From natural environment to animal tissues: A review of microplastics(nanoplastics) translocation and hazards studies

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

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

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

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

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

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

Binding between Cu2+/Zn2+ and aged polyethylene and polyethylene terephthalate microplastics in swine wastewaters: Adsorption behavior, and mechanism insights

Microplastics (MPs) have aroused growing environmental concerns due to their biotoxicity and vital roles in accelerating the spread of toxic elements. Illuminating the interactions between MPs and heavy metals (HMs) is crucial for understanding the transport and fate of HM-loaded MPs in specific environmentally relevant scenarios. Herein, the adsorption of copper (Cu2+) and zinc (Zn2+) ions over polyethylene (PE) and polyethylene terephthalate (PET) particulates before and after heat persulfate oxidation (HPO) treatment was comprehensively evaluated in simulated and real swine wastewaters. The effects of intrinsic properties (i.e., degree of weathering, size, type) of MPs and environmental factors (i.e., pH, ionic strength, and co-occurring species) on adsorption were investigated thoroughly. It was observed that HPO treatment expedites the fragmentation of pristine MPs, and renders MPs with a variety of oxygen-rich functional groups, which are likely to act as new active sites for binding both HMs. The adsorption of both HMs is pH- and ionic strength-dependent at a pH of 4-6. Co-occurring species such as humic acid (HA) and tetracycline (TC) appear to enhance the affinity of both aged MPs for Cu2+ and Zn2+ ions via bridging complexation. However, co-occurring nutrient species (e.g., phosphate and ammonia) demonstrate different impacts on the adsorption, improving uptake of Cu2+ by precipitation while lowering affinity for Zn2+ owing to the formation of soluble zinc-ammonia complex. Spectroscopic analysis indicates that the dominant adsorption mechanism mainly involves electrostatic interactions and surface complexation. These findings provided fundamental insights into the interactions between aged MPs and HMs in swine wastewaters and might be extended to other nutrient-rich wastewaters.

Microplastic accumulation in a lizard species: Observations from the terrestrial environments

Microplastics are a global environmental problem, polluting both aquatic and terrestrial environments. Terrestrial lizards are suitable model organisms to study human-induced pollution in these areas, as they can live in urbanized areas where microplastics are most abundant. Therefore, we analyzed the prevalence of microplastics (MPs) in a common Lacertid lizard, the snake-eyed lizard, Ophisops elegans. We detected MPs in the gastrointestinal tract (GIT) of 33 of 152 specimens from 18 populations. The detected MPs had six distinct polymer compositions, namely Polyethylene terephthalate, Polyacrylonitrile, Polypropylene, Polyethylene, Poly methyl methacrylate and Polyamide. The majority of these MPs were fiber-type and the dominant color was navy blue. The lengths of MPs varied from 37 to 563 μm, with an average length of 175 μm. MPs were detected in the GITs of 43% of juveniles (n = 7), 30% of males (n = 105), and 18% of females (n = 40), with a mean of 0.27 per specimen. Furthermore, we found that microplastic densities varied with habitat distance from human settlements, supporting the theory that high levels of microplastic contamination are associated with extensive anthropogenic activity.

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.

Raman microspectroscopy and laser-induced breakdown spectroscopy for the analysis of polyethylene microplastics in human soft tissues

People are exposed to microplastics (MPs) on a large scale in everyday life. However, it is not clear whether MPs can also be distributed and retained in certain tissues. Therefore, the development of analytical methods capable of detecting MPs in specific human organs/tissues is of utmost importance. In this study, the use and combination of spectroscopic techniques, namely Raman microspectroscopy and laser-induced breakdown spectroscopy (LIBS), was tested for the detection of polyethylene (PE) MPs in human tonsils. Preliminary results showed that Raman microspectroscopy was able to detect MPs down to 1 μm in size and LIBS down to 10 μm. In the next step, human tonsils were spiked with PE MPs, and digested. The filtered particles were analyzed using Raman microspectroscopy and LIBS, and complemented by X-ray fluorescence (XRF). The results showed that Raman microspectroscopy could reliably detect PE MPs in spiked human tonsils, while LIBS and XRF served as a reference analytical method to characterize particles that could not be classified by Raman microspectroscopy for their non-organic origin. The results of this study, supported by a current feasibility study conducted on clinical samples, demonstrated the reliability and feasibility of this approach for monitoring MPs in biotic samples.

Activated hedgehog and insulin ligands by decreased transcriptional factor DAF-16 mediate transgenerational nanoplastic toxicity in Caenorhabditis elegans

In Caenorhabditis elegans, transcriptional factor DAF-16 in insulin signaling pathway played important role in regulating transgenerational nanoplastic toxicity. Activation of insulin signals mediated transgenerational toxicity of polystyrene nanoparticle (PS-NP) by inhibiting DAF-16. Among identified germline ligands, expression of wrt-3 encoding hedgehog ligand was increased by RNAi of daf-16 in PS-NP exposed C. elegans. In PS-NP exposed C. elegans, expressions of 4 other germline hedgehog ligand genes and 10 hedgehog receptor genes were increased by daf-16 RNAi. Among these candidate genes, expressions of hedgehog ligand genes (grl-15, grl-16, qua-1, and wrt-1) and hedgehog receptor genes (ptr-23, scp-1, ptd-2, and ncr-1) could be increased by PS-NP (1-100 μg/L), and their transgenerational expressions were observed after PS-NP exposure. RNAi of grl-15, grl-16, qua-1, wrt-1, ptr-23, scp-1, ptd-2, and ncr-1 caused resistance to transgenerational PS-NP toxicity. In nematodes exposed to PS-NPs, RNAi of wrt-3, grl-15, grl-16, qua-1, and wrt-1 at parental generation (P0-G) inhibited expressions of ptr-23, scp-1, ptd-2, and ncr-1 in their offspring. Moreover, we observed increased expressions of insulin peptides genes (ins-3, ins-39, and daf-28) in PS-NP exposed daf-16(RNAi) nematodes, suggesting formation of feedback loop. We raise the molecular basis for formation of toxicity on multiple generations after nanoplastic exposure at P0-G.

Percutaneous coronary intervention leads to microplastics entering the blood: Interventional devices are a major source

Microplastics (MPs) is an emerging pollutant potentially harmful to health. Medical practices using plastic devices, such as percutaneous coronary interventions (PCI), may result in MPs entering into the blood. The purpose of this study was to quantify the effect of PCI on microplastic levels in patients' blood. Laser direct infrared (LDIR) was used to detect MPs in the blood of 23 patients before and after PCI. MPs in the water in which devices used in PCI were washed were also examined. The concentration of MPs in the blood was significantly elevated (93.57 ± 35.95 vs. 4.96 ± 3.40 particles/10 mL of blood, P < 0.001) after PCI compared to before, and the increased MPs were polyamide (PA), polyethylene (PE), polyurethane (PU), and polyethylene terephthalate (PET), which was consistent with the types of MPs detected in the device washing water. The maximum diameter of MPs in blood before PCI was 50 µm, whereas after PCI it was 213 µm, and even 336 µm in device washing water. These findings indicated that PCI will cause MPs to enter the blood, and devices used during PCI were a major source, a range of medical practices that use plastic devices may be a new route for MPs to enter the human body.

Inter-annual variation in the microplastics abundance in feces of the Baird's tapir (Tapirus bairdii) from the Selva Maya, México

Microplastics (MPs) are found in a wide range of ecosystems, from the Arctic to the deep ocean. However, there is no data on their presence in terrestrial mammals that inhabit the Selva Maya. The aim of this study is to detect the presence of MPs in the feces of the Baird's tapir (Tapirus bairdii) from the region of Calakmul, located in the Yucatan Peninsula, Mexico. We analyzed 129 fecal samples collected during 2017 and 2018, obtaining 57 and 72 samples during the rainy and dry seasons respectively. Sixty-eight percent of the samples contained 743 MPs with a mean of 19.3 ± 28.1 MPs/kg of dry weight (DW) feces in both years. An inter-annual variation in the average abundance of microplastic was observed during the two-year period (2017-2018), with a 72 % increase in these plastic particles in feces. Fourteen polymers were identified, with ethylene vinyl acetate (EVA), polypropylene (PP) and polyester (PES) being the most abundant during both years. Although the effects of MPs on the health of tapirs are not known, their presence is cause for concern. There is an urgent need for the implementation of appropriate plastic waste management programs in communities of the Selva Maya to diminish the consumption of MPs in species including humans where they pose a significant risk to health. ENVIRONMENTAL IMPLICATIONS: The use of plastics worldwide is increasing every day, so the presence of microplastics is and will continue to be a major environmental problem. It is known that contaminants can adhere to plastics, making them hazardous materials. Microplastics can contaminate remote areas such as Biosphere Reserves. Terrestrial species such as the tapir can ingest microplastics, putting their health at risk. Knowing the dispersion of microplastics is very important in order to manage them properly, taking into account their emission sources and type of polymer.

Disposition of [14C]-polystyrene microplastics after oral administration to lactating sheep

Microplastics have become a ubiquitous contaminant, but their fate in food animals is largely unknown. In this study, [14C]-polystyrene microplastic (PS-MP) particles were orally dosed to lactating sheep to evaluate their absorption and disposition. Elimination of the [14C]-PS-MP was predominately through faeces with faecal radioactivity peaking at 24 h post-dosing but continuing to be present throughout the entire 72 h study period. Only a small fraction (≤ 1%) of the dosed [14C]-PS-MP was present in blood, milk, and urine. Pharmacokinetic analysis of blood plasma radioactivity, using non-compartment modeling, indicated rapid absorption (T1/2 0.4 to 3 h) with slow elimination (T1/2 37 to 48 h). Radioactivity in milk and urine had similar elimination patterns with radiocarbon activities peaking 24 h post-dosing with detectable elimination throughout the 72 h study period. No radioactivity was quantifiable in tissues at the 72 h withdrawal period.

The porcine corpus luteum as a model for studying the effects of nanoplastics

Nanoplastics (NPs) affect fertility. We evaluated the effects of NPs treatment on luteal and endothelial cells. We examined crucial markers of growth and redox status. NPs treatment did not induce changes in ATP levels in luteal cells, while it increased (p< 0.05) their proliferation. In endothelial cells, no change in proliferation was detected, while an increase (p<0.05) in ATP levels was observed. The increase of reactive oxygen species, superoxide anion (p<0.05) and nitric oxide (p<0.001) was detected in both cell types, which also showed changes in superoxide dismutase enzyme activity as well as an increase of non-enzymatic antioxidant power (p<0.05). A decrease (p<0.05) in progesterone production as well as an increase of vascular endothelial growth factor A levels were detected (p<0.05). In addition, a dose-dependent accumulation of NPs in endothelial cells was shown, that likely occurred through adhesion and internalization. Results underline potential risk of NPs for corpus luteum functionality.

Interaction behavior, mechanisms and hazardous changes of microplastics on single and binary component pesticide in the environment and food: Diethofencarb and pyrimethanil

In order to investigate the adsorption behavior and mechanism of microplastics (MPs) on multiple coexisting pesticides in practical systems, as well as their hazardous changes upon binding, diethofencarb and pyrimethanil were selected to be studied with four MPs. The adsorption rate of both pesticides would be faster in the binary-component case, conforming to pseudo-second-order kinetics, with adsorption sites and chemical adsorption dominating. And the more hydrophobic the pesticide, the faster the adsorption rate and the higher the adsorption capacity. Diethofencarb belonged to monolayer adsorption, whereas pyrimethanil belonged to monomolecular combined with multilayer adsorption, depending on the size of pesticides. And the adsorption process was both competitive and synergistic when pesticides coexist. In addition, the adsorption process was a spontaneous heat absorption process. Electrostatic forces have little effect on adsorption, while the adsorption capacity can be altered by the adsorption sites and hydrophobicity of MPs. The salting-out effect also facilitated the adsorption process. As for changes in hazard, the bioluminescence of A. fischeri wasn't significantly inhibited, lacking of acute environmental toxicity. However, in vitro digestion experiments demonstrated a significant increase in bioavailability of diethofencarb and pyrimethanil in combination with MPs. These findings suggest the stronger adsorption behaviors and higher loading capacities between pesticides and MPs could lead more serious hazards to the human body, which deserves further attention.

A review of advancements in chitosan-essential oil composite films: Better and sustainable food preservation with biodegradable packaging

In response to the environmental pollution caused by non-degradable and non-recyclable plastic packaging films (PPFs) and the resulting health concerns due to the migration of microplastics into food, the development of biodegradable food packaging films has gained great attention. Chitosan has been extensively utilized in the food industry owing to its abundant availability, exceptional biocompatibility, degradability, and antimicrobial properties. Chitosan-essential oil composite films (CEOs) represent a promising avenue to replace conventional PPFs. This review provides an overview of the advancements in CEOs over the past decade, focusing on the effects of essential oils (EOs) on CEOs in terms of antimicrobial activity, antioxidant effect, gas barrier, light barrier, and mechanical properties. It also offers insights into the controlled release of EOs in CEOs and summarizes the application of CEOs in fresh food preservation.

Oral Exposure to Microplastics Affects the Neurochemical Plasticity of Reactive Neurons in the Porcine Jejunum

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects.

Special Distribution of Nanoplastics in the Central Nervous System of Zebrafish during Early Development

There is growing concern about the distribution of nanoplastics (NPs) in the central nervous system (CNS), whereas intrusion is poorly understood. In this study, fluorescent-labeled polystyrene NPs (PS-NPs) were microinjected into different areas of zebrafish embryo to mimic different routes of exposure. PS-NPs were observed in the brain, eyes, and spinal cord through gametal exposure. It indicated that maternally derived PS-NPs were specially distributed in the CNS of zebrafish during early development. Importantly, these NPs were stranded in the CNS but not transferred to other organs during development. Furthermore, using neuron GFP-labeled transgenic zebrafish, colocalization between NPs and the neuron cells revealed that NPs were mostly enriched in the CNS surrounded but not the neurons. Even so, the intrusion of NPs into the CNS induced the significant upregulation of some neurotransmitter receptors, leading to an inhibited effect on the movement of zebrafish larvae. This work provides insights into understanding the intrusion and distribution of NPs in the CNS and the subsequent potential adverse effects.

Unveiling the impact of microplastics and nanoplastics on vascular plants: A cellular metabolomic and transcriptomic review

With increasing plastic manufacture and consumption, microplastics/nanoplastics (MP/NP) pollution has become one of the world's pressing global environmental issues, which poses significant threats to ecosystems and human health. In recent years, sharp increasing researches have confirmed that MP/NP had direct or indirect effects on vegetative growth and sexual process of vascular plant. But the potential mechanisms remain ambiguous. MP/NP particles can be adsorbed and/or absorbed by plant roots or leaves and thus cause diverse effects on plant. This holistic review aims to discuss the direct effects of MP/NP on vascular plant, with special emphasis on the changes of metabolic and molecular levels. MP/NP can alter substance and energy metabolism, as well as shifts in gene expression patterns. Key aspects affected by MP/NP stress include carbon and nitrogen metabolism, amino acids biosynthesis and plant hormone signal transduction, expression of stress related genes, carbon and nitrogen metabolism related genes, as well as those involved in pathogen defense. Additionally, the review provides updated insights into the growth and physiological responses of plants exposed to MP/NP, encompassing phenomena such as seed/spore germination, photosynthesis, oxidative stress, cytotoxicity, and genotoxicity. By examining the direct impact of MP/NP from both physiological and molecular perspectives, this review sets the stage for future investigations into the complex interactions between plants and plastic pollutants.

The boom era of emerging contaminants: A review of remediating agricultural soils by biochar

Emerging contaminants (ECs) are widely sourced persistent pollutants that pose a significant threat to the environment and human health. Their footprint spans global ecosystems, making their remediation highly challenging. In recent years, a significant amount of literature has focused on the use of biochar for remediation of heavy metals and organic pollutants in soil and water environments. However, the use of biochar for the remediation of ECs in agricultural soils has not received as much attention, and as a result, there are limited reviews available on this topic. Thus, this review aims to provide an overview of the primary types, sources, and hazards of ECs in farmland, as well as the structure, functions, and preparation types of biochar. Furthermore, this paper emphasizes the importance and prospects of three remediation strategies for ECs in cropland: (i) employing activated, modified, and composite biochar for remediation, which exhibit superior pollutant removal compared to pure biochar; (ii) exploring the potential synergistic efficiency between biochar and compost, enhancing their effectiveness in soil improvement and pollution remediation; (iii) utilizing biochar as a shelter and nutrient source for microorganisms in biochar-mediated microbial remediation, positively impacting soil properties and microbial community structure. Given the increasing global prevalence of ECs, the remediation strategies provided in this paper aim to serve as a valuable reference for future remediation of ECs-contaminated agricultural lands.

Subchronic co-exposure of polystyrene nanoplastics and 3-BHA significantly aggravated the reproductive toxicity of ovaries and uterus in female mice

Both nanoplastics (NPs) and 3-tert-butyl-4-hydroxyanisole (3-BHA) are environmental contaminants that can bio-accumulate through the food chain. However, the combined effects of which on mammalian female reproductive system remain unclear. Here, the female ICR-CD1 mice were used to evaluate the damage effects of ovaries and uterus after NPs and 3-BHA co-treatment for 35 days. Firstly, co-exposure significantly reduced the body weight and organ index of ovaries and uterus in mice. Secondly, combined effects of NPs and 3-BHA exacerbated the histopathological abnormalities to the ovaries and uterus and decreased female sex hormones such as FSH and LH while increased antioxidant activities including CAT and GSH-Px. Moreover, the apoptotic genes, inflammatory cytokines and the key reproductive development genes such as FSTL1 were significantly up-regulated under co-exposure conditions. Thirdly, through transcriptional and bioinformatics analysis, immunofluorescence and western blotting assays, together with molecular docking simulation, we determined that co-exposure up-regulated the FSTL1, TGF-β and p-Smad1/5/9 but down-regulated the expression of BMP4. Finally, the pharmacological rescue experiments further demonstrated that co-exposure of NPs and 3-BHA mainly exacerbated the female reproductive toxicity through FSTL1-mediated BMP4/TGF-β/SMAD signaling pathway. Taken together, our studies provided the theoretical basis of new environmental pollutants on the reproductive health in female mammals.

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

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

Inhibiting ferroptosis in brain microvascular endothelial cells: A potential strategy to mitigate polystyrene nanoplastics‒induced blood‒brain barrier dysfunction

Polystyrene nanoplastics (PS-NPs), a group of ubiquitous pollutants, may injure the central nervous system through the blood‒brain barrier (BBB). However, whether exposure to PS-NPs contributes to BBB disruption and the underlying mechanisms are still unclear. In vivo, we found that PS-NPs (25 mg/kg BW) could significantly increase BBB permeability in mice and downregulate the distribution of the tight junction-associated protein zona occludens 1 (ZO-1) in brain microvascular endothelial cells (BMECs). Using an in vitro BBB model, exposure to PS-NPs significantly reduced the transendothelial electrical resistance and altered ZO-1 expression and distribution in a dose-dependent manner. RNA-seq analysis and functional investigations were used to investigate the molecular pathways involved in the response to PS-NPs. The results revealed that the ferroptosis and glutathione metabolism signaling pathways were related to the disruption of the BBB model caused by the PS-NPs. PS-NPs treatment promoted ferroptosis in bEnd.3 cells by inducing disordered glutathione metabolism in addition to Fe2+ and lipid peroxide accumulation, while suppressing ferroptosis with ferrostatin-1 (Fer-1) suppressed ferroptosis-related changes in bEnd.3 cells subjected to PS-NPs. Importantly, Fer-1 alleviated the decrease in ZO-1 expression in bEnd.3 cells and the exacerbation of BBB damage induced by PS-NPs. Collectively, our findings suggest that inhibiting ferroptosis in BMECs may serve as a potential therapeutic target against BBB disruption induced by PS-NPs exposure.

Green synthesis of Poria cocos polysaccharides-silver nanoparticles and their applications in food packaging

To reduce pollution caused by traditional plastic packaging and preparation of silver nanoparticles (AgNPs), this work aims to develop biological macromolecular packaging films with green synthesized AgNPs. In this study, a novel P. cocos polysaccharide (PCP) with a unique monosaccharide composition was extracted from Poria cocos (Schw.) Wolf. Then, this polysaccharide containing 24.68 % rhamnose was used as a stabilizer for the green synthesis of PCP-AgNPs for the first time. PCP-AgNPs exhibited excellent antibacterial activity against P. aeruginosa, E. coli, and S. aureus, with the highest antibacterial activity against E. coli (inhibition zone diameter = 11.14 ± 0.79 mm). Subsequently, PCP-AgNPs/chitosan (CS) film was successfully prepared by incorporating PCP-AgNPs into the CS film solution. Several experiments demonstrated that the addition of this nanomaterial promoted the formation of noncovalent interactions between CS and PCP-AgNPs, resulting in a more regular and denser film. Compared to the CS film and control group, the PCP-AgNPs/CS film significantly maintained the quality indexes of strawberries. Therefore, this composite film successfully extended the shelf life of strawberries. Regarding safety, these packaging films were not cytotoxic toward RAW264.7 cells. In conclusion, the environmentally friendly PCP-AgNPs/CS film has the potential to replace some traditional food packaging materials.

Nano-sized microplastics exposure induces skin cell senescence via triggering the mitochondrial localization of GSDMD

Nano-sized microplastic pollution is distributed worldwide. Nano-sized microplastics can enter the blood through the digestive tract, and then transported to various tissues and organs of the body, resulting in a series of toxicological effects. In addition, nano-sized microplastics can penetrate the skin barrier. However, the toxicological effects of nano-sized microplastics on the skin are still not completely understood. Two skin cell lines were used as in vitro models to investigate the toxicological effects of nano-sized microplastics on skin cells and their potential molecular mechanisms. First, cellular behavioral research results showed that nano-sized microplastics can be internalized into skin cells in a time- and dose-dependent manner. Further experiments using western blotting, indirect immunofluorescence, and ELISA assays demonstrated that nano-sized microplastics cause an increase in skin cell inflammation levels. Additionally, our research showed that nano-sized microplastics caused skin cell senescence damage by evaluating aging-marker molecules such as p16 and p21. Subsequently, we studied the potential molecular mechanism by which nano-sized microplastics cause pathological skin injury and found that they induce mitochondrial oxidative stress, depolarize the mitochondrial membrane potential, and recruit GSDMD to the mitochondria. Subsequently, mtDNA enters the cytoplasm via GSDMD pores, which then activates the AIM2 Inflammasome. Ultimately, it causes a series of biochemical reactions such as inflammation and aging in cells. In an in vivo model, we tested the effect of nano-sized microplastics on skin regeneration and found that they acted as an inhibitor to skin regeneration and aggravated the inflammatory reaction of the skin. Overall, our results provide new evidence of the skin toxicity of nano-sized microplastics. This study provides a theoretical foundation for further research on the potential toxicological effects of nano-sized microplastics on the skin.

Microplastics in human blood: Polymer types, concentrations and characterisation using μFTIR

Microplastics (MPs) are an everyday part of life, and are now ubiquitous in the environment. Crucially, MPs have not just been found within the environment, but also within human bodies, including the blood. We aimed to provide novel information on the range of MP polymer types present, as well as their size and shape characteristics, in human whole blood from 20 healthy volunteers. Twenty-four polymer types were identified from 18 out of 20 (90 %) donors and quantified in blood, with the majority observed for the first time. Using an LOQ approach, five polymer types met the threshold with a lower mean ± SD of 2466 ± 4174 MP/L. The concentrations of plastics analysed in blood samples ranged from 1.84 - 4.65 μg/mL. Polyethylene (32 %), ethylene propylene diene (14 %), and ethylene-vinyl-acetate/alcohol (12 %) fragments were the most abundant. MP particles that were identified within the blood samples had a mean particle length of 127.99 ± 293.26 µm (7-3000 µm), and a mean particle width of 57.88 ± 88.89 µm (5-800 µm). The MPs were predominantly categorised as fragments (88 %) and were white/clear (79 %). A variety of plastic additive chemicals were identified including endocrine disrupting-classed phthalates. The procedural blank samples comprised 7 polymer types, that were distinct from those identified in blood, mainly resin (25 %), polyethylene terephthalate (17 %), and polystyrene (17 %) with a mean ± SD of 4.80 ± 5.59 MP/L. This study adds to the growing evidence that MPs are taken up into the human body and are transported via the bloodstream. The shape and sizes of the particles raise important questions with respect to their presence and associated hazards in terms of potential detrimental impacts such as vascular inflammation, build up within major organs, and changes to either immune cell response, or haemostasis and thrombosis.

Microplastics in three types of human arteries detected by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS)

Microplastics are ubiquitous in the environment. Human body can be exposed to microplastics through inhalation and ingestion and some microplastics can enter the blood and accumulate in various tissues and organs throughout the body. Animal experiments have suggested that microplastics may promote atherosclerosis. However, data on microplastics in human arteries and clinical evidence supporting a link between microplastics and atherosclerosis are currently lacking. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used in this study to detect microplastics in three types of human arteries: coronary and carotid arteries with atherosclerotic plaques, as well as the aorta without plaques. Microplastics were detected in all 17 arterial samples, with an average concentration of 118.66 ± 53.87 μg/g tissue. Four types of microplastics were identified: polyethylene terephthalate (PET, 73.70%), polyamide-66 (PA-66, 15.54%), polyvinyl chloride (PVC, 9.69%), and polyethylene (PE, 1.07%). Most importantly, the concentration of microplastics in arteries containing atherosclerotic plaques, both coronary arteries (156.50 ± 42.14 vs. 76.26 ± 14.86 μg/g tissue, P = 0.039), and carotid arteries (133.37 ± 60.52 vs. 76.26 ± 14.86 μg/g tissue, P = 0.015), was significantly higher than that in aortas which did not contain atherosclerotic plaques, suggesting that microplastics might be associated with atherosclerosis in humans. This study provides valuable data for further hazard assessments of microplastics on human cardiovascular health.

Molecular insights into nanoplastics-peptides binding and their interactions with the lipid membrane

Micro- and nanoplastics have become a significant concern, due to their ubiquitous presence in the environment. These particles can be internalized by the human body through ingestion, inhalation, or dermal contact, and then they can interact with environmental or biological molecules, such as proteins, resulting in the formation of the protein corona. However, information on the role of protein corona in the human body is still missing. Coarse-grain models of the nanoplastics and pentapeptides were created and simulated at the microscale to study the role of protein corona. Additionally, a lipid bilayer coarse-grain model was reproduced to investigate the behavior of the coronated nanoplastics in proximity of a lipid bilayer. Hydrophobic and aromatic amino acids have a high tendency to create stable bonds with all nanoplastics. Moreover, polystyrene and polypropylene establish bonds with polar and charged amino acids. When the coronated nanoplastics are close to a lipid bilayer, different behaviors can be observed. Polyethylene creates a single polymeric chain, while polypropylene tends to break down into its single chains. Polystyrene can both separate into its individual chains and remain aggregated. The protein corona plays an important role when interacting with the nanoplastics and the lipid membrane. More studies are needed to validate the results and to enhance the complexity of the systems.

Blueprint for the design, construction, and validation of a plastic and phthalate-minimised laboratory

Micro and nanosized plastics (MNPs), and a range of associated additive chemicals, have become pervasive contaminants that humans and the environment are exposed to everyday. However, one of the principal challenges in their analysis is adequate strategies to minimise background contamination. Here a blueprint for a specialised plastics and additive-minimised clean room laboratory built for this purpose is presented. Common laboratory construction materials (n = 23) were tested, including acoustic baffles, ceiling materials, floor materials, glazing rubber, and silicone sealant. The % polymer content ranged from 2-76% w/w while the sum concentration of six phthalates ranged from 0.81 (0.73-0.86) to 21000 (15000-27000) mg/kg, assigning many of these materials as inappropriate for use in a clean room environment. The final design of the laboratory consisted of three interconnected rooms, operated under positive pressure with the inner rooms constructed almost entirely of stainless steel. Background concentrations of MNPs and phthalates in the new laboratory were compared to two Physical Containment Level 2 (PC2) laboratory environments, with concentrations of MNPs reduced by > 100 times and phthalates reduced by up to 120 times. This study reports the first known clean room of its kind and provides a blueprint for reference and use by future plastics research.

Lignin derived hydrophobic deep eutectic solvents for the extraction of nanoplastics from water

As a growing concern in aqueous systems, micro- and nano-plastics, especially nanoplastics (NPs), have been widely detected in the environment and organisms, posing a potential threat to ecosystems and human health. Hydrophobic deep eutectic solvents (HDESs) have emerged as environmentally friendly solvents that have shown promise for extracting pollutants from water, either for detection or removal purposes. Herein, we investigated the extraction of polystyrene (PS) and polyethylene terephthalate (PET) NPs from aqueous solution using lignin based HDESs as sustainable solvents. Rapid extraction of both PET and PS NPs was observed with the high extraction efficiency achieved (> 95%). The extraction capacities for PET and PS could reach up to 525.877 mg/mL and 183.520 mg/mL, respectively, by the Thymol-2,6-dimethoxyphenol 1:2 HDES. Moreover, the extraction mechanism was studied using various techniques including Fourier-transform infrared analysis, contact angle measurements, molecular dynamics simulation, kinetics, and isotherm studies. This work lays a foundational basis for the future development of innovative HDES-based technologies in the detection and remediation of NPs as part of the grand challenge of plastic pollution.

A meta-analysis of potential biomarkers associated with microplastic ingestion in marine fish

Over the past decade, global reports have shown a rise in the harmful effects of microplastics (MPs) on marine fish. This study analysed marine species' biochemical biomarker responses to microplastic exposure, finding that MPs can induce oxidative stress in marine fish through meta-regression results. Overall, exposure to MPs resulted in the activation of antioxidant defence mechanisms, such as superoxide dismutase, catalase and glutathione reductase, detoxification enzymes such as glutathione-S-transferase, the detection of malondialdehyde, and inhibition of acetylcholinesterase. Moreover, results highlight oxidative stress biomarkers were activated in wild species that had ingested MPs, indicating potential harm to marine fish, as confirmed in experimental studies. Furthermore, even though MPs' exposure is better regulated in an experimental setting, it is challenging to replicate actual exposure and environmental factors. The study's findings show the need for more investigation into the hazardous consequences of exposure to environmental MPs on species surveyed in the maritime environment.

Biodegradable and multifunctional black mulch film decorated with darkened lignin induced by iron ions for "green" agriculture

High-value utilization of bleached lignin has been widely used in different fields, whereas the investigation on darkened lignin in composite materials was often ignored. In this work, a sort of eco-friendly and structurally robust sodium carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA)/sodium lignosulfonate (SLS) black composite mulch film was elaborately designed. The chelation and redox reaction effect between Fe ions and SLS lead to the formation of a more quinones structure on lignin, darkening both lignin and the mulch films. The chelation effect between Fe ions and biopolymer formed three-dimensional structures, which can be used as sacrifice bonds to dissipate energy and improve the mechanical properties of the composite films. In particular, the maximum elongation at break and toughness increased from 48.4 % and 1141 kJ/m3 for the CMC/PVA film to 210.9 % and 1426 kJ/m3 for the optimized CMC/PVA/SLS/Fe black mulch film, respectively. In addition, the optimized black mulch film also possesses good soil water retention, thermal preservation effect, controlled urea release, and well biodegradability. This work offered a novel strategy for designing eco-friendly black mulch with reinforced mechanical strength, slow-release urea, soil moisture retention, and heat preservation performances.

Tracking the micro- and nanoplastics in the terrestrial-freshwater food webs. Bivalves as sentinel species

Micro- (MPs) and nanoplastics (NPs) are currently ubiquitous in the ecosystems, and freshwater biota is still insufficiently studied to understand the global fate, transport paths, and consequences of their presence. Thus, in this study, we investigated the role of bivalves and a trophic transfer of MPs and NPs in an experimental food chain. The food chain consisted of terrestrial non-selective detritivore Dendrobaena (Eisenia) sp., freshwater benthic filter feeder Unio tumidus, and freshwater benthic detritivore-collectors Asellus aquaticus or Gammarus sp. Animals were exposed to different fluorescently labeled micro- and nanoplastics (PMMA 20 μm, nanoPS 15-18 nm, and 100 nm, PS 1 μm and 20 μm, PE from cosmetics) as well as to the faeces of animals exposed to plastics to assess their influence on the environmental transportation, availability to biota, and bioaccumulation of supplied particles. Damaged and intact fluorescent particles were observed in the faeces of terrestrial detritivores and in the droppings of aquatic filter feeders, respectively. They were also present in the guts of bivalves and of crustaceans which were fed with bivalve droppings. Bivalves (Unio tumidus, and additionally Unio pictorum, and Sphaerium corneum) produced droppings containing micro- and nanoparticles filtered from suspension and deposited them onto the tank bottom, making them available for broader feeding guilds of animals (e.g. collectors, like crustaceans). Finally, the natural ageing of PS and its morphological changes, leakage of the fluorescent labelling, and agglomeration of particles were demonstrated. That supports our hypothesis of the crucial role of the characterization of physical and chemical materials in adequately understanding the mechanisms of their interaction with biota. Microscopical methods (confocal, fluorescent, scanning electron) and Raman and FT-IR spectroscopy were used to track the particles' passage in a food web and monitor structural changes of the MPs' and NPs' surface.

Regulatory Science Perspective on the Analysis of Microplastics and Nanoplastics in Human Food

Microplastics are increasingly reported, not only in the environment but also in a wide range of food commodities. While studies on microplastics in food abound, the current state of science is limited in its application to regulatory risk assessment by a continued lack of standardized definitions, reference materials, sample collection and preparation procedures, fit-for purpose analytical methods for real-world and environmentally relevant plastic mixtures, and appropriate quality controls. This is particularly the case for nanoplastics. These methodological challenges hinder robust, quantitative exposure assessments of microplastic and nanoplastic mixtures from food consumption. Furthermore, limited toxicological studies on whether microplastics and nanoplastics adversely impact human health are also impeded by methodology challenges. Food safety regulatory agencies must consider both the exposure and the risk of contaminants of emerging concern to ascertain potential harm. Foundational to this effort is access to and application of analytical methods with the capability to quantify and characterize micro- and nanoscale sized polymers in complex food matrices. However, the early stages of method development and application of early stage methods to study the distribution and potential health effects of microplastics and nanoplastics in food have largely been done without consideration of the stringent requirements of methods to inform regulatory activities. We provide regulatory science perspectives on the state of knowledge regarding the occurrence of microplastics and nanoplastics in food and present our general approach for developing, validating, and implementing analytical methods for regulatory purposes.

Interactions between inhalable aged microplastics and lung surfactant: Potential pulmonary health risks

The relationship between microplastics (MPs) and human respiratory health has garnered significant attention since inhalation constitutes the primary pathway for atmospheric MP exposure. While recent studies have revealed respiratory risks associated with MPs, virgin MPs used as plastic surrogates in these experiments did not represent the MPs that occur naturally and that undergo aging effects. Thus, the effects of aged MPs on respiratory health remain unknown. We herein analyzed the interaction between inhalable aged MPs with lung surfactant (LS) extracted from porcine lungs vis-à-vis interfacial chemistry employing in-vitro experiments, and explored oxidative damage induced by aged MPs in simulated lung fluid (SLF) and the underlying mechanisms of action. Our results showed that aged MPs significantly increased the surface tension of the LS, accompanied by a diminution in its foaming ability. The stronger adsorptive capacity of the aged MPs toward the phospholipids of LS appeared to produce increased surface tension, while the change in foaming ability might have resulted from a variation in the protein secondary structure and the adsorption of proteins onto MPs. The adsorption of phospholipid and protein components then led to the aggregation of MPs in SLF, where the aged MPs exhibited smaller hydrodynamic diameters in comparison with the unaged MPs, likely interacting with biomolecules in bodily fluids to exacerbate health hazards. Persistent free radicals were also formed on aged MPs, inducing the formation of reactive oxygen species such as superoxide radicals (O2•-), hydrogen peroxide (HOOH), and hydroxyl radicals (•OH); this would lead to LS lipid peroxidation and protein damage and increase the risk of respiratory disease. Our investigation was the first-ever to reveal a potential toxic effect of aged MPs and their actions on the human respiratory system, of great significance in understanding the risk of inhaled MPs on lung health.

Ferroptosis participated in inhaled polystyrene nanoplastics-induced liver injury and fibrosis

The emerging contaminant nanoplastics (NPs) have received considerable attention. Due to their tiny size and unique colloidal properties, NPs could more easily enter the body and cross biological barriers with inhalation exposure. While NPs-induced hepatotoxicity has been reported, the hepatic impact of inhaled NPs was still unknown. To close this gap, a 40 nm polystyrene NPs (PS-NPs) inhalation exposure mice model was developed to explore the hepatotoxicity during acute (1 week), subacute (4 weeks), and subchronic period (12 weeks), with four exposure doses (0, 16, 40, and 100 μg/day). Results showed that inhaled PS-NPs caused a remarkable increase of ALT, AST, and ALP with a decrease of CHE, indicating liver dysfunction. Various histological abnormalities and significantly higher levels of inflammation in a dose- and time-dependent manner were observed. Moreover, after 4 weeks and 12 weeks of exposure, Masson staining and upregulated expression of TGF-β, α-SMA, and Col1a1 identified that inhaled PS-NPs exposure triggered the progression of liver fibrosis with the exposure time prolonged. From the mechanistic perspective, transcriptome analysis revealed that ferroptosis was involved in PS-NPs-induced liver hepatotoxicity, and key features of ferroptosis were detected, including persistent oxidative stress, iron overload, increased LPO, mitochondria damage, and the expression changes of GPX4, TFRC, and Ferritin. And in vitro and in vivo recovery tests showed that ferroptosis inhibitor Fer-1 treatment alleviated liver injury and fibrosis. The above results confirmed the critical role of ferroptosis in PS-NPs-induced hepatotoxicity. Furthermore, to better conclude our findings and understand the mechanistic causality within it, an adverse outcome pathway (AOP) framework was established. In total, this present study conducted the first experimental assessment of inhalation exposure to PS-NPs on the liver, identified that continuous inhaled PS-NPs could cause liver injury and fibrosis, and PS-NPs- ferroptosis provided a novel mechanistic explanation.

Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage

BACKGROUND

With rapid increase in the global use of various plastics, microplastics (MPs) and nanoplastics (NPs) pollution and their adverse health effects have attracted global attention. MPs have been detected out in human body and both MPs and NPs showed female reproductive toxicological effects in animal models. Miscarriage (abnormal early embryo loss), accounting for 15-25% pregnant women worldwide, greatly harms human reproduction. However, the adverse effects of NPs on miscarriage have never been explored.

RESULTS

In this study, we identified that polystyrene (PS) plastics particles were present in women villous tissues. Their levels were higher in villous tissues of unexplained recurrent miscarriage (RM) patients vs. healthy control (HC) group. Furthermore, mouse assays further confirmed that exposure to polystyrene nanoplastics (PS-NPs, 50 nm in diameter, 50 or 100 mg/kg) indeed induced miscarriage. In mechanism, PS-NPs exposure (50, 100, 150, or 200 µg/mL) increased oxidative stress, decreased mitochondrial membrane potential, and increased apoptosis in human trophoblast cells by activating Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3 signaling through mitochondrial pathway. The alteration in this signaling was consistent in placental tissues of PS-NPs-exposed mouse model and in villous tissues of unexplained RM patients. Supplement with Bcl-2 could efficiently suppress apoptosis in PS-NPs-exposed trophoblast cells and reduce apoptosis and alleviate miscarriage in PS-NPs-exposed pregnant mouse model.

CONCLUSIONS

Exposure to PS-NPs activated Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3, leading to excessive apoptosis in human trophoblast cells and in mice placental tissues, further inducing miscarriage.

Continuous generation and release of microplastics and nanoplastics from polystyrene by plastic-degrading marine bacteria

Plastic waste released into the environments breaks down into microplastics due to weathering, ultraviolet (UV) radiation, mechanical abrasion, and animal grazing. However, little is known about the plastic fragmentation mediated by microbial degradation. Marine plastic-degrading bacteria may have a double-edged effect in removing plastics. In this study, two ubiquitous marine bacteria, Alcanivorax xenomutans and Halomonas titanicae, were confirmed to degrade polystyrene (PS) and lead to microplastic and nanoplastic generation. Biodegradation occurred during bacterial growth with PS as the sole energy source, and the formation of carboxyl and carboxylic acid groups, decreased heat resistance, generation of PS metabolic intermediates in cultures, and plastic weight loss were observed. The generation of microplastics was dynamic alongside PS biodegradation. The size of the released microplastics gradually changed from microsized plastics on the first day (1344 nm and 1480 nm, respectively) to nanoplastics on the 30th day (614 nm and 496 nm, respectively) by the two tested strains. The peak release from PS films reached 6.29 × 106 particles/L and 7.64 × 106 particles/L from degradation by A. xenomutans (Day 10) and H. titanicae (Day 5), respectively. Quantification revealed that 1.3% and 1.9% of PS was retained in the form of micro- and nanoplastics, while 4.5% and 1.9% were mineralized by A. xenomutans and H. titanicae at the end of incubation, respectively. This highlights the negative effects of microbial degradation, which results in the continuous release of numerous microplastics, especially nanoplastics, as a notable secondary pollution into marine ecosystems. Their fates in the vast aquatic system and their impact on marine lives are noted for further study.

Occurrence of microplastics in edible tissues of livestock (cow and sheep)

Plastic contamination is widely recognized as a major environmental concern due to the entry of small plastic particles into the food chain, thereby posing potential hazards to human health. However, the current understanding of microplastic (MP; < 5 mm) particles in livestock, which serve as an important food source, is limited. This study aims to investigate the concentration and characteristics of MPs in edible tissues of cow and sheep, namely liver, meat, and tripe, obtained from butcher shops in five areas of Bushehr port, Iran. The mean concentration of MPs in different tissues of cow and sheep were 0.14 and 0.13 items/g, respectively. Among the examined tissues, cow meat exhibited the highest concentration of MPs, with a concentration of 0.19 items/g. Nylon and fiber were identified as the predominant polymer types and shapes of MPs found in cow and sheep tissues, respectively. Furthermore, no statistically significant difference was observed in MP concentration across different tissues of cow and sheep. Significantly, this study highlights the elevated hazards associated with exposure to MPs through the consumption of edible cow and sheep tissues, particularly for children who consume meat. The results underscore the potential transfer of MPs from the environment to livestock bodies through their food, contamination during meat processing, and subsequent health hazards for consumers.

Toxic effects of polystyrene nanoplastics and polycyclic aromatic hydrocarbons (chrysene and fluoranthene) on the growth and physiological characteristics of Chlamydomonas reinhardtii

While the toxicity of nano-microplastics and polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms is well-studied, their joint impact on microalgae is less explored. This study focused on single and combined effects of PS-NPs (30 nm; concentrations: 2, 5, 10, and 25 mg/L) and two PAHs (chrysene and fluoranthene at 10, 100 µg/L) for 96 h on the accumulation, growth, photosynthetic parameters, and oxidative stress in the Chlamydomonas reinhardtii. The findings revealed that exposure to increasing concentrations of PS-NPs significantly reduced the growth inhibition ratio and chlorophyll-a content after 96 h. Both PAHs (100 µg/L) + PS-NPs (25 mg/L), significantly reduced the growth inhibition ratio and chlorophyll-a levels. Individual and combined exposures of PS-NPs and PAHs can prompt antioxidant responses like SOD, GPx, and GST, as well as an unaffected level of non-enzymatic antioxidant GSH and diminished CAT activity. Furthermore, both PAHs + PS-NPs triggered ROS levels, resulting in cell membrane damage. However, the reduced oxidative effect of LPO of combined exposures can be attributed to the activation of antioxidant defenses. In addition, the microscopic visualization data shows that PS-NPs adhered to the surface of microalgae. Also, PS-NPs reduced the adsorption of PAHs on the surface of C. reinhardtii. Altogether, this study implied that the influence of coexistent PS-NPs should be considered in the environmental risk assessment of PAHs in aquatic environments.

Biological roles of soil microbial consortium on promoting safe crop production in heavy metal(loid) contaminated soil: A systematic review

Heavy metal(loid) (HM) pollution of agricultural soils is a growing global environmental concern that affects planetary health. Numerous studies have shown that soil microbial consortia can inhibit the accumulation of HMs in crops. However, our current understanding of the effects and mechanisms of inhibition is fragmented. In this review, we summarise extant studies and knowledge to provide a comprehensive view of HM toxicity on crop growth and development at the biological, cellular and the molecular levels. In a meta-analysis, we find that microbial consortia can improve crop resistance and reduce HM uptake, which in turn promotes healthy crop growth, demonstrating that microbial consortia are more effective than single microorganisms. We then review three main mechanisms by which microbial consortia reduce the toxicity of HMs to crops and inhibit HMs accumulation in crops: 1) reducing the bioavailability of HMs in soil (e.g. biosorption, bioaccumulation and biotransformation); 2) improving crop resistance to HMs (e.g. facilitating the absorption of nutrients); and 3) synergistic effects between microorganisms. Finally, we discuss the prospects of microbial consortium applications in simultaneous crop safety production and soil remediation, indicating that they play a key role in sustainable agricultural development, and conclude by identifying research challenges and future directions for the microbial consortium to promote safe crop production.

Emerging isolation and degradation technology of microplastics and nanoplastics in the environment

Microplastics (MPs, less than 5 mm in size) are widely distributed in surroundings in various forms and ways, and threaten ecosystems security and human health. Its environmental behavior as pollutants carrier and the after-effects exposed to MPs has been extensively exploited; whereas, current knowledge on technologies for the separation and degradation of MPs is relatively limited. It is essential to isolate MPs from surroundings and/or degrade to safe levels. This in-depth review details the origin and distribution of MPs. Provides a comprehensive summary of currently available MPs separation and degradation technologies, and discusses the mechanisms, challenges, and application prospects of these technologies. Comparison of the contribution of various separation methods to the separation of NPs and MPs. Furthermore, the latest research trends and direction in bio-degradation technology are outlooked.

Polystyrene Nanoplastics Activate Autophagy and Suppress Trophoblast Cell Migration/Invasion and Migrasome Formation to Induce Miscarriage

Nanoplastics (NPs), as emerging pollutants, have attracted global attention. Nevertheless, the adverse effects of NPs on female reproductive health, especially unexplained miscarriage, are poorly understood. Defects of trophoblast cell migration and invasion are associated with miscarriage. Migrasomes were identified as cellular organelles with largely unidentified functions. Whether NPs might affect migration, invasion, and migrasome formation and induce miscarriage has been completely unexplored. In this study, we selected polystyrene nanoplastics (PS-NPs, 50 nm) as a model of plastic particles and treated human trophoblast cells and pregnant mice with PS-NPs at doses near the actual environmental exposure doses of plastic particles in humans. We found that exposure to PS-NPs induced a pregnant mouse miscarriage. PS-NPs suppressed ROCK1-mediated migration/invasion and migrasome formation. SOX2 was identified as the transcription factor of ROCK1. PS-NPs activated autophagy and promoted the autophagy degradation of SOX2, thus suppressing SOX2-mediated ROCK1 transcription. Supplementing with murine SOX2 or ROCK1 could efficiently rescue migration/invasion and migrasome formation and alleviate miscarriage. Analysis of the protein levels of SOX2, ROCK1, TSPAN4, NDST1, P62, and LC-3BII/I in PS-NP-exposed trophoblast cells, villous tissues of unexplained miscarriage patients, and placental tissues of PS-NP-exposed mice gave consistent results. Collectively, this study revealed the reproductive toxicity of nanoplastics and their potential regulatory mechanism, indicating that NP exposure is a risk factor for female reproductive health.

Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles.

Fate and disposition of [14C]-polystyrene microplastic after oral administration to laying hens

Micro/nanoplastics (MP) are emerging environmental contaminants of great concern because of their ubiquitous distribution in air, soil, water, and food. Reports have described MP in the excreta of food animals, but their absorption, distribution, and elimination in terrestrial animals used for human consumption is essentially unexplored. To determine the absorption and distribution of [14C]-polystyrene (PS) MP, laying hens (n = 15) were bolus dosed with 10 μCi/hen (11.1 ± 0.8 mg/kg) and the extent of radioactivity in blood and tissues was determined in birds harvested on withdrawal days (WD) 1, 2, 3, 4, and 7 (3 hens per WD). Radiocarbon was also determined in egg fractions and excreta collected throughout the study. Blood, eggs, and tissues contained a total of <1 % of the administered dose, demonstrating that polystyrene microparticles were poorly absorbed. Recovery of radioactivity in excreta within the first withdrawal day was nearly quantitative (96.8 ± 14.5 %, n = 15), suggesting exposure of poultry to dietary PS-MP would not likely represent subsequent food safety risks and that most PS-MP present in poultry diets would return to the environment.

Interaction and mechanistic studies of thiram and common microplastics in food and associated changes in hazard

Microplastics (MPs), an emerging pollutant in the environment and food, may adsorb other contaminants such as pesticide due to particles' properties. The adsorption behavior and their hazardous changes of four common types of MPs to thiram was investigated. The adsorption kinetics and isotherm models were fitted well using the pseudo-second-order model and the Langmuir model respectively, indicating forces such as van der Waals forces dominate, and the maximum adsorption capacity at pH values of 6-7 also indicates that electrostatic forces play a smaller role. The adsorption thermodynamic studies showed that the adsorption was a spontaneous and exothermic process. The decrease in the adsorption capacity as the concentration of MPs increases and more adsorption by aged MPs demonstrate that the adsorption process is related to the sites on the surface of MPs. Due to the influence of ionic strength, the adsorption capacity of MPs for thiram increases significantly when the adsorption process takes place in solutions with salinity or in orange and apple juices. The bioavailability of thiram adsorbed by PVC and PET increased significantly. This study highlights the strong role of MPs in food as carriers of pesticide residues in food systems and that the combined hazard should also be of concern.

Toxicity of Polystyrene Nanoplastics in the Liver and Intestine of Normal and High-Fat-Diet Juvenile Zebrafish

Nanoplastics (NPs) are widely found and threaten environmental and biological safety, because they do not degrade completely. We aimed to preliminarily explore the toxicity of NPs in obese children, because childhood obesity is a growing global health concern. We used zebrafish as a vertebrate toxicological model to examine the hepatic lipid metabolism and gut microbiota in juvenile zebrafish exposed to 1000 μg/L polystyrene NPs and a high-fat diet (HFD) using Raman spectroscopy, pathological examination, transcriptome analysis, and 16S sequencing techniques. Our study showed that polystyrene NPs perturb the lipid metabolism and gut microbiota stability in zebrafish. Furthermore, the combined effects of polystyrene NPs and HFD resulted in gastrointestinal injury. Our study is one of the first to investigate the toxicity of polystyrene NPs to normal-diet and HFD juvenile zebrafish using confocal Raman spectroscopy. Our results show the importance of a healthy diet and a reduction in the use of plasticware. Environ Toxicol Chem 2024;43:147-158. © 2023 SETAC.

Exposure to phagolysosomal simulated fluid altered the cytotoxicity of PET micro(nano)plastics to human lung epithelial cells

The occurrence of micro(nano)plastics into various environmental and biological settings influences their physicochemical and toxic behavior. Simulated body fluids are appropriate media for understanding the degradation, stability, and interaction with other substances of any material in the human body. When the particles enter the human body via inhalation, which is one of the avenues for micro(nano)plastics, they first come into contact with the lung lining fluid under neutral conditions and then are phagocytosed under acidic conditions to be removed. Therefore, it is important to examine the physicochemical transformation and toxicity characteristics after interaction with phagolysosomal simulant fluid (PSF). Here, we focused on exploring how the physicochemical differences (e.g. surface chemistry, elemental distribution, and surface charge) of micro(nano)plastics under pH 4.5 phagolysosome conditions impact cytotoxicity and the oxidative characteristics of lung epithelia cells. The cytotoxicity of lung epithelia cells to those treated with PSF and non-treated micro(nano)plastics was tested by various viability indicators including cell counting kit-8 (CCK-8), MTT, and LDH. Furthermore, the cytotoxicity background was examined through the oxidative processes (e.g. reactive oxygen species, antioxidant, superoxide dismutase (SOD), catalase, and reduced glutathione). The results showed that all tested surface physicochemical characteristics were significantly influenced by the phagolysosome conditions. The staged responses were observed with the treatment duration, and significant changes were calculated in carbonyl, carbon-nitrogen, and sulfonyl groups. Moreover, the negativity of the zeta potentials declined between exposure of 2-40 h and then increased at 80 h compared to control owing to the chemical functional groups and elemental distribution of the plastic particles. The tested viability indicators showed that the micro(nano)plastics treated with PSF were cytotoxic to the lung epithelia cells compared to non-treated micro(nano)plastics, and SOD was the dominant enzyme triggering cytotoxicity due to the particle degradation and instability.

Polystyrene nanoplastics exposure causes inflammation and death of esophageal cell

Nanoplastics (NPs) are widely detected in food and drinking water, and human exposure to NPs is ubiquitous. The digestive tract is the main route of exposure to NPs in humans, and the esophagus is one of the main target organs for NPs exposure. However, the toxicological effects of polystyrene nanoplastics (PS-NPs) on the esophagus are not fully understood. Here, we used two esophageal cell lines as models to explore the effects of NPs exposure on esophageal cells and the underlying molecular mechanisms. Western blot analysis, indirect immunofluorescence assay, and enzyme-linked immunosorbent assay revealed that NPs exposure caused inflammatory responses and cell death. Mechanistic investigations showed that PS-NPs exposure induced iron overload in esophageal cells, leading to the accumulation of mitochondrial reactive oxygen species and promoting inflammatory responses and cell death. Additionally, PS-NPs treatment suppressed mitochondrial autophagy, which exacerbated NP-induced cell inflammation and death. Collectively, our experimental findings provide new evidence for the toxicological effects of PS-NPs and offer new insights and avenues for future research.

Biodegradation of microplastics: Advancement in the strategic approaches towards prevention of its accumulation and harmful effects

Microplastics (MPs) are plastic particles in a size ranging from 1 mm to 5 mm in diameter, and are formed by the breakdown of plastics from different sources. They are emerging environmental pollutants, and pose a great threat to living organisms. Improper disposal, inadequate recycling, and excessive use of plastic led to the accumulation of MP in the environment. The degradation of MP can be done either biotically or abiotically. In view of that, this article discusses the molecular mechanisms that involve bacteria, fungi, and enzymes to degrade the MP polymers as the primary objective. As per as abiotic degradation is concerned, two different modes of MP degradation were discussed in order to justify the effectiveness of biotic degradation. Finally, this review is concluded with the challenges and future perspectives of MP biodegradation based on the existing research gaps. The main objective of this article is to provide the readers with clear insight, and ideas about the recent advancements in MP biodegradation.

Emergence of nanoplastics in the aquatic environment and possible impacts on aquatic organisms

Plastic production on a global scale is instrumental in advancing modern society. However, plastic can be broken down by mechanical and chemical forces of humans and nature, and knowledge of the fate and effects of plastic, especially nanoplastics, in the aquatic environment remains poor. We provide an overview of current knowledge on the environmental occurrence and toxicity of nanoplastics, and suggestions for future research. There are nanoplastics present in seas, rivers, and nature reserves from Asia, Europe, Antarctica, and the Arctic Ocean at levels of 0.3-488 microgram per liter. Once in the aquatic environment, nanoplastics accumulate in plankton, nekton, benthos through ingestion and adherence, with multiple toxic results including inhibited growth, reproductive abnormalities, oxidative stress, and immune system dysfunction. Further investigations should focus on chemical analysis methods for nanoplastics, effect and mechanism of nanoplastics at environmental relevant concentrations in aquatic organisms, as well as the mechanism of the Trojan horse effect of nanoplastics.

The hepatotoxicity assessment of micro/nanoplastics: A preliminary study to apply the adverse outcome pathways

Plastic pollution has become a significant global problem over the years, leading to the continuous decomposition and accumulation of micro/nanoplastics (MNPLs) in the environment. As a result, human exposure to these MNPLs is inevitable. The liver, in particular, is highly susceptible to potential MNPL toxicity. In this study, we systematically reviewed the current literature on MNPLs-induced hepatotoxicity and collected data on toxic events occurring at different biological levels. Then, to better understand the cause-mechanism causality, we developed an Adverse Outcome Pathway (AOP) framework for MNPLs-induced hepatotoxicity. The AOP framework provided insights into the mechanism of MNPL-induced hepatotoxicity and highlighted potential health risks such as liver dysfunction and inflammation, metabolism disorders and liver fibrosis. Moreover, we discussed the potential application of emerging toxicological models in the hepatotoxicity study. Liver organoids and liver-on-chips, which can simulate the structure and function of the liver in vitro, offer a promising alternative platform for toxicity testing and risk assessment. We proposed combining the AOP framework with these emerging toxicological models to improve our understanding of the hepatotoxic effects of MNPLs. Overall, this study performed a preliminary exploration of novel toxicological methodologies to assess the hepatotoxicity of MNPLs, providing a deeper understanding of environmental toxicology.