Toxicological impacts of micro(nano)plastics in the benthic environment

Oxidative and metabolic responses in Crassostrea gasar under combined stressors of elevated temperature and microplastic exposure

This study investigates two critical threats to species such as the oyster Crassostrea gasar: elevated temperatures and microplastic (MP) contamination. To assess the combined effects of MP and temperature, oysters were exposed to different temperatures (20 °C, 26 °C, and 28 °C, with 20 °C considered the control group) and to a nominal concentration of 100 μg/L of MP (spherical polystyrene, 1.1 μm) at the same temperatures for 7 days. Oxidative stress parameters were analyzed, including the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST), as well as glutathione (GSH) levels and lipid peroxidation. Additionally, energy metabolism indicators, such as glucose and lactate levels and lactate dehydrogenase activity, were evaluated, along with the accumulation of MP in the gills and digestive glands of oysters. The results showed that regardless of temperature both gills and digestive gland accumulated MP. Besides, the thermal stress increased GST activity in both tissues and altered GSH levels. At the highest temperature, MP exposure led to increased SOD activity in the gills and decreased CAT activity in the digestive gland. GST activity was elevated in oysters exposed to MP at 20 °C, alongside higher GSH levels. At 26 °C, glucose and lactate levels, as well as lactate dehydrogenase activity, were significantly elevated. Co-exposure to MP notably affected oysters at 26 °C, reducing glucose levels in the gills while increasing them in the digestive gland. The Integrated Biomarker Response (IBR) index revealed that co-exposure had a more pronounced impact on the gills than on the digestive gland. Overall, this study underscores how a commercially important oyster species could be adversely affected by the combined impacts of global warming and MP contamination.

Ocean current modulation of the spatial distribution of microplastics in the surface sediments of the Beibu Gulf, China

Microplastic pollution, a major global environmental issue, is gaining heightened attention worldwide. Marginal seas are particularly susceptible to microplastic contamination, yet data on microplastics in marine sediments remain scarce, especially in the Beibu Gulf. This study presents a large-scale investigation of microplastics in the surface sediments of the Beibu Gulf to deciphering their distribution, sources and risk to marginal seas ecosystems. The results reveal widespread microplastic contamination, with an average abundance of 391 ± 27 items/kg in sediments. The spatial variability of microplastic abundance was significant, with lower levels in the western Beibu Gulf and higher concentrations in the northeastern and southeastern regions. The spatial distribution of microplastics was largely driven by geological features, hydrodynamic conditions, and human activity, with minimal influence from local environmental factors such as water depth, sediment grain size, organic carbon content, and sediment types. The pollution load index (PLI) suggests a low level of microplastic contamination, but the polymer hazard index (PHI) identified a high ecological risk, likely due to the presence of PVC, a polymer with higher chemical toxicity. Our findings highlight the significant role of hydrodynamic processes in determining microplastic distribution in the Beibu Gulf. These insights enhance our understanding of microplastic dispersal and its governing factors in semi-enclosed marginal seas, providing foundation for targeted pollution control strategies.

Review of mayflies (Insecta Ephemeroptera) as a bioindicator of heavy metals and microplastics in freshwater

Heavy metal and microplastic pollutions are prevalent in freshwater ecosystems, with many freshwater bodies being contaminated by one or both of these pollutants. Recent studies reported extreme detections of Cd, Pb and Zn, high concentrations of Cr, Pb and Cu and microplastics acting as vectors of pollutants, including heavy metals. Mayflies can serve as bioindicators of heavy metal contamination in freshwater ecosystems because changes in their community structure, physiology, and behaviour can reflect and help predict the concentrations of metals in these environments. This review discusses the ecological alterations induced by tissue metal concentration in mayflies and other macroinvertebrates. As sensitive taxa to heavy metal contamination, mayflies can reflect the impacts of this pollution through their ethology and relationship to the substrate, highlighting issues such as eutrophication, alterations in community structure, inhibitory effects and sediment toxicity. Mayflies are also highly affected by microplastic exposure, which leads to ingestion, bioaccumulation, biomagnification, habitat and community alteration, behavioural changes, physiology alteration and toxicity. Mayflies bioindication metrics for assessing the impact of heavy metals and microplastics include the examination of community alteration, functional feeding behaviour, molecular structure, dietary and toxicity impacts, bioaccumulation and biomagnification and biomarkers. Current challenges for the utilization of mayflies as bioindicators include temporal variations in sensitivity, lack of universally recognised protocols and need for standardised protocols for microplastic analysis. Additionally, the applicability of mayflies as bioindicators may vary across different ecosystems, emphasising the need for selecting suitable indicators that align with the unique characteristics of the ecosystem.

Bioaccumulation and biochemical impact of polyethylene terephthalate microplastics in Cipangopaludina chinensis: Tissue-specific analysis and homeostasis disruption

Microplastics are a novel pollutant that adversely affect freshwater benthic organisms. However, few studies have investigated the mechanism underlying the bioaccumulation and the toxicity of microplastics. In this study, microplastics bioaccumulation of wild Cipangopaludina chinensis in the Songhua River were utilized, and a 28-day aquatic toxicity test was performed to determine the effects of exposure to polyethylene terephthalate (PET), the bioaccumulation of PET, and changes in multiple biomarkers in the muscle, gill, and kidney tissues. The concentration pattern of microplastics was as follows: kidney tissue > muscle tissue > gill tissue. Microplastic ingestion caused AChE inhibition led to significant increases in redox and energy metabolism indicators. Furthermore, the IBR analysis presented a "response-resistance-breakdown" process, indicating that Cipangopaludina chinensis possessed resistance with time (D14 and D21) and concentration (0.10 mg/L and 1.00 mg/L) thresholds. Tissue sensitivity to microplastics was ranked as gill > muscle > kidney, which was the opposite order of microplastic accumulation. These findings implied that less sensitive tissues stored a larger amount of pollutants, suggesting a reduction in tissue sensitivity to microplastics with higher microplastic occurrence rates. This study provides new insights into biological resistance to pollutant stress, warranting further investigation into the underlying mechanisms.

Micro(nano)plastic and Related Chemicals: Emerging Contaminants in Environment, Food and Health Impacts

Microplastic pollution is a problem of increasing concern in food, and while food safety issues around the world are serious, an increasing number of food safety issues related to microplastics have become the focus of people's attention. The presence of microplastics in food is a worldwide problem, and they are present in all kinds of foods, foods of both animal and plant origin, food additives, drinks, plastic food packaging, and agricultural practices. This can cause problems for both humans and the environment. Microplastics have already been detected in human blood, heart, placenta, and breastmilk, but their effects in humans are not well understood. Studies with mammals and human cells or organoids have given perspective about the potential impact of micro(nano)plastics on human health, which affect the lungs, kidneys, heart, neurological system, and DNA. Additionally, as plastics often contain additives or other substances, the potentially harmful effects of exposure to these substances must also be carefully studied before any conclusions can be drawn. The study of microplastics is very complex as there are many factors to account for, such as differences in particle sizes, constituents, shapes, additives, contaminants, concentrations, etc. This review summarizes the more recent research on the presence of microplastic and other plastic-related chemical pollutants in food and their potential impacts on human health.

Evidence of size-dependent toxicity of polystyrene nano- and microplastics in sea cucumber Apostichopus japonicus (Selenka, 1867) during the intestinal regeneration

Microplastics are ubiquitous pollutants in the global marine environment. However, few studies have adequately explored the different toxic mechanisms of microplastics (MPs) and nanoplastics (NPs) in aquatic organisms. The sea cucumber, Apostichopus japonicus, is a key organism in the marine benthic ecosystem due to its crucial roles in biogeochemical cycles and food web. This study investigated the bioaccumulation and adverse effects of polystyrene micro- and nanoplastics (PS-M/NPs) of different sizes (20 μm, 1 μm and 80 nm) in the regenerated intestine of A. japonicus using multi-omics analysis. The results showed that after 30-day exposure at the concentration of 0.1 mg L-1, PS-MPs and PS-NPs accumulated to 155.41-175.04 μg g-1 and 337.95 μg g-1, respectively. This excessive accumulation led to increased levels of antioxidases (SOD, CAT, GPx and T-AOC) and reduced activities of immune enzymes (AKP, ACP and T-NOS), indicating oxidative damage and compromised immunity in the regenerated intestine. PS-NPs had more profound negative impacts on cell proliferation and differentiation compared to PS-MPs. Transcriptomic analysis revealed that PS-NPs primarily affected pathways related to cellular components, e.g., ribosome, and oxidative phosphorylation. In comparison, PS-MPs had greater influences on actin-related organization and organic compound metabolism. In the PS-M/NPs-treated groups, differentially expressed metabolites were mainly amino acids, fatty acids, glycerol phospholipid, and purine nucleosides. Additionally, microbial community reconstruction in the regenerated intestine was severely disrupted by the presence of PS-M/NPs. In the PS-NPs group, Burkholderiaceae abundance significantly increased while Rhodobacteraceae abundance decreased. Correlation analyses demonstrated that intestinal regeneration of A. japonicus was closely linked to its enteric microorganisms. These microbiota-host interactions were notably affected by different PS-M/NPs, with PS-NPs exposure causing the most remarkable disruption of mutual symbiosis. The multi-omic approaches used here provide novel insights into the size-dependent toxicity of PS-M/NPs and highlight their detrimental effects on invertebrates in M/NPs-polluted marine benthic ecosystems.

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

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

Research Progress on Micro(nano)plastic-Induced Programmed Cell Death Associated with Disease Risks

Due to their robust migration capabilities, slow degradation, and propensity for adsorbing environmental pollutants, micro(nano)plastics (MNPs) are pervasive across diverse ecosystems. They infiltrate various organisms within different food chains through multiple pathways including inhalation and dermal contact, and pose a significant environmental challenge in the 21st century. Research indicates that MNPs pose health threats to a broad range of organisms, including humans. Currently, extensive detection data and studies using experimental animals and in vitro cell culture indicate that MNPs can trigger various forms of programmed cell death (PCD) and can induce various diseases. This review provides a comprehensive and systematic analysis of different MNP-induced PCD processes, including pyroptosis, ferroptosis, autophagy, necroptosis, and apoptosis, based on recent research findings and focuses on elucidating the links between PCD and diseases. Additionally, targeted therapeutic interventions for these diseases are described. This review provides original insights into the opportunities and challenges posed by current research findings. This review evaluates ways to mitigate various diseases resulting from cell death patterns. Moreover, this paper enhances the understanding of the biohazards associated with MNPs by providing a systematic reference for subsequent toxicological research and health risk mitigation efforts.

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

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

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.

Insights into short chain polyethylene penetration of phospholipid bilayers via atomistic molecular dynamics simulations

The escalation of global plastic production, reaching an annual output of 400 million tons, has significantly intensified concerns regarding plastic waste management. This has been exacerbated by improper recycling and disposal practices, contributing to the impending crisis of plastic pollution. Predictions indicate that by 2025, the environment will bear the burden of over ten billion metric tons of accumulated plastic waste. This situation has led to the concerning release of microplastics and nanoplastics (NPs) into the environment as plastic materials degrade, thereby posing risks to both ecosystems and human health. Nanoparticle interactions with living organisms have garnered significant attention due to their potential to disrupt vital biological processes. Of particular interest are lipid membranes, acting as crucial gatekeepers, underscoring the importance of comprehending the intricate process of NP penetration. Molecular dynamics (MD) simulations serve as a robust tool, offering molecular-level insights into these intricate interactions. In this study, we leverage all-atom MD simulations to delve into the interactions between lipid bilayers and polyethylene (PETH) chains of varying lengths. The investigation spans diverse lipid bilayer compositions-ranging from pure POPC to POPC:DPPC mixtures-revealing how PETH accommodates itself, adopts extended conformations, and influences membrane structure and ordering. Significantly, while longer PETH chains demonstrate limited passive diffusion, their potential to penetrate bilayers over extended timescales emerges as a significant revelation. Overall, this research significantly advances our comprehension of NP-membrane interactions, shedding light on the potential environmental and health implications that lie ahead.

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

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

Phthalates contamination in sediments: A review of sources, influencing factors, benthic toxicity, and removal strategies

Sediments provide habitat and food for benthos, and phthalates (PAEs) have been detected in numerous river and marine sediments as a widely used plastic additive. PAEs in sediments is not only toxic to benthos, but also poses a threat to pelagic fish and human health through the food chain, so it is essential to comprehensively assess the contamination of sediments with PAEs. This paper presents a critical evaluation of PAEs in sediments, which is embodied in the analysis of the sources of PAEs in sediments from multiple perspectives. Biological production is indispensable, while artificial synthesis is the most dominant, thus the focus was on analyzing the industrial and commercial sources of synthetic PAEs. In addition, since the content of PAEs in sediments varies, some factors affecting the content of PAEs in sediments are summarized, such as the properties of PAEs, the properties of plastics, and environmental factors (sediments properties and hydrodynamic conditions). As endocrine disruptors, PAEs can produce toxicity to its direct contacts. Therefore, the effects of PAEs on benthos immunity, endocrinology, reproduction, development, and metabolism were comprehensively analyzed. In addition, we found that reciprocal inhibition and activation of the systems lead to genotoxicity and apoptosis. Finally, the paper discusses the feasible measures to control PAEs in wastewater and leachate from the perspective of source control, and summarizes the in-situ treatment measures for PAEs contamination in sediments. This paper provides a comprehensive review of PAEs contamination in sediments, toxic effects and removal strategies, and provides an important reference for reducing the contamination and toxicity of PAEs to benthos.

The invisible Threat: Assessing the reproductive and transgenerational impacts of micro- and nanoplastics on fish

Micro- and nanoplastics (MNPs), emerging as pervasive environmental pollutants, present multifaceted threats to diverse ecosystems. This review critically examines the ability of MNPs to traverse biological barriers in fish, leading to their accumulation in gonadal tissues and subsequent reproductive toxicity. A focal concern is the potential transgenerational harm, where offspring not directly exposed to MNPs exhibit toxic effects. Characterized by extensive specific surface areas and marked surface hydrophobicity, MNPs readily adsorb and concentrate other environmental contaminants, potentially intensifying reproductive and transgenerational toxicity. This comprehensive analysis aims to provide profound insights into the repercussions of MNPs on fish reproductive health and progeny, highlighting the intricate interplay between MNPs and other pollutants. We delve into the mechanisms of MNPs-induced reproductive toxicity, including gonadal histopathologic alterations, oxidative stress, and disruptions in the hypothalamic-pituitary-gonadal axis. The review also underscores the urgency for future research to explore the size-specific toxic dynamics of MNPs and the long-term implications of chronic exposure. Understanding these aspects is crucial for assessing the ecological risks posed by MNPs and formulating strategies to safeguard aquatic life.

Exposure to polystyrene nanoplastics and PCB77 induced oxidative stress, histopathological damage and intestinal microbiota disruption in white hard clam Meretrix lyrata

The toxic effects of organic pollutants and nanoplastics on fish have been extensively studied, but there is limited research available on their combined toxicity to bivalves. This research aimed to investigate the accumulation and ecotoxicological impacts such as antioxidant capacity, histopathology and intestinal microbiota in white hard clam Meretrix lyrata, resulting from 7 days of single and mixture exposure to 3,3',4,4'-tetrachlorobiphenyl (PCB77, 0.1 mg/L) and polystyrene nanoplastics (PS-NPs, 80 nm, 1 mg/L). Our findings revealed that PS-NPs accumulated in various tissues such as the intestine, gill, mantle, foot, and siphon. And when compared to the PCB-PSNPs (PP) co-exposure group, the intestinal fluorescence intensity mediated by plastic particles in the PS-NPs (PS group) was significantly higher. The gill, digestive gland, and intestine were all damaged to varying extent by single exposure to PS-NPs or PCB77, according to histopathological analysis, which was aggravated by PP group. Moreover, the co-exposure induced a higher level of oxidative stress, which reflected by increase of activities of superoxide dismutase, catalase, glutamate oxaloacetate transaminase and glutamic-pyruvic transaminase and malondialdehyde content. In addition, the intestine microbial composition was dramatically altered by the combined exposure, reducing the abundance of probiotics such as Firmicutes, thereby posing a great threat to the health and metabolism of M. lyrata. In conclusion, our findings showed that PS-NPs and PCB77 co-exposure induced a higher toxicity to M. lyrata, including histopathological changes, altered antioxidant capacity and intestinal microbiota disruption. This study provides novel insights into PCB77 and PS-NPs' combined toxicity to marine organisms and its underlying molecular mechanisms of ecotoxicological effects.

Microplastic pollution in water environment of typical nature reserves and scenery districts in southern China

Microplastics were frequently detected in the ocean, freshwater environment and wastewater treatment plants. This study aims to fill up the knowledge gap of microplastic distribution in nature reserves and scenery districts. Microplastic samples were collected, the distribution characteristics were analyzed with a stereoscopic microscope and a Fourier transform infrared spectrometer, and the ecological risks of microplastic pollution were calculated. Microplastics were detected in all the collected water samples and the average abundances of microplastics in the surface water of eleven investigated nature reserves and scenery districts ranged from 542 to 5500 items/m3. The degrees of microplastic pollution of all the surveyed nature reserves and scenery districts were classified as hazard level I. Fiber microplastics represented the largest average proportion (67.4 %) and 91.7 % of the detected microplastics were smaller than 2 mm. Corresponding to the frequent detection of fiber microplastics, cotton was the most abundant (25.5 %) polymer type of the suspected microplastics, followed by polyamide (PA, 20.6 %), polyester (PET, 17.0 %), and cellulose (15.6 %). For the ecological risk of the microplastic polymers, six, two and three nature reserves and scenery districts were defined to be at hazard level I, II and III, respectively. In brief, microplastic pollution occurred in all the surveyed nature reserves/scenery districts and posed different degrees of ecological risks.

Uptake, accumulation and translocation of traditional and novel organophosphate esters by rice seedlings in the presence of micro(nano)-polystyrene plastics: Effects of concentration and size of particles

Micro(nano)plastics (MNPs) and organophosphate esters (OPEs) are becoming ubiquitous as emerging pollutants. To data, the effects of MNPs on the uptake, accumulation and translocation of OPEs by rice plant are still unclear, especially for novel OPE species. In this study, the impacts of polystyrene MNPs of different sizes and concentrations on the uptake of eight OPEs (six traditional organophosphate triesters and two novel discovered aryl organophosphate triesters) by rice seedlings were investigated in hydroponic exposure experiments. The results showed that OPEs accumulated in a concentration-dependent manner in both the roots and shoots of rice seedlings. The impacts of MNPs on uptake by rice seedlings were concentration- and size-dependent by influencing the transpiration rate or activities of antioxidant enzymes. Especially, significant effects were usually found in exposure group of medium-size and high-concentration MNPs. MNPs had more obvious effects on OPE species with lower logKow in roots, whereas, more obvious effects on OPE species with higher logKow in shoots were observed. There was a significantly positive linear relationship between logTF and logKow (p < 0.001), and a significantly negative linear relationship between logRCF and logKow (p < 0.001), indicating that OPEs with higher hydrophobicity seemed to be more liable to be absorbed from solutions to roots, but difficult to further translocate to shoots. Without novel OPEs (bis-(2-ethylhexyl)-phenyl phosphate and tris(2,4-di-tert-butylphenyl)phosphate), better fits for a linear model for logKow and logRCF (or logTF) were exhibited, indicating differences between novel and traditional OPEs. This work highlights that the presence of MNPs could altered the characteristics of uptake, translocation and accumulation of OPEs in rice seedlings, and provides an important evidence for comprehensive control strategy of new pollutants.

Metabolomic responses in freshwater benthic invertebrate, Chironomus tepperi, exposed to polyethylene microplastics: A two-generational investigation

The accumulation of microplastics (MPs) in sediments could pose risks to benthic organisms and their progeny. Here, we examined effects on traditional apical endpoints along with changes to whole body metabolite profiles induced by irregular shaped polyethylene MPs (1-45 µm) at environmentally relevant concentrations (125, 250, 500 and 1000 MPs/kg sediment) in Chironomus tepperi using a two-generation exposure regime. Survival and emergence of C. tepperi were negatively affected in the parental generation at the two highest concentrations, whereas endpoints associated with growth were only impacted at 1000 MPs/kg sediment. Metabolites associated with several amino acid and energy metabolism pathways were present at lower abundances at the highest exposure concentration suggesting an overall impact on bioenergetics which relates to the inhibition of food acquisition or nutrient assimilation caused by ingestion of MPs, rather than a traditional receptor-mediated toxicity response. In contrast, no significant effects on apical endpoints were observed in the continuous exposure of first filial generation, and lactic acid was the only metabolite that differed significantly between groups. Larvae in unexposed conditions showed no differences in survival or metabolite profiles suggesting that effects in the parental generation do not carry over to the next filial generation. The findings provide evidence on the underlying impacts of MP ingestion and potential adaption to MP exposure of C. tepperi.

Effects of exposure to nanoplastics on the gill of mussels Mytilus galloprovincialis: An integrated perspective from multiple biomarkers

The pervasive presence of nanoplastics (NPs) in marine environments poses a threat to marine organisms. Gills, as the organ in direct contact with the environment in marine invertebrates, maybe the first to accumulate NPs. To date, the toxic effects of NPs on the gills of marine invertebrates are still largely unknown. In this study, the response of multiple biomarkers (i.e., total antioxidant capacity, the activity of acetylcholine, ion content and transport enzyme, metabolic enzymes, and lipids content) in mussels Mytilus galloprovincialis exposed to polystyrene nanoplastics (PS-NPs) for 7 days were evaluated. Significant inductions of total antioxidant capacity (T-AOC) and inhibition of acetylcholine (AChE) activity were detected after 7 days of PS-NPs exposure. PS-NPs also triggered significant alteration in ion content (Na+ and K+) and suppressed the activities of the ion transport enzyme (Na+/K+-ATPase). Moreover, we found the activity of metabolic enzymes (succinate dehydrogenase and pyruvate kinase) and lipids content (triacylglycerol and cholesterol) were significantly altered, suggesting the interference of PS-NPs on energy metabolism and lipid metabolism. This investigation provides substantial information to understand the physical responses of invertebrate gills to PS-NPs exposure. Given the crucial ecological roles of invertebrates, the presence of PS-NPs in the marine environment may have far-reaching impacts on population abundance, biodiversity, and stability of the marine ecosystem.

Ecotoxicological significance of bio-corona formation on micro/nanoplastics in aquatic organisms

The unsustainable manufacturing, utilization and inadequate handling of plastics have led to a surge in global plastic pollution. In recent times, there has been increasing concern about the plausible hazards associated with exposure to micro/nanoplastics (M/NPs). As aquatic systems are considered to be the likely sink for M/NPs, it is crucial to comprehend their environmental behavior. The bioavailability, toxicity and fate of M/NPs in the environment are predominantly dictated by their surface characteristics. In the aquatic environment, M/NPs are prone to be internalized by aquatic organisms. This may facilitate their interaction with a diverse array of biomolecules within the organism, resulting in the formation of a biocorona (BC). The development of BC causes modifications in the physicochemical attributes of the M/NPs including changes to their size, stability, surface charge and other properties. This review details the concept of BC formation and its underlying mechanism. It provides insight on the analytical techniques employed for characterizing BC formation and addresses the associated challenges. Further, the eco-toxicological implications of M/NPs and the role of BC in modifying their potential toxicity on aquatic organisms is specified. The impact of BC formation on the fate and transport of M/NPs is discussed. A concise outlook on the future perspectives is also presented.

Nanoplastic exposure inhibits feeding and delays regeneration in a freshwater planarian

The concentration of nanoplastics (NPs) is expected to increase in aquatic environments thus potentially threatening freshwater organisms through interactions with plastic particles that variously float, circulate in the water column or sink into the benthos. Studies into the mechanisms of any NP effects are still scarce, particularly with respect to the regenerative ability of biota for which there is no recognised model organism. The present study therefore aimed to investigate behavioural and regeneration responses of the freshwater planarian Girardia tigrina after 10 days exposed to along a gradient 0.01-10 mg/L of poly (styrene-co-methyl methacrylate) NPs (∼426 ± 175 nm). Exposure to NPs induced a significant reduction in planarian feeding rate even at low concentrations (LOEC of 0.01 mg/L), while head regeneration was delayed in a clear dose response way (LOEC of 0.1 mg/L for blastema length). Planaria locomotion assessed was not affected. Our results highlight the potential adverse effects of exposure to poly (styrene-co-methyl methacrylate) NPs and show that feeding behaviour and regeneration of a freshwater benthic organism can be indicators of the resulting toxicity. Planarians are becoming widely used model organisms in ecotoxicology and can help to address potential effects of plastic polymers on regeneration.

Polystyrene nanoplastics' accumulation in roots induces adverse physiological and molecular effects in water spinach Ipomoea aquatica Forsk

The ubiquity of plastic pollution has emerged as a perplexing issue for aquatic and terrestrial plants. To assess the toxic effects of polystyrene NPs (PS-NPs, 80 nm), we conducted a hydroponic experiment in which water spinach (Ipomoea aquatica Forsk) was subjected to low (0.5 mg/L), medium (5 mg/L), and high (10 mg/L) concentrations of fluorescent PS-NPs for 10 days to examine their accumulation and transportation in water spinach and associated impacts on growth, photosynthesis, antioxidant defense systems. Laser confocal scanning microscopy (LCSM) observations at 10 mg/L PS-NPs exposure indicated that PS-NPs only adhered to the root surface of water spinach and were not transported upward, indicating that short-term exposure to high concentrations of PS-NPs (10 mg/L) did not cause the internalization of PS-NPs in the water spinach. However, this high concentration of PS-NPs (10 mg/L) discernibly inhibited the growth parameters (fresh weight, root length and shoot length), albeit failed to induce any significant impact on chlorophyll a and chlorophyll b concentrations. Meanwhile, high concentration of PS-NPs (10 mg/L) significantly decreased the SOD and CAT activities in leaves (p < 0.05). At the molecular level, low and medium concentrations of PS-NPs (0.5, 5 mg/L) significantly promoted the expression of photosynthesis (PsbA and rbcL) and antioxidant-related (SIP) genes in leaves (p < 0.05), and high concentration of PS-NPs (10 mg/L) significantly increased the transcription levels of antioxidant-related (APx) genes (p < 0.01). Our results imply that PS-NPs accumulate in the roots of water spinach, compromising the upward transport of water and nutrients and undermining the antioxidant defense system of the leaves at the physiological and molecular levels. These results provide a fresh perspective to examine the implications of PS-NPs on edible aquatic plants, and future efforts should be focused intensively on the impacts of PS-NPs on agricultural sustainability and food security.

Studies of Endocrine Disruptors: Nonylphenol and Isomers in Biological Models

Certain emerging pollutants are among the most widely used chemicals globally, causing widespread concern in relation to their use in products devoted to cleaniness and asepsis. Nonylphenol ethoxylate (NPEOn) is one such contaminant, along with its degradation product, nonylphenol, an active ingredient presents in nonionic surfactants used as herbicides, cosmetics, paints, plastics, disinfectants, and detergents. These chemicals and their metabolites are commonly found in environmental matrices. Nonylphenol and NPEOn, used, are particularly concerning, given their role as endocrine disruptors chemical and possible neurotoxic effects recorded in several biological models, primarily aquatic organisms. Limiting and detecting these compounds remain of paramount importance. The objective of the present review was to evaluate the toxic effects of nonylphenol and NPEOn in different biological models. Environ Toxicol Chem 2023;00:1-12. © 2023 SETAC.

Biodegradable polymeric nanoparticles increase risk of cardiovascular diseases by inducing endothelium dysfunction and inflammation

Biodegradable polymers are expected to be an alternative to plastics. Because of its high biocompatibility, poly (lactic-co-glycolic acid) (PLGA) is widely used in medicine. It has been reported that micro-nano plastics can be accumulated in the circulatory system and cause tissue injury. With the increasing environmental exposure of degradable polymer nanoparticles (NPs), the impact of this risk factor on cardiovascular disease deserves attention. Thus, we aim to study the harmful effect of PLGA NPs on the process of vascular stenosis which is a typical pathological feature of cardiovascular diseases. We establish a mouse vascular stenosis model with intravenously injecting of PLGA NPs for 2 weeks. This model leads to a significant narrowing of the left common carotid artery which is characterized by the increasing intima area and focal stenosis. We observe that PLGA NPs accelerate stenosis progression by inducing inflammation and impairing vascular function. It promotes the proliferation of smooth muscle cells and causes abnormal collagen distribution. The combination of wall shear stress and PLGA NPs uptake speed up endothelial cell damage, decrease endothelial permeability and cell migration capacity. Our results suggest that PLGA NPs may pose a risk in cardiovascular stenosis which inspire us to concern the biodegradable polymeric materials in our living especially the clinic applications.

Bioaccumulation of functionalized polystyrene nanoplastics in sea cucumber Apostichopus japonicus (Selenka, 1867) and their toxic effects on oxidative stress, energy metabolism and mitochondrial pathway

Micro/nano-plastics (M/NPs) are emerging contaminants in aquatic environment, however, little knowledge regarding the adverse effects of functionalized NPs has been documented so far. This study investigated the accumulation of different polystyrene nanoplastics (PS-NPs, i.e., plain PS, carboxyl-functional PS-COOH and amino-functional PS-NH₂) at two particle sizes of 100 nm and 200 nm, and evaluated the impacts on oxidative stress, energy metabolism and mitochondrial pathway responses in intestine and respiratory tree of Apostichopus japonicus during the 20-d exposure experiment. The results showed that there were significant interactions of particle size and nanoplastic type on the accumulation of different PS-NPs. Exposure to NPs significantly increased the production of malondialdehyde, glutathione and reactive oxygen species, as well as the activities of antioxidant enzymes including glutathione reductase, superoxide dismutase and catalase, resulting in various degrees of oxidative damage in sea cucumber. The significant decrease in adenosine triphosphate content and increases in alkaline phosphatase and lactate dehydrogenase activities suggested that NPs impaired energy metabolism and modified their energy allocation. After 20-d exposure, the complex I, II and III activities in mitochondrial respiratory chain were significantly inhibited. Meanwhile, the Bax and Caspase-3 gene expression were significantly up-regulated, and Bacl-2 was down-regulated, indicating the toxicity on mitochondrial pathway of A. japonicus. The calculated IBR values elucidated the greater detriment to mitochondrial pathway than oxidative stress and energy metabolism. For 100 nm particle size, plain PS has stronger influence on all the biomarkers compared to PS-COOH/NH₂, however, the opposite trends were observed in 200 nm PS-NPs. Furthermore, 100 nm PS-NPs were recognized to be more hazardous to sea cucumber than 200 nm microbeads. These findings provide new insights for understanding the differentiated toxic effects of functionalized NPs in marine invertebrates.

Evaluation of antioxidant capacity and digestive enzyme activities in Mytilus galloprovincialis exposed to nanoplastics under different patterns of hypoxia

In the marine environment, plastic pollution may occur simultaneously with hypoxia. However, current ecological risk assessments of nanoplastics have rarely considered the impact of additional environmental factors, such as hypoxia. In this study, we investigated the effect of polystyrene nanospheres (PS-NPs) on the digestive performance (antioxidant system and digestive enzymes) of mussels Mytilus galloprovincialis under different patterns of hypoxia (normoxia, constant hypoxia, and fluctuating hypoxia). The result showed that PS-NPs caused oxidative damage in the digestive glands of mussels, while all patterns of hypoxia exacerbated this oxidative damage. Activities of four digestive enzymes (α-amylase, cellulase, trypsin, and lipase) were examined. Among these, the activity of the α-amylase was inhibited by PS-NPs, and the inhibition was aggravated by all the hypoxia patterns. The cellulase activity and trypsin activity was enhanced by PS-NPs, and the increase was further stimulated by hypoxia. Lipase activity was not affected by PS-NPs alone, but significant inhibition was detected after the coexposure to PS-NPs and hypoxia. Conclusively, the combined stress of hypoxia and nanoplastics can significantly affect the digestive performance of mussels and may alter the mussel nutrient uptake strategy. Our work has provided new insight into the ecological risk assessment of plastics under global climate change.

A review on the effect of micro- and nano-plastics pollution on the emergence of antimicrobial resistance

The recent upsurge in the studies on micro/nano plastics and antimicrobial resistance genes has proven their deleterious effects on the environmental and human health. Till-date, there is a scarcity of studies on the interactions of these two factors and their combined influence. The interaction of microplastics has led to the formation of new plastics namely plastiglomerates, pyroplastics. and anthropoquinas. It has long been ignored that the occurrence of microplastics has become a breeding ground for the emergence of antimicrobial resistance genes. Evidently microplastics are also associated with the occurrence of other pollutants such as polyaromatic hydrocarbons and pesticides. The increased use of antibiotics (after Covid breakout) has further elevated the detrimental effects on human health. Therefore, this study highlights the relation of microplastics with antibiotic resistance generation. The factors such as uncontrolled use of antibiotics and negligent plastic consumption has been evaluated. Furthermore, the future research prospective was provided that can be helpful in correctly identifying the seriousness of the environmental occurrence of these pollutants.

Environmental impacts of post-consumer plastic wastes: Treatment technologies towards eco-sustainability and circular economy

The huge amounts of plastic production (millions of tons) are carried out all around world every year and EU is one of the biggest consumers of these products. In 2021, recycling rate of plastic wastes around 32.5% in the EU and the rest end up on their journey in landfills and oceans that lead to environmental pollution which is a crucial global concern. Thus, it is important to take necessary steps to control the use of such plastic and to sustainably dispose them. One of the solutions to the problem is to use a better alternative to plastics which doesn't degrade land, water or air nor affects living organisms. Circular economy is another answer to this problem, it would ensure prevention of post-consumer plastic waste from getting formed. In addition, sustainable disposal approaches for plastic waste such as pyrolysis, plasma gasification, photocatalytic degradation, and production of value-added products from polymer waste can be explored. These recycling methods has huge potential for research and studies and can play a crucial in eliminating post-consumer plastic waste. This review paper aims to discuss the environmental effects of post-consumer plastic wastes as well as the emerging approaches for the treatment of these environmental wastes towards eco-sustainability and circular economy.