Polystyrene nanoplastics exacerbated the ecotoxicological and potential carcinogenic effects of tetracycline in juvenile grass carp (Ctenopharyngodon idella)

Bibliometrics analysis of hotspots research on infertility syndromes and polystyrene

Polystyrene plastic pollution poses a pressing environmental concern and represents a significant risk factor for infertility. Despite this, a comprehensive overview of the field remains scarce, with future trends largely unknown. Bibliometrics, an applied mathematical and statistical method, offers a means to analyze textual information across various levels, facilitating quantitative assessments of all knowledge carriers and unveiling the nature and developmental trajectories of a discipline. This study aimed to employ bibliometric methods to scrutinize the current status and research hotspots within the realm of polystyrene and infertility. Literature spanning from 1980 to 2023 pertaining to polystyrene and infertility was retrieved from the core database of Web of Science. Quantitative analyses were conducted utilizing CiteSpace (version 5.7.R7), VOSviewer (version 1.6.18.0), and an online literature analysis website (https://bibliometric.com/). The analysis visually represented countries, institutions, authors, journals, and keywords within the field. This study delved into the development history, knowledge structure, research hotspots, and potential trends in the field, furnishing a macro perspective for researchers. The investigation encompassed 267 articles published across 120 journals by 1,352 authors affiliated with 417 institutions in 51 countries, with these articles garnering 10,310 citations across 2,811 journals. The top three countries contributing the most articles were China, the United States, and Germany. In essence, the research hotspots primarily revolved around metabolism, endocrinology, and immunity. Despite China's relatively recent entry into this field, its rapid development is evident. However, the low citation frequency suggests a need for improved article quality.

Immunotoxicity of microplastics in fish

Plastic waste degrades slowly in aquatic environments, transforming into microplastics (MPs) and nanoplastics (NPs), which are subsequently ingested by fish and other aquatic organisms, causing both physical blockages and chemical toxicity. The fish immune system serves as a crucial defense against viruses and pollutants present in water. It is imperative to comprehend the detrimental effects of MPs on the fish immune system and conduct further research on immunological assessments. In this paper, the immune response and immunotoxicity of MPs and its combination with environmental pollutants on fish were reviewed. MPs not only inflict physical harm on the natural defense barriers like fish gills and vital immune organs such as the liver and intestinal tract but also penetrate cells, disrupting intracellular signaling pathways, altering the levels of immune cytokines and gene expression, perturbing immune homeostasis, and ultimately compromising specific immunity. Initially, fish exposed to MPs recruit a significant number of macrophages and T cells while activating lysosomes. Over time, this exposure leads to apoptosis of immune cells, a decline in lysosomal degradation capacity, lysosomal activity, and complement levels. MPs possess a small specific surface area and can efficiently bind with heavy metals, organic pollutants, and viruses, enhancing immune responses. Hence, there is a need for comprehensive studies on the shape, size, additives released from MPs, along with their immunotoxic effects and mechanisms in conjunction with other pollutants and viruses. These studies aim to solidify existing knowledge and delineate future research directions concerning the immunotoxicity of MPs on fish, which has implications for human health.

Neurobehavioral toxicity induced by combined exposure of micro/nanoplastics and triphenyltin in marine medaka (Oryzias melastigma)

Microplastics/nanoplastics (MNPs) inevitably coexist with other pollutants in the natural environment, making it crucial to study the interactions between MNPs and other pollutants as well as their combined toxic effects. In this study, we investigated neurotoxicity in marine medaka (Oryzias melastigma) exposed to polystyrene micro/nanoplastics (PS-MNPs), triphenyltin (TPT), and PS-MNPs + TPT from physiological, behavioral, biochemical, and genetic perspectives. The results showed that marine medaka exposed to 200 ng/L TPT or 200 μg/L PS-NPs alone exhibited some degree of neurodevelopmental deficit, albeit with no significant behavioral abnormalities observed. However, in the PS-MP single exposure group, the average acceleration of short-term behavioral indices was significantly increased by 78.81%, indicating a highly stress-responsive locomotor pattern exhibited by marine medaka. After exposure to PS-MNPs + TPT, the swimming ability of marine medaka significantly decreased. In addition, PS-MNPs + TPT exposure disrupted normal neural excitability as well as activated detoxification processes in marine medaka larvae. Notably, changes in neural-related genes suggested that combined exposure to PS-MNPs and TPT significantly increased the neurotoxic effects observed with exposure to PS-MNPs or TPT alone. Furthermore, compared to the PS-MPs + TPT group, PS-NPs + TPT significantly inhibited swimming behavior and thus exacerbated the neurotoxicity. Interestingly, the neurotoxicity of PS-MPs was more pronounced than that of PS-NPs in the exposure group alone. However, the addition of TPT significantly enhanced the neurotoxicity of PS-NPs compared to PS-MPs + TPT. Overall, the study underscores the combined neurotoxic effects of MNPs and TPT, providing in-depth insights into the ecotoxicological implications of MNPs coexisting with pollutants and furnishing comprehensive data.

Combined Effects of Polystyrene Nanosphere and Homosolate Exposures on Estrogenic End Points in MCF-7 Cells and Zebrafish

BACKGROUND

Micro- and nanoplastics (MNPs) and homosalate (HMS) are ubiquitous emerging environmental contaminants detected in human samples. Despite the well-established endocrine-disrupting effects (EDEs) of HMS, the interaction between MNPs and HMS and its impact on HMS-induced EDEs remain unclear.

OBJECTIVES

This study aimed to investigate the influence of MNPs on HMS-induced estrogenic effects and elucidate the underlying mechanisms in vitro and in vivo.

METHODS

We assessed the impact of polystyrene nanospheres (PNSs; 50  nm , 1.0 mg / L ) on HMS-induced MCF-7 cell proliferation (HMS: 0.01 - 1 μ M , equivalent to 2.62 - 262 μ g / L ) using the E-SCREEN assay and explored potential mechanisms through transcriptomics. Adult zebrafish were exposed to HMS (0.0262 - 262 μ g / L ) with or without PNSs (50  nm , 1.0 mg / L ) for 21 d. EDEs were evaluated through gonadal histopathology, fertility tests, steroid hormone synthesis, and gene expression changes in the hypothalamus-pituitary-gonad-liver (HPGL) axis.

RESULTS

Coexposure of HMS and PNSs resulted in higher expression of estrogen receptor α (ESR1) and the mRNAs of target genes (pS2, AREG, and PGR), a greater estrogen-responsive element transactivation activity, and synergistic stimulation on MCF-7 cell proliferation. Knockdown of serum and glucocorticoid-regulated kinase 1 (SGK1) rescued the MCF-7 cell proliferation induced by PNSs alone or in combination with HMS. In zebrafish, coexposure showed higher expression of SGK1 and promoted ovary development but inhibited spermatogenesis. In addition, coexposure led to lower egg hatchability, higher embryonic mortality, and greater larval malformation. Coexposure also modulated steroid hormone synthesis genes (cyp17a2, hsd17[Formula: see text]1, esr2b, vtg1, and vtg2), and resulted in higher 17 β -estradiol (E 2 ) release in females. Conversely, males showed lower testosterone, E 2 , and gene expressions of cyp11a1, cyp11a2, cyp17a1, cyp17a2, and hsd17[Formula: see text]1.

DISCUSSION

PNS exposure exacerbated HMS-induced estrogenic effects via SGK1 up-regulation in MCF-7 cells and disrupting the HPGL axis in zebrafish, with gender-specific patterns. This offers new mechanistic insights and health implications of MNP and contaminant coexposure. https://doi.org/10.1289/EHP13696.

Micro(nano)plastics in marine medaka: Entry pathways and cardiotoxicity with triphenyltin

The simultaneous presence of micro(nano)plastics (MNPs) and pollutants represents a prevalent environmental challenge that necessitates understanding their combined impact on toxicity. This study examined the distribution of 5 μm (PS-MP5) and 50 nm (PS-NP50) polystyrene plastic particles during the early developmental stages of marine medaka (Oryzias melastigma) and assessed their combined toxicity with triphenyltin (TPT). Results showed that 2 mg/L PS-MP5 and PS-NP50 could adhere to the embryo surface. PS-NP50 can passively enter the larvae and accumulate predominantly in the intestine and head, while PS-MP5 cannot. Nonetheless, both types can be actively ingested by the larvae and distributed in the intestine. 2 mg/L PS-MNPs enhance the acute toxicity of TPT. Interestingly, high concentrations of PS-NP50 (20 mg/L) diminish the acute toxicity of TPT due to their sedimentation properties and interactions with TPT. 200 μg/L PS-MNPs and 200 ng/L TPT affect complement and coagulation cascade pathways and cardiac development of medaka larvae. PS-MNPs exacerbate TPT-induced cardiotoxicity, with PS-NP50 exhibiting stronger effects than PS-MP5, which may be related to the higher adsorption capacity of NPs to TPT and their ability to enter the embryos before hatching. This study elucidates the distribution of MNPs during the early developmental stages of marine medaka and their effects on TPT toxicity, offering a theoretical foundation for the ecological risk assessment of MNPs.

Histopathological, physiological, and multi-omics insights into the hepatotoxicity mechanism of nanopolystyrene and/or diclofenac in Mylopharyngodon piceus

Nanopolystyrene (NP) and diclofenac (DCF) are common environmental contaminants in the aquatic ecosystem; therefore, the present study aimed to investigate the hepatotoxicity of NP and/or DCF exposure on aquatic organisms and the underlying mechanisms. Juvenile Mylopharyngodon piceus were used as a model organism to study the effects of NP and/or DCF exposure at environmentally relevant concentrations for 21 days. Subchronic exposure to NP and/or DCF resulted in liver histological damage. In the NP group, the presence of large lipid droplets was observed, whereas the DCF group exhibited marked hepatic sinusoidal dilatation accompanied by inflammation. Additionally, this exposure induced liver oxidative stress, as evidenced by the changes in several physiological parameters, including catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), reactive oxygen species (ROS), and malondialdehyde (MDA). Integrated transcriptomic and metabolomic analysis was performed to further investigate the molecular mechanism underlying hepatotoxicity. Multi-omics analysis demonstrated, for the first time to our knowledge, that NP induced hepatic steatosis mainly through activating the glycerol-3-phosphate pathway and inhibiting VLDL assembly by targeting several key enzyme genes including GPAT, DGAT, ACSL, APOB, and MTTP. Furthermore, NP exposure disrupted arachidonic acid metabolism, which induced the release of inflammatory factors and inhibited the release of anti-inflammatory factors, ultimately causing liver inflammation in M. piceus. In contrast, DCF induced interleukin production and downregulated KLF2, causing hepatic sinusoidal dilatation with inflammation in juvenile M. piceus, which is consistent with the finding of JAK-STAT signaling pathway activation. In addition, the upregulated AMPK signaling pathway in the DCF group suggested perturbation of energy metabolism. Collectively, these findings provide novel insights into the molecular mechanism of the multiple hepatotoxicity endpoints of NP and/or DCF exposure in aquatic organisms.

Gut microbiota related response of Oryzias melastigma to combined exposure of polystyrene microplastics and tetracycline

The co-existence of microplastics (MPs) and antibiotics in the coastal environment poses a combined ecological risk. Single toxic effects of MPs or antibiotics on aquatic organisms have been verified, however, the exploration of their combined toxic effects remains limited. Here, foodborne polystyrene microplastics (PS-MPs, 10 μm, 0.1 % w/w in food) and waterborne tetracyclines (TC, 50 μg/L) were used to expose an estuarine fish Oryzias melastigma for four weeks. We found that the aqueous availability of TC was not significantly altered coexisting with MPs. The fish body weight gain was significantly slower in TC alone or combined groups than the control group, consistent with the lower lipid content in livers. The body length gain was significantly inhibited by the combined presence compared to the single exposure. Both exposures led to a shift of gut microbiota composition and diversity. TC and the combined group possessed similar gut microbiota which is distinct from PS-MPs and the control group. The Firmicutes/Bacteroidetes (F/B) ratio in the TC and combined groups were significantly lower compared to the control, while the PS-MPs group showed no significant impact. Metabolomic analysis of the fish liver confirmed the shift of metabolites in specific pathways after different exposures. More, a number of gut microbiota-related metabolites on lipid metabolism was perturbed, which were annotated in arachidonic acid metabolism and linoleic acid metabolism. In all, TC modulates bacterial composition in the fish gut and disturbs their liver metabolites via the gut-liver axis, which led to the slower growth of O. melastigma. More, the adverse impact was aggravated by the co-exposure to foodborne PS-MPs.

Interactive effects of polystyrene nanoplastics and 6:2 chlorinated polyfluorinated ether sulfonates on the histomorphology, oxidative stress and gut microbiota in Hainan Medaka (Oryzias curvinotus)

Nanoplastics adsorb surrounding organic contaminants in the environment, which alters the physicochemical properties of contaminants and affects associated ecotoxicological effects on aquatic life. The current work aims to explore the individual and combined toxicological implications of polystyrene nanoplastics (80 nm) and 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFAES, trade name: F-53B) in an emerging freshwater fish model Hainan Medaka (Oryzias curvinotus). Therefore, O. curvinotus were exposed to 200 μg/L of PS-NPs or 500 μg/L of F-53B in the single or mixture exposure for 7 days to investigate the effects on fluorescence accumulation, tissue damage, antioxidant capacity and intestinal flora. The PS-NPs fluorescence intensity was significantly higher in the single exposure treatment than it in combined exposure treatment (p < 0.01). Histopathological results showed that exposure to PS-NPs or F-53B inflicted varying degree of damages to the gill, liver, and intestine, and these damage were also present in the corresponding tissues of the combined treatment group, illustrating a stronger extent of destruction of these tissues by the combined treatment. Compared to the control group, combined exposure group elevated the malondialdehyde (MDA) content, superoxide dismutase (SOD) and catalase (CAT) activities except in the gill. In addition, the adverse contribution of PS-NPs and F-53B on the enteric flora in the single and combined exposure groups was mainly characterised in the form of reductions in the number of probiotic bacteria (Firmicutes) and this reduction was aggravated by the combined exposure group. Collectively, our results indicated that the toxicological effects of PS-NPs and F-53B on pathology, antioxidant capacity and microbiomics of medaka may be modulated by the interaction of two contaminants with mutually interactive effects. And our work offers fresh information on the combined toxicity of PS-NPs and F-53B to aquatic creatures along with a molecular foundation for the environmental toxicological mechanism.

Effects of microplastics and tetracycline on intestinal injury in mice

Microplastics (MPs) and tetracycline are both emerging environmental pollutants that threaten human health. The toxic impacts of their single and coexposure on the intestine and gut microbiota have not been well studied in mammals. Given the spatial functional characteristics of the intestine, it is important to know whether the toxicities of MPs and tetracycline in different intestinal segments are distinct. This study investigated the pathological and functional injuries of different intestinal segments and the microbial disorder upon exposure to polystyrene microplastics (PS-MPs) and/or tetracycline hydrochloride (TCH). Both PS-MPs and TCH altered the intestinal morphology and induced functional impairment. However, the PS-MPs primarily damaged the colon, while TCH mainly damaged the small intestine, especially the jejunum. Combined treatment evoked ameliorative adverse effects on the intestinal segments except for the ileum. Gut microbiota analysis revealed that PS-MPs and/or TCH decreased gut microbiota diversity, especially PS-MPs. In addition, PS-MPs and TCH affected the microflora metabolic processes, especially protein absorption and digestion. Gut microbiota dysbiosis could partly lead to the physical and functional damage induced by PS-MPs and TCH. These findings enhance our knowledge regarding the hazards of coexisting microplastics and antibiotics for mammalian intestinal health.

Effects of microplastics on the toxicity of co-existing pollutants to fish: A meta-analysis

Aquatic ecosystems are among the main destination for microplastics (MPs) in the environment. MPs that enter aquatic ecosystems can contribute to pollution together with other co-existing pollutants. However, whether such pollution results in higher or lower toxicity to fish than that caused by co-existing pollutants alone remains controversial. This study aimed at closing this research gap based on 1380 biological endpoints under the background of environmental MP concentrations collected from 55 laboratory studies. Overall, MPs in co-existing pollutant solutions significantly increased the toxicity to fish. Specifically, MPs elevated negative effects on the immune system, metabolism, and oxidative damage. Subgroup analysis indicated that changes in toxicity were related to fish life stage and MP size, but not to co-existing pollutant or MP type. Meta-regression analysis indicated that changes in toxicity were not related to the logarithm of the octanol-water partition coefficient (logKow) or exposure time. Finally, the differences between laboratory research and the actual aquatic environment were discussed from four aspects: MPs, co-existing pollutants, environmental factors, and experimental objects. Our study provides a basis for further understanding the potential impact of MPs on aquatic organisms from a combined pollution perspective. Moreover, our results can provide a reference for the conservation and management of aquatic ecosystems.

Dysregulation of the microbiota-brain axis during long-term exposure to polystyrene nanoplastics in rats and the protective role of dihydrocaffeic acid

Polystyrene nano-plastics (PS-NPs) can be accumulated in the food chain and can penetrate biological barriers to affect multiple physiological functions. However, the adverse effects of nano-plastics on mammals and the underlying mechanism still remain unknown. To fill the gaps, our study administrated low-dose PS-NPs (50 and 100 μg/L) for 24 consecutive weeks in rats. Behavioral and morphological evaluations were performed to assess the neurobehavoirs. A combined analysis of multiple omics was used to evaluate the dysfunctions of the gut-microbe-brain axis. After dihydrochalcone(NHDC) treatment in the PS-NPs rat model, the inflammation response and apoptosis process were assessed and proteomics was used to explore the underlying mechanism. Our results indicated that long-term exposure to low-dose PS-NPs could induce abnormal neurobehaviors and amygdaloid nucleus impairment, and stimulate inflammatory responses and apoptosis. Metagenomics results revealed that four microbial phyla including Proteobacteria, Firmicutes, Defferibacteres, and Bacteroidetes changed significantly compared to the control. Targeted metabolomics analysis in the feces showed alteration of 122 metabolites induced by the PS-NPs exposure, among which the content of dihydrocaffeic acid was significantly associated with the different microbial genera and pivotal differential metabolites in the amygdaloid nucleus. And NHDC treatment significantly alleviated PS-NP-induced neuroinflammation and apoptosis and the cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/phosphorylated cAMP-response element binding protein(p-CREB)/plasma membrane calcium-transporting ATPase 2(Atp2b2) signaling pathway was identified in the proteomics. In conclusion, long-term exposure to low-dose PS-NPs has adverse effects on emotion through the dysregulation of the gut-brain axis, and dihydrocaffeic acid can alleviate these effects via the cAMP/PKA/p-CREB/Atp2b2 signaling pathway.

Combined exposure to titanium dioxide and tetracycline induces neurotoxicity in zebrafish

In aquatic environment, engineered materials may inevitably interact with the coexisted organic pollutants, which affect their bioavailability and toxicity. In this contribution, the combined impacts of tetracycline (TC) and titanium dioxide nanoparticles (TiO₂ NPs) on the neurodevelopment of zebrafish larvae were investigated, and the underlying mechanisms were further elucidated. Firstly, it was confirmed that the co-existence of TC would increase the size and decrease the zeta potential of TiO₂ NPs. Following, developmental indicators and motor behaviors were investigated. Our results indicated that co-exposure to TC and TiO₂ NPs exhibited enhanced embryonic malformation rates and abnormal nervous system development in zebrafish embryos. Meanwhile, the locomotor behavior was increased upon treatment of TC and TiO₂ NP. Further, pathway enrichment analyses of transcriptomic sequencing provided detailed information that either lipid metabolism or PPAR signaling pathway were significantly affected in the co-exposure group. Also, TC + TiO₂ NP exposure significantly changed the mRNA expression of neural development-related genes and up-regulated the expression levels of neurotransmitters like 5-hydroxytryptamine, dopamine, acetylcholinesterase, and γ-aminobutyric acid. Taken together, our results demonstrated that the co-exposure of TC and TiO₂ NPs had the potential to cause neurotoxicity in zebrafish embryos.

Parental exposure to polystyrene nanoplastics and di(2-ethylhexyl) phthalate induces transgenerational growth and reproductive impairments through bioaccumulation in Daphnia magna

The ubiquitous presence of polystyrene nanoplastics (PSNPs) and di(2-ethylhexyl) phthalate (DEHP) in the aquatic environment may cause unpredictable negative effects on aquatic organisms and even continue to the offspring. This study assessed the transgenerational impacts of parental exposure to PSNPs and DEHP over four generations (F0-F3) of Daphnia magna. A total of 480 D. magna larvae (F0, 24 h old) were divided into four groups with six replicates (each of them contains 20 D. magna) and exposed with dechlorinated tap water (control), 1 mg/L PSNPs, 1 μg/L DEHP, and 1 mg/L PSNPs + 1 μg/L DEHP (PSNPs-DEHP) until spawning begins. Subsequent to exposure, all the surviving F1 offspring were transferred to new water and continued to be cultured until the end of F3 generation births in all groups. The results showed that the PSNPs accumulated in F0 generation and were inherited into F1 and F2 generations, and disappeared in F3 generation in PSNPs and PSNPs-DEHP groups. However, the accumulation of DEHP lasted from F0 generation to F3 generation, despite a significant decline in F2 and F3 generations in DEHP and PSNPs-DEHP groups. The accumulation of PSNPs and DEHP caused overproduction of reactive oxygen species in F0-F2 generations and fat deposition in F0-F3 generations. Additionally, single and in combination parental exposure to PSNPs and DEHP induced regulation of growth-related genes (cyp18a1, cut, sod and cht3) and reproduction-related genes (hr3, ftz-f1, vtg and ecr) in F0-F3 generations. Survival rates were decreased in F0-F1 generations and recovered in F2 generation in all treatment groups. Furthermore, the spawning time was prolonged and the average number of offspring was increased in F1-F2 generaions as a defense mechanism against population mortality. This study fosters a greater comprehension of the transgenerational and reproductive effects and associated molecular mechanisms in D. magna.

Polystyrene exacerbates cadmium-induced mitochondrial damage to lung by blocking autophagy in mice

Cadmium (Cd) is an environmental heavy metal, and its accumulation is harmful to animal and human health. The cytotoxicity of Cd includes oxidative stress, apoptosis, and mitochondrial histopathological changes. Furthermore, polystyrene (PS) is a kind of microplastic piece derived from biotic and abiotic weathering courses, and has toxicity in various aspects. However, the potential mechanism of action of Cd co-treated with PS is still poorly unclear. The objective of this study was to investigate the effects of PS on Cd-induced histopathological injury of mitochondria in the lung of mice. In this study, the results have showed that Cd could induce the activity of oxidative enzymes of the lung cells in mice, increasing the content of partial microelement and the phosphorylation of inflammatory factor NF-κB p65. Cd further destroys the integrity of mitochondria by increasing the expression of apoptotic protein and blocking the autophagy. In addition, PS solely group aggravated the lung damage in mice, especially mitochondrial toxicity, and played a synergistic effect with Cd in lung injury. However, how PS can augment mitochondrial damage and synergism with Cd in lung of mice requiring further exploration. Therefore, PS was able to exacerbate Cd-induced mitochondrial damage to the lung in mice by blocking autophagy, and was associated with the apoptosis.

Nanoplastic-induced vascular endothelial injury and coagulation dysfunction in mice

Nanoplastics are the persistent pollutants in a variety of environments, representing a potential threat to human health. Notably, plastic particles have been detected in sample of human bloodstream. It is thus significant to investigate the effects of nanoplastics on the cardiovascular system owing to its ease transfer through the bloodstream to other organs. However, few studies have been performed to evaluate the cardiovascular toxicity of nanoplastics. Herein, we pursued to investigate the adverse cardiovascular impacts of polystyrene (PS), PS-NH₂ and PS-COOH nanoplastics on mice. Experimental results demonstrated that the exposure to these nanoplastics could result in structural damage of vascular endothelial cells and inflammatory response. Moreover, it was found out that the dysfunctions of coagulation and prethrombotic state were caused by nanoplastics, which could be ascribed to the activation of JAK1/STAT3/TF signaling pathway. In summary, results clearly indicated that nanoplastic exposure lead to vascular toxicity to mice, which serves as a basis for future studies about the potential physiological threat of nanoplastics to humans.

A novel framework-based meta-analysis for in-depth characterization of microplastic pollution and associated ecological risks in Chinese Bays

Among aquatic ecosystems, bays are ubiquitously contaminated with microplastics (MPs, size <5 mm), but a comprehensive understanding of their pollution characterization in Chinese Bays is largely elusive. The current study aims to systematically highlight factors intricating MP contamination as well as their geographic distribution, interactions, risk evaluation, and abundance prediction in bays. MPs' abundance was varied in different bays, at concentrations ranging between 0.26 ± 0.14-89, 500 ± 20, 600 items/m³ in water, 15 ± 6-6433.5 items/kg dry weight in sediment and 0.21 ± 0.10-103.5 items/individual in biota. Redundancy analysis, Permannova, and GeoDetector model revealed that the sampling and extraction/identification methods, and geographical locations were the major drivers affecting MP distribution and characteristics. The Mantel test highlighted that the MP characteristics changed with geographic distance, higher in water than that in sediment and biota. ANOSIM results showed that the different environmental media exhibit significant differences in MP characteristics (e.g., color, shape, and polymer). The ARIMA model predicted that Sanggou Bay and Hangzhou Bay have a higher potential for significantly increasing MP contamination in the future. The highest hazard index (HI) values for water, sediment, and biota were respectively reported at Jiaozhou Bay (18,844.16), Bohai Bay (11,485.37), and Dongshan Bay (48,485.11). The highest values for the ecological risk index (RI) in water, sediment, and biota were detected at Beibu Gulf (6,129,559.02), Haikou Bay (2229.14), and Dongshan Bay (561,563.05), respectively. Overall, this framework can be used at different scales and in different environments, which makes it useful for understanding and controlling MP pollution in the ecosystem.

Transgenerational impacts of micro(nano)plastics in the aquatic and terrestrial environment

Plastic particles of diameters ranging from 1 to 1000 nm and > 1 µm to 5 mm are respectively known as nanoplastics and microplastics, and are collectively termed micro(nano)plastics (MNPs). They are ubiquitously present in aquatic and terrestrial environments, posing adverse multifaceted ecological impacts. Recent transgenerational studies have demonstrated that MNPs negatively impact both the exposed parents and their unexposed generations. Therefore, this review summarizes the available research on the transgenerational impacts of MNPs in aquatic and terrestrial organisms, induced by exposure to MNPs alone or in combination with other organic and inorganic chemicals. The most commonly reported transgenerational effects of MNPs include tissue bioaccumulation and transfer, affecting organisms' survival, growth, reproduction, and energy metabolism; inducing oxidative stress; enzyme and genetic responses; and causing tissue damage. Similarly, co-exposure to MNPs and chemicals (organic and inorganic pollutants) significantly impacts survival, growth, and reproduction and induces oxidative stress, thyroid disruption, and genetic toxicity in organisms. The characteristics of MNPs (degree of aging, size, shape, polymer type, and concentration), exposure type and duration (parental exposure vs. multigenerational exposure and acute exposure vs. chronic exposure), and MNP-chemical interactions are the main factors affecting transgenerational impacts. Selecting MNP properties based on their realistic environmental behavior, employing more diverse animal models, and considering chronic exposure and MNP-chemical mixture exposure are salient research prospects for an in-depth understanding of the transgenerational impacts of MNPs.

Combined toxicity of micro/nanoplastics loaded with environmental pollutants to organisms and cells: Role, effects, and mechanism

Micro/nanoplastics (MPs/NPs) are ubiquitous in the environment and living organisms have been exposed to these substances for a long time. When MPs/NPs enter different organisms, they transport various pollutants, including heavy metals, persistent organic pollutants, drugs, bacteria, and viruses, from the environment. On this basis, this paper summarizes the combined toxicity induced by MPs/NPs accumulating contaminants from the environment and entering organisms through a systematic review of 162 articles. Moreover, the factors influencing toxic interactions are critically discussed, thus highlighting the dominant role of the relative concentrations of contaminants in the combined toxic effects. Furthermore, for the first time, we describe the threats posed by MPs/NPs combined with other pollutants to human health, as well as their cytotoxic behavior and mechanism. We found that the "Trojan horse" effect of nanoplastics can increase the bioaccessibility of environmental pollutants, thus increasing the carcinogenic risk to humans. Simultaneously, the complex pollutants entering the cells are observed to be constantly dissociated due to the transport of lysosomes. However, current research on the intracellular release of MP/NP-loaded pollutants is relatively poor, which hinders the accurate in vivo toxicity assessment of combined pollutants. Based on the findings of our critical review, we recommend analyzing the toxic effects by clarifying the dose relationship of each component pollutant in cells, which is challenging yet crucial to exploring the toxic mechanism of combined pollution. In the future, our findings can contribute to establishing a system modeling the complete load-translocation toxicological mechanism of MP/NP-based composite pollutants.

Acute toxicity, biochemical and transcriptomic analysis of Procambarus clarkii exposed to avermectin

BACKGROUND

Pesticides are extensively applied globally. Pesticide residues induce calamitous effects on the environment and untargeted organisms. Public concerns for the safety of freshwater organisms and the challenges posed by aquatic contaminants remain high. In the present study, the acute toxicity of avermectins (AVMs) to the crayfish, Procambarus clarkii was evaluated. We also evaluated the potential effects of AVM on the biochemical and transcriptomic status of the hepatopancreas and gastrointestinal tract in P. clarkii.

RESULTS

The 24, 48, 72, 96 h median lethal concentrations (LC₅₀ ) of AVM on crayfish were 2.626, 1.162, 0.723, 0.566 mg L^-1 , respectively. The crayfish were then exposed to 0.65 mg L^-1 of AVM for 96 h. AVM significantly altered biochemical parameters including AChE and CAT activities in the hepatopancreas, and AChE, SOD and Na + -K + -ATPase activities in the gastrointestinal tract at several time points. Furthermore, transcriptomic analysis identified 953 and 1851 differentially-expressed genes (DEGs) in the hepatopancreas and gastrointestinal tract, respectively. KEGG enrichment showed that the gene expression profiles of the hepatopancreas and gastrointestinal tract were distinct from each other. The DEGs in the hepatopancreas were mostly enriched with stress-response pathways, while the majority of the DEGs in the gastrointestinal tract belonged to metabolism-related pathways.

CONCLUSION

We demonstrated that the AVM induced acute toxicity, oxidative stress, osmoregulation disturbance, neurotoxicity and transcriptome imbalance in crayfish. These findings unraveled the detrimental effects of AVMs exposure on crayfish. © 2022 Society of Chemical Industry.

Understanding the Interplay between Antimicrobial Resistance, Microplastics and Xenobiotic Contaminants: A Leap towards One Health?

According to the World Health Organization, the two major public health threats in the twenty-first century are antibiotic-resistant bacteria and antibiotic-resistant genes. The reason for the global prevalence and the constant increase of antibiotic-resistant bacteria is owed to the steady rise in overall antimicrobial consumption in several medical, domestic, agricultural, industrial, and veterinary applications, with consequent environmental release. These antibiotic residues may directly contaminate terrestrial and aquatic environments in which antibiotic-resistance genes are also present. Reports suggest that metal contamination is one of the main drivers of antimicrobial resistance (AMR). Moreover, the abundance of antibiotic-resistance genes is directly connected to the predominance of metal concentrations in the environment. In addition, microplastics have become a threat as emerging contaminants because of their ubiquitous presence, bio-inertness, toughness, danger to aquatic life, and human health implications. In the environment, microplastics and AMR are interconnected through biofilms, where genetic information (e.g., ARGs) is horizontally transferred between bacteria. From this perspective, we tried to summarize what is currently known on this topic and to propose a more effective One Health policy to tackle these threats.

Neurotoxic effects of different sizes of plastics (nano, micro, and macro) on juvenile common carp (Cyprinus carpio)

Using common carp as a model, we assessed the effects of polyethylene (PE) plastics on the brain. We measured activity of acetylcholinesterase (AChE), monoamine oxidase (MAO), and the content of nitric oxide (NO) in carp brain following exposure to 100 mg/L of either macroplastics (MaP), microplastics (MPs), or nanoplastic (NPs) for 15 days compared to an unexposed group. Following exposure, each biochemical biomarker was reduced 30–40%, with a higher magnitude of change corresponding to the smaller size of the particles (NPs > MPs > MaPs). In the carp tectum, exposure for 15 days to plastic particles caused varying degrees of necrosis, fibrosis, changes in blood capillaries, tissue detachment, edema, degenerated connective tissues, and necrosis in large cerebellar neurons and ganglion cells. In the carp retina, there was evidence for necrosis, degeneration, vacuolation, and curvature in the inner layer. Here we provide evidence that exposure to plastic particles can be associated with neurotoxicity in common carp.

Effects of nanoplastic exposure on the immunity and metabolism of red crayfish (Cherax quadricarinatus) based on high-throughput sequencing

Previous studies have shown that nanoplastics (NPs) are harmful pollutants that threaten aquatic organisms and ecosystems, however, less research has been conducted on the hazards of NPs for aquaculture animals. In this study, Cherax quadricarinatus was used as an experimental model to evaluate the possible effects of three concentrations (25, 250 and 2500 μg/L) of NPs on red crayfish. The toxicological effects of NPs on this species were investigated based on transcriptomics and microbiome. A total of 67,668 genes were obtained from the transcriptome. The annotation rate of the four major libraries (Nr, KEGG, KOG, Swissprot) was 40.17 %, and the functions of differential genes were mainly related to antioxidant activity, metabolism and immune processes. During the experiment, the activities of superoxide dismutase (SOD) and catalase (CAT) in the high concentration group were significantly decreased, while the concentration of malondialdehyde (MDA) increased after nanoplastics (NPs) exposure, and SOD1, Jafrac1 were significantly reduced at high concentrations. expression is inhibited. The immune genes LYZ and PPO2 were highly expressed at low concentrations and suppressed at high concentrations. After 14 days of exposure to NPs, significant changes in gut microbiota were observed, such as decreased abundances of Actinobacteria, Bacteroidetes, and Firmicutes. NPs compromise host health by inducing changes in microbial communities and the production of beneficial bacterial metabolites. Overall, these results suggest that NPs affect immune-related gene expression and antioxidant enzyme activity in red crayfish and cause redox imbalance in the body, altering the composition and diversity of the gut microbiota.

Wastewater plastisphere enhances antibiotic resistant elements, bacterial pathogens, and toxicological impacts in the environment

Microplastics (MPs) are plastic particles with a size <5 mm that have raised alarming concerns owing to their ecological and human health impacts. They are largely released into the environment through the dumping of plastic waste and wastewater from treatment plants, domestic sewage, agricultural runoff, and industrial sources. Conventional wastewater treatment plants (WWTPs) are unable to remove micro and nano-sized plastic particles, which end up in the natural aquatic and terrestrial environment, causing multifaceted toxic impacts. Moreover, plastics in wastewater generate biofilm that potentially enriches antibiotic resistant bacteria (ARBs), antibiotic resistant genes (ARGs), and bacterial pathogens, which can largely impact antibiotic resistance development among organisms in the environment and transfer to humans through the food chain. Therefore, the current review aims to highlight the potential role of wastewater plastisphere in the enrichment and dissemination of ARBs, ARGs, and potential bacterial pathogens through mobile genetic elements (MGEs) in the environment. Further, the interaction of wastewater MPs with organic and inorganic contaminants and the associated ecological and human health impacts have been presented. Last but not the least, control strategies and future research perspectives on wastewater plastisphere are also highlighted.

Long-term exposure to nanoplastics alters molecular and functional traits related to the carcinogenic process

Micro/nanoplastics (MNPLs) are considered emergent pollutants widely spread over all environmental compartments. Although their potential biological effects are being intensively evaluated, many doubts remain about their potential health effects in humans. One of the most underdeveloped fields is the determination of the potential tumorigenic risk of MNPLs exposure. To shed light on this topic, we have designed a wide battery of different hallmarks of cancer applied to prone-to-transformed progress MEF cells exposed to polystyrene nanoplastics (PSNPLs) in the long term (6 months). Interestingly, most of the evaluated hallmarks of cancer are exacerbated after exposure, independently if they are associated with an early tumoral phenotype (changes in stress-related genes, or microRNA deregulation), advanced tumoral phenotype (growing independently of anchorage ability, and migration capacity), or an aggressive tumoral phenotype (invasion potential, changes in pluripotency markers, and ability to grow to form tumorspheres). This set of obtained data constitutes a relevant warning on the potential carcinogenic risk associated with long-term exposures to MNPLs, specifically that induced by the PSNPLs evaluated in this study.

Di-(2-ethylhexyl) phthalate exacerbated the toxicity of polystyrene nanoplastics through histological damage and intestinal microbiota dysbiosis in freshwater Micropterus salmoides

Organic pollutants such as di-(2-ethylhexyl) phthalate (DEHP) interact with nanoplastics (NPs) and change their bioavailability and toxicity to aquatic organisms. This study aims to assess the ecotoxicological impacts of NPs in the presence and absence of DEHP on juvenile largemouth bass (LMB) Micropterus salmoides. Therefore, LMB was fed with diets containing various concentrations (0, 2, 10, and 40 mg/g) of polystyrene nanoplastics (PSNPs) by the weight of diets. After a 21-day of PSNPs dietary exposure, LMB was treated with DEHP at 450 μg/L through waterborne exposure for three days. Our results showed that PSNPs were accumulated in the intestinal tissues, which significantly decreased the feeding and growth rates in LMB. The histopathological analysis showed the intestine and liver of LMB were subjected to various degrees of structural damage caused by PSNPs, and DEHP-PSNP co-exposure enhanced those histopathological damages in both tissues. Additionally, the co-exposure induced oxidative stress in terms of increased activities of glutathione S-transferase, catalase, and superoxide dismutase enzymes in the liver, intestine, spleen, and serum. Furthermore, the co-exposure significantly changed the intestinal microbial composition, i.e., the decrease in the abundance of probiotics (Bacteroidetes and Proteobacteria) and the increase in pathogenic bacteria (Firmicutes) posed a great threat to fish metabolism and health. Therefore, this study highlights that the presence of DEHP enhances the toxicity of NPs on LMB in freshwater and suggests the regulated use of plastic and its additives for improving the health status of aquaculture fish for food safety in humans.