The Pressing Issue of Micro- and Nanoplastic Contamination: Profiling the Reproductive Alterations Mediated by Oxidative Stress

Genotoxic and neurotoxic potential of intracellular nanoplastics: A review

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

Microplastics in water resources: Global pollution circle, possible technological solutions, legislations, and future horizon

Beneath the surface of our ecosystems, microplastics (MPs) silently loom as a significant threat. These minuscule pollutants, invisible to the naked eye, wreak havoc on living organisms and disrupt the delicate balance of our environment. As we delve into a trove of data and reports, a troubling narrative unfolds: MPs pose a grave risk to both health and food chains with their diverse compositions and chemical characteristics. Nevertheless, the peril extends further. MPs infiltrate the environment and intertwine with other pollutants. Worldwide, microplastic levels fluctuate dramatically, ranging from 0.001 to 140 particles.m-3 in water and 0.2 to 8766 particles.g-1 in sediment, painting a stark picture of pervasive pollution. Coastal and marine ecosystems bear the brunt, with each organism laden with thousands of microplastic particles. MPs possess a remarkable ability to absorb a plethora of contaminants, and their environmental behavior is influenced by factors such as molecular weight and pH. Reported adsorption capacities of MPs vary greatly, spanning from 0.001 to 12,700 μg·g-1. These distressing figures serve as a clarion call, demanding immediate action and heightened environmental consciousness. Legislation, innovation, and sustainable practices stand as indispensable defenses against this encroaching menace. Grasping the intricate interplay between microplastics and pollutants is paramount, guiding us toward effective mitigation strategies and preserving our health ecosystems.

Microplastics and nanoplastics in soil: Sources, impacts, and solutions for soil health and environmental sustainability

The present review discusses the growing concern of microplastics (MPs) and nanoplastics (NPs) in soil, together with their sources, concentration, distribution, and impact on soil microorganisms, human health, and ecosystems. MPs and NPs can enter the soil through various pathways, such as agricultural activities, sewage sludge application, and atmospheric deposition. Once in the soil, they can accumulate in the upper layers and affect soil structure, water retention, and nutrient availability. The presence of MPs and NPs in soil can also have ecological consequences, acting as carriers for pollutants and contaminants, such as heavy metals and persistent organic pollutants. Additionally, the leaching of chemicals and additives from MPs and NPs can pose public health risks through the food web and groundwater contamination. The detection and analyses of MPs and NPs in soil can be challenging, and methods involve spectroscopic and microscopy techniques, such as Fourier-transform infrared spectroscopy and scanning electron microscopy. To mitigate the presence and effects of MPs and NPs in soil, it is essential to reduce plastic waste production, improve waste management practices, and adopt sustainable agricultural practices. Effective mitigation measures include implementing stricter regulations on plastic use, promoting biodegradable alternatives, and enhancing recycling infrastructure. Additionally, soil amendments, such as biochar and compost, can help immobilize MPs and NPs, reducing their mobility and bioavailability. This review article aims to provide a comprehensive understanding of these emerging environmental issues and identify potential solutions to alleviate their impact on soil health, ecosystem functioning, and community health.

The Impact of Maternal Nanoplastic and Microplastic Particle Exposure on Mammal's Offspring

The issue of environmental nanoplastic (NPl) particle and microplastic (MPl) particle pollution is becoming increasingly severe, significantly impacting ecosystems and biological health. Research shows that NPl/MPl can penetrate the placental barrier and enter the fetus, leading to transgenerational effects. This review integrates the existing literature on the effects of prenatal NPl/MPl exposure on mammalian offspring, focusing particularly on its negative impacts on the central nervous system, liver, intestinal health, reproductive function, and skeletal muscles. The vast majority of previous studies on prenatal NPl/MPl in mammals have used polystyrene material. Future research should explore the effects of other prenatal NPl/MPl materials on offspring to better reflect the realities of the human environment. It is also essential to investigate the potential harm and underlying mechanisms associated with prenatal NPl/MPl exposure to offspring in greater depth. This will aid in developing appropriate prevention and treatment strategies in the future.

The Potential Mechanisms Involved in the Disruption of Spermatogenesis in Mice by Nanoplastics and Microplastics

BACKGROUND

Plastic-based products are ubiquitous due to their tremendous utility in our daily lives. Nanoplastic (NP) and microplastic (MP) pollution has become a severe threat to the planet and is a growing concern. It has been widely reported that polystyrene (PS) MPs are severely toxic to the male reproduction system, with effects including decreased sperm parameters, impaired spermatogenesis, and damaged testicular structures. However, the molecular mechanisms for impaired spermatogenesis remain poorly understood.

METHODS

C57BL/6 male mice were treated with PS-NPs (80 nm) and PS-MPs (5 μm) by oral gavage every day for 60 days. A series of morphological analyses were completed to explore the influence of PS-NP and PS-MP exposure on the testes. Compared to other cell types in the seminiferous tubule, PS-NP and PS-MP exposure can lead to decreased spermatocytes. Then, more refined molecular typing was further performed based on gene expression profiles to better understand the common and specific molecular characteristics after exposure to PS-NPs and PS-MPs.

RESULTS

There were 1794 common DEGs across the PS-NP groups at three different doses and 1433 common DEGs across the PS-MP groups at three different doses. GO and KEGG analyses of the common DEGs in the PS-NP and PS-MP groups were performed to enrich the common and specific functional progress and signaling pathways, including 349 co-enriched GO entries and 13 co-enriched pathways. Moreover, 348 GO entries and 33 pathways were specifically enriched in the PS-NP group, while 526 GO entries and 15 pathways were specifically enriched in the PS-MPs group.

CONCLUSIONS

PS-NPs were predominantly involved in regulating retinoic acid metabolism, whereas PS-MPs primarily influenced pyruvate metabolism and thyroid hormone metabolism. Our results highlight the different molecular mechanisms of PS-NPs and PS-MPs in the impairment of spermatogenesis in male mammals for the first time, providing valuable insights into the precise mechanisms of PS-NPs and PS-MPs in male reproduction.

Microplastics and Oxidative Stress-Current Problems and Prospects

Microplastics (MPs) are plastic particles between 0.1 and 5000 µm in size that have attracted considerable attention from the scientific community and the general public, as they threaten the environment. Microplastics contribute to various harmful effects, including lipid peroxidation, DNA damage, activation of mitogen-activated protein kinase pathways, cell membrane breakages, mitochondrial dysfunction, lysosomal defects, inflammation, and apoptosis. They affect cells, tissues, organs, and overall health, potentially contributing to conditions like cancer and cardiovascular disease. They pose a significant danger due to their widespread occurrence in food. In recent years, information has emerged indicating that MPs can cause oxidative stress (OS), a known factor in accelerating the aging of organisms. This comprehensive evaluation exposed notable variability in the reported connection between MPs and OS. This work aims to provide a critical review of whether the harmfulness of plastic particles that constitute environmental contaminants may result from OS through a comprehensive analysis of recent research and existing scientific literature, as well as an assessment of the characteristics of MPs causing OS. Additionally, the article covers the analytical methodology used in this field. The conclusions of this review point to the necessity for further research into the effects of MPs on OS.

Physiological and transcriptomic responses of seawater halobios to micro/nano-scale polystyrene-cadmium exposure in a marine food web

Micro/nano-plastics (MPs/NPs) represent an emerging contaminant, posing a significant threat to oceanic halobios. While the adverse effects of joint pollutants on marine organisms are well-documented, the potential biological impacts on the food chain transmission resulting from combinations of MPs/NPs and heavy metals (HMs) remain largely unexplored. This study exposed the microbial loop to combined contaminants (MPs/NPs + HMs) for 48h, bacteria and contaminants are washed away before feeding to the traditional food chain, employing microscopic observation, biochemical detection, and transcriptome analysis to elucidate the toxicological mechanisms of the top predator. The findings revealed that MPs/NPs combined with Cd2+ could traverse both the microbial loop and classical food chain. Acute exposure significantly affected the carbon biomass of the top predator Tigriopus japonicus (75.8% lower). Elevated antioxidant enzyme activity led to lipid peroxidation, manifesting in increased malondialdehyde levels. Transcriptome sequencing showed substantial differential gene expression levels in T. japonicus under various treatments. The upregulation of genes associated with apoptosis and inflammatory responses, highlighting the impact of co-exposure on oxidative damage and necroptosis within cells. Notably, NPs-Cd exhibited stronger toxicity than MPs-Cd. NPs-Cd led to a greater decrease in the biomass of top predators, accompanied by lower activities of GSH, SOD, CAT, and GSH-PX, resulting in increased production of lipid peroxidation product MDA and higher oxidative stress levels. This investigation provides novel insights into the potential threats of MPs/NPs combined with Cd2+ on the microbial loop across traditional food chain, contributing to a more comprehensive assessment of the ecological risks associated with micro/nano-plastics and heavy metals.

Impact of Polyethylene Terephthalate Microplastics on Drosophila melanogaster Biological Profiles and Heat Shock Protein Levels

Microplastics and nanoplastics are abundant in the environment. Further research is necessary to examine the consequences of microplastic contamination on living species, given its widespread presence. In our research, we determined the toxic effects of PET microplastics on Drosophila melanogaster at the cellular and genetic levels. Our study revealed severe cytotoxicity in the midgut of larvae and the induction of oxidative stress after 24 and 48 h of treatment, as indicated by the total protein, Cu-Zn SOD, CAT, and MDA contents. For the first time, cell damage in the reproductive parts of the ovaries of female flies, as well as in the accessory glands and testes of male flies, has been observed. Furthermore, a decline in reproductive health was noted, resulting in decreased fertility among the flies. By analyzing stress-related genes such as hsp83, hsp70, hsp60, and hsp26, we detected elevated expression of hsp83 and hsp70. Our study identified hsp83 as a specific biomarker for detecting early redox changes in cells caused by PET microplastics in all the treated groups, helping to elucidate the primary defense mechanism against PET microplastic toxicity. This study offers foundational insights into the emerging environmental threats posed by microplastics, revealing discernible alterations at the genetic level.

Chemical reactivity theory to analyze possible toxicity of microplastics: Polyethylene and polyester as examples

Micro- and nanoplastics are widespread throughout the world. In particular, polyethylene (PE) and polyethylene terephthalate or polyester (PET) are two of the most common polymers, used as plastic bags and textiles. To analyze the toxicity of these two polymers, oligomers with different numbers of units were used as models. The use of oligomers as polymeric templates has been used previously with success. We started with the monomer and continued with different oligomers until the chain length was greater than two nm. According to the results of quantum chemistry, PET is a better oxidant than PE, since it is a better electron acceptor. Additionally, PET has negatively charged oxygen atoms and can promote stronger interactions than PE with other molecules. We found that PET forms stable complexes and can dissociate the guanine-cytosine nucleobase pair. This could affect DNA replication. These preliminary theoretical results may help elucidate the potential harm of micro- and nanoplastics.

Occurrence, transport, and toxicity of microplastics in tropical food chains: perspectives view and way forward

Microplastics, which have a diameter of less than 5 mm, are becoming an increasingly prevalent contaminant in terrestrial and aquatic ecosystems due to the dramatic increase in plastic production to 390.7 million tonnes in 2021. Among all the plastics produced since 1950, nearly 80% ended up in the environment or landfills and eventually reached the oceans. Currently, 82-358 trillion plastic particles, equivalent to 1.1-4.9 million tonnes by weight, are floating on the ocean's surface. The interactions between microorganisms and microplastics have led to the transportation of other associated pollutants to higher trophic levels of the food chain, where microplastics eventually reach plants, animals, and top predators. This review paper focuses on the interactions and origins of microplastics in diverse environmental compartments that involve terrestrial and aquatic food chains. The present review study also critically discusses the toxicity potential of microplastics in the food chain. This systematic review critically identified 206 publications from 2010 to 2022, specifically reported on microplastic transport and ecotoxicological impact in aquatic and terrestrial food chains. Based on the ScienceDirect database, the total number of studies with "microplastic" as the keyword in their title increased from 75 to 4813 between 2010 and 2022. Furthermore, various contaminants are discussed, including how microplastics act as a vector to reach organisms after ingestion. This review paper would provide useful perspectives in comprehending the possible effects of microplastics and associated contaminants from primary producers to the highest trophic level (i.e. human health).

Metabolic equilibrium and reproductive resilience: Freshwater gastropods under nanoplastics exposure

Nanoplastics (NPs) have gained increasing attention due to their widespread presence in aquatic environments and potential adverse effects on organisms. The interaction between NPs and freshwater gastropods can lead to a range of physiological and reproductive disturbances. In this study, we investigated the adverse effects of NPs (two size: 20 nm and 100 nm; three concentrations: 0.5, 50 and 100 ppm) on energy metabolism and reproductive fitness in freshwater gastropods Lymnean stagnalis after 21 days exposure. Briefly, the condition index negatively correlated with increasing NPs concentrations for both sizes. Bioaccumulation revealed a concentration-dependent trend in the 100 nm group, and the highest accumulation appeared in the 100 ppm group, compared to all the rest groups. This phenomenon could be attributed to the larger surface area which facilitates stronger attachment to tissues, while smaller particles could be cleared more readily from body. Carbohydrate and protein reserves remained largely unaffected at all concentrations. However, 100 nm NPs triggered stress responses, increasing lipid production, and 20 nm NPs potentially interfered with mitochondrial function, affecting electron transport system activity. Despite the variations observed in lipid levels and energy cost, the ratio of available energy to energy cost remained stable across for both NPs sizes, and this resilience suggests that cellular energy allocation endured undisturbed, hinting at mechanisms that enable gastropods to maintain their metabolic equilibrium. Reproductively, NPL-exposed groups had fewer clutches, with clutches per collection time decreasing over time for both sizes. In terms of egg development, shell growth and hatching rates remained unaffected, suggesting resilience in aquatic ecosystems.In conclusion, this study underscores the substantial impact of NPs on freshwater gastropods, raising ecological and reproductive concerns. The intricate interplay between nanoparticle size, concentration, and physiological responses highlights the complexity of NPs interactions in aquatic ecosystems, necessitating further research and regulatory measures.

Effects of combined exposure to polystyrene microplastics and 17α-Methyltestosterone on the reproductive system of zebrafish

Polystyrene microplastics (PS-MPs) are important carriers of pollutants in water. 17α-Methyltestosterone (MT) is a synthetic environmental endocrine disrupting chemical (EDC) with androgenic effects. To study the effects of PS-MPs and MT on zebrafish reproductive systems, zebrafish were exposed to 0 or 50 ng L-1 MT, 0.5 mg∙L-1 PS-MPs, or 50 ng∙L-1 MT + 0.5 mg∙L-1 PS-MPs for 21 d. The results showed that the different exposure reagents caused varying degrees of damage to the reproductive systems in zebrafish, with the extent of damage increasing as the exposure duration increased. Histological analysis of the gonads revealed that the ratio of mature oocytes and mature spermatozoa in the gonad decreased gradually with increased exposure time, with the ratio being Control > PS-MPs > MT > MT + PS-MPs in decreasing order. The results of quantitative real-time PCR (qRT‒PCR) showed that in female fish treated for 7 d, the expression of cyp11a mRNA was significantly reduced in all three treatment groups(MT, PS-MPs, and MT + PS-MPs), while in the group treated for 14 d with MT + PS-MPs, the expression of cyp19a1a and StAR mRNA was significantly increased. In male fish exposed for 21 d, the expression of cyp11a, cyp17a1, cyp19a1a, StAR, 3β-HSD, and 17β-HSD3 mRNA was significantly decreased in MT + PS-MPs. ELISA results showed that after 14 d of exposure, the levels of E2, LH, and FSH in the ovaries of female fish were significantly reduced in all three treatment groups. Similarly, the levels of T, E2, LH, and FSH in the testis of male fish were significantly reduced after 14 d of exposure to PS-MPs and MT + PS-MPs. Offspring of zebrafish exposed to MT and MT + PS-MPs exhibited delayed incubation time and slow development. The cross-generational toxicity of PS-MPs themselves may be negligible, but it can exacerbate the toxicity of MT, making the cross-generational effects more pronounced in the offspring, causing offspring mortality and malformations. Offspring of zebrafish exposed to MT and MT + PS-MPs exhibited delayed incubation time and slow development. In addition, MT caused malformations such as pericardial edema, yolk cysts, and spinal deformities in zebrafish during the incubation period.

Microplastics absent from reef fish in the Marshall Islands: Multistage screening methods reduced false positives

Island communities, like the Republic of the Marshall Islands (RMI), depend on marine resources for food and economics, so plastic ingestion by those resources is a concern. The gastrointestinal tracts of nine species of reef fish across five trophic groups (97 fish) were examined for plastics >1 mm. Over 2100 putative plastic particles from 72 fish were identified under light microscopy. Only 115 of these from 47 fish passed a plastic screening method using Fourier-transform infrared microspectroscopy (μFTIR) in reflectance mode. All of these were identified as natural materials in a final confirmatory analysis, attenuated total reflectance FTIR. The high false-positive rate of visual and μFTIR methods highlight the importance of using multiple polymer identification methods. Limited studies on ingested plastic in reef fish present challenging comparisons because of different methods used. No plastic >1 mm were found in the RMI reef fish, reassuring human consumers.

Uptake of Nanoplastic particles by zebrafish embryos triggers the macrophage response at early developmental stage

Plastic pollution continues to erupt as a global ecological concern. As plastic debris is degraded into nanoscale and microscale particles via biodegradation, UV-irradiation, and mechanical processes, nanoplastic pollution arises as a threat to virtually every biological and ecological system on the planet. In this study, zebrafish (Danio rerio) embryos were exposed to fluorescently labeled plastic particles at nanoscales (30 nm and 100 nm). The uptake of both the nanoplastic particles (NPs) was found to exponentially increase with incubation time. Penetration of NPs through the natural barrier of the zebrafish embryos, the chorion, was observed prior to the hatching of the embryo. As a result, the NPs were found to accumulate on the body surface as well as inside the body of the zebrafish. The invasion of NPs into zebrafish embryos induced the upregulation of several stress and immune response genes including interleukins (il6 and il1b), cytochrome P450 (cyp1a and cyp51), and reactive oxygen species (ROS) removal protein-encoding genes (sod and cat). This suggested the initiation of ROS generation and removal as well as the activation of the immune response of zebrafish embryos. Colocalization of macrophages and NPs in zebrafish embryos indicated the involvement of macrophage response to the NP invasion at the early developmental stage of zebrafish.

Microplastics in cultivated soil environment: Construction of toxicity grading evaluation system, development of priority control checklist, and toxicity mechanism analysis

The present study aimed to comprehensively evaluate the toxicological effects of microplastics (MPs) on cultivated soil quality. Based on improved G1 evaluation method, we first constructed a grading evaluation system comprising of the indicators of toxicological effects of cultivated soil quality under MPs exposure, while focusing on types of MPs that had significant/non-significant toxicity effects. Furthermore, we verified reliability of screening results of significance-links at each level, using several data processing methods. Then, using natural breakpoint classification method, a priority control checklist of toxicological effects of 18 types of MPs on cultivated soil was developed to determine the types of MPs having significant toxicity risks and cultivated soil quality links significantly affected by the toxicity of MPs exposure. Finally, quantum-mechanics/molecular-mechanics (QM/MM) methods were used to carry out the differential toxicity mechanism analysis. The results showed that MPs with higher non-polar surface area may lead to stronger toxicity effect to the cultivated soil quality. Notably, the MPs that have abundant binding sites enhance the binding affinity, and less polar MPs bind more strongly to the non-polar amino acids of target receptors. Our study provides a new theoretical perspective for multi-dimensional analysis toxicological effects of different MPs exposure on cultivated soil quality.

Toxicity of microplastics and nanoplastics: invisible killers of female fertility and offspring health

Microplastics (MPs) and nanoplastics (NPs) are emergent pollutants, which have sparked widespread concern. They can infiltrate the body via ingestion, inhalation, and cutaneous contact. As such, there is a general worry that MPs/NPs may have an impact on human health in addition to the environmental issues they engender. The threat of MPs/NPs to the liver, gastrointestinal system, and inflammatory levels have been thoroughly documented in the previous research. With the detection of MPs/NPs in fetal compartment and the prevalence of infertility, an increasing number of studies have put an emphasis on their reproductive toxicity in female. Moreover, MPs/NPs have the potential to interact with other contaminants, thus enhancing or diminishing the combined toxicity. This review summarizes the deleterious effects of MPs/NPs and co-exposure with other pollutants on female throughout the reproduction period of various species, spanning from reproductive failure to cross-generational developmental disorders in progenies. Although these impacts may not be directly extrapolated to humans, they do provide a framework for evaluating the potential mechanisms underlying the reproductive toxicity of MPs/NPs.

Fish welfare during slaughter: the European Council Regulation 1099/09 application

The Treaty of Lisbon states that animals are sentient beings. Fish species show physiological differences from terrestrial animals and are slaughtered and killed in a very different context. Many existing commercial killing methods expose fish to extensive suffering over a prolonged period of time, and some of the slaughtering practices they experience can cause pain and distress. This study highlights the limited feasibility of European Council Regulation 1099/09 requirements on welfare when killing cephalopods and crustaceans. Sentience is the animal's capacity to have positive (comfort, excitement) and negative (pain, anxiety, distress, or harm) feelings. Considerable evidence is now showing that the major commercial fish species, including cephalopods and crustaceans, possess complex neurological substrates supporting pain sensitivity and conscious experiences. In the legislation applied to scientific procedures, the concept of sentience in these species is important. Therefore, it would be appropriate to acknowledge current scientific evidence and establish reference criteria for fish welfare. For the welfare of fish species during slaughter, European Council Regulation 1099/09 applicability is limited. Fish welfare during slaughter is more than just an ethical problem. According to the One-Health approach, food safety should also include the concept of sentience for fish welfare. Pending studies that dispel all doubt, the precautionary principle of European Council Regulation 178/04 remains valid and should be applied to fish welfare.

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.

Effects of microplastics, pesticides and nano-materials on fish health, oxidative stress and antioxidant defense mechanism

Microplastics and pesticides are emerging contaminants in the marine biota, which cause many harmful effects on aquatic organisms, especially on fish. Fish is a staple and affordable food source, rich in animal protein, along with various vitamins, essential amino acids, and minerals. Exposure of fish to microplastics, pesticides, and various nanoparticles generates ROS and induces oxidative stress, inflammation, immunotoxicity, genotoxicity, and DNA damage and alters gut microbiota, thus reducing the growth and quality of fish. Changes in fish behavioral patterns, swimming, and feeding habits were also observed under exposures to the above contaminants. These contaminants also affect the Nrf-2, JNK, ERK, NF-κB, and MAPK signaling pathways. And Nrf2-KEAP1 signalling modulates redox status marinating enzymes in fish. Effects of pesticides, microplastics, and nanoparticles found to modulate many antioxidant enzymes, including superoxide dismutase, catalase, and glutathione system. So, to protect fish health from stress, the contribution of nano-technology or nano-formulations was researched. A decrease in fish nutritional quality and population significantly impacts on the human diet, influencing traditions and economics worldwide. On the other hand, traces of microplastics and pesticides in the habitat water can enter humans by consuming contaminated fish which may result in serious health hazards. This review summarizes the oxidative stress caused due to microplastics, pesticides and nano-particle contamination or exposure in fish habitat water and their impact on human health. As a rescue mechanism, the use of nano-technology in the management of fish health and disease was discussed.

Reproductive toxicity of micro- and nanoplastics

Large-scale plastic pollution occurs in terrestrial and marine environments and degrades into microparticles (MP) and nanoparticles (NP) of plastic. Micro/nanoplastics (MP/NPs) are found throughout the environment and different kinds of marine organisms and can enter the human body through inhalation or ingestion, particularly through the food chain. MPs/NPs can enter different organisms, and affect different body systems, including the reproductive, digestive, and nervous systems via the induction of different stresses such as oxidative stress and endoplasmic reticulum stress. This paper summarizes the effects of MPs/NPs of different sizes on the reproduction of different organisms including terrestrial and marine invertebrates and vertebrates, the amplification of toxic effects between them through the food chain, the serious threat to biodiversity, and, more importantly, the imminent challenge to human reproductive health. There is a need to strengthen international communication and cooperation on the remediation of plastic pollution and the protection of biodiversity to build a sustainable association between humans and other organisms.

Impact of Microplastics and Nanoplastics on Livestock Health: An Emerging Risk for Reproductive Efficiency

Pollution due to microplastics and nanoplastics is one of the major environmental issues of the last decade and represents a growing threat to human and animal health. In aquatic species, there is a large amount of information regarding the perturbation of marine organisms; instead, there are only a few studies focusing on the pathophysiological consequences of an acute and chronic exposure to micro- and nanoplastics in mammalian systems, especially on the reproductive system. There are several studies that have described the damage caused by plastic particles, including oxidative stress, apoptosis, inflammatory response, dysregulation of the endocrine system and accumulation in various organs. In addition to this, microplastics have recently been found to influence the evolution of microbial communities and increase the gene exchange, including antibiotic and metal resistance genes. Special attention must be paid to farm animals, because they produce food such as milk, eggs and meat, with the consequent risk of biological amplification along the food chain. The results of several studies indicate that there is an accumulation of microplastics and nanoplastics in human and animal tissues, with several negative effects, but all the effects in the body have not been ascertained, especially considering the long-term consequences. This review provides an overview of the possible adverse effects of the exposure of livestock to micro- and nanoplastics and assesses the potential risks for the disruption of reproductive physiological functions.

The hazardous impact of true-to-life PET nanoplastics in Drosophila

Plastic pollution is a continuously growing problem that can threaten wildlife and human beings. Environmental plastic waste is degraded into small particles termed micro/ nanoplastics (MNPLs) that, due to their small size, can be easily internalized into the exposed organisms, increasing the risks associated with their exposure. To appropriately determine the associated health risk, it is essential to obtain/test representative MNPLs' environmental samples. To such end, we have obtained NPLs resulting from sanding commercial water polyethylene terephthalate (PET) bottles. These true-to-life PETNPLs were extensively characterized, and their potential hazard impacts were explored using Drosophila melanogaster. To highlight the internalization through the digestive tract and the whole body, transmission electron microscopy (TEM) and confocal microscopy were used. In spite of the observed efficient uptake of PETNPLs into symbiotic bacteria, enterocytes, and hemocytes, the exposure failed to reduce flies' survival rates. Nevertheless, PETNPLs exposure disturbed the expression of stress, antioxidant, and DNA repair genes, as well as in those genes involved in the response to physical intestinal damage. Importantly, both oxidative stress and DNA damage induction were markedly increased as a consequence of the exposure to PETNPLs.

A Systematic Review of the Placental Translocation of Micro- and Nanoplastics

PURPOSE OF REVIEW

Despite increasing awareness of the ubiquity of microplastics (MPs) in our environments, little is known about their risk of developmental toxicity. Even less is known about the environmental distribution and associated toxicity of nanoplastics (NPs). Here, we review the current literature on the capacity for MPs and NPs to be transported across the placental barrier and the potential to exert toxicity on the developing fetus.

RECENT FINDINGS

This review includes 11 research articles covering in vitro, in vivo, and ex vivo models, and observational studies. The current literature confirms the placental translocation of MPs and NPs, depending on physicochemical properties such as size, charge, and chemical modification as well as protein corona formation. Specific transport mechanisms for translocation remain unclear. There is emerging evidence of placental and fetal toxicity due to plastic particles based on animal and in vitro studies. Nine out of eleven studies examined in this review found that plastic particles were capable of placental translocation. In the future, more studies are needed to confirm and quantify the existence of MPs and NPs in human placentas. Additionally, translocation of different plastic particle types and heterogenous mixtures across the placenta, exposure at different periods of gestation, and associations with adverse birth and other developmental outcomes should also be investigated.

Subchronic Exposure to Polystyrene Microplastic Differently Affects Redox Balance in the Anterior and Posterior Intestine of Sparus aurata

Microplastics (MPs) are pollutants widely distributed in aquatic ecosystems. MPs are introduced mainly by ingestion acting locally or in organs far from the gastroenteric tract. MPs-induced health consequences for fish species still need to be fully understood. We aimed to investigate the effects of the subchronic oral exposure to polystyrene microplastics (PS-MPs) (1-20 μm) in the gilthead seabreams (Sparus aurata) used as the experimental model. We studied the detrimental impact of PS-MPs (25 and 250 mg/kg b.w./day) on the redox balance and antioxidant status in the intestine using histological analysis and molecular techniques. The research goal was to examine the anterior (AI) and posterior intestine (PI) tracts, characterized by morphological and functional differences. PS-MPs caused an increase of reactive oxygen species and nitrosylated proteins in both tracts, as well as augmented malondialdehyde production in the PI. PS-MPs also differently affected gene expression of antioxidant enzymes (i.e., superoxide dismutase, catalase, glutathione reductase). Moreover, an increased up-regulation of protective heat shock proteins (HSPs) (i.e., hsp70 and hsp90) was observed in PI. Our findings demonstrate that PS-MPs are responsible for oxidative/nitrosative stress and alterations of detoxifying defense system responses with differences in AI and PI of gilthead seabreams.

Warmer water, high light intensity, lithium and microplastics: Dangerous environmental combinations to zooplankton and Global Health?

Nowadays there is a high concern about the combined effects of global warming and emerging environmental contaminants with significant increasing trends of use, such as lithium (Li) and microplastics (MPs), both on wildlife and human health. Therefore, the effects of high light intensity (26,000 lx) or warmer water temperature (25 °C) on the long-term toxicity of Li and mixtures of Li and MPs (Li-MPs mixtures) were investigated using model populations of the freshwater zooplankton species Daphnia magna. Three 21-day bioassays were done in the laboratory at the following water temperatures and light intensities: (i) 20 °C/10830 lx; (ii) 20 °C/26000 lx (high light intensity); (iii) 25 °C/10830 lx (warmer temperature). Based on the 21-day EC50s on reproduction, high light intensity increased the reproductive toxicity of Li and Li-MPs mixtures by ~1.3 fold; warmer temperature increased the toxicity of Li by ~1.2 fold, and the toxicity of Li-MPs mixtures by ~1.4 fold based on the concentration of Li, and by ~2 fold based on the concentrations of MPs. At high light intensity, Li (0.04 mg/L) and Li-MPs mixtures (0.04 Li + 0.09 MPs mg/L) reduced the population fitness by 32 % and 41 %, respectively. Warmer temperature, Li (0.05 mg/L) and Li-MPs mixtures (0.05 Li + 0.09 MPs mg/L) reduced it by 63 % and 71 %, respectively. At warmer temperature or high light intensity, higher concentrations of Li and Li-MPs mixtures lead to population extinction. Based on the population growth rate and using data of bioassays with MPs alone done simultaneously, Li and MPs interactions were antagonistic or synergistic depending on the scenario. High light intensity and chemical stress generally acted synergistically. Warmer temperature and chemical stress always acted synergistically. These findings highlight the threats of long-term exposure to Li and Li-MPs mixtures to freshwater zooplankton and Global Health in a warmer world.

Combined effects of copper oxide and nickel oxide coated chitosan nanoparticles adsorbed to styrofoam resin beads on hydrothermal vent bacteria

Microplastics are potential carriers of harmful contaminants but their combined effects are largely unknown. It needs intensive monitoring in order to achieve a better understanding of metal-oxide nanoparticles and their dispersion via microplastics such as styrofoam in the aquatic environment. In the present study, an effort was made to provide a preferable perception about the toxic effects of engineered nanoparticles (NPs), namely, copper oxide (CuO NPs), nickel oxide (NiO NPs), copper oxide/chitosan (CuO/CS NPs) and nickel oxide/chitosan (NiO/CS NPs). Characterizations of synthesized NPs included their morphology (SEM and EDX), functional groups (FT-IR) and crystallinity (XRD). Their combined toxic effect after adsorption to styrofoam (SF) was monitored using the hydrothermal vent bacterium Jeotgalicoccus huakuii as a model. This was done by determining MIC (minimum inhibitory concentration) through a resazurin assay measuring ELISA, growth, biofilm inhibition and making a live and dead assay. Results revealed that at high concentrations (60 mg/10 mL) of CuO, CuO/CS NPs and 60 mg of SF adsorbed CuO and CuO/CS NPs inhibited the growth of J. huakuii. However, NPs rather than SF inhibited the growth of bacteria. The toxicity of NPs adsorbed on plain SF was found to be less compared to NPs alone. This study revealed new dimensions regarding the positive impacts of SF at low concentrations. Synthesized NPs applied separately were found to affect the growth of bacteria substantially more than if coated to SF resin beads.

Unraveling the potential human health risks from used disposable face mask-derived micro/nanoplastics during the COVID-19 pandemic scenario: A critical review

With the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), disposable face masks (DFMs) have caused negative environmental impacts. DFMs will release microplastics (MPs) and nanoplastics (NPs) during environmental degradation. However, few studies reveal the release process of MPs/NPs from masks in the natural environment. This review presents the current knowledge on the abiotic and biotic degradation of DFMs. Though MPs and NPs have raised serious concerns about their potentially detrimental effects on human health, little attention was paid to their impacts on human health from DFM-derived MPs and NPs. The potential toxicity of mask-derived MPs/NPs, such as gastrointestinal toxicity, pneumotoxicity, neurotoxicity, hepatotoxicity, reproductive and transgenerational toxicity, and the underlying mechanism will be discussed in the present study. MPs/NPs serve as carriers of toxic chemicals and pathogens, leading to their bioaccumulation and adverse effects of biomagnification by food chains. Given human experiments are facing ethical issues and animal studies cannot completely reveal human characteristics, advanced human organoids will provide promising models for MP/NP risk assessment. Moreover, in-depth investigations are required to identify the release of MPs/NPs from discarded face masks and characterize their transportation through the food chains. More importantly, innovative approaches and eco-friendly strategies are urgently demanded to reduce DFM-derived MP/NP pollution.

The effects of nanoplastics on adipose stromal cells from swine tissues

Plastic is one of the main sources of marine and terrestrial pollution. This material can fragment into micro- (<-5 mm) and nanoplastics (NPs) (<100 nm) following degradation. Animals are exposed to these particles by ingesting contaminated food, respiration or filtration, and transdermally. In organisms, NPs can cross biological membranes, and cause oxidative stress, cell damage, apoptosis, and endocrine interference. We previously demonstrated that polystyrene - NPs interfered with ovarian cell functions. Since reproduction involves a high energy expenditure and a crucial role is played by adipose tissue, the aim of the present study was to evaluate the effects of NPs on primary adipose stromal cells (ASCs) isolated from swine adipose tissues. In particular, the effects on cell viability, proliferation, metabolic activity, inflammatory process mediators and oxidative stress markers were assessed. The obtained results did not reveal a significant variation in cell proliferation, metabolic activity was increased (P < 0.01) but only at the lowest concentration, while viability showed a significant decrease after prolonged exposure to NPs (P < 0.01). TNF-α was increased (P < 0.05), while PAI-1 was inhibited (P < 0.001). Redox status was significantly modified; in particular, the production of O₂^-_, H₂O₂ and NO was stimulated (P < 0.05), the non-enzymatic antioxidant power was reduced (P < 0.05) while catalase activity was significantly (P < 0.01) increased.

Environmental Pollutants and Oxidative Stress in Terrestrial and Aquatic Organisms: Examination of the Total Picture and Implications for Human Health

There is current great international concern about the contribution of environmental pollution to the global burden of disease particularly in the developing, low- and medium-income countries. Industrial activities, urbanization, developmental projects as well as various increased anthropogenic activities involving the improper generation, management and disposal of pollutants have rendered today's environment highly polluted with various pollutants. These pollutants include toxic metals (lead, cadmium, mercury, arsenic), polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides and diesel exhaust particles most of which appear to be ubiquitous as well as have long-term environmental persistence with a wide range of toxicities such as oxidative stress among others. Oxidative stress, which may arise from increased production of damaging free radicals emanating from increased pollutant burden and depressed bioavailability of antioxidant defenses causes altered biochemical and physiological mechanisms and has been implicated in all known human pathologies most of which are chronic. Oxidative stress also affects both flora and fauna and plants are very important components of the terrestrial environment and significant contributors of nutrients for both man and animals. It is also remarkable that the aquatic environment in which sea animals and creatures are resident is also highly polluted, leading to aquatic stress that may affect the survival of the aquatic animals, sharing in the oxidative stress. These altered terrestrial and aquatic environments have an overarching effect on human health. Antioxidants neutralize the damaging free radicals thus, they play important protective roles in the onset, progression and severity of the unmitigated generation of pollutants that ultimately manifest as oxidative stress. Consequently, human health as well as that of aquatic and terrestrial organisms may be protected from environmental pollution by mitigating oxidative stress and employing the principles of nutritional medicine, essentially based on antioxidants derived mainly from plants, which serve as the panacea of the vicious state of environmental pollutants consequently, the health of the population. Understanding the total picture of oxidative stress and integrating the terrestrial and aquatic effects of environmental pollutants are central to sustainable health of the population and appear to require multi-sectoral collaborations from diverse disciplinary perspectives; basically the environmental, agricultural and health sectors.