Source, distribution and emerging threat of micro- and nanoplastics to marine organism and human health: Socio-economic impact and management strategies

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.

Nanoplastics in Water: Artificial Intelligence-Assisted 4D Physicochemical Characterization and Rapid In Situ Detection

For the first time, we present a much-needed technology for the in situ and real-time detection of nanoplastics in aquatic systems. We show an artificial intelligence-assisted nanodigital in-line holographic microscopy (AI-assisted nano-DIHM) that automatically classifies nano- and microplastics simultaneously from nonplastic particles within milliseconds in stationary and dynamic natural waters, without sample preparation. AI-assisted nano-DIHM identifies 2 and 1% of waterborne particles as nano/microplastics in Lake Ontario and the Saint Lawrence River, respectively. Nano-DIHM provides physicochemical properties of single particles or clusters of nano/microplastics, including size, shape, optical phase, perimeter, surface area, roughness, and edge gradient. It distinguishes nano/microplastics from mixtures of organics, inorganics, biological particles, and coated heterogeneous clusters. This technology allows 4D tracking and 3D structural and spatial study of waterborne nano/microplastics. Independent transmission electron microscopy, mass spectrometry, and nanoparticle tracking analysis validates nano-DIHM data. Complementary modeling demonstrates nano- and microplastics have significantly distinct distribution patterns in water, which affect their transport and fate, rendering nano-DIHM a powerful tool for accurate nano/microplastic life-cycle analysis and hotspot remediation.

A review of nanotechnology in enzyme cascade to address challenges in pre-treating biomass

Nanotechnology has become a revolutionary technique for improving the preliminary treatment of lignocellulosic biomass in the production of biofuels. Traditional methods of pre-treatment have encountered difficulties in effectively degrading the intricate lignocellulosic composition, thereby impeding the conversion of biomass into fermentable sugars. Nanotechnology has enabled the development of enzyme cascade processes that present a potential solution for addressing the limitations. The focus of this review article is to delve into the utilization of nanotechnology in the pretreatment of lignocellulosic biomass through enzyme cascade processes. The review commences with an analysis of the composition and structure of lignocellulosic biomass, followed by a discussion on the drawbacks associated with conventional pre-treatment techniques. The subsequent analysis explores the importance of efficient pre-treatment methods in the context of biofuel production. We thoroughly investigate the utilization of nanotechnology in the pre-treatment of enzyme cascades across three distinct sections. Nanomaterials for enzyme immobilization, enhanced enzyme stability and activity through nanotechnology, and nanocarriers for controlled enzyme delivery. Moreover, the techniques used to analyse nanomaterials and the interactions between enzymes and nanomaterials are introduced. This review emphasizes the significance of comprehending the mechanisms underlying the synergy between nanotechnology and enzymes establishing sustainable and environmentally friendly nanotechnology applications.

A critical review on male-female reproductive and developmental toxicity induced by micro-plastics and nano-plastics through different signaling pathways

It is widely accepted that humans are constantly exposed to micro-plastics and nano-plastics through various routes, including inhalation of airborne particles, exposure to dust, and consumption of food and water. It is estimated that humans may consume thousand to millions of micro-plastic particles, equating to several milligrams per day. Prolonged exposure to micro-plastics and nano-plastics has been linked to negative effects on different living organisms, including neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and hepatotoxicity, and developmental toxicities. The main purpose of this review is to explore the effect of micro-plastics and nano-plastics on the male and female reproductive system, as well as their offspring, and the associated mechanism implicated in the reproductive and developmental toxicities. Micro-plastics and nano-plastics have been shown to exert negative effects on the reproductive system of both male and female mammals and aquatic animals, including developmental impacts on gonads, gametes, embryo, and their subsequent generation. In addition, micro-plastics and nano-plastics impact the hypothalamic-pituitary axes, leading to oxidative stress, reproductive toxicity, neurotoxicity, cytotoxicity, developmental abnormalities, poor sperm quality, diminishes ovarian ovulation and immune toxicity. This study discusses the so many different signaling pathways associated in the male and female reproductive and developmental toxicity induced by micro-plastics and nano-plastics.

An insight decipher on photocatalytic degradation of microplastics: Mechanism, limitations, and future outlook

Plastic material manufacturing and buildup over the past 50 years has significantly increased pollution levels. Microplastics (MPs) and non-biodegradable residual plastic films have become the two most pressing environmental issues among the numerous types of plastic pollution. These tiny plastic flakes enter water systems from a variety of sources, contaminating the water. Since MPs can be consumed by people and aquatic species and eventually make their way into the food chain, their presence in the environment poses a serious concern. Traditional technologies can remove MPs to some extent, but their functional groups, stable covalent bonds, and hydrophobic nature make them difficult to eliminate completely. The urgent need to develop a sustainable solution to the worldwide contamination caused by MPs has led to the exploration of various techniques. Advanced oxidation processes (AOPs) such as photo-catalytic oxidation, photo-degradation, and electrochemical oxidation have been investigated. Among these, photocatalysis stands out as the most promising method for degrading MPs. Photocatalysis is an environmentally friendly process that utilizes light energy to facilitate a chemical reaction, breaking down MPs into carbon dioxide and water-soluble hydrocarbons under aqueous conditions. In photocatalysis, semiconductors act as photocatalysts by absorbing energy from a light source, becoming excited, and generating reactive oxygen species (ROS). These ROS, including hydroxyl radicals (•OH) and superoxide ions ( [Formula: see text] ), play a crucial role in the degradation of MPs. This extensive review provides a detailed exploration of the mechanisms and processes underlying the photocatalytic removal of MPs, emphasizing its potential as an efficient and environmentally friendly approach to address the issue of plastic pollution.

Microplastics as carriers of toxic pollutants: Source, transport, and toxicological effects

Microplastic pollution has emerged as a new environmental concern due to our reliance on plastic. Recent years have seen an upward trend in scholarly interest in the topic of microplastics carrying contaminants; however, the available review studies have largely focused on specific aspects of this issue, such as sorption, transport, and toxicological effects. Consequently, this review synthesizes the state-of-the-art knowledge on these topics by presenting key findings to guide better policy action toward microplastic management. Microplastics have been reported to absorb pollutants such as persistent organic pollutants, heavy metals, and antibiotics, leading to their bioaccumulation in marine and terrestrial ecosystems. Hydrophobic interactions are found to be the predominant sorption mechanism, especially for organic pollutants, although electrostatic forces, van der Waals forces, hydrogen bonding, and pi-pi interactions are also noteworthy. This review reveals that physicochemical properties of microplastics, such as size, structure, and functional groups, and environmental compartment properties, such as pH, temperature, and salinity, influence the sorption of pollutants by microplastic. It has been found that microplastics influence the growth and metabolism of organisms. Inadequate methods for collection and analysis of environmental samples, lack of replication of real-world settings in laboratories, and a lack of understanding of the sorption mechanism and toxicity of microplastics impede current microplastic research. Therefore, future research should focus on filling in these knowledge gaps.

Size-Resolved Identification and Quantification of Micro/Nanoplastics in Indoor Air Using Pyrolysis Gas Chromatography-Ion Mobility Mass Spectrometry

Humans are exposed to differing levels of micro/nanoplastics (MNPs) through inhalation, but few studies have attempted to measure <1 μm MNPs in air, in part due to a paucity of analytical methods. We developed an approach to identify and quantify MNPs in indoor air using a novel pyrolysis gas chromatographic cyclic ion mobility mass spectrometer (pyr-GCxcIMS). Four common plastic types were targeted for identification, namely, (polystyrene (PS), polyethylene (PE), polypropylene (PP), and polymethyl methacrylate (PMMA). The method was applied to size-resolved particulate (56 nm to 18 μm) collected from two different indoor environments using a Micro-Orifice Uniform Deposit Impactors (MOUDI) model 110 cascade impactor. Comprehensive two-dimensional separation by GCxcIMS also enabled the retrospective analysis of other polymers and plastic additives. The mean concentrations of MNP particles with diameters of <10 μm and <2.5 μm in the laboratory were estimated to be 47 ± 5 and 27 ± 4 μg/m3, respectively. In the private residence, the estimated concentrations were 24 ± 3 and 16 ± 2 μg/m3. PS was the most abundant MNP type in both locations. Nontargeted screening revealed the presence of plastic additives, such as TDCPP (tris(1,3-dichloro-2-propyl)phosphate) whose abundance correlated with that of polyurethane (PU). This is consistent with their use as flame retardants in PU-based upholstered furniture and building insulation. This study provides evidence of indoor exposure to MNPs and underlines the need for further study of this route of exposure to MNPs and the plastic additives carried with them.

Nanotechnology in sustainable agriculture: A double-edged sword

Nanotechnology is a rapidly developing discipline that has the potential to transform the way we approach problems in a variety of fields, including agriculture. The use of nanotechnology in sustainable agriculture has gained popularity in recent years. It has various applications in agriculture, such as the development of nanoscale materials and devices to boost agricultural productivity, enhance food quality and safety, improve the efficiency of water and nutrient usage, and reduce environmental pollution. Nanotechnology has proven to be very beneficial in this field, particularly in the development of nanoscale delivery systems for agrochemicals such as pesticides, fertilizers, and growth regulators. These nanoscale delivery technologies offer various benefits over conventional delivery systems, including better penetration and distribution, enhanced efficacy, and lower environmental impact. Encapsulating agrochemicals in nanoscale particles enables direct delivery to the targeted site in the plant, thereby reducing waste and minimizing off-target effects. Plants are fundamental building blocks of all ecosystems and evaluating the interaction between nanoparticles (NPs) and plants is a crucial aspect of risk assessment. This critical review therefore aims to provide an overview of the latest advances regarding the positive and negative effects of nanotechnology in agriculture. It also explores potential future research directions focused on ensuring the safe utilization of NPs in this field, which could lead to sustainable development. © 2024 Society of Chemical Industry.

Advanced technologies for the determination of quantitative structure-activity relationships and degradation efficiency of micropollutants and their removal in water - A review

The growing concentrations of micropollutants in aquatic ecosystems are a global water quality issue. Understanding micropollutants varied chemical composition and potency is essential to solving this complex issue. Micropollutants management requires identifying contaminants to reduce, optimal reduction targets, and the best wastewater recycling locations. Management requires appropriate technological measures. Pharmaceuticals, antibiotics, hormones, and other micropollutants can enter the aquatic environment from point and diffuse sources, with wastewater treatment plants (WWTPs) distributing them in urban areas. Micropollutants like pharmaceuticals and hormones may not be removed by conventional WWTPs. Micropollutants affect the EU, especially in densely populated areas where surface water is consumed. This review examines several technological options that can be integrated into existing treatment methods to address this issue. In this work, oxidation, activated carbon, and their combinations as potential solutions, considering their efficacy and cost were evaluated. This study illuminates micropollutants origin and physico-chemical properties, which affect distribution, persistence, and environmental impacts. Understanding these factors helps us develop targeted micropollutant mitigation strategies to protect water quality. This review can inform policy and decision-making to reduce micropollutant impacts on aquatic ecosystems and human health.

Micro (nano) plastics uptake, toxicity and detoxification in plants: Challenges and prospects

Plastic pollution has emerged as a global challenge affecting ecosystem health and biodiversity conservation. Terrestrial environments exhibit significantly higher plastic concentrations compared to aquatic systems. Micro/nano plastics (MNPs) have the potential to disrupt soil biology, alter soil properties, and influence soil-borne pathogens and roundworms. However, limited research has explored the presence and impact of MNPs on aquaculture systems. MNPs have been found to inhibit plant and seedling growth and affect gene expression, leading to cytogenotoxicity through increased oxygen radical production. The article discusses the potential phytotoxicity process caused by large-scale microplastics, particularly those unable to penetrate cell pores. It also examines the available data, albeit limited, to assess the potential risks to human health through plant uptake.

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

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

Analytical challenges in detecting microplastics and nanoplastics in soil-plant systems

Microplastics (MPx) and nanoplastics (NPx) are increasingly accumulating in terrestrial ecosystems, heightening concerns about their potential adverse effects on human health via the food chain. Techniques aimed at recovering the most challenging colloidal fractions of MPx and NPx, especially for analytical purposes, are limited. This systematic review emphasises the absence of a universal, efficient, and cost-effective analytical method as the primary hindrance to studying MPx and NPx in soil and plant samples. The study reveals that several methods, including density separation, organic matter removal, and filtration, are utilized to detect MPx or NPx in soil through vibrational spectroscopy and visual identification. Instruments such as Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, and fluorescence microscopy are employed to identify MPx and NPx in plant tissue. In extraction procedures, organic solvents and sonication are used to isolate NPx from plant tissues, while Pyrolysis GC-MS quantifies the plastics. SEM and TEM serve to observe and characterize NPx within plant tissues. Additionally, FTIR and fluorescence microscopy are utilized to identify polymers of MPx and NPx based on their spectral characteristics and fluorescence signals. The findings from this review clarify the identification and quantification methods for MPx and NPx in soil and plant systems and provide a comprehensive methodology for assessing MPx/NPx in the environment.

A critical review on nanoplastics and its future perspectives in the marine environment

Nanoplastics (plastic particles smaller than 1 μm) are the least-known type of marine litter. Nanoplastics (NPs) have attracted much interest in recent years because of their prevalence in the environment and the potential harm they can cause to living organisms. This article focuses on understanding NPs and their fate in the marine environment. Sources of NPs have been identified, including accidental release from products or through nano-fragmentation of larger plastic debris. As NPs have a high surface area, they may retain harmful compounds. The presence of harmful additives in NPs poses unique practical challenges for studies on their toxicity. In this review, several methods specifically adapted for the physical and chemical characterization of NPs have been discussed. Furthermore, the review provides an overview of the translocation and absorption of NPs into organisms, along with an evaluation of the release of potential toxins from NPs. Further, we have provided an overview about the existing methods suggested for the possible degradation of these NPs. We conclude that the hazards of NPs are plausible but unknown, necessitating a thorough examination of NPs' sources, fate, and effects to better mitigate and spread awareness about this emerging contaminant.

Improvement of biodegradation of PET microplastics with whole-cell biocatalyst by interface activation reinforcement

Polyethylene terephthalate (PET) is an important basic polymer, which was used widely in variety of fields. Due to its high crystallinity, compact structure and strong surface hydrophobicity, PET has prominent resistance to biodegradation. In recent years, microplastics, especially polyethylene terephthalate (PET) microplastics, was considered as serious threaten to ecosystems. In this study, alkali-resistant bacteria were used as whole-cell catalysts to try to improve the biodegradation of PET microplastics by increasing the bio-interfacial activity of the polymer substrate. Surfactants were applicated to enhance interfacial activation of enzyme and PET interactions. And an integrated strategy was constructed based on alkali resistant bacteria to catalysis the hydrolysis of PET. The results showed that Tween 20 had the most obvious promoting effect among the four interfacial biocatalysts on biological-chemical combined hydrolysis of PET microplastics with whole-cell biocatalysts in alkaline environment. Obvious etching and fracture were observed on the PET fibre surface after biodegradation in presence of surfactant. The weight loss rate of PET substrate can reach 11.04% after 5 days of biodegradation. Thus, this research provides a promising method for efficient degradation of PET microplastics.

Recent advances in biodegradation of emerging contaminants - microplastics (MPs): Feasibility, mechanism, and future prospects

Plastics have become an essential part of life. When it enters the environment, it migrates and breaks down to form smaller size fragments, which are called microplastics (MPs). Compared with plastics, MPs are detrimental to the environment and pose a severe threat to human health. Bioremediation is being recognized as the most environmentally friendly and cost-effective degradation technology for MPs, but knowledge about the biodegradation of MPs is limited. This review explores the various sources of MPs and their migration behavior in terrestrial and aquatic environments. Among the existing MPs removal technologies, biodegradation is considered to be the best removal strategy to alleviate MPs pollution. The biodegradation potential of MPs by bacteria, fungi and algae is discussed. Biodegradation mechanisms such as colonization, fragmentation, assimilation, and mineralization are presented. The effects of MPs characteristics, microbial activity, environmental factors and chemical reagents on biodegradation are analyzed. The susceptibility of microorganisms to MPs toxicity might lead to decreased degradation efficiency, which is also elaborated. The prospects and challenges of biodegradation technologies are discussed. Eliminating prospective bottlenecks is necessary to achieve large-scale bioremediation of MPs-polluted environment. This review provides a comprehensive summary of the biodegradability of MPs, which is crucial for the prudent management of plastic waste.

Two genes related to apoptosis in the hepatopancreas of juvenile prawn, Macrobrachium nipponense: Molecular characterization and transcriptional response to nanoplastic exposure

Nanoplastics have been widely found in the global water environment, causing plastic pollution and affecting human beings and numerous organisms. Studies involving freshwater crustacean exposure to nanoplastics, however, are limited. In this study, juvenile prawns (Macrobrachium nipponense) were exposed to 75 nm polystyrene nanoplastics at different concentrations (0, 5, 10, 20, or 40 mg/L) for a 28-d chronic exposure experiment. To study the effects of exposure to nanoplastics on hepatopancreas cell apoptosis, C-Jun N-terminal kinase (JNK) and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) genes were selected, and hepatotoxic enzyme activities and Toll pathway- and apoptosis-related gene expression were determined. For the first time, full-length Mn-JNK and Mn-PIK3CA cDNAs were cloned from M. nipponense. Homologous comparisons showed that JNK and PIK3CA had conserved functional sequences. The apoptosis rate in the high-concentration nanoplastic group (40 mg/L) was significantly higher than in the low-concentration nanoplastic (5 mg/L) and control groups (0 mg/L). The alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl transpeptidase (GGT) and xanthine oxidase (XOD) enzyme activities in the hepatopancreas increased with exposure to higher concentrations of nanoplastics. In addition, the levels of apoptosis- and Toll pathway-related gene expression and JNK and PIK3CA gene expression were initially increased, then decreased with exposure to higher concentrations of nanoplastics. This study showed that polystyrene nanoplastics activate toll-related pathways leading to apoptosis and hepatopancreas damage, which provides theoretical support for future aquatic toxicological research.

Integrated fecal microbiome and metabolome analysis explore the link between polystyrene nanoplastics exposure and male reproductive toxicity in mice

Microplastics (MPs) and nanoplastics (NPs) are novel environmental pollutants that are ubiquitous in the environment and everyday life. NPs can easily enter the tissues and have more significant potential health risks due to their smaller diameter. Previous studies have shown that NPs can induce male reproductive toxicity, but the detailed mechanisms remain uncertain. In this study, intragastric administration treated mice with polystyrene NPs (PS-NPs, 50, and 90 nm) at 3 and 15 mg/mL/day doses for 30 days. Then, the fresh fecal samples were collected from those mice that the exposure doses of 50 nm PS-NPs at 3 mg/mL/day and 90 nm at 15 mg/mL/day for subsequent investigations of 16S rRNA and metabolomics according to significant toxicological effects (Sperm number, viability, abnormality, and testosterone level). The conjoint analysis findings indicated that PS-NPs disrupted the homeostasis of the gut microbiota, metabolism, and male reproduction, suggesting that abnormal gut microbiota-metabolite pathways may be important in PS-NPs-induced male reproductive toxicity. Meanwhile, the common differential metabolites such as 4-deoxy-Erythronic acid, 8-iso-15-keto-PGE2, apo-10'-violaxanthin, beta-D-glucosamine, isokobusone, oleamide, oxoadipic acid, sphingosine induced by 50 and 90 nm PS-NPs might be used as biomarkers to explore PS-NPs-induced male reproductive toxicity. In addition, this study systematically demonstrated that nano-scale PS-NPs induced male reproductive toxicity via the crosstalk of gut microbiota and metabolites. It also provided valuable insights into the toxicity of PS-NPs, which was conducive to reproductive health risk assessment for public health prevention and treatment.

Adverse health effects and mechanisms of microplastics on female reproductive system: a descriptive review

Microplastics (MPs), with a diameter of less than 5 mm, include polymers such as polystyrene, polypropylene, and polyethylene. The MPs occur in different morphologies including fragments, beads, fibers, and films that are swallowed by fresh water and land-based animals and enter their food chain, where they produce hazardous effects such as uterine toxicity, infertility, and neurotoxicity. The aim of this review is to explore the effects of polystyrene MPs (PS-MPs) on the female reproductive system and understand the mechanisms by which they produce reproductive toxicity. Several studies suggested that the exposure to PS-MPs increased the probability of larger ovaries with fewer follicles, decreased the number of embryos produced, and decreased the number of pregnancies in female mice. It also changed sex hormone levels and caused oxidative stress, which could have an impact on fertility and reproduction. Exposure to PS-MPs caused the death of granulosa cells through apoptosis and pyroptosis via activation of the NLRP3/caspase pathway and disruption of the Wnt-signaling pathway. Activation of TL4/NOX2 caused the uterine fibrosis resulting in endometrium thinning. The PS-MPs had a negative impact on ovarian capacity, oocyte maturation, and oocyte quality. Furthermore, the PS-MPs disrupted the hypothalamus-pituitary-gonadal axis in marine animals, resulting in a decrease in hatching rate and offspring body size, causing trans-generational effects. It also reduced fecundity and produced germ-line apoptosis. The main focus of this review was to explore the different mechanisms and pathways through which PS-MPs adversely impact the female reproductive system.

Effects of petroleum-based and biopolymer-based nanoplastics on aquatic organisms: A case study with mechanically degraded pristine polymers

Mismanaged plastic litter submitted to environmental conditions may breakdown into smaller fragments, eventually reaching nano-scale particles (nanoplastics, NPLs). In this study, pristine beads of four different types of polymers, three oil-based (polypropylene, PP; polystyrene, PS; and low-density polyethylene, LDPE) and one bio-based (polylactic acid, PLA) were mechanically broken down to obtain more environmentally realistic NPLs and its toxicity to two freshwater secondary consumers was assessed. Thus, effects on the cnidarian Hydra viridissima (mortality, morphology, regeneration ability, and feeding behavior) and the fish Danio rerio (mortality, morphological alterations, and swimming behavior) were tested at NPLs concentrations in the 0.001 to 100 mg/L range. Mortality and several morphological alterations were observed on hydras exposed to 10 and 100 mg/L PP and 100 mg/L LDPE, whilst regeneration capacity was overall accelerated. The locomotory activity of D. rerio larvae was affected by NPLs (decreased swimming time, distance or turning frequency) at environmentally realistic concentrations (as low as 0.001 mg/L). Overall, petroleum- and bio-based NPLs elicited pernicious effects on tested model organisms, especially PP, LDPE and PLA. Data allowed the estimation of NPLs effective concentrations and showed that biopolymers may also induce relevant toxic effects.

Polystyrene microplastics significantly facilitate influenza A virus infection of host cells

Microplastics (MPs) are emerging pollutants which exist in various environments and pose a potential threat to human health. However, the effect of MP on respiratory pathogens-infected organisms is unknown. In order to explore the effect of MP on respiratory pathogen infection, we studied the effect of polystyrene microplastics (PS) on influenza A virus (IAV)-infected A549 cells. Western blot, qPCR, and viral plaque assay demonstrated that PS could promote IAV infection. Further study by bioluminescence imaging showed that a large number of IAV could be enriched on PS and entered cells through endocytosis. Meanwhile, the expression of IFITM3 in cells was significantly reduced. In addition, our results showed that PS down-regulated IRF3 and its active form P-IRF3 by down-regulating RIG-I and inhibiting TBK1 phosphorylation activation, which then significantly reduced IFN-β expression and affected the cellular innate antiviral immune system. Taken together, our results indicate the potential threat of MPs to respiratory diseases caused by IAV and provide new insights into human health protection.

The risks of marine micro/nano-plastics on seafood safety and human health

A considerable mass of plastics has been released into the marine environment annually through different human activities, including industrial, agriculture, medical, pharmaceutical and daily care products. These materials are decomposed into smaller particles such as microplastic (MP) and nanoplastic (NP). Hence, these particles can be transported and distributed in coastal and aquatic areas and are ingested by the majority of marine biotas, including seafood products, thus causing the contamination of the different parts of aquatic ecosystems. In fact, seafood involves a wide diversity of edible marine organisms, such as fish, crustaceans, molluscs, and echinoderms, which can ingest the micro/nanoplastics particles, and then transmit them to humans through dietary consumption. Consequently, these pollutants can cause several toxic and adverse impacts on human health and the marine ecosystem. Therefore, this chapter provides information on the potential risks of marine micro/nanoplastics on seafood safety and human health.

Nano/micro-plastics: Sources, trophic transfer, toxicity to the animals and humans, regulation, and assessment

Being in an era of revolutionized production, consumption, and poor management of plastic waste, the existence of these polymers has resulted in an accumulation of plastic litter in nature. With macro plastics themselves being a major issue, the presence of their derivatives like microplastics which are confined to the size limitations of less than 5mm has ascended as a recent type of emergent contaminant. Even though there is size confinement, their occurrence is not narrowed and is extensively seen in both aquatic and terrestrial extents. The vast incidence of these polymers causing harmful effects on various living organisms through diverse mechanisms such as entanglement and ingestion have been reported. The risk of entanglement is mainly limited to smaller animals, whereas the risk associated with ingestion concerns even humans. Laboratory findings indicate the alignment of these polymers toward detrimental physical and toxicological effects on all creatures including humans. Supplementary to the risk involved with their presence, plastics also proceed as carters of certain toxic contaminants complemented during their industrial production process, which is injurious. Nevertheless, the assessment regarding the severity of these components to all creatures is comparatively restricted. This chapter focuses on the sources, complications, and toxicity associated with the presence of micro and nano plastics in the environment along with evidence of trophic transfer, and quantification methods.

Distribution and sources of microplastics in the Beibu Gulf using in-situ filtration technique

The Beibu Gulf is a vital link between China and the ASEAN nations, and microplastic contamination is rising due to fast growth, coastal life, fisheries, and mariculture. The abundance, distribution, and source analyses were conducted at 25 sample points for this study. According to this study, the average MPs was 0.25 ± 0.05 items/m³, ranging from 0.01 items/m³ to 0.89 items/m³. Fibers, white, cellulose, and 0.33-1 mm were abundant in shape, color, composition, and size, respectively. Multi-statistics-based source analysis indicated land-based inputs (packing materials, textile materials, fisheries, and mariculture) were dominant in the Beibu Gulf. In this study, we also acknowledged a comprehensive comparison and convenience between plankton pumps and other conventional designs to collect microplastic samples from water. We suggested that using a uniform design could elevate the data quality of microplastics.

Regenerated silk fibroin loaded with natural additives: a sustainable approach towards health care

According to World Health Organization (WHO), on average, 0.5 Kg of hazardous waste is generated per bed every day in high-income countries. The adverse effects imposed by synthetic materials and chemicals on the environment and humankind have urged researchers to explore greener technologies and materials. Amidst of all the natural fibers, silk fibroin (SF), by virtue of its superior toughness (6 × 10⁴∼16 × 10⁴ J/kg), tensile strength (47.2-67.7 MPa), tunable biodegradability, excellent Young's modulus (1.9-3.9 GPa), presence of functional groups, ease of processing, and biocompatibility has garnered an enormous amount of scientific interests. The use of silk fibroin conjoint with purely natural materials can be an excellent solution for the adverse effects of chemical-based treatment techniques. Considering this noteworthiness, vigorous research is going on in silk-based biomaterials, and it is opening up new vistas of opportunities. This review enswathes the structural aspects of silk fibroin along with its potency to form composites with other natural materials, such as curcumin, keratin, alginate, hydroxyapatite, hyaluronic acid, and cellulose, that can replace the conventionally used synthetic materials, providing a sustainable pathway to biomedical engineering. It was observed that a large amount of polar functional moieties present on the silk fibroin surface enables them to compatibilize easily with the natural additives. The conjunction of silk with natural additives initiates synergistic interactions that mitigate the limitations offered by individual units as well as enhance the applicability of materials. Further the current status and challenges in the commercialization of silk-based biomedical devices are discussed.

Single and composite damage mechanisms of soil polyethylene/polyvinyl chloride microplastics to the photosynthetic performance of soybean (Glycine max [L.] merr.)

INTRODUCTION

Adverse impacts of soil microplastics (MPs, diameter<5 mm) on vegetative growth and crop production have been widely reported, however, the single and composite damage mechanisms of polyethylene (PE) /polyvinyl chloride (PVC) microplastics (MPs) induced photosynthesis inhibition are still rarely known.

METHODS

In this study, two widely distributed MPs, PE and PVC, were added to soils at a dose of 7% (dry soil) to examine the single and composite effects of PE-MPs and PVC-MPs on the photosynthetic performance of soybean.

RESULTS

Results showed PE-MPs, PVC-MPs and the combination of these two contaminants increased malondialdehyde (MDA) content by 21.8-97.9%, while decreased net photosynthesis rate (Pn) by 11.5-22.4% compared to those in non-stressed plants, PVC MPs caused the most severe oxidative stress, while MPs stress resulted in Pn reduction caused by non-stomatal restriction. The reason for this is the single and composite MPs stress resulted in a 6% to 23% reduction in soybean PSII activity RCs reaction centers, along with negative effects on soybean PSII energy uptake, capture, transport, and dissipation. The presence of K-band and L-band also represents an imbalance in the number of electrons on the donor and acceptor side of PSII and a decrease in PSII energy transfer. Similarly, PVC single stress caused greater effects on soybean chloroplast PSII than PE single stress and combined stresses.

DISCUSSION

PE and PVC microplastic stress led to oxidative stress in soybean, which affected the structure and function of photosynthetic PSII in soybean, ultimately leading to a decrease in net photosynthetic rate in soybean.

Size-independent quantification of nanoplastics in various aqueous media using surfaced-enhanced Raman scattering

In this work, we successfully developed an intriguing preparation strategy to reduce the size-dependent effect of nanoplastics (NPLs), which is the limitation of NPLs quantification by surface-enhanced Raman scattering (SERS). This simple and low-cost technique enabled us to quantify different sizes (i.e., 100, 300, 600, and 800 nm) of polystyrene nanospheres (PS NSs) in various aqueous media. The SERS substrate was simply prepared by sputtering gold particles to cover on a glass cover slide. By dissolving PS NSs in toluene and preconcentrating by coffee-ring effect, SERS measurement can quantify NPLs at a very low concentration with a limit of detection (LOD) of approximately 0.10-0.26 μg/mL. The experiment was also conducted in the presence of interferences, including salts, sugars, amino acids, and detergents. The method was validated for quantitative analysis using a mixture of 100-, 300-, 600-, and 800-nm PS NSs in a ratio of 1:1:1:1 in real-world media (i.e., tap water, mineral water, and river water), which successfully approaches the evaluation of PS NSs in the range of 10-40 µg/mL with an LOD of approximately 0.32-0.52 µg/mL.

Spatiotemporal characterisation of microplastics in the coastal regions of Singapore

In the 21st century, plastic production continues to increase at an unprecedented rate, leading to the global issue of plastic pollution. In marine environments, a significant fraction of plastic litter are microplastics, which have a wide range of effects in marine ecosystems. Here, we examine the spatiotemporal distribution of microplastics along the Johor and Singapore Straits, at surface and at depth. Generally, more microplastics were recorded from the surface waters across both Straits. Fragments were the dominant microplastic type (70%), followed by film (25%) and fiber (5%). A total of seven colours of microplastics were identified, with clear microplastics as the most abundant (64.9%), followed by black (25.1%) and blue (5.5%). Microplastics under 500 μm in size accounted for 98.9%, followed by particles 500-1000 μm (1%) and 1-5 mm (0.1%). During the monsoon season, the abundance of microplastics across various sites were observed to be > 1.1 times when compared to the inter-monsoon period. Rainfall was a closely related to the increased microplastic abundance across various sites in the Singapore Strait. This suggests that weather variations during climate change can play critical roles in modulating microplastic availability. Beach sediments facing the Singapore Strait recorded an abundance of 13.1 particles/kg, with polypropylene fragments, polyethylene pellets and thermoplastic polyester foam identified via Fourier transform infrared spectroscopy. Hence, it is crucial to profile the spatiotemporal variation of microplastic abundance in both the surface and in the water column to gain a better understanding of the threat caused by microplastic pollution in the coastal regions of Singapore.

Does thermal stress modulate the biochemical and physiological responses of Ruditapes decussatus exposed to the progestin levonorgestrel?

In this study, we investigated the effects of 1000 ng/l levonorgestrel (LNG) alone or combined with increased temperature of 20, 24, and 28 °C on the biochemical and physiological responses of the clam (Ruditapes decussatus) for 28 days. Our results revealed that female clams treated with levonorgestrel (LNG) alone showed enhancement of the antioxidant defense against oxidative stress related to the inductions of catalase (CAT), gluthatione -S -transferase (GST), and protein sulfhydryl (PSH), while the elevated temperatures of 20, 24, and 28 °C diminished most of the specific responses to LNG and was the main factor in the determining the responses to combine exposures. The responses of lysosomal membrane stability, alkaline phosphatase, and NADP⁺-dependent isocitrate dehydrogenase detected were the most common signs of an adverse effect in all exposures. Female clams' testosterone and estradiol responses to LNG were the most particular manifestations depending on the exposure. Overall, these findings showed clearly that chronic warming stress caused disruption in physiological, biochemical parameters of the female clam R. decussatus, and this may have implications for the whole organism and populations.

Algae: a frontline photosynthetic organism in the microplastic catastrophe

Recalcitrancy in microplastics (MPs) contributes to white pollution. Bioremediation can remove MPs and facilitate environmental sustainability. Although recent studies have been conducted on the interaction of algae and MPs, the role of algae in MP removal with the simultaneous implementation of 'omics studies has not yet been discussed. Here, we review the adverse effects of MPs on the environment and possible approaches to remove them from the aquatic environment by using algae. We highlight the mechanism of MP biodegradation, the algal species that have been used, and how these are affected by MPs. We propose that algomics, characterization of biodegrading enzymes, and genetic engineering could be effective strategies for optimizing MP degradation.

Threats, challenges and sustainable conservation strategies for freshwater biodiversity

Increasing human population, deforestation and man-made climate change are likely to exacerbate the negative effects on freshwater ecosystems and species endangerment. Consequently, the biodiversity of freshwater continues to dwindle at an alarming rate. However, this particular topic lacks sufficient attention from conservation ecologists and policymakers, resulting in a dearth of data and comprehensive reviews on freshwater biodiversity, specifically. Despite the widespread awareness of risks to freshwater biodiversity, organized action to reverse this decline has been lacking. This study reviews prospective conservation and management strategies for freshwater biodiversity and their associated challenges, identifying current key threats to freshwater biodiversity. Engineered nanomaterials pose a significant threat to aquatic species, and will make controlling health risks to freshwater biodiversity increasingly challenging in the future. When fish are exposed to nanoparticles, the surface area of their respiratory and ion transport systems can decline to 60% of their total surface area, posing serious health risks. Also, about 50% of freshwater fish species are threatened by climate change, globally. Freshwater biodiversity that is heavily reliant on calcium perishes when the calcium content of their environments degrades, posing another severe threat to world biodiversity. To improve biodiversity, variables such as species diversity, population and water quality, and habitat are essential components that must be monitored continuously. Existing research on freshwater biota and ecosystems is still lacking. Therefore, data collection and the establishment of specialized policies for the conservation of freshwater biodiversity should be prioritized.

Removal of nanoplastics in water treatment processes: A review

Nanoplastics are drawing a significant attention as a result of their propensity to spread across the environment and pose a threat to all organisms. The presence of nanoplastics in water is given attention nowadays as the transit of nanoplastics occurs through the aquatic ecosphere besides terrestrial mobility. The principal removal procedures for macro-and micro-plastic particles are effective, but nanoparticles escape from the treatment, increasing in the water and significantly influencing the society. This critical review is aimed to bestow the removal technologies of nanoplastics from aquatic ecosystems, with a focus on the treatment of freshwater, drinking water, and wastewater, as well as the importance of transit and its impact on health concerns. Still, there exists a gap in providing a collective knowledge on the methods available for nanoplastics removal. Hence, this review offered various nanoplastic removal technologies (microorganism-based degradation, membrane separation with a reactor, and photocatalysis) that could be the practical/effective measures along with the traditional procedures (filtration, coagulation, centrifugation, flocculation, and gravity settling). From the analyses of different treatment systems, the effectiveness of nanoplastics removal depends on various factors, source, size, and type of nanoplastics apart from the treatment method adopted. Combined removal methods, filtration with coagulation offer great scope for the removal of nanoplastics from drinking water with >99 % efficiency. The collected data could serve as base-line information for future research and development in water nanoplastics cleanup.

The Impact of Metal Nanoparticles on Female Reproductive System: Risks and Opportunities

Humans have always been exposed to tiny particles via dust storms, volcanic ash, and other natural processes, and our bodily systems are well adapted to protect us from these potentially harmful external agents. However, technological advancement has dramatically increased the production of nanometer-sized particles or nanoparticles (NPs), and many epidemiological studies have confirmed a correlation between NP exposure and the onset of cardiovascular diseases and various cancers. Among the adverse effects on human health, in recent years, potential hazards of nanomaterials on female reproductive organs have received increasing concern. Several animal and human studies have shown that NPs can translocate to the ovary, uterus, and placenta, thus negatively impacting female reproductive potential and fetal health. However, NPs are increasingly being used for therapeutic purposes as tools capable of modifying the natural history of degenerative diseases. Here we briefly summarize the toxic effects of few but widely diffused NPs on female fertility and also the use of nanotechnologies as a new molecular approach for either specific pathological conditions, such as ovarian cancer and infertility, or the cryopreservation of gametes and embryos.

Micro- and nanoplastic contamination in livestock production: Entry pathways, potential effects and analytical challenges

The abundant and widespread presence of particulate plastics in the environment is considered an area of increasing environmental, animal and human health concern. Despite the abundance and the potential to cause deleterious biological effects, studies related to the impact of micro and nanoplastics (MNPs) on livestock animals are limited. This review evaluates the sources and entry pathways of particulate plastics in all the types of livestock production systems. The potential health effects of MNPs on mouse models, ruminant animals and a few other livestock animals are discussed. Since evaluation of MNPs in almost all types of matrices in hindered by analytical challenges, this review also evaluates the commonly used methods, emerging techniques, and quality control/quality assurance (QC/QA) procedures. Plastic mulching, fragmentation of plastic wastes and stream water runoff have been identified as major routes of MNPs entry in grazing-based and mixed livestock production systems. Notwithstanding the controlled indoor environment and relatively efficient waste management, MNPs have been detected in industrial livestock systems. The bioaccumulation and biomagnification of chemical toxicants can exacerbate the adverse effects of MNPs on higher trophic level species. Although there are several methods for the analysis of MNPs, dearth of standardized methods, certified reference materials, MPs standards, and global database libraries are major impediments. The adverse effects of MNPs on the internal organs of different livestock animals have to be studied using large sample sizes and without raising ethical concerns. Importantly, investigations on the accurate quantification of MNPs and its adverse effects in various livestock animals using rapid, cost-effective and robust analytical methods are required.

Presence of polystyrene microplastics in Cd contaminated water promotes Cd removal by nano zero-valent iron and ryegrass (Lolium Perenne L.)

Microplastics, as emerging contaminants, have attracted widespread attention for their increasing detection frequency in aquatic environment. It has been reported that microplastics may co-presence with heavy metals in water, which might have impact on heavy metals removal in water. Furthermore, the effects of microplastics on the co-remediation efficiency of plants with engineered nanomaterials are ambiguous. To this end, this study was dedicated to unveil the intrinsic effects of polystyrene microplastics (PSMPs) on the cadmium (Cd) removal efficiency by co-remediation of ryegrass (Lolium perenne L.) and three engineered nanomaterials, respectively were nano-zerovalent iron (nZVI), carboxymethylcellulose-modified-nZVI (C-nZVI) and sulfidated nZVI (S-nZVI). Significant changes were observed in Cd content, plant biomass, chlorophyll b and antioxidant enzymes. It was surprising to find that with the treatment of nZVI or C-nZVI, polystyrene microplastics would enter plants roots, and these plants were found to contain more Cd among all series. Accordingly, four possible mechanisms were proposed to explain why plants that observed the internalization of PSMPs contained more Cd. This work reveals the impact of coexisting microplastics in water on Cd remediation efficiency and provides new insights into the entry of polystyrene microplastics into plant roots.

Testing an Iron Oxide Nanoparticle-Based Method for Magnetic Separation of Nanoplastics and Microplastics from Water

Nanoplastic pollution is increasing worldwide and poses a threat to humans, animals, and ecological systems. High-throughput, reliable methods for the isolation and separation of NMPs from drinking water, wastewater, or environmental bodies of water are of interest. We investigated iron oxide nanoparticles (IONPs) with hydrophobic coatings to magnetize plastic particulate waste for removal. We produced and tested IONPs synthesized using air-free conditions and in atmospheric air, coated with several polydimethylsiloxane (PDMS)-based hydrophobic coatings. Particles were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) magnetometry, dynamic light scattering (DLS), X-ray diffraction (XRD) and zeta potential. The IONPs synthesized in air contained a higher percentage of the magnetic spinel phase and stronger magnetization. Binding and recovery of NMPs from both salt and freshwater samples was demonstrated. Specifically, we were able to remove 100% of particles in a range of sizes, from 2-5 mm, and nearly 90% of nanoplastic particles with a size range from 100 nm to 1000 nm using a simple 2-inch permanent NdFeB magnet. Magnetization of NMPs using IONPs is a viable method for separation from water samples for quantification, characterization, and purification and remediation of water.

Unraveling the hazardous impact of diverse contaminants in the marine environment: Detection and remedial approach through nanomaterials and nano-biosensors

Marine pollution is one of the most underlooked forms of pollution as it affects most aquatic lives and public health in the coastal area. The diverse form of the hazardous pollutant in the marine ecosystem leads the serious genetic level disorders and diseases which include cancer, diabetes, arthritis, reproductive, and neurological diseases such as Parkinson's, Alzheimer's, and several microbial infections. Therefore, a recent alarming study on these pollutants, the microplastics have been voiced out in many countries worldwide, it was even found to be in the human placenta. In recent times, nanomaterials have demonstrated their potential in the detection and remediation of sensitive contaminants. In this review, we presented a comprehensive overview of the source, and distribution of diverse marine pollution on both aquatic and human health by summarizing the concentration of diverse pollutions (heavy metals, pesticides, microbial toxins, and micro/nano plastics) in marine samples such as soil, water, and seafood. Followed by emphasizing its ecotoxicological impact on aquatic animal life and coastal public health. Also discussed are the applicability and advancements of nanomaterials and nano-based biosensors in the detection, prevention, and remediation of diverse pollution in the marine ecosystem.

Pyrolysis-GC-MS analysis of ingested polystyrene microsphere content in individual Daphnia magna

Microplastic (MP) pollution in the aquatic environment is a cause for increasing concern. However, analyzing MPs ingested by small organisms, such as zooplankton, is difficult because of the low content and small size of the ingested MPs. We attempted to determine the content of ingested MPs in individual zooplankton using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). To establish zooplankton model of MP ingestion, individual Daphnia magna were cultivated separately in microplate cells with polystyrene (PS) microspheres (10 μm in diameter, 245,000 particles, 135 μg) under different conditions. To prepare calibration curves for determining ingested PS content, approximately 100-150 μg of commercially available Daphnia-based powdered fish food, roughly corresponding to the weight of a single D. magna organism, was mixed with PS microspheres (0.005-26 μg) and analyzed using Py-GC-MS at 600 °C. In the resulting pyrograms, peaks of the styrene monomer and trimer from PS were detected, and linear relationships were obtained between the relative peak area and the amount of added PS. Finally, the cultivated zooplankton were individually subjected to Py-GC-MS analysis, and the ingested PS content in each zooplankton was successfully determined. Individual zooplankton cultured with PS in the absence of food ingested 2.3-7.9 μg of PS particles, whereas that in the presence of food (Chlorella vulgaris) ingested only 0.1-0.2 μg of PS particles. This result suggests that zooplankton might preferentially ingest ordinary food when both food and MPs are present, although further systematic studies are necessary to validate this observation.

Recent Advances in the Decontamination and Upgrading of Waste Plastic Pyrolysis Products: An Overview

Extensive research on the production of energy and valuable materials from plastic waste using pyrolysis has been widely conducted during recent years. Succeeding in demonstrating the sustainability of this technology economically and technologically at an industrial scale is a great challenge. In most cases, crude pyrolysis products cannot be used directly for several reasons, including the presence of contaminants. This is confirmed by recent studies, using advanced characterization techniques such as two-dimensional gas chromatography. Thus, to overcome these limitations, post-treatment methods, such as dechlorination, distillation, catalytic upgrading and hydroprocessing, are required. Moreover, the integration of pyrolysis units into conventional refineries is only possible if the waste plastic is pre-treated, which involves sorting, washing and dehalogenation. The different studies examined in this review showed that the distillation of plastic pyrolysis oil allows the control of the carbon distribution of different fractions. The hydroprocessing of pyrolytic oil gives promising results in terms of reducing contaminants, such as chlorine, by one order of magnitude. Recent developments in plastic waste and pyrolysis product characterization methods are also reported in this review. The application of pyrolysis for energy generation or added-value material production determines the economic sustainability of the process.

Micro (nano) plastics in wastewater: A critical review on toxicity risk assessment, behaviour, environmental impact and challenges

With millions of tonnes of plastic pollution generated every year, small-sized plastic particles, including micro- and nanoplastics, end up in freshwater systems. Due to the very small size and very large specific surface area of nanoplastics, they are known to be persistent and toxic in our environment. These particles are also known to react with other water-borne contaminants and cause acute toxicity in organisms. Nanoplastics are prone to biomagnification and can be transported to humans through various pathways. This study aims to contribute towards understanding the behaviour of nanoplastics in our environment, specifically through identification of various sources, detection techniques, toxicity estimation, health risk in humans, environmental fate, recovery and reuse, and future challenges and limitations. Detailed review on the toxic effects of nanoplastics on various organisms and their degradation rates in soil and water matrices are provided. The suitability of small- and large-scale separation techniques for the removal of nanoplastics in wastewater treatment plants is also discussed. Current challenges and future perspectives in understanding the fate and transport of nanoplastics in the environment are also discussed. Research gaps, including the development of quantification techniques, estimation of degradation mechanisms, transport in marine ecosystems, and development of sensors to examine nanoplastics in the environment, are explored. Finally, we can limit the release of nanoplastics to the environment through reduction, reuse and recycling (3 Rs) of bulk plastic products.

Green approaches in synthesising nanomaterials for environmental nanobioremediation: Technological advancements, applications, benefits and challenges

Green synthesis approaches of nanomaterials (NMs) have received considerable attention in recent years as it addresses the sustainability issues posed by conventional synthesis methods. However, recent works of literature do not present the complete picture of biogenic NMs. This paper addresses the previous gaps by providing insights into the stability and toxicity of NMs, critically reviewing the various biological agents and solvents required for synthesis, sheds light on the factors that affect biosynthesis, and outlines the applications of NMs across various sectors. Despite the advantages of green synthesis, current methods face challenges with safe and appropriate solvent selection, process parameters that affect the synthesis process, nanomaterial cytotoxicity, bulk production and NM morphology control, tedious maintenance, and knowledge deficiencies. Consequently, the green synthesis of NMs is largely trapped in the laboratory phase. Nevertheless, the environmental friendliness, biocompatibility, and sensitivities of the resulting NMs have wider applications in biomedical science, environmental remediation, and consumer industries. To the scale-up application of biogenic NMs, future research should be focused on understanding the mechanisms of the synthesis processes, identifying more biological and chemical agents that can be used in synthesis, and developing the practicality of green synthesis at the industrial scale, and optimizing the factors affecting the synthesis process.

Separation and identification of nanoplastics in tap water

Microplastics pollution in freshwater has attracted global attentions, but when microplastics are broken into nanoplastics, they may present higher toxicity mainly due to their greater potential to cross biological membranes. So far almost no work has been done on the separation and identification of nanoplastics in tap water. Herein we removed large particles from tap water by 0.45 μm filter and then sequentially screened nanoparticles in filtrate by Anopore with pore size of 200, 100, and 20 nm, the most frequent particle sizes of which concentrate at 255 nm, 148 nm, and 58 nm, respectively. Based on characterization of FTIR, AFM-IR and Pyr-GC/MS, the polymers were identified to be polyolefins, polystyrene, polyvinyl chloride, polyamide, and some plastic additives. The abundance of nanoplastics with the most frequent particle sizes in range of 58-255 nm was 1.67-2.08 μg/L in tap water. This work provides a feasible method for separation and identification of nanoplastics in tap water, and manifests the existence of nanoplastics, which poses a potential threat to the health of residents.

SARS-CoV-2 variants and environmental effects of lockdowns, masks and vaccination: a review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.

Influence of polystyrene microplastics on levofloxacin removal by microalgae from freshwater aquaculture wastewater

Chlorella vulgaris (C. vulgaris) has attracted widespread attention because of its ability to absorb, enrich, and degrade typical endocrine-disrupting antibiotics (such as levofloxacin) in aquaculture wastewater. However, microplastic pollution in wastewater, which is becoming an increasingly severe problem, will exert a toxic effect on aquatic organisms (such as C. vulgaris and other microalgae). Polystyrene microplastics (PS-MPs), which are commonly found in freshwater aquaculture wastewater, are the most harmful. Therefore, clarifying the effects of PS-MPs on the ability of C. vulgaris to degrade typical endocrine-disrupting antibiotics in freshwater aquaculture wastewater and determining the mechanism of the effect are particularly important. The results of this study showed that under the stress of PS-MPs, the growth of C. vulgaris was significantly inhibited; the EPS-polysaccharide content per algal cell, EPS adsorption, intracellular enrichment and degradation of levofloxacin, total CYP450 content, and total CYP450 activity all decreased; and the relative expression of key genes related to the metabolic activity of algal cells, such as psbA, psaB, and rbcL, was generally downregulated. PS-MPs mainly affected the removal of a typical endocrine-disrupting antibiotic by C. vulgaris by altering adsorption, enrichment, and enzyme degradation. The results provide a reference for research on the impact of microplastic pollution on the treatment of freshwater aquaculture wastewater.

Micro/nano-plastics occurrence, identification, risk analysis and mitigation: challenges and perspectives

Micro/nanoplastics (MP/NPs) are emerging global pollutants that garnered enormous attention due to their potential threat to the ecosystem in virtue of their persistence and accumulation. Notably, United Nations Environment Programme (UNEP) yearbook in 2014 proposed MPs as one among ten emergent issues that the Earth is facing today. MP/NPs can be found in most regularly used products (primary microplastics) or formed by the fragmentation of bigger plastics (secondary microplastics) and are inextricably discharged into the environment by terrestrial and land-based sources, particularly runoff. They are non-degradable, biologically incompatible, and their presence in the air, soil, water, and food can induce ecotoxicological issues and also a menace to the environment. Due to micro size and diverse chemical nature, MP/NPs easily infiltrate wastewater treatment processes. This communication reviews the current understanding of MP/NPs occurrence, mobility, aggregation behavior, and degradation/assimilation in terrestrial, aquatic (fresh & marine), atmospheric depositions, wetlands and trophic food chain. This communication provide current perspectives and understanding on MP/NPs concerning (1) Source, occurrence, distribution, and properties (2) Impact on the ecosystem and its services, (3) Techniques in detection and identification and (4) Strategies to manage and mitigation.

Presence and Characterization of Microplastics in Coastal Fish around the Eastern Coast of Thailand

Marine microplastic has been in the limelight recently. This study aimed to describe microplastic types ingested by 274 fish from Thailand’s eastern coast in 2020 and to compare the microplastic content among different feeding traits. The microplastics in the gastrointestinal tracts and gills were extracted, analyzed, and identified using FT-IR spectroscopy. Approximately 13.14% of the total specimen ingested microplastics, with an average of 0.14 items per individual. The detection frequency of microplastics was relatively high compared with other regions in Thailand but relatively low compared to global standards. Of the microplastic contaminated specimens, 56.41% had at least one piece of microplastic in their gastrointestinal tract. Pelagic (14.47%) species were found to have ingested more microplastics than the demersal (12.63%) group. Dominant aspects found included PET (as in polymers), fiber (as in shape), and black (as in color). However, microplastic numbers fluctuated with the size, weight, and feeding behavior of fish. This result suggested that the pelagic has a higher exposure risk and microplastic ingestion in relatively small quantities in a range of fish species. Our results indicated that the occurrence of microplastics in fish is not influenced by organism habitat or trophic level, although the characteristics of pelagic fish might significantly increase the chance of exposure to microplastics in pelagic species.

Catalytic and Physicochemical Evaluation of a TiO2/ZnO/Laccase Biocatalytic System: Application in the Decolorization of Azo and Anthraquinone Dyes

A TiO₂/ZnO oxide system was proposed as a support for the immobilization of laccase from Trametes versicolor (LTV). The obtained TiO₂/ZnO/LTV biocatalytic system was then applied in the decolorization/degradation of C.I. Reactive Black 5 and C.I. Acid Green 25 dyes. The efficiency of immobilization was evaluated based on catalytic properties (Bradford method, oxidation reaction of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and physicochemical (spectroscopic, porous, electrokinetic) analysis. The immobilization process was carried out with high performance (99.4%). Immobilized laccase retained about 40% of its activity in the whole analyzed temperature range and after 10 reaction cycles. Immobilization efficiency was also indirectly confirmed by the presence of characteristic functional groups (–C–H and –C–O), nitrogen and carbon on the TiO₂/ZnO/LTV biocatalytic surface, identified by spectroscopic analyses. The increase in the surface area to 126 m²/g, change of isoelectric point (2.0) and zeta potential ranges (from +12.0 to −20.0 mV) after the immobilization process were also observed. The results show that the designed biocatalytic system enables the removal of acid dyes (C.I. Reactive Black 5 and C.I. Acid Green 25) with high efficiency (99% and 70%, respectively). Mass spectroscopy analysis indicated possible degradation products formed by the cleavage of N=N and C–N bonds.

Micro (nano) plastic pollution: The ecological influence on soil-plant system and human health

Global plastic pollution has been a serious problem since many years and micro (nano) plastics (MNPs) have gained attention from researchers around the world. This is because MNPs able to exhibit toxicology and interact with potentially toxic elements (PTEs) in the environment, causing soil toxicity. The influences of MNPs on the soil systems and plant crops have been overlooked despite that MNPs can accumulate in the plant root system and generate detrimental impacts to the terrestrial environments. The consumption of these MNPs-contaminated plants or fruits by humans and animals will eventually lead to health deterioration. The identification and measurement of MNPs in various soil samples is challenging, making the understanding of the fate, environmental and ecological of MNPs in terrestrial ecosystem is limited. Prior to sample assessment, it is necessary to isolate the plastic particles from the environment samples, concentrate the plastic particles for analysis purpose to meet detection limit for analytical instrument. The isolation and pre-concentrated steps are challenging and may cause sample loss. Herein, this article reviews MNPs, including their fate in the environment and toxic effects exhibited towards soil microorganisms, plants and humans along with the interaction of MNPs with PTEs. In addition, various analysis methods of MNPs and management of MNPs as well as the crucial challenges and future research studies in combating MNPs in soil system are also discussed.