measures exist for reproductive injury caused by microplastics. The aim of this study was therefore to explore the mechanism of spermatogenic injury induced by polystyrene microplastics (PS-MPs) and the intervention effect of probiotics based on the gut microbiota-testis axis. Mice were orally exposed for 35 days to 5 µm of PS-MPs with a gavage dose was 0.1 mg/day, and the intervention group was given probiotics (Lactobacillus, Bifidobacterium longum, and Enterococcus) orally. Fecal samples were then subjected to 16 S rRNA sequencing analysis, and sperm motion was analyzed by a Hamilton-Thorne Sperm analyzer. The results showed that PS-MPs exposed mice had significant spermatogenic dysfunction and testicular inflammation. In addition, the intestinal microbial structure of exposed mice changed significantly; the abundance of Lactobacillus decreased, and the abundance of Prevotella increased. Furthermore, with fecal microbiota transplantation, the recipient mice showed a significant decrease in sperm quality. However, probiotics supplementation helped inhibit the activation of IL-17A signaling driven by gut microbes, thereby alleviating the inflammatory response and improving sperm quality decline caused by PS-MPs. These results may provide a scientific basis for further understanding of the mechanism of male reproductive damage caused by environmental pollutants such as microplastics and for novel reproductive damage intervention measures.

Microplastics, a Global Issue: Human Exposure through Environmental and Dietary Sources

Plastic production has grown dramatically over the years. Microplastics (MPs) are formed from the fragmentation of larger plastic debris by combining chemical, physical, and biological processes and can degrade further to form nanoplastics (NPs). Because of their size, MPs and NPs are bioavailable to many organisms and can reach humans through transport along the food chain. In addition to the risk from ingesting MPs themselves, there are risks associated with the substances they carry, such as pesticides, pathogenic microorganisms, and heavy metals, and with the additives added to plastics to improve their characteristics. In addition, bioaccumulation and biomagnification can cause a cumulative exposure effect for organisms at the top of the food chain and humans. Despite the growing scientific interest in this emerging contaminant, the potential adverse effects remain unclear. The aim of this review is to summarize the characteristics (size, shape, color, and properties) of MPs in the environment, the primary sources, and the transport pathways in various environmental compartments, and to shed more light on the ecological impact of MPs and the potential health effects on organisms and humans by identifying human exposure pathways.

Personal protective equipment-derived pollution during Covid-19 era: A critical review of ecotoxicology impacts, intervention strategies, and future challenges

During the COVID-19 pandemic, people used personal protective equipment (PPE) to lessen the spread of the virus. The release of microplastics (MPs) from discarded PPE is a new threat to the long-term health of the environment and poses challenges that are not yet clear. PPE-derived MPs have been found in multi-environmental compartments, e.g., water, sediments, air, and soil across the Bay of Bengal (BoB). As COVID-19 spreads, healthcare facilities use more plastic PPE, polluting aquatic ecosystems. Excessive PPE use releases MPs into the ecosystem, which aquatic organisms ingest, distressing the food chain and possibly causing ongoing health problems in humans. Thus, post-COVID-19 sustainability depends on proper intervention strategies for PPE waste, which have received scholarly interest. Although many studies have investigated PPE-induced MPs pollution in the BoB countries (e.g., India, Bangladesh, Sri Lanka, and Myanmar), the ecotoxicity impacts, intervention strategies, and future challenges of PPE-derived waste have largely gone unnoticed. Our study presents a critical literature review covering the ecotoxicity impacts, intervention strategies, and future challenges across the BoB countries (e.g., India (162,034.45 tons), Bangladesh (67,996 tons), Sri Lanka (35,707.95 tons), and Myanmar (22,593.5 tons). The ecotoxicity impacts of PPE-derived MPs on human health and other environmental compartments are critically addressed. The review's findings infer a gap in the 5R (Reduce, Reuse, Recycle, Redesign, and Restructure) Strategy's implementation in the BoB coastal regions, hindering the achievement of UN SDG-12. Despite widespread research advancements in the BoB, many questions about PPE-derived MPs pollution from the perspective of the COVID-19 era still need to be answered. In response to the post-COVID-19 environmental remediation concerns, this study highlights the present research gaps and suggests new research directions considering the current MPs' research advancements on COVID-related PPE waste. Finally, the review suggests a framework for proper intervention strategies for reducing and monitoring PPE-derived MPs pollution in the BoB countries.

Plastic bottles for chilled carbonated beverages as a source of microplastics and nanoplastics

Carbonated beverages are characterized by low temperatures, multiple microbubbles, high pressure, and an acidic environment, creating ideal conditions for releasing contaminants from plastic bottles. However, the release patterns of microplastics (MPs) and nanoplastics (NPs) are poorly understood. We investigated the effects of plastic type, CO2 filling volume, temperature, sugar content, and additive on the leakage of MPs/NPs and heavy metals. Our results showed that polypropylene bottles released greater MPs (234±9.66 particles/L) and NPs (9.21±0.73 × 107 particles/L) than polyethylene and polyethylene terephthalate bottles. However, subjecting the plastic bottles to 3 repeated inflation treatments resulted in 91.65-93.18% removal of MPs/NPs. The release of MPs/NPs increased with increasing CO2 filling volume, driven by the synergistic effect of CO2 bubbles and pressure. After 4 freeze-thaw cycles, the release of MPs and NPs significantly increased, reaching 450±38.65 MPs and 2.91±0.10 × 108 NPs per liter, respectively. The presence of sugar leads to an elevation in MPs release compared to sucrose-free carbonated water, while the addition of additives to carbonated water exhibits negligible effects on MPs release. Interestingly, actual carbonated beverages demonstrated higher MPs concentrations (260.52±27.18-281.38±61.33 particles/L) than those observed in our well-controlled experimental setup. Our study highlights the non-negligible risk of MPs/NPs in carbonated beverages at low temperatures and suggests strategies to mitigate human ingestion of MPs/NPs, such as selecting appropriate plastic materials, high-pressure carbonated water pretreatment, and minimizing freeze-thaw cycles. Our findings provide insights for further study of the release patterns of the contaminants in natural environments with bubbles, pressure, low temperature, and freeze-thaw conditions.

Face mask derived micro(nano)plastics and organic compounds potentially induce threat to aquatic ecosystem security revealed by toxicogenomics-based assay

Micro(nano)plastics widely detected in aquatic environments have caused serious threat to water quality security. However, as a potential important source of micro(nano)plastics in surface water during the COVID-19 pandemic, the ecological risks of face mask waste to aquatic environments remain poorly understood. Herein, we comprehensively characterized the micro(nano)plastics and organic compounds released from four daily used face masks in aqueous environments and further evaluated their potential impacts on aquatic ecosystem safety by quantitative genotoxicity assay. Results from spectroscopy and high-resolution mass spectrum showed that plastic microfibers/particles (∼11%-83%) and leachable organic compounds (∼15%-87%) were dominantly emitted pollutants, which were significantly higher than nanoplastics (< ∼5%) based on mass of carbon. Additionally, a toxicogenomics approach using green fluorescence protein-fused whole-cell array revealed that membrane stress was the primary response upon the exposure to micro(nano)plastics, whereas the emitted organic chemicals were mainly responsible for DNA damage involving most of the DNA repair pathways (e.g., base/nucleotide excision repair, mismatch repair, double-strand break repair), implying their severe threat to membrane structure and DNA replication of microorganisms. Therefore, the persistent release of discarded face masks derived pollutants might exacerbate water quality and even adversely affect aquatic microbial functions. These findings would contribute to unraveling the potential effects of face mask waste on aquatic ecosystem security and highlight the necessity for more developed management regulations in face mask disposal.

Pouring hot water through drip bags releases thousands of microplastics into coffee

Microplastics (MPs) released from food packaging have attracted widespread attention. In this study, drip bags made from polyethylene (PE), polypropylene (PP), polyester (PET), and rayon selected from eight brands were employed to investigate MPs releasing. Fourier-transform infrared microspectroscopy (μ-FTIR), optical microscope and scanning electron microscope (SEM) were used to study the effects of brewing time and temperature on the release of MPs. The results showed that a single plastic coffee bag steeped at 95 ℃ for 5 min could release more than 10,000 MPs particles into a cup of coffee. Irregular blocks, long strips, and size range of 10-500 μm MPs were easier to be released, implying that consuming 3-4 cups of coffee will lead to an intake of 50 thousand MPs particles daily. Rayon was the primary type of released MPs, accounting for over 80% of the total amount of the released MPs. Our results are hoped to provide evaluation standards of material selection for processing coffee bags.

Xanthoceras sorbifolia Husk Extract Incorporation for the Improvement in Physical and Antioxidant Properties of Soy Protein Isolate Films

With the increasing awareness of ecological and environmental protection, the research on eco-friendly materials has experienced a considerable increase. The objective of our study was to explore a novel soy protein isolate (SPI) film functionalized with antioxidants extracted from Xanthoceras sorbifolia husk (XSHE) as bio-based active packaging films. The films were evaluated in light of their structure, physical machinery, and antioxidant performance using advanced characterization techniques. The FTIR and microscopy results revealed the hydrogen-bond interaction between the SPI and XSHE and their good compatibility, which contributed to the improvement in various properties of the composite films, such as tensile strength (TS), UV blocking, and the water barrier property. As the XSHE content increased to 5%, the TS of the films dramatically increased up to 7.37 MPa with 47.7% and the water vapor permeability decreased to 1.13 × 10-10 g m m-2 s-1 Pa-1 with 22.1%. Meanwhile, the introduction of XSHE caused further improvement in the antioxidant capacity of films, and the release of active agents from films was faster and higher in 10% ethanol than it was in a 50% ethanol food simulant. Overall, SPI-based films functionalized with XSHE demonstrated promising potential applications in food packaging.

Microplastic Pollution Prevention: The Need for Robust Policy Interventions to Close the Loopholes in Current Waste Management Practices

Plastic materials that are less than 5 mm in size are defined as Microplastics (MPs). MPs that are intentionally produced are called primary MPs; however, the most abundant type in the environment consists of the remainder created by the fragmentation of large plastic debris through physical, chemical, and oxidative processes, which are called secondary MPs. Due to their abundance in the environment, poor degradability, toxicological properties, and negative impact on aquatic and terrestrial organisms, including humans, MP pollution has become a global environmental issue. Combatting MP pollution requires both remediation and preventive measures. Although remediation is a must, considering where the technology stands today, it may take long time to make it happen. Prevention, on the other hand, can be and should be done now. However, the effectiveness of preventive measures depends heavily on how well MP escape routes are researched and understood. In this research, we argue that such escape routes (rather, loopholes) exist not only due to mismanaged plastic waste, but also due to cracks in the current waste management systems. One known MP loophole is facilitated by wastewater treatment plants (WWTP). The inability of existing WWTP to retain finer MPs, which are finally released to water bodies together with the treated wastewater, along with the return of captured larger MPs back to landfills and their release into the environment through land applications, are a few examples. Organic waste composting and upcycling of waste incineration ash provide other MP escape pathways. In addition, it is important to understand that the plastics that are in current circulation (active use as well as idling) are responsible for producing MPs through regular wear and tear. Closing these loopholes may be best attempted through policy interventions.

Oral exposure to polystyrene nanoplastics reduced male fertility and even caused male infertility by inducing testicular and sperm toxicities in mice

Nanoplastics (NPs) are the novel hazardous materials and ubiquitous in environment with different sizes. Although recent studies showed testicular toxicity of PS-NPs, whether and how NPs affect male fertility and whether they have the size-dependent effect remain ambiguous in mammals. In this study, the male mice were orally exposed to 25-, 50-, and 100-nm polystyrene NPs (PS-NPs) for 56 days. All three sized PS-NPs reduced male fertility and even caused male infertility. They accumulated in the testes, induced oxidative stress, affected the expression of apoptosis- and inflammation-related genes, and compromised energy metabolism, resulting in damaged testicular microstructure and functions. PS-NPs caused more severe testicular toxicity in infertile mice than in fertile mice. In addition, PS-NPs inhibited sperm capacitation and capacitation-dependent processes in infertile mice but not in fertile mice. In infertile mice, PS-NPs reduced the sperm levels of two Rho GTPases (RAC1 and CDC42) via increasing their ubiquitination levels and diminished sperm filamentous actin polymerization, thus inhibiting sperm capacitation. However, these testicular and sperm toxicities showed no size-dependent effect among three sized PS-NPs. In conclusion, PS-NPs inhibit male fertility by their multifaceted toxicity on testes and sperm in mice, providing novel insights into reproductive risks of NPs to mammals.

Toxicological impact of microplastics and nanoplastics on humans: understanding the mechanistic aspect of the interaction

Plastic is a pervasive material that has become an indispensable part of our daily lives and is used in various commercial products. However, plastic waste has significantly impacted the environment, accumulating in water and land ecosystems and harming all forms of life. When plastic degrades, it breaks down into smaller particles called microplastics (MPs), which can further breakdown into nanoplastics (NPs). Due to their small size and potential toxicity to humans, NPs are of particular concern. During the COVID-19 pandemic, the production of plastic had reached unprecedented levels, including essential medical kits, food bags, and personal protective equipment (PPE), which generate MPs and NPs when burned. MPs and NPs have been detected in various locations, such as air, food, and soil, but our understanding of their potential adverse health effects is limited. This review aims to provide a comprehensive overview of the sources, interactions, ecotoxicity, routes of exposure, toxicity mechanisms, detection methods, and future directions for the safety evaluation of MPs and NPs. This would improve our understanding of the impact of MPs and NPs on our health and environment and identify ways to address this global crisis.