Polystyrene nanoplastics affect digestive function and growth in juvenile groupers

Co-exposure of decabromodiphenyl ethane and polystyrene nanoplastics damages grass carp (Ctenopharyngodon idella) hepatocytes: Focus on the role of oxidative stress, ferroptosis, and inflammatory reaction

Decabromodiphenyl ethane (DBDPE) and polystyrene nanoplastics (PS-NPs) are emerging pollutants that seriously threaten the ecological safety of the aquatic environment. However, the hepatotoxicity effect of their combined exposure on aquatic organisms has not been reported to date. In, this study, the effects of single or co-exposure of DBDPE and PS-NPs on grass carp hepatocytes were explored and biomarkers related to oxidative stress, ferroptosis, and inflammatory cytokines were evaluated. The results show that both single and co-exposure to DBDPE and PS-NPs caused oxidative stress. Oxidative stress was induced by increasing the contents of pro-oxidation factors (ROS, MDA, and LPO), inhibiting the activity of antioxidant enzymes (CAT, GPX, T-SOD, GSH, and T-AOC), and downregulating the mRNA expressions of antioxidant genes (GPX1, GSTO1, SOD1, and CAT); the effects of combined exposure were stronger overall. Both single and co-exposure to DBDPE and PS-NPs also elevated Fe2+ content, promoted the expressions of TFR1, STEAP3, and NCOA4, and inhibited the expressions of FTH1, SLC7A11, GCLC, GSS, and GPX4; these effects resulted in iron overload-induced ferroptosis, where co-exposure had stronger adverse effects on ferroptosis-related biomarkers than single exposure. Moreover, single or co-exposure enhanced inflammatory cytokine levels, as evidenced by increased mRNA expressions of IL-6, IL-12, IL-17, IL-18, IL-1β, TNF-α, IFN-γ, and MPO. Co-exposure exhibited higher expression of pro-inflammatory cytokines compared to single exposure. Interestingly, the ferroptosis inhibitor ferrostatin-1 intervention diminished the above changes. In brief, the results suggest that DBDPE and PS-NPs trigger elevated levels of inflammatory cytokines in grass crap hepatocytes. This elevation is achieved via oxidative stress and iron overload-mediated ferroptosis, where cytotoxicity was stronger under co-exposure compared to single exposure. Overall, the findings contribute to elucidating the potential hepatotoxicity mechanisms in aquatic organisms caused by co-exposure to DBDPE and PS-NPs.

Impact of sub-chronic polystyrene nanoplastics exposure on hematology, histology, and endoplasmic reticulum stress-related protein expression in Nile tilapia (Oreochromis niloticus)

Nanoplastics (NPs) are one of the most hazardous marine litters, having the potential to cause far-reaching impacts on the environment and humankind. The effect of NPs on fish health has been studied, but their impact on the subcellular organelles remains unexplored. The present investigation studied the possible implications of polystyrene-nanoplastics (PS-NPs) on the hematology, tissue organization, and endoplasmic reticulum (ER) stress-related proteins in Nile tilapia (Oreochromis niloticus). Fish were exposed to ∼100 nm PS-NPs at environmentally relevant (0.1 mg/L), and sublethal (1, 10 mg/L) concentrations for 14 days through water exposure. The growth performance and hematological parameters such as erythrocytes, hemoglobin, hematocrit, and leucocytes decreased, while thrombocytes increased with PS-NPs dose-dependently. The gills, liver, kidney, and heart tissues displayed increasing degrees of pathology with increased concentrations of PS-NPs. The gills showed severe epithelial hyperplasia and lamellar fusion. The liver had an abstruse cellular framework, membrane breakage, and vacuolation. While glomerular and tubular atrophy was the most prominent pathology in the kidney tissue, the heart displayed extensive myofibrillar loss and disorderly arranged cardiac cells. The ER-stress-related genes such as bip, atf6, ire1, xbp1, pkr, and apoptotic genes such as casp3a, and bax were over-expressed, while, the anti-apoptotic bcl2 was under-expressed with increasing concentrations of PS-NPs. Immunohistochemistry and blotting results of GRP78, CHOP, EIF2S, and ATF6 in gills, liver, kidney, and heart tissues affirmed the translation to ER stress proteins. The results revealed the sub-lethal adverse effects and the activation of the ER-stress pathway in fish with sub-chronic exposure to PS-NPs.

Understanding the links between micro/nanoplastics-induced gut microbes dysbiosis and potential diseases in fish: A review

At present, the quantity of micro/nano plastics in the environment is steadily rising, and their pollution has emerged as a global environmental issue. The tendency of their bioaccumulation in aquatic organisms (especially fish) has intensified people's attention to their persistent ecotoxicology. This review critically studies the accumulation of fish in the intestines of fish through active or passive intake of micro/nano plastics, resulting in their accumulation in intestinal organs and subsequent disturbance of intestinal microflora. The key lies in the complex toxic effect on the host after the disturbance of fish intestinal microflora. In addition, this review pointed out the characteristics of micro/nano plastics and the effects of their combined toxicity with adsorbed pollutants on fish intestinal microorganisms, in order to fully understand the characteristics of micro/nano plastics and emphasize the complex interaction between MNPs and other pollutants. We have an in-depth understanding of MNPs-induced intestinal flora disorders and intestinal dysfunction, affecting the host's systemic system, including immune system, nervous system, and reproductive system. The review also underscores the imperative for future research to investigate the toxic effects of prolonged exposure to MNPs, which are crucial for evaluating the ecological risks posed by MNPs and devising strategies to safeguard aquatic organisms.

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.

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.

Environmental and Sublethal Concentrations of Polystyrene Nanoplastics Induced Antioxidant System, Transcriptomic Responses, and Disturbed Gut Microbiota in Oyster Magallana Hongkongensis

Nanoplastics (NPs) are emerging contaminants having persistent nature, diverse ecological impacts, and potential food safety risks. Here, we examined the ecotoxicity of 80 nm polystyrene nanoplastics (PS-NPs) at environmentally relevant concentrations (ERCs, 10 and 100 μg/L), and sublethal concentrations (SLCs, 500 and 2500 μg/L) in Magallana hongkongensis. Results showed that SLCs significantly (p < 0.05) increased superoxide dismutase (SOD), catalase (CAT), and alkaline phosphatase (AKP) activities and altered tnfα, cat, gst, sod, and se-gpx genetic expressions. Further, PS-NP exposure at both levels reduced beneficial bacteria and increased potentially pathogenic bacteria in the gut. In transcriptomic analysis, 5118 and 4180 differentially expressed genes (DEGs) were identified at ERCs, while 5665 and 4817 DEGs were found at SLCs, respectively. Upregulated DEGs enriched lysosomes, ABC transporters, and apoptosis pathways, while downregulated DEGs enriched ribosomal pathways. Overall, ERCs significantly altered gut microbiota and transcriptomic responses, while SLCs, in addition, also impacted the antioxidant and immune systems.

Physiological and histopathological effects of polystyrene nanoparticles on the filter-feeding fish Hypophthalmichthys molitrix

Excessive use of plastics in daily life is causing plastic pollution in aquatic environment and threatening the aquatic life. Therefore, research on the plastic pollution in aquatic environment is crucial to understand its impact and develop effective solution for safeguarding aquatic life and ecosystem. The current study investigated the effects of water borne polystyrene nanoparticles (PS-NPs) on hemato-immunological indices, serum metabolic enzymes, gills, and liver antioxidant parameters, plasma cortisol level and histopathological changes in liver and gill tissues of the widely distributed fish Hypophthalmichthys molitrix. The fingerlings of H. molitrix were exposed to different concentrations (T1-0.5, T2-1.0, and T3-2.0 mg/L) of PS-NPs respectively for 15 days consecutively. Our results indicated the dose dependent negative effects of PS-NPs on the physiology and histopathology of H. molitrix. Immuno-hematological indices showed significant increase in WBCs count, phagocytic activity, and lysozyme activity, while decreased RBC count, Hct%, Hb level, total proteins, IgM, and respiratory burst activity were observed. The levels of antioxidant enzymes like SOD, CAT and POD showed the decreasing trends while metabolic enzymes (AST, ALT, ALP and LDH), LPO, ROS activities and relative expressions of SOD1, CAT, HIF1-α and HSP-70 genes increased with increased concentrations of PS-NPs. Moreover, blood glucose and cortisol levels also showed significant increasing trends with dose dependent manner. Histopathological examination indicated moderate to severe changes in the gills and liver tissues of the group treated with 2.0 mg/L of PS-NPs. Overall, the results showed the deleterious effects of PS-NPs on physiology, immunity, metabolism, and gene expressions of H. molitrix. It is concluded that particulate plastic pollution has deleterious effects on filter feeding fish, which might affect human health through food chain and particulate chemical toxicity.

Impacts of Nile Tilapia (Oreochromis niloticus) exposed to microplastics in bioflocs system

Microplastics (MPs) are abundant in aquaculture water, including in bioflocs aquaculture systems. Compared with other aquaculture systems, biofloc technology systems have the richest microbes and are beneficial to cultivated organisms. Therefore, this study provides a comprehensive assessment of the potential effects of MPs on aquaculture organisms in bioflocs systems. Here, Nile Tilapia (Oreochromis niloticus) were exposed to MPs (polystyrene; 32-40 μm diameter) with 0, 80 items/L (30 μg/L), and 800 items/L (300 μg/L) for 28 days in a bioflocs aquaculture system. The results showed that the MPs generally had no apparent effect on water quality, tilapia growth, or digestive enzyme activity. However, MPs accumulated the most in the liver (5.65 ± 0.74 μg/mg) and significantly increased the hepato-somatic index of tilapia and reduced the crude protein and lipid of tilapia muscle (p < 0.05). The levels of the antioxidant enzymes catalase and glutathione S-transferase increased significantly in response to MPs (p < 0.05). In contrast, MPs did not affect the content of glutathione, glutathione peroxidase, oxidized glutathione, and malondialdehyde, or the enzyme activity of Na+/K+-ATPase. Moreover, using an improved integrated biomarker response index, growth performance was found to be less responsive to MPs than to oxidative stress and digestive activity. Exposure to MPs did not significantly influence the microbial communities of the bioflocs and tilapia guts (p < 0.05). These results suggest that MPs barely affected tilapia in the bioflocs system. This study contributes to the evaluation of the ecological risk of MPs in aquaculture systems and a better understanding of the integrated response of cultivated vertebrates to MPs in biofloc technology systems.

Temporal stability and assembly mechanisms of gut microbiota in sea cucumbers response to nanoplastics treatment

Aquaculture provides essential food for humans, and the health of farmed species is particularly important for the aquaculture industry. Aquaculture environment could be a sink of plastic debris (PDs) due to the enclosed character and heavy use of plastics. Gut microbiota of aquaculture species could respond to the exogenous pollutants and regulate the health of hosts. Here, variations in gut microbiota of Apostichopus japonicus induced by the ingested nanoplastics (NPs) were investigated by a lab experiment. We selected a NPs concentration gradient of 100 mg/kg and 500 mg/kg to simulate microplastic pollution to A. japonicus, and the significant differences in gut microbiota composition after 21 days of NP exposure were evaluated. According to the high-throughput sequencing from time series samples, a decrease of diversity in gut microbiota of A. japonicus with dietary NPs was observed. In addition, the gut microbiota compositions of sea cucumbers with and without NPs exposure were also distinct, expressing as enrichment of Bacteroidota while reducement of Proteobacteria under NPs stresses. Combined the results of network analysis, the less complexity and stability of gut microbiota in sea cucumbers with dietary NPs were proved. Based on the neutral community model, the ingested NPs elevated the contribution of stochastic processes for the gut microbiota assembly in sea cucumbers. Our study showed that substantial variations in gut microbiota of A. japonicus under NPs stresses, and also explored the underlying mechanisms regulating these changes. This research would offer new meaningful insights into the toxicity of NPs on sea cucumbers, contributing a solid fundament to improve the health of sea cucumbers under NPs stresses.

Co-exposure to environmentally relevant concentrations of cadmium and polystyrene nanoplastics induced oxidative stress, ferroptosis and excessive mitophagy in mice kidney

Nanoplastics (NPs) are defined as a group of emerging pollutants. However, the adverse effect of NPs and/or heavy metals on mammals is still largely unclear. Therefore, we performed a 35-day chronic toxicity experiment with mice to observe the impacts of exposure to Cadmium (Cd) and/or polystyrene nanoplastics (PSNPs). This study revealed that combined exposure to Cd and PSNPs added to the mice's growth toxicity and kidney damage. Moreover, Cd and PSNPs co-exposure obviously increased the MDA level and expressions of 4-HNE and 8-OHDG while decreasing the activity of antioxidase in kidneys via inhibiting the Nrf2 pathway and its downstream genes and proteins expression. More importantly, the results suggested for the first time that Cd and PSNPs co-exposure synergistically increased iron concentration in kidneys, and induced ferroptosis through regulating expression levels of SLC7A11, GPX4, PTGS2, HMGB1, FTH1 and FTL. Simultaneously, Cd and PSNPs co-exposure further increased the expression levels of Pink, Parkin, ATG5, Beclin1, and LC3 while significantly reducing the P62 expression level. In brief, this study found that combined exposure to Cd and PSNPs synergistically caused oxidative stress, ferroptosis and excessive mitophagy ultimately aggravating kidney damage in mice, which provided new insight into the combined toxic effect between heavy metals and PSNPs on mammals.

Could probiotics protect against human toxicity caused by polystyrene nanoplastics and microplastics?

Nanoplastics (NPs) and microplastics (MPs) made of polystyrene (PS) can be toxic to humans, especially by ingestion of plastic particles. These substances are often introduced into the gastrointestinal tract, where they can cause several adverse effects, including disturbances in intestinal flora, mutagenicity, cytotoxicity, reproductive toxicity, neurotoxicity, and exacerbated oxidative stress. Although there are widespread reports of the protective effects of probiotics on the harm caused by chemical contaminants, limited information is available on how these organisms may protect against PS toxicity in either humans or animals. The protective effects of probiotics can be seen in organs, such as the gastrointestinal tract, reproductive tract, and even the brain. It has been shown that both MPs and NPs could induce microbial dysbiosis in the gut, nose and lungs, and probiotic bacteria could be considered for both prevention and treatment. Furthermore, the improvement in gut dysbiosis and intestinal leakage after probiotics consumption may reduce inflammatory biomarkers and avoid unnecessary activation of the immune system. Herein, we show probiotics may overcome the toxicity of polystyrene nanoplastics and microplastics in humans, although some studies are required before any clinical recommendations can be made.

Adverse effects of polystyrene nanoplastics on sea cucumber Apostichopus japonicus and their association with gut microbiota dysbiosis

The mariculture environment is a sink of microplastics (MPs) due to its enclosed nature and mass use of plastics. Nanoplastics (NPs) are MPs with a diameter <1 μm that have a more toxic effect on aquatic organisms than other MPs. However, little is known about the underlying mechanisms of NP toxicity on mariculture species. Here, we performed a multi-omics investigation to explore gut microbiota dysbiosis and associated health problems induced by NPs in juvenile sea cucumber Apostichopus japonicus, a commercially and ecologically important marine invertebrate. We observed significant differences in gut microbiota composition after 21 days of NP exposure. Ingestion of NPs significantly increased core gut microbes, especially Rhodobacteraceae and Flavobacteriaceae families. Additionally, gut gene expression profiles were altered by NPs, especially those related to neurological diseases and movement disorders. Correlation and network analyses indicated close relationships between transcriptome changes and gut microbiota variation. Furthermore, NPs induced oxidative stress in sea cucumber intestines, which may be associated with intraspecies variation in Rhodobacteraceae in the gut microbiota. The results suggested that NPs were harmful to the health of sea cucumbers, and they highlighted the importance of the gut microbiota in the responses to NP toxicity in marine invertebrates.

Nanoplastics affect the growth of sea urchins (Strongylocentrotus intermedius) and damage gut health

Nanoplastics (NPs) are abundant and widespread throughout the ocean, not only causing severe environmental pollution, but also worsening the aquatic organisms. To elucidate the mechanism of biological toxic effects underlying the responses of marine invertebrates to NPs, Strongylocentrotus intermedius was stressed with three different NPs concentrations (0 particles/L, 10² particles/L and 10⁴ particles/L). Specific growth rates, enzyme activity, gut tissue section observation and structural characteristics of the gut bacterial community were analyzed. After 28 days of exposure, the specific growth rate of S. intermedius decreased significantly with NPs groups. Further, both lysozyme, pepsin, lipase and amylase activities decreased, while the superoxide dismutase activity increased, indicating that NPs negatively affected digestive enzyme and immune enzyme activity. The analysis of gut tissue sections revealed that NPs caused atrophy and cytoplasmic reduction in the epithelial cells of the S. intermedius intestine. Moreover, the structural characterization of the gut bacterial community indicated significant changes in the abundances of members from Campylobacterota, Chlamydiae, and Firmicutes. Members from Arcobacteraceae, Christensenellaceae and Clostridia were endemic to the NPs treatment. The KEGG database analysis demonstrated that the metabolic pathways specific to the NPs treatment group were significantly associated with growth, energy metabolism, and immunity. In summary, NPs have negatively affected on physiological response and altered gut microecological environment.

Chronic nanoplastic exposure induced oxidative and immune stress in medaka gonad

Nanoplastic (NP) pollution is a global issue because of its widespread occurrence and potential toxicity. Many studies have investigated the impacts of the short-term toxicity of NPs on organisms. Until now, only a few studies have assessed the toxicological effects of prolonged exposure to NPs at low concentrations in fish. In this study, the effects of NPs (nano-polystyrene microspheres, diameter: 100 nm) on immune and oxidative stress response, histopathology, and survival in medaka were evaluated. The effects of different concentrations (0, 10, 10⁴, and 10⁶ particles/L) of nanoplastics were studied in medaka Oryzias latipes after 3 months of exposure. Lysozyme enzyme activity, oxidative stress-related biomarkers (i.e., superoxide dismutase, catalase, and glutathione peroxidase), and malondialdehyde levels were decreased under NP exposure. The gonadal histology showed that high NP exposure (10⁶ particles/L) inhibited the process of spermatogenesis and oogenesis processes, implying delayed maturation of the gonad. Furthermore, the IBR and PCA analysis revealed the potential biotoxicity of NPs and the total survival rate of medaka was significantly reduced due to the long-term exposure to NPs. Overall, prolonged exposure to low concentrations of NPs is harmful to the health of medaka gonads. In the long run, this may threaten the fish reproduction and population, suggesting the need for long-term toxicological studies to predict the aquatic animal health in nature.

Nanoplastics and Microplastics May Be Damaging Our Livers

Plastics in the environment can be degraded and even broken into pieces under the action of natural factors, and the degraded products with a particle size of less than 5 mm are called microplastics (MPs). MPs exist in a variety of environmental media that come into contact with the human body. It can enter the body through environmental media and food chains. At present, there are many studies investigating the damage of MPs to marine organisms and mammals. The liver is the largest metabolizing organ and plays an important role in the metabolism of MPs in the body. However, there is no available systematic review on the toxic effects of MPs on the liver. This paper summarizes the adverse effects and mechanisms of MPs on the liver, by searching the literature and highlighting the studies that have been published to date, and provides a scenario for the liver toxicity caused by MPs.

Nanoplastics are bioaccumulated in fish liver and muscle and cause DNA damage after a chronic exposure

The extent of the widespread, planetary contamination by plastic waste is difficult to fully capture. Nanoplastics (NPs) are currently in the center of research concerning plastic litter, both for the analytical challenges they pose and for their potential to provoke hazardous effects in organisms. However, there are still many unanswered questions in this multidisciplinary field, with a crucial missing piece being the quantification of NPs in fish tissues after in vivo exposures. Another relevant question that is still greatly unexplored is how a chronic exposure to NPs will affect fish health. This study aims to provide answers to both of these relevant knowledge gaps. To this end, goldfish (Carassius auratus) were exposed to 44 nm polystyrene (PS)-NPs via water for 30 days. Following the exposure, gastrointestinal tract, liver and muscle were sampled for PS-NPs analysis by means of size exclusion chromatography coupled to high resolution mass spectrometry. PS-NPs were detected in all liver and muscle samples of exposed fish, with higher concentrations in liver than in muscle, whereas no PS-NPs were detected in the gastrointestinal tract. Nevertheless, exposure to PS-NPs did not induce changes in hematology parameters nor in cortisol and glucose levels in plasma. On the other hand, even a relatively low concentration of PS-NPs was able to cause DNA damage, measured by an increase in erythrocyte nuclear abnormalities, suggesting that PS-NPs can reach the cell nucleus and cause genotoxicity. These results show for the first time that PS-NPs find their way to fish muscle after chronic exposure, where they bioaccumulate, but do not alter fish survival nor hematological or physiological stress indicators. The accumulation of PS-NPs in fish muscle can represent a threat to human health as a possible route of exposure to small-sized plastics. The present results in a model fish species open windows for future studies in edible fish species.

Recent advances in toxicological research and potential health impact of microplastics and nanoplastics in vivo

As emerging pollutants, direct and indirect adverse impacts of micro(nano)plastics (MPs/NPs) are raising an increasing environmental concern in recent years due to their poor biodegradability and difficulty in recycling. MPs/NPs can act as carriers of bacteria, viruses, or pollutants (such as heavy metals and toxic organic compounds), and may potentially change the toxicity and bioavailability of pollutants. Ingested or attached MPs/NPs can also be transferred from low-trophic level organisms to high-nutrient organisms or even the human body through the food chain transfer process. This article reviews the emerging field of micro- and nanoplastics on organisms, including the separate toxicity and toxicity of compound after the adsorption of organic pollutants or heavy metals, as well as possible mechanism of toxicological effects and evaluate the nano- and microplastics potential adverse effects on human health. The inherent toxic effects MPs/NPs mainly include the following: physical injury, growth performance decrease and behavioral alteration, lipid metabolic disorder, induced gut microbiota dysbiosis and disruption of the gut's epithelial permeability, neurotoxicity, damage of reproductive system and offspring, oxidative stress, immunotoxicity, etc. Additionally, MPs/NPs may release harmful plastic additives and toxic monomers such as bisphenol A, phthalates, and toluene diisocyanate. The vectors' effect also points out the potential interaction of MPs/NPs with pollutants such as heavy metals, polycyclic aromatic hydrocarbons, organochlorine pesticides, polychlorinated biphenyls, perfluorinated compounds, pharmaceuticals, and polybrominated diphenyl ethers. Nevertheless, these potential consequences of MPs/NPs being vectors for contaminants are controversial.