Unraveling individual and combined toxicity of nano/microplastics and ciprofloxacin to Synechocystis sp. at the cellular and molecular levels

Unveiling the toxicological effects and risks of prometryn on red swamp crayfish (Procambarus clarkii): Health assessments, ecological, and molecular insights

Prometryn is commonly used in agricultural and non-agricultural settings. However, possible harm to aquatic organisms remains a persistent concern. Prometryn was also the only one of the 26 triazine herbicides detected in this study. Numerous studies have assessed the harmful effects of prometryn in teleost fish and shrimp. There is a lack of information regarding the ecological and human health risks, as well as the toxic mechanisms affecting crayfish. In this study, human health risk assessment (THQ) and ecological risk assessment (RQ) were conducted on P. clarkii in the rice-crayfish co-culture (IRCC) farming model. The 96 h of exposure to 0.286 mg/L and 1.43 mg/L prometryn was conducted to investigate the potential effects and molecular mechanisms of hepatopancreatic resistance to prometryn in P. clarkii. The original sample analysis revealed that the THQ calculated from the prometryn levels in the muscle and hepatopancreas was below 0.1, suggesting no threat to human health. However, the calculated RQ values were >0.1, indicating a risk to P. clarkii. Histological analysis and biochemical index detection of the experimental samples revealed that the hepatopancreatic injury and oxidative damage in P. clarkii were caused by prometryn. Moreover, transcriptome analysis identified 2512 differentially expressed genes (DEGs) after 96 h of prometryn exposure. Prometryn exposure caused significant changes in metabolic pathways, including oxoacid metabolic processes and cytochrome P450-associated drug metabolism. Further hub gene analysis via PPI indicated that exposure to prometryn may inhibit lipid synthesis, storage, and amino acid transport and affect glucose metabolic pathways and hormone synthesis. Additionally, we hypothesized that prometryn-triggered cell death could be linked to the PI3K-Akt signaling cascade. This study's findings have significant meaning for the efficient and logical application of herbicides in IRCC, ultimately aiding in advancing a highly productive agricultural system.

Combined effects of microplastics and pharmaceutical and personal care products on algae: A critical review

Microplastics (MPs) and pharmaceuticals and personal care products (PPCPs) are ubiquitous in aquatic environments. Algae play an important role in aquatic environments. Thus, it is important to study the response of algae to combined exposure of MPs and PPCPs. Here, we review the effects of MPs and PPCPs on algae. First, the individual effects of MPs and PPCPs on algae were summarized. Second, the combined effects of MPs and PPCPs on algae were systematically analyzed. (1) Antagonism: ① when the MPs are too large to enter the algal cells, the adsorption of PPCPs onto MPs results in decreased the contact of MPs and PPCPs with algae; ② PPCPs and MPs have opposing actions on the same biological target; ③ MPs increase the activity of metabolic enzymes in algae, thus promoting the PPCP degradation. (2) Synergy: ① when the MPs are small enough to enter algal cells, the adsorption of PPCPs on MPs promotes the entry of PPCPs; ② when MPs are negatively charged, the adsorption of positively charged PPCPs by MPs decreases the electrostatic repulsion, increasing the interaction between algae and MPs; ③ complementary modes of action between MPs and PPCPs show combined effects on the same biological target. Third, the relative importance of the factors that impact the combined effects are evaluated using the random forest model decreased in the following order: PPCP types > algal species > MP size > MP concentration > MP types > exposure time. Finally, future directions for the combined effects of MPs and PPCPs are proposed, which will facilitate a better understanding of the environmental fate and risks of both MPs and PPCPs.

Oxidative stress and metabolic process responses of Chlorella pyrenoidosa to nanoplastic exposure: Insights from integrated analysis of transcriptomics and metabolomics

Oxidative stress is a universal interpretation for the toxicity mechanism of nanoplastics to microalgae. However, there is a lack of deeper insight into the regulation mechanism in microalgae response to oxidative stress, thus affecting the prevention and control for nanoplastics hazard. The integrated analysis of transcriptomics and metabolomics was employed to investigate the mechanism for the oxidative stress response of Chlorella pyrenoidosa to nanoplastics and subsequently lock the according core pathways and driver genes induced. Results indicated that the linoleic acid metabolism, glycine (Gly)-serine (Ser)-threonine (Thr) metabolism, and arginine and proline metabolism pathways of C. pyrenoidosa were collectively involved in oxidative stress. The analysis of linoleic acid metabolism suggested that nanoplastics prompted algal cells to secrete more allelochemicals, thereby leading to destroy the immune system of cells. Gly-Ser-Thr metabolism and arginine and proline metabolism pathways were core pathways involved in algal regulation of cell membrane function and antioxidant system. Key genes, such as LOX2.3, SHM1, TRPA1, and proC1, are drivers of regulating the oxidative stress of algae cells. This investigation lays the foundation for future applications of gene editing technology to limit the hazards of nanoplastics on aquatic organism.

Amide groups within polystyrene accelerates tetracycline removal in a continuous advanced microalgal treatment system

Livestock effluents are challenging to be treated owing that antibiotics and microplastics are untargeted for most biological technologies. As far, microalgal wastewater treatment is recognized as an effective technique for dealing with. In this study, a continuous-flow system was conducted over 45 days to evaluate the effectiveness of Chlamydomonas sp. JSC4 in removing tetracycline (TCH) under the influence of polystyrene (PS). It shows that PS significantly enhanced the dissipation efficiency of TCH from livestock effluents, and 9.83 % TCH removal was increased under 5 mg/L of both TCH and PS exposure. Meanwhile, higher microalgal bioactivity was a significant factor in achieving desirable pollutants removal efficiency, as 87.14 % microalgal biomass was improved owing to reduction of oxidative stress and augmentation of photosynthesis. Importantly, the pivotal active sites, NH2 and CO, were rapidly covered via π-π interactions and hydrogen bonds during adsorption process between TCH and PS, accounting for mitigation of TCH-PS complexes toxicity and improvement of microalgal ribosome metabolism. Additionally, co-exposure to TCH and PS resulted in maximum lipids (0.57 g/L) and energy (20.79 kJ/L) production, further encouraging a fantastic vision for the tertiary process of livestock effluents via advanced microalgal treatment.

Enhancing aggregation of microalgae on polystyrene microplastics by high light: Processes, drivers, and environmental risk assessment

Microplastics (MPs) are emerging pollutants, causing potential threats to aquatic ecosystems and serious concern in aggregating with microalgae (critical primary producers). When entering water bodies, MPs are expected to sink below the water surface and disperse into varying water compartments with different light intensities. However, how light influences the aggregation processes of algal cells onto MPs and the associated molecular coupling mechanisms and derivative risks remain poorly understood. Herein, we investigated the aggregation behavior between polystyrene microplastics (mPS, 10 µm) and Chlorella pyrenoidosa under low (LL, 15 μmol·m-2·s-1), normal (NL, 55 μmol·m-2·s-1), and high light (HL, 150 μmol·m-2·s-1) conditions from integrated in vivo and in silico assays. The results indicated that under LL, the mPS particles primarily existed independently, whereas under NL and HL, C. pyrenoidosa tightly bounded to mPS by secreting more protein-rich extracellular polymeric substances. Infrared spectroscopy analysis and density functional theory calculation revealed that the aggregation formation was driven by non-covalent interaction involving van der Waals force and hydrogen bond. These processes subsequently enhanced the deposition and adherence capacity of mPS and relieved its phytotoxicity. Overall, our findings advance the practical and theoretical understanding of the ecological impacts of MPs in complex aquatic environments.

Ecotoxicological Effects of Microplastics Combined With Antibiotics in the Aquatic Environment: Recent Developments and Prospects

Both microplastics and antibiotics are commonly found contaminants in aquatic ecosystems. Microplastics have the ability to absorb antibiotic pollutants in water, but the specific adsorption behavior and mechanism are not fully understood, particularly in relation to the impact of microplastics on toxicity in aquatic environments. We review the interaction, mechanism, and transport of microplastics and antibiotics in water environments, with a focus on the main physical characteristics and environmental factors affecting adsorption behavior in water. We also analyze the effects of microplastic carriers on antibiotic transport and long-distance transport in the water environment. The toxic effects of microplastics combined with antibiotics on aquatic organisms are systematically explained, as well as the effect of the adsorption behavior of microplastics on the spread of antibiotic resistance genes. Finally, the scientific knowledge gap and future research directions related to the interactions between microplastics and antibiotics in the water environment are summarized to provide basic information for preventing and treating environmental risks. Environ Toxicol Chem 2024;43:1950-1961. © 2024 SETAC.

Toxicological effects of di(2-ethylhexyl)phthalate on dandelions: Insights into physiological, metabolic, and molecular docking perspectives

Di(2-ethylhexyl)phthalate (DEHP) is one of the most widely used plasticizers in plastic manufacturing. However, the toxicological effects of DEHP on dandelions remain poorly understood. This study comprehensively analyzed and explored the response mechanisms of dandelions to 1, 10, 50, and 100 mg L-1 DEHP influencing the morphophysiological growth, metabolomics, and molecular docking. DEHP reduced chlorophyll synthesis, inhibited plant growth, and induced oxidative-state-associated stress, which was manifested by the excessive production of reactive oxygen species, an increase in antioxidant enzyme activities, and enhanced synthesis of some osmoregulatory compounds, including proline and soluble protein. An analysis of the integrated biological response index showed that the toxicity was dose-dependent. Molecular docking demonstrated that DEHP could bind stably to three enzymes, and the binding energy was peroxidase (POD) > catalase (CAT) > superoxide dismutase (SOD). Metabolomics revealed that metabolite abundance and metabolic pathways were altered by DEHP, with 88 and 72 primary metabolites identified in shoots and roots, respectively. Amino acid, sugar, and organic acid metabolism were severely disturbed, with the most significant effects being on carbohydrate metabolism, valine, leucine, and isoleucine biosynthesis. Our study elucidated the influence of DEHP exposure on dandelions, providing new insights into the toxicity mechanisms and toxicological risk assessment.

Nanoplastics enhanced the developmental toxicity of aromatic disinfection byproducts to a marine polychaete at non-feeding early life stage

Micro/nanoplastics can act as vectors for organic pollutants and enhance their toxicity, which has been attributed to the ingestion by organisms and the "Trojan horse effect". In this study, we disclosed a non-ingestion pathway for the toxicity enhancement effect of nanoplastics. Initially, the combined toxicity of polystyrene microplastics (40 μm) or nanoplastics (50 nm) with three disinfection byproducts (DBPs) to a marine polychaete, Platynereis dumerilii, was investigated. No toxic effect was observed for the micro/nanoplastics alone. The microplastics showed no effect on the toxicity of the three DBPs, whereas the nanoplastics significantly enhanced the toxicity of two aromatic DBPs when the polychaete was in its non-feeding early life stage throughout the exposure period. The microplastics showed no interaction with the P. dumerilii embryos, whereas the nanoplastics agglomerated strongly on the embryonic chorion and fully encapsulated the embryos. This could contribute to higher actual exposure concentrations in the microenvironment around the embryos, as the concentrations of the two aromatic DBPs on the nanoplastics were 1200 and 120 times higher than those in bulk solution. Our findings highlight an important and previously overlooked mechanism by which nanoplastics and organic pollutants, such as DBPs, pose a higher risk to marine species at their vulnerable early life stages. This study may contribute to a broader understanding of the environmental impacts of plastic pollution and underscore the necessity to mitigate their risks associated with DBPs.

Alleviating effects of microplastics together with tetracycline hydrochloride on the physiological stress of Closterium sp

Microplastics have significant influence on both freshwater cyanobacteria and marine microalgae, especially under co-exposure with other pollutants such as heavy metals, antibiotics, and pharmaceuticals. In the present study, combined effects of microplastics (polyethylene terephthalate (PET) or polybutylene terephthalate (PBT)) and tetracycline hydrochloride (TCH) on the microalgae Closterium sp. were studied to evaluate their acute toxicity, and the cell density, total chlorophyll concentration, photosynthetic activity, antioxidant system, and subcellular structure of Closterium sp. under different treatments were used to explain the physiological stress mechanism of the combined effects. The results indicate that both the single and combined treatments have inhibition effects on the cell growth and photosynthetic activity, with inhibition efficiencies (in terms of cell density) of 5.0%, 9.2%, 66.7%, 55.1%, and 59.8% for PET (100 mg L-1), PBT (100 mg L-1), TCH (10 mg L-1), PET/TCH (PET 100 mg L-1 and TCH 10 mg L-1), and PBT/TCH (PBT 100 mg L-1 and TCH 10 mg L-1), respectively, and relative electron-transport rates (rETRs) of 7.3%, 12.7%, 66.8%, 54.0%, and 59.9%, respectively, for each treatment compared with the control on the 7th day. Moreover, both PET and PBT have positive effects in alleviating TCH toxicity toward Closterium sp., and at the same time, the malondialdehyde level (MDA), superoxide dismutase (SOD) activity, and catalase (CAT) activity induced by the combined treatments were much higher than those from the single microplastic treatments but lower than those from TCH treatment after 7 days. It was demonstrated that TCH causes a much more serious oxidative stress than PET/TCH and PBT/TCH, and the lower oxidative stress of the PET/TCH and PBT/TCH groups could be attributed to the adsorption of TCH to PET or PBT. This work improves the understanding of the combined toxicity effects of microplastics and TCH on Closterium sp.

Micro/nano-plastics and microalgae in aquatic environment: Influence factor, interaction, and molecular mechanisms

Micro/nano-plastics, as emerging persistent pollutant, are frequently detected in aquatic environments together with other environmental pollutants. Microalgae are the major primary producers and bear an important responsibility for maintaining the balance of aquatic ecosystems. Numerous studies have been conducted on the influence of micro/nano-plastics on the growth, photosynthesis, oxidative stress, gene expression and metabolites of microalgae in laboratory studies. However, it is difficult to comprehensively evaluate the toxic effects of micro/nano-plastics on microalgae due to different experimental designs. Moreover, there is a lack of effective analysis of the aforementioned multi-omics data and reports on shared biological patterns. Therefore, the purpose of this review is to compare the acute, chronic, pulsed, and combined effect of micro/nano-plastics on microalgae and explore hidden rules in the molecular mechanisms of the interaction between them. Results showed that the effect of micro/nano-plastics on microalgae was related to exposure mode, exposure duration, exposure size, concentration, and type of micro/nano-plastics. Meanwhile, the phenomenon of poisoning and detoxification between micro/nano-plastics and microalgae was found. The inhibitory mechanism of micro/nano-plastics on algal growth was due to the micro/nano-plastics affected the photosynthesis, oxidative phosphorylation, and ribosome pathways of algal cells. This brought the disruption of the functions of chloroplasts, mitochondria, and ribosome, as well as impacted on energy metabolism and translation pathways, eventually leading to impairment of cell function. Besides, algae resisted this inhibitory effect by regulating the alanine, aspartate, and glutamate metabolism and purine metabolism pathways, thereby increasing the chlorophyll synthesis, inhibiting the increase of reactive oxygen species, delaying the process of lipid peroxidation, balancing the osmotic pressure of cell membrane.

Combined contamination of microplastic and antibiotic alters the composition of microbial community and metabolism in wheat and maize rhizosphere soil

The widespread application of antibiotics and plastic films in agriculture has led to new characteristics of soil pollution. The impacts of combined contamination of microplastics and antibiotics on plant growth and rhizosphere soil bacterial community and metabolisms are still unclear. We conducted a pot experiment to investigate the effects of polyethylene (0.2%) and norfloxacin/doxycycline (5 mg kg-1), as well as the combination of polyethylene and antibiotics, on the growth, rhizosphere soil bacterial community and metabolisms of wheat and maize seedlings. The results showed that combined contamination caused more serious damage to plant growth than individual contamination, and aggravated root oxidative stress responses. The diversity and structure of soil bacterial community were not markedly altered, but the composition of the bacterial community, soil metabolisms and metabolic pathways were altered. The co-occurrence network analysis indicated that combined contamination may inhibit the growth of wheat and maize seedings by simplifying the interrelationships between soil bacteria and metabolites, and altering the relative abundance of specific bacteria genera (e.g. Kosakonia and Sphingomonas) and soil metabolites (including sugars, organic acids and amino acids). The results help to elucidate the potential mechanisms of phytotoxicity of the combination of microplastic and antibiotics.

When antibiotics encounter microplastics in aquatic environments: Interaction, combined toxicity, and risk assessments

Antibiotics and microplastics (MPs), known as emerging pollutants, are bound to coexist in aquatic environments due to their widespread distribution and prolonged persistence. To date, few systematic summaries are available for the interaction between MPs and antibiotics in aquatic ecosystems, and a comprehensive reanalysis of their combined toxicity is also needed. Based on the collected published data, we have analyzed the source and distribution of MPs and antibiotics in global aquatic environments, finding their coexistence occurs in a lot of study sites. Accordingly, the presence of MPs can directly alter the environmental behavior of antibiotics. The main influencing factors of interaction between antibiotics and MPs have been summarized in terms of the characteristics of MPs and antibiotics, as well as the environmental factors. Then, we have conducted a meta-analysis to evaluate the combined toxicity of antibiotics and MPs on aquatic organisms and the related toxicity indicators, suggesting a significant adverse effect on algae, and inapparent on fish and daphnia. Finally, the environmental risk assessments for antibiotics and MPs were discussed, but unfortunately the standardized methodology for the risk assessment of MPs is still challenging, let alone assessment for their combined toxicity. This review provides insights into the interactions and environment risks of antibiotics and MPs in the aquatic environment, and suggests perspectives for future research.

Temperature fluctuation in soil alters the nanoplastic sensitivity in wheat

Despite the wide acknowledgment that plastic pollution and global warming have become serious agricultural concerns, their combined impact on crop growth remains poorly understood. Given the unabated megatrend, a simulated soil warming (SWT, +4 °C) microcosm experiment was carried out to provide a better understanding of the effects of temperature fluctuations on wheat seedlings exposed to nanoplastics (NPs, 1 g L-1 61.71 ± 0.31 nm polystyrene). It was documented that SWT induced oxidative stress in wheat seedlings grown in NPs-contaminated soil, with an 85.56 % increase in root activity, while decreasing plant height, fresh weight, and leaf area by 8.72 %, 47.68 %, and 15.04 % respectively. The SWT also resulted in reduced photosynthetic electron-transfer reaction and Calvin-Benson cycle in NPs-treated plants. Under NPs, SWT stimulated the tricarboxylic acid (TCA) metabolism and bio-oxidation process. The decrease in photosynthesis and the increase in respiration resulted in an 11.94 % decrease in net photosynthetic rate (Pn). These results indicated the complicated interplay between climate change and nanoplastic pollution in crop growth and underscored the potential risk of nanoplastic pollution on crop production in the future climate.

Mitigating salinity stress through interactions between microalgae and different forms (free-living & alginate gel-encapsulated) of bacteria isolated from estuarine environments

Salinity stress in estuarine environments poses a significant challenge for microalgal survival and proliferation. The interaction between microalgae and bacteria shows promise in alleviating the detrimental impacts of salinity stress on microalgae. Our study investigates this interaction by co-cultivating Chlorella sorokiniana, a freshwater microalga, with a marine growth-promoting bacterium Pseudomonas gessardii, both of which were isolated from estuary. In this study, bacteria were encapsulated using sodium alginate microspheres to establish an isolated co-culture system, preventing direct exposure between microalgae and bacteria. We evaluated microalgal responses to different salinities (5 PSU, 15 PSU) and interaction modes (free-living, gel-encapsulated), focusing on growth, photosynthesis, cellular metabolism, and extracellular polymeric substances (EPS) properties. High salinity inhibited microalgal proliferation, while gel-fixed interaction boosted Chlorella growth rate by 50.7 %. Both attached and free-living bacteria restored Chlorella's NPQ to normal levels under salt stress. Microalgae in the free-living interaction group exhibited a significantly lower respiratory rate compared to the pure algae group (-17.2 %). Increased salinity led to enhanced EPS polysaccharide secretion by microalgae, particularly in interaction groups (19.7 %). Both salt stress and interaction increased the proportion of aromatic proteins in microalgae's EPS, enhancing its stability by modulating EPS glycosidic bond C-O-C and protein vibrations. This alteration caused microalgal cells to aggregate, free-living bacteria co-culture group, and fixed co-culture group increasing by 427.5 %, 567.1 %, and 704.1 %, respectively. In gel-fixed bacteria groups, reduced neutral lipids don't accumulate starch instead, carbon redirects to cellular growth, aiding salt stress mitigation. These synergistic activities between salinity and bacterial interactions are vital in mitigating salinity stress, improving the resilience and growth of microalgae in saline conditions. Our research sheds light on the mechanisms of microalgal-bacterial interactions in coping with salt stress, offering insights into the response of estuarine microorganisms to global environmental changes and their ecological stability.

Toxic effects and action mechanism of metal-organic framework UiO-66-NH2 in Microcystisaeruginosa

The zirconium metal-organic framework UiO-66-NH2 has garnered considerable attention for their potentials of removing environmental contaminants from water. The production and application of UiO-66-NH2 make their releases into the aquatic environment inevitable. Nevertheless, little information is available regarding its potential risk to the environment and aquatic organisms, thus limiting the evaluation of its safe and sustainable use. In this study, the ecotoxicity of UiO-66-NH2 was evaluated, specifically its impacts on growth, extracellular organic matter release, and metabolomic changes of the model phytoplankton Microcystis aeruginosa (M. aeruginosa). UiO-66-NH2 exhibited moderate effects on algal physiology including growth, viability, and photosynthetic system. At concentrations below 20 mg/L, UiO-66-NH2 induced negligible inhibition of algal growth, algal viability, and photosynthesis. In contrast, UiO-66-NH2 boosted the release of extracellular organic matter even at concentration as low as 0.02 mg/L. These findings indicated that, while no evident damage to algal cells was observed, UiO-66-NH2 was hazardous to the aquatic environment as it stimulated the release of algal toxins. Moreover, UiO-66-NH2 entered algal cells rather than adhering to the surface of M. aeruginosa as observed by the fluorescence imaging. Based on metabolic analysis, UiO-66-NH2 influenced the cyanobacteria mainly through interference with purine metabolism and ABC transporter. This study sheds light on the potential threat UiO-66-NH2 posing to microalgae, and has potential implications for its safe utilization in the environmental field.

New insights into the size-independent bioactive potential of pristine and UV-B aged polyethylene microplastics

The present study investigates the morphological, physicochemical, and structural changes occurred by the UV-B aging process of low-density polyethylene microplastics (LDPE MPs), as well as the bioactive potential of both pristine and UVaged MPs towards healthy peripheral blood lymphocytes. Specifically, LDPE MPs (100-180 μm) prepared by mechanical milling of LDPE pellets, were UV-B irradiated for 120 days (wavelength 280 nm; temperature 25 °C; relative humidity 50 %) and further examined for alterations in their particle size and surface, their functional groups, thermal stability, and crystallinity (by means of SEM, FTIR spectroscopy, XRD patterns, and TGA measurements, respectively). In parallel, isolated human peripheral blood lymphocytes were treated with different concentrations (25-500 μg mL-1) of either pristine or aged MPs (UVfree and UV120d LDPE MPs) for assessing the cytogenotoxic (by means of trypan blue exclusion test and the cytokinesis-block micronucleus assay using cytochalasin-B) and oxidative effects (using the DCFH-DA staining) in both cases. According to the results, UVfree and UV120d-LDPE MPs, with a size ranging from 100 to 180 μm, can differentially promote cytogenotoxic and oxidative alterations in human lymphocytes. In fact, UVfree LDPE MPs not being able to be internalized by cells due to their size, could indirectly promote the onset of mild oxidative and cytogenotoxic damage in human peripheral lymphocytes, via a dose-dependent but size-independent manner. The latter is more profound in case of the irregular-shaped UV120d-LDPE MPs, bearing improved dispersibility and sharp edges (by means of cracks and holes), as well as oxygen-containing and carbonyl groups. To our knowledge, the present findings provide new data regarding the bioactive behavior of pristine and UV-B aged LDPE MPs, at least in the in vitro biological model tested, thus giving new evidence for their size-independent and/or indirect mode of action.

Polystyrene microplastics enhanced the effect of PFOA on Chlorella sorokiniana: Perspective from the cellular and molecular levels

Microplastics (MPs) commonly coexist with other contaminants and alter their toxicity. Perfluorooctanoic acid (PFOA), an emerging pollutant, may interact with MPs but remain largely unknown about the joint toxicity of PFOA and MPs. Hence, this research explored the single and joint effects of PFOA and polystyrene microplastics (PS-MPs) on microalgae (Chlorella sorokiniana) at the cellular and molecular levels. Results demonstrated that PS-MPs increased PFOA bioavailability by altering cell membrane permeability, thus aggravating biotoxicity (synergistic effect). Meanwhile, the defense mechanisms (antioxidant system modulation and extracellular polymeric substances secretion) of Chlorella sorokiniana were activated to alleviate toxicity. Additionally, transcriptomic analysis illustrated that co-exposure had more differential expression genes (DEGs; 4379 DEGs) than single-exposure (PFOA: 2533 DEGs; PS-MPs: 492 DEGs), which were mainly distributed in the GO terms associated with the membrane composition and antioxidant system. The molecular regulatory network further revealed that PS-MPs and PFOA primarily regulated the response mechanisms of Chlorella sorokiniana by altering the ribosome biogenesis, photosynthesis, citrate cycle, oxidative stress, and antioxidant system (antioxidant enzyme, glutathione-ascorbate cycle). These findings elucidated that PS-MPs enhanced the effect of PFOA, providing new insights into the influences of MPs and PFOA on algae and the risk assessment of multiple contaminants. ENVIRONMENTAL IMPLICATION: MPs and PFAS, emerging contaminants, are difficult to degrade and pose a non-negligible threat to organisms. Co-pollution of MPs and PFAS is ubiquitous in the aquatic environment, while risks of co-existence to organisms remain unknown. The present study revealed the toxicity and defense mechanisms of microalgae exposure to PS-MPs and PFOA from cellular and molecular levels. According to biochemical and transcriptomic analyses, PS-MPs increased PFOA bioavailability and enhanced the effect of PFOA on Chlorella sorokiniana, showing a synergistic effect. This research provides a basis for assessing the eco-environmental risks of MPs and PFAS.

Micro- and nanoplastics interact with conventional pollutants on microalgae: Synthesis through meta-analysis

Micro- and nanoplastics (MNPs) have been found to occur intensively in aquatic environments, along with other conventional pollutants (Po) such as heavy metals, pesticides, pharmaceuticals, etc. However, our understanding of how MNPs and Po interact on aquatic primary producers is fragmented. We performed a quantitative meta-analysis based on 933 published experimental assessments from 44 studies to examine the coupled effects of MNPs and Po on microalgae. Although the results based on interaction type frequency (the proportion of each interaction type in all results) revealed dominantly additive interactions (56%) for overall physiological performance, an overall antagonistic effect was observed based on the mean interaction effect sizes. A higher proportion of antagonistic interaction type frequency was found in marine species compared to fresh species. The antagonistic effects were particularly significant for growth, oxidative responses, and photosynthesis, which could be attributed to the adsorption effect of MNPs on Po and thus the decreasing concentrations of pollutants in the medium. Larger-sized, negatively charged or uncharged and aged MNPs had higher proportions of antagonistic effects compared to smaller-sized, positively charged and virgin MNPs, due to their stronger adsorption capacity to Po. This study provides a comprehensive insight into the interactive effects of MNPs and Po on microalgae.

Short-term influence of polytetrafluoroethylene micro/nano-plastics on the inhibition of copper and/or ciprofloxacin on the nitrifying sludge activities based on concentration addition and independent action models

Short-term influence of polytetrafluoroethylene micro/nano-plastics (PTFE-MPs/NPs) on the inhibition of copper (Cu2+) and/or ciprofloxacin (CIP) on the nitrifying sludge activities was explored based on concentration addition (CA) and independent action (IA) models. The half maximal inhibitory concentration (IC50) of Cu2+, CIP, PTFE-MPs (3 μm), and PTFE-NPs (800 nm) on the specific ammonium oxidation rate (SAOR) of nitrifying sludge was 64.57, 51.29, 102.33 and 93.33 mg L-1, respectively, while those on the specific nitrite oxidation rate (SNOR) of nitrifying sludge were 77.62, 32.36, 104.70 and 97.72 mg L-1, respectively. Among the five binary mixtures and two ternary mixtures composed by Cu2+, CIP, and/or PTFE-MPs/NPs, it was found that the two joint inhibitory actions from ternary mixtures on the SAOR and SNOR of the sludge showed time-dependent characteristics by analyzing of CA and IA models, while the five combined inhibitory effects from different binary mixtures did not all have time-dependent features. The two joint inhibition actions from diverse ternary mixtures on the SAOR at the exposure time of 60 min and on the SNOR at 90 min showed always concentration-dependent features, while the combined inhibitions with concentration-dependent characteristics had never been observed in the binary Cu2+ and PTFE-NPs mixtures at different exposure time. The Cu2+, CIP, and PTFE-MPs mixtures (or Cu2+, CIP, and PTFE-NPs mixtures) had synergistic actions on the SAOR at 90 min and antagonistic effects on the SNOR at 60 min based on CA and IA models, and these combined inhibitions did not exhibit concentration-dependent characteristics. In contrast, the joint inhibitory effects (on the SAOR and SNOR) with concentration-dependent features were found in the binary mixtures of CIP and PTFE-MPs at different exposure time, and the join inhibition changed from synergism to antagonism as the increasing concentration of mixed CIP and PTFE-MPs. This study provides novel perspectives for understanding the combined influence of plastic particles with different sizes, antibiotics, and heavy metals on the biological wastewater treatment process.

Polystyrene nanoplastics alter the ecotoxicological effects of diclofenac on freshwater microalgae Scenedesmus obliquus

Due to the escalating risk of plastic pollution, nanoplastics have attracted considerable attention in the recent past. They can co-exist and interact with other contaminants like pharmaceuticals in the aquatic environment. Therefore, it is pertinent to understand how these pollutants interact with one another in the ecosystem. The current study examined the individual and combined effects of fluorescent polystyrene nanoplastics (FNPs) and diclofenac (DCF) on Scenedesmus obliquus using a full factorial design. The toxicity of S. obliquus significantly increased in a dose-dependent manner upon exposure to pristine forms of DCF and FNPs. The major cause of individual toxicity of DCF and FNPs in S. obliquus was oxidative stress. In the combined toxicity tests when FNPs (0.01, 0.1, and 1 mg L-1) and DCF (1 mg L-1) were mixed, a synergistic effect was noted compared to the respective pristine FNPs. However, when the DCF concentration in the mixture was decreased to 0.25 mg L-1, the combined toxicity with FNPs (0.01, 0.1, and 1 mg L-1) reduced indicating an antagonistic effect. The independent action model also showed an antagonistic effect for low-dose combinations of DCF and a synergistic effect for high-dose combinations. The estimation of oxidative stress parameters, antioxidant enzyme activity, and photosynthetic pigment content in the algae further validated the cytotoxicity data. The mean hydrodynamic diameter and surface charge analyses further indicated that the colloidal stability of the FNPs in the medium was affected when they were combined with DCF. The key reason for differences in the cytotoxicity of combinations could be observed variations in the aggregation of FNPs and differential adsorption patterns of DCF on the FNPs. These factors efficiently altered cell-particle interactions in the mixture demonstrating a hormesis effect. Thus, this current study highlighted the hazardous nature of the nanoplastics and their co-exposure risks with pharmaceuticals on microalgae in freshwater environments.

Microplastic pollution in terrestrial ecosystems: Global implications and sustainable solutions

Microplastic (MPs) pollution has become a global environmental concern with significant impacts on ecosystems and human health. Although MPs have been widely detected in aquatic environments, their presence in terrestrial ecosystems remains largely unexplored. This review examines the multifaceted issues of MPs pollution in terrestrial ecosystem, covering various aspects from additives in plastics to global legislation and sustainable solutions. The study explores the widespread distribution of MPs worldwide and their potential antagonistic interactions with co-occurring contaminants, emphasizing the need for a holistic understanding of their environmental implications. The influence of MPs on soil and plants is discussed, shedding light on the potential consequences for terrestrial ecosystems and agricultural productivity. The aging mechanisms of MPs, including photo and thermal aging, are elucidated, along with the factors influencing their aging process. Furthermore, the review provides an overview of global legislation addressing plastic waste, including bans on specific plastic items and levies on single-use plastics. Sustainable solutions for MPs pollution are proposed, encompassing upstream approaches such as bioplastics, improved waste management practices, and wastewater treatment technologies, as well as downstream methods like physical and biological removal of MPs. The importance of international collaboration, comprehensive legislation, and global agreements is underscored as crucial in tackling this pervasive environmental challenge. This review may serve as a valuable resource for researchers, policymakers, and stakeholders, providing a comprehensive assessment of the environmental impact and potential risks associated with MPs.

Effects of polyethylene terephthalate microplastics on cell growth, intracellular products and oxidative stress of Scenedesmus sp

Polyethylene terephthalate (PET) has been widely utilized in the synthesis of textile materials and packaging of foods and beverages. In recent years, it has been commonly detected in the form of microplastics (MPs) in wastewater. However, the effects of PET MPs on microalgal intracellular products and their interrelationships have been poorly investigated. In this study, the microalgae Scenedesmus sp. Strain H-1 was exposed to PET MPs to explore their effects on the growth, intracellular products (such as lipids, carbohydrates, and proteins), and antioxidative defense systems of Scenedesmus sp. The results demonstrated that PET MPs significantly reduced Scenedesmus sp. cell growth, with a maximum inhibition rate of 38.25% in the 500 mg L-1 treatment group. PET MPs had negative effects on glucose and nitrate utilization rates and reduced intracellular carbohydrates, intracellular proteins, and photosynthetic pigments. Surprisingly, PET MPs reduced acetyl-CoA carboxylase activity but induced lipid accumulation in microalgae. In addition, PET MPs significantly decreased the essential linoleic acid concentration and increased the palmitic acid content, resulting in reduced biodiesel quality. PET MPs induced the production of reactive oxygen species and malondialdehyde as well as the activities of superoxide dismutase and catalase. The results of the PCA indicated that the response mechanism of Scenedesmus sp. to PET MPs exposure was synergistic. This study provides fundamental data on the impact of MPs on the intracellular products of microalgae.

Microplastics released from disposable medical devices and their toxic responses in Caenorhabditis elegans

Owing to accelerated urbanization and industrialization, many plastic products have been manufactured and discharged into the environment, causing environmental and public health problems. Plastics in environmental media are further degraded by prolonged exposure to light, heat, mechanical friction, and other factors to form new pollutants called microplastics (MPs). Medical plastics have become a crucial source of plastics in environmental media. However, the release profiles of MPs from medical plastics and their potential ecological and health risks remain unclear. We used optical photothermal infrared spectroscopy to explore the release profiles of eight typical disposable medical devices under high-temperature steam disinfection (HSD). We also evaluated the toxicity of disposable medical devices-derived MPs in Caenorhabditis elegans (C. elegans). Our results showed that the changes in the surface morphology and modification of the disposable medical devices were mainly associated with the material. Polypropylene (PP) and polystyrene (PS) materials exhibited high aging phenomena (e.g., bumps, depressions, bulges and cracks), and HSD broke their oxygen-containing functional groups and carbon chains. By contrast, minor changes in the chemical and physical properties were observed in the polyvinyl chloride (PVC)-prepared disposable medical devices under the same conditions. Further physicochemical characterization indicated that the amount of MPs released from PP-prepared disposable medical devices (P4: 1.27 ± 0.34 × 106) was greater than that from PVC-prepared disposable medical devices (P7: 1.08 ± 0.14 × 105). The particle size of the released MPs was the opposite, PVC-prepared disposable medical devices (P7: 11.45 ± 1.79 μm) > PP-prepared disposable medical devices (P4: 7.18 ± 0.52 μm). Toxicity assessment revealed that disposable medical devices-released MPs significantly increased germ cell apoptosisin C. elegans. Moreover, MPs from PP-prepared disposable medical devices disrupted the intestinal barrier of worms, decreasing their lifespan. Our findings provided novel information regarding the profiles and mechanisms of MP release from disposable medical devices and revealed their potential risks to ecological environment.

Interaction between antibiotics and microplastics: Recent advances and perspective

Both microplastics and antibiotics are emerging pollutants, which are ubiquitous in aquatic environments. With small size, high specific surface area, and attached biofilm, microplastics are capable of adsorbing or biodegrading antibiotic pollutants across aquatic environments. However, the interactions between them are poorly understood, especially factors that affect microplastics' chemical vector effects and the mechanisms driving these interactions. In this review, the properties of microplastics and their interaction behavior and mechanisms towards antibiotics were comprehensively summarized. Particularly, the impact of weathering properties of microplastics and the growth of attached biofilm was highlighted. We concluded that compared with virgin microplastics, aged microplastics usually adsorb more types and quantities of antibiotics from aquatic environments, whilst the attached biofilm could further enhance the adsorption capacities and biodegrade some antibiotics. This review can answer the knowledge gaps of the interaction between microplastics and antibiotics (or other pollutants), offer basic information for evaluating their combined toxicity, provide insights into the distribution of both emerging pollutants in the global water chemical cycle, and inform measures to remove microplastic-antibiotic pollution.

Differential toxicity of various mineral nanoparticles to Synechocystis sp.: With and without ciprofloxacin

Mineral nanoparticles (M-NPs) are ubiquitous in aquatic environments, but their potential harms to primary producers and impacts on the toxicity of coexisting pollutants are largely unknown. Herein, the toxicity mechanisms of various M-NPs (i.e., SiO2, Fe2O3, Al2O3, and TiO2 NPs) to Synechocystis sp. in absence and presence of ciprofloxacin (CIP) were comprehensively investigated. The heteroaggregation of cells and M-NPs can hinder substrate transfer or light acquisition. The attraction between Synechocystis sp. and M-NPs increased in the order of SiO2 < Fe2O3 < Al2O3 ≈ TiO2 NPs. Therefore, SiO2 and Fe2O3 NPs exerted slight effects on physiology and proteome of Synechocystis sp.. Al2O3 NPs with the rod-like shape caused physical damage to cells. Differently, TiO2 NPs with photocatalytic activities provided photogenerated electrons for Synechocystis sp., promoting photosynthesis and the Calvin cycle for CO2 fixation. SiO2, Fe2O3, and Al2O3 NPs alleviated the toxicity of CIP in an adsorption-depended manner. Conversely, the combination of CIP and TiO2 NPs exerted more pronounced toxic effects compared to their individuals, and CIP disturbed the extracellular electron transfer from TiO2 NPs to cells. The findings highlight the different effects of TiO2 NPs from other M-NPs on cyanobacteria, either alone or in combination with CIP, and improve the understanding of toxic mechanisms of M-NPs.

Ciprofloxacin enhances cadmium toxicity to earthworm Eisenia fetida by altering the gut microorganism composition

The concurrent existence of cadmium (Cd) and ciprofloxacin (CIP) in agricultural soils is very common, but presents a challenge to soil organisms. As more attention has been paid to the effect of toxic metals on the migration of antibiotic resistance genes, the critical role of the gut microbiota in CIP-modifying Cd toxicity in earthworms remains unclear. In this study, Eisenia fetida was exposed to Cd and CIP alone or in combination at environmentally relevant concentrations. Cd and CIP accumulation in earthworm increased as their respective spiked concentrations increased. In fact, Cd accumulation increased by 39.7% when 1 mg/kg CIP was added; however, the addition of Cd did not affect CIP uptake. Compared with exposure to Cd alone, a greater ingestion of Cd following combined exposure to Cd and 1 mg/kg CIP resulted in greater oxidative stress and energy metabolism disturbances in earthworms. The reactive oxygen species (ROS) contents and apoptosis rate of coelomocytes were more sensitive to Cd than these biochemical indicators. In fact, 1 mg/kg Cd induced the derivation of ROS. Similarly, the toxicity of Cd (5 mg/kg) to coelomocytes was promoted by CIP (1 mg/kg), ROS content in coelomocytes and the apoptosis rate increased by 29.2% and 113.1%, respectively, due to increased Cd accumulation. Further investigation of the gut microorganisms revealed that the decreased abundance of Streptomyces strains (known as Cd accumulation taxa) could be a critical factor for enhanced Cd accumulation and greater Cd toxicity to earthworms following exposure to both Cd and CIP; this was because this microorganism group was eliminated by the simultaneous ingestion of CIP. This study stressed the role of gut microorganisms in altering the toxicity of Cd and CIP combined contamination in soil organisms. More attention should be paid to the ecological risks of such combined contamination in soils.

Involvement of Microplastics in the Conflict Between Host Immunity Defense and Viral Virulence: Promoting the Susceptibility of Shrimp to WSSV Infection

As the concentration of microplastics/microspheres (MPs) in coastal and estuarine regions increases, the likelihood of disease outbreaks and epidemics also rises. Our study investigated the impact of polyvinyl chloride MPs (PVC-MPs) on white spot syndrome virus (WSSV) infection in shrimp. The results revealed that PVC-MPs obviously increased WSSV replication in vivo, leading to a high mortality rate among the larvae and facilitating the horizontal transmission of WSSV. Furthermore, the data of WSSV loads detected together with qPCR, agarose gel electrophoresis, and flow cytometry approaches indicated that PVC-MPs could interact with the virus to prolong survival and maintain the virulence of WSSV at different temperatures and pH values. In terms of host resistance, metabolomics and transcriptomics analysis demonstrated that exposure to PVC-MPs upregulated metabolic concentrations and gene expressions associated with phospholipid metabolism that were associated with innate immunity responses. Particularly, PVC-MPs stimulated the synthesis of phosphatidylcholine (PC) and induced lipid peroxidation. The inhibition of PC on Stimulator of Interferon Genes (STING) translocation from the endoplasmic reticulum to the Golgi apparatus reduces expression of the innate immunity genes (IFN-like genes Vago4 and Vago5) regulated by STING signaling pathways, resulting in a significant decrease in the shrimp's resistance to WSSV infection. Notably, a recovery operation in which the exposed larvae were transferred to a MPs-free aquatic environment led to decreased WSSV infectivity over time, indicating the restoration of antiviral properties in shrimp. Overall, these findings highlight that MPs promote shrimp susceptibility to WSSV in two aspects: host immune defense and viral virulence.

Bacterial Argonaute Proteins Aid Cell Division in the Presence of Topoisomerase Inhibitors in Escherichia coli

Prokaryotic Argonaute (pAgo) proteins are guide-dependent nucleases that function in host defense against invaders. Recently, it was shown that TtAgo from Thermus thermophilus also participates in the completion of DNA replication by decatenating chromosomal DNA. Here, we show that two pAgos from cyanobacteria Synechococcus elongatus (SeAgo) and Limnothrix rosea (LrAgo) are active in heterologous Escherichia coli and aid cell division in the presence of the gyrase inhibitor ciprofloxacin, depending on the host double-strand break repair machinery. Both pAgos are preferentially loaded with small guide DNAs (smDNAs) derived from the sites of replication termination. Ciprofloxacin increases the amounts of smDNAs from the termination region and from the sites of genomic DNA cleavage by gyrase, suggesting that smDNA biogenesis depends on DNA replication and is stimulated by gyrase inhibition. Ciprofloxacin enhances asymmetry in the distribution of smDNAs around Chi sites, indicating that it induces double-strand breaks that serve as a source of smDNA during their processing by RecBCD. While active in E. coli, SeAgo does not protect its native host S. elongatus from ciprofloxacin. These results suggest that pAgo nucleases may help to complete replication of chromosomal DNA by promoting chromosome decatenation or participating in the processing of gyrase cleavage sites, and may switch their functional activities depending on the host species. IMPORTANCE Prokaryotic Argonautes (pAgos) are programmable nucleases with incompletely understood functions in vivo. In contrast to eukaryotic Argonautes, most studied pAgos recognize DNA targets. Recent studies suggested that pAgos can protect bacteria from invader DNA and counteract phage infection and may also have other functions including possible roles in DNA replication, repair, and gene regulation. Here, we have demonstrated that two cyanobacterial pAgos, SeAgo and LrAgo, can assist DNA replication and facilitate cell division in the presence of topoisomerase inhibitors in Escherichia coli. They are specifically loaded with small guide DNAs from the region of replication termination and protect the cells from the action of the gyrase inhibitor ciprofloxacin, suggesting that they help to complete DNA replication and/or repair gyrase-induced breaks. The results show that pAgo proteins may serve as a backup to topoisomerases under conditions unfavorable for DNA replication and may modulate the resistance of host bacterial strains to antibiotics.

Toxicity interaction of polystyrene nanoplastics with sulfamethoxazole on the microalgae Chlamydomonas reinhardtii: A closer look at effect of light availability

The coexistence of nanoplastics and antibiotics in the aquatic environment has raised a complicated risk for ecosystems and human health. How the environmental factors e.g., light, regulate the interaction between nanoplastics and antibiotics and the resulting combined toxicity is poorly understood. Here, we investigated the individual and combined toxicity of polystyrene nanoplastics (nPS, 100 mg L¹) and sulfamethoxazole (SMX, 2.5 and 10 mg L^-1) toward the microalgae Chlamydomonas reinhardtii under low (LL, 16 μmol m^-2·s^-1), normal (NL, 40 μmol m^-2·s^-1), and high light (HL, 150 μmol m^-2·s^-1) in terms of cellular responses. Results indicated that the joint toxicity of nPS and SMX commonly exhibited a strong antagonistic/mitigative effect under LL/NL at 24 h, and under NL at 72 h. nPS could adsorb more SMX under LL/NL at 24 h (1.90/1.33 mg g^-1) and under NL at 72 h (1.01 mg g^-1), thereby alleviating SMX toxicity to C. reinhardtii. However, the self-toxicity of nPS had a negative influence on the degree of antagonism between nPS and SMX. The experimental results coupled with computational chemistry further revealed that the adsorption capacity of SMX on nPS was stimulated by low pH under LL/NL at 24 h (∼7.5), while by less co-existing saline ions (0.83 ppt) and algae-derived dissolved organic matter (9.04 mg L^-1) under NL at 72 h. nPS toxicity that was responsible for the toxic action modes was mainly attributed to the shading effect induced by hetero-aggregation and hindrance of light transmittance (>60%), as well as being regulated by additives leaching (0.49-1.07 mg L^-1) and oxidative stress. Overall, these findings provided a critical basis for the risk assessment and management of multiple pollutants in the complex natural environment.

Assessing the ecological risk of tritium and Carbon-14 discharge on cyanobacteria through metabolic profiling

The ecological risk posed by tritium (T) and carbon-14 (C-14) discharge from nuclear accidents has gained attention. This study evaluated the toxic impact of T and C-14 (at a concentration of 37 kBq/L for 15 days) on the cyanobacteria (Synechococcus elongatus). The results showed that the assimilation efficiency of cyanobacteria was significantly higher for C-14 than T, and the intracellular C-14 activity reached 30.62-40.58 kBq/kg. T and C-14 exposure had no significant effect on cell proliferation but impacted photosynthesis and respiration. T exposure increased the content of Ca, Mg, Na, P, K, and Mn, while C-14 exposure primarily affected trace element absorption in cyanobacteria. 31, 27, and 58 different metabolites (DEMs) were identified under T, C-14, and combined exposure conditions. These DEMs were enriched in the amino acid biosynthesis pathway, and nitrogen assimilation was one of the crucial pathways affected by T and C-14 exposure. The absorption of mineral elements by cyanobacteria was influenced by the variation in metabolites in the ABC transporter pathway caused by T and C-14 exposure. Our findings provide insights into the metabolic response of cyanobacteria to T and C-14 exposure and will help to guide the ecological risk evaluation of nuclear accidents.

Antibiotic profiles and their relationships with multitrophic aquatic communities in an urban river

Antibiotics have garnered worldwide attention due to their omnipresence and detrimental effects on aquatic organisms, yet their potential relationships with multitrophic aquatic communities in natural rivers remain largely unknown. Here, we examined 107 antibiotics in water and sediment from an urban river in Chengdu, Sichuan province (China). The bacterial, algal, macroinvertebrates, and fish communities were synchronously measured based on the environmental DNA (eDNA) metabarcoding approach, and their relationships with antibiotics were further investigated. The results showed that the total antibiotic concentrations ranged from 1.12 to 377 ng/L and from 7.95 to 145 ng/g in water and sediment, respectively. Significant seasonal variations in the concentrations and compositions of antibiotics in water were observed. eDNA metabarcoding revealed great compositional variations of bacterial, algal, macroinvertebrates, and fish communities along the river, and antibiotics had significant negative relationships with the community diversities of aquatic organisms (p < 0.05) except for fish. Meanwhile, significant negative correlations were observed between antibiotic concentrations and the relative abundances of essential metabolism pathways of bacteria, e.g., energy metabolism (p < 0.05), carbohydrate metabolism (p < 0.05), and lipid metabolism (p < 0.01). Moreover, antibiotics demonstrated greater effects on the function of bacterial community compared with environmental variables. The findings highlight the significance of eDNA metabarcoding approach in revealing the relationships between aquatic communities and antibiotics, and call for further studies on the effects of antibiotics on multitrophic aquatic communities in natural waters.

UV-induced microplastics (MPs) aging leads to comprehensive toxicity

Herein, the toxicity of 4 MPs and additives released from MPs during UV-aging was quantitatively evaluated by the transcriptional effect level index (TELI) based on E. coli whole-cell microarray assay, and MPs-antibiotics complex pollutants. Results showed that MPs and these additives had high toxicity potential, the maximum TELI was 5.68/6.85 for polystyrene (PS)/bis(2-ethylhexyl) phthalate (DEHP). There were many similar toxic pathways between MPs and additives, indicating that part of the toxicity risk of MPs was caused by the release of additives. MPs were compounded with antibiotics, the toxicity value changed significantly. The TELI values of amoxicillin (AMX) + polyvinyl chloride (PVC) and ciprofloxacin (CIP) + PVC were as high as 12.30 and 14.58 (P < 0.05). Three antibiotics all decreased the toxicity of PS and had little effect on polypropylene (PP) and polyethylene (PE). The combined toxicity mechanism of MPs and antibiotics was very complicated, and the results could be divided into four types: MPs (PVC/PE + CIP), antibiotics (PVC + TC, PS + AMX/ tetracycline (TC)/CIP, PE + TC), both (PP + AMX/TC/CIP), or brand-new mechanisms (PVC + AMX).

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.

The geno-toxicological impacts of microplastic (MP) exposure on health: mechanistic pathways and research trends from a Chinese perspective

Due to their large-scale manufacture and widespread application, global concern regarding microplastics (MPs) has been increasing rapidly over the past decade, in particular their potential genotoxicity. The genome is constantly exposed to genotoxic insults that can lead to accumulation of reactive oxygen species (ROS), DNA damage, cell death, inflammation or genetic regulation which in turn can have consequences for health, such as the induction of carcinogenesis. In this review, we presented a comprehensive landscape of the effects of MPs on genotoxicity including the molecular mechanisms. Followed by the MP research trend analysis from a global viewpoint including the comparative research between China and USA and point out that scientists should continue to substantially contribute to the field of MPs through more extensive academic investigation, global cooperation, and the development of novel control methods. Challenges are also discussed. Overall, this review provides insights into the genotoxic effects of MPs on human health and related research trends in this field.

Polystyrene nanoplastics promote the apoptosis in Caco-2 cells induced by okadaic acid more than microplastics

Microplastics (MPs) are widespread in the environment and can be ingested through food, water, and air, posing a threat to human health. In addition, MPs can have a potential combined effect with other toxic compounds. Polystyrene (PS) has been shown to enhance the cytotoxicity of okadaic acid (OA). However, it remains unclear whether this enhancement effect is related to the size of PS particles. In this study, we investigated the mechanism of the combined effect of PS microplastics (PS-MPs) or PS nanoplastics (PS-NPs) and OA on Caco-2 cells. The results indicated that PS-NPs enhanced the cytotoxicity of OA and induced endoplasmic reticulum (ER) stress-mediated apoptosis in Caco-2 cells, compared to PS-MPs. Specifically, PS-NPs and OA cause more severe oxidative stress, lactate dehydrogenase (LDH) release, and mitochondrial membrane depolarization. Furthermore, it induced intracellular calcium overload through store-operated channels (SOCs) and activated the PERK/ATF-4/CHOP pathway to cause ER stress. ER stress promoted mitochondrial damage and finally activated the caspase family to induce apoptosis. This study provided an indirect basis for the assessment of the combined toxicity of MPs or NPs with OA.

Black carbon and humic acid alleviate the toxicity of antibiotics to a cyanobacterium Synechocystis sp

Natural organic matters (NOMs), omnipresent in natural water, challenge the toxicity assessment of pollutants to aquatic organisms due to their complex interactions with chemicals and organisms. Here, we investigated the combined toxicity of one solid NOM (black carbon, BC) or one soluble NOM (humic acid, HA) with antibiotics, roxithromycin (RTM) or gatifloxacin (GAT), to the cyanobacterium Synechocystis sp.. The NOMs alleviated the toxicity of RTM and GAT to Synechocystis sp., and BC had greater alleviation effects than HA due to its stronger adsorption to antibiotics. Antibiotics disturbed the photosynthesis of Synechocystis sp. significantly, which were also mitigated by BC and HA. Proteomic analysis showed that BC up-regulated the pathway of ribosome and photosynthetic antenna protein. GAT down-regulated the pathways of ABC transporter and oxidative phosphorylation. RTM interfered the pathway of porphyrin and chlorophyll metabolism. Furthermore, the addition of BC reduced the number of differentially expressed proteins caused by antibiotics, corroborating its mitigation effects on the toxicity of antibiotics. The disturbance of HA on the pathway of ABC transporters inhibited the internalization of RTM, thus decreasing its toxicity. This study underscores the significance of NOMs in mediating the toxicity of organic pollutants to aquatic organisms in natural waters.

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.

Physiological and metabolic toxicity of polystyrene microplastics to Dunaliella salina

The toxicity of microplastics (MPs) to marine microalgae has raised much concern. However, research at metabolic level is quite limited. In this study, the physiological and metabolic effects of polystyrene (PS) and aged polystyrene (A-PS) MPs on Dunaliella salina were investigated. Both PS and A-PS inhibited the growth of microalgae, but promoted the pigment synthesis in algal cells. The oxidative stress analysis indicated that PS and A-PS induced high production of reactive oxygen species (ROS), and caused oxidative damage to algal cells. Particularly, the highest ROS level in PS and A-PS groups were 1.70- and 2.24-fold of that in the control group, respectively. Untargeted metabolomics analysis indicated that PS and A-PS significantly increased the differential metabolites. Compared with the control group, the significant upregulation of glycerophospholipids metabolites illustrated that severe membrane lipid peroxidation occurred in the MPs groups. Metabolic pathways analysis showed that PS and A-PS perturbed the amino acid-related metabolic pathways. In particular, the amino acid biosynthesis and ATP-binding cassette (ABC) transporter pathways were significantly upregulated, thus promoting nitrogen storage and transmembrane transport in Dunaliella salina. Transmembrane transport requires a large amount of ATP; as a result, algal cell division is inhibited. In addition, A-PS stimulated more active glutathione metabolism than PS. These results enrich the understanding of the toxicity of PS MPs to microalgae at the metabolic level, and are helpful for further assessing the ecological impacts of MPs on microalgae.

Individual and combined toxicity of microplastics and diuron differs between freshwater and marine diatoms

Microplastics are considered as the emerging pollutants, which not only directly affect aquatic organisms, but also causes combined pollution by adsorbing other pollutants. Diuron, as one of the most widely used herbicides, is frequently monitored in the aquatic environment for its adverse effects on aquatic organisms. However, little is known about the combined toxicity of microplastics and diuron to aquatic organisms, especially diatoms. In this study, freshwater diatom (Cyclotella meneghiniana) and marine diatom (Skeletonema costatum) were selected to study the individual and combined toxicity of microplastics (polystyrene, 0.6- 1.0 μm) and diuron. Experimental concentrations of microplastics and diuron were set at 50 mg/L and 100 μg/L, respectively, which have been shown to significantly inhibit the growth of aquatic organisms. Results suggested that both single microplastics and single diuron significantly inhibited the growth of the two diatoms, while significant SOD and MDA increase were only found in single diuron exposure. For diatoms exposed to individual microplastics, the microplastic particles adsorbed inside Cyclotella sp. and those aggregated around Skeletonema sp. were the major factor inhibiting the growth of diatom, respectively. According to the independent action model, the combined toxicity for both diatoms were all antagonistic. The adsorption behavior of microplastics to diuron alleviated the intracellular damage to diatoms caused by diuron, and the oxidative stress induced by diuron mitigated the physical damage to diatoms caused by microplastics. Collectively, our findings suggest that the co-existence of microplastics and diuron may affect their respective toxicity to diatoms. The mechanism of this "cross-phenomenon" between microplastics and diuron and their combined toxicity to different aquatic organisms need to be further studied.

Complex behavior between microplastic and antibiotic and their effect on phosphorus-removing Shewanella strain during wastewater treatment

Owing to their widespread application and use, microplastics (MPs) and antibiotics coexist in the sewage treatment systems. In this study, the effects and mechanisms of the combined stress of MPs and ciprofloxacin (CIP) on phosphorus removal by phosphorus-accumulating organisms (PAOs) were investigated. This study found that the four types of MPs and CIP exhibited different antagonistic effects on the inhibition of phosphorus removal by PAO. MPs reduced the effective concentration of CIP through adsorption and thus reduced its toxicity, which was affected by the biofilms on MPs. In addition, CIP may cause PAO to produce more extracellular polymeric substances, which reduces the physical and oxidative stress of MPs on PAO. Our results are helpful as they increase the understanding of the effects of complex emerging pollutants in sewage systems and propose measures to strengthen the biological phosphorus removal in sewage treatment processes.

Microplastic-Induced Oxidative Stress in Metolachlor-Degrading Filamentous Fungus Trichoderma harzianum

While there has been intensive research on the influence of microplastics (MPs) on aquatic organisms and humans, their effect on microorganisms is relatively little-known. The present study describes the response of the Trichoderma harzianum strain to low-density polyethylene (LDPE) microparticles. MPs, either separately or with metolachlor (MET), were added to the cultures. Initially, MP was not found to have a negative effect on fungal growth and MET degradation. After 72 h of cultivation, the content of fungal biomass in samples with MPs was almost three times higher than that in the cultures without MPs. Additionally, a 75% degradation of the initial MET was observed. However, due to the qualitative and quantitative changes in individual classes of phospholipids, cell membrane permeability was increased. Additionally, MPs induced the overproduction of reactive oxygen species. The activity of superoxide dismutase and catalase was also increased in response to MPs. Despite these defense mechanisms, there was enhanced lipid peroxidation in the cultures containing the LDPE microparticles. The results of the study may fill the knowledge gap on the influence of MPs on filamentous fungi. The findings will be helpful in future research on the biodegradation of contaminants coexisting with MPs in soil.

Interactions of microplastics with organic, inorganic and bio-pollutants and the ecotoxicological effects on terrestrial and aquatic organisms

As emerging contaminants, microplastics (MPs) have attracted global attention. They are a potential risk to organisms, ecosystems and human health. MPs are characterized by small particle sizes, weak photodegradability, and are good environmental carriers. They can physically adsorb or chemically react with organic, inorganic and bio-pollutants to generate complex binary pollutants or change the environmental behaviors of these pollutants. We systematically reviewed the following aspects of MPs: (i) Adsorption of heavy metals and organic pollutants by MPs and the key environmental factors affecting adsorption behaviors; (ii) Enrichment and release of antibiotic resistance genes (ARGs) on MPs and the effects of MPs on ARG migration in the environment; (iii) Formation of "plastisphere" and interactions between MPs and microorganisms; (iv) Ecotoxicological effects of MPs and their co-exposures with other pollutants. Finally, scientific knowledge gaps and future research areas on MPs are summarized, including standardization of study methodologies, ecological effects and human health risks of MPs and their combination with other pollutants.

Antagonistic and synergistic effects of warming and microplastics on microalgae: Case study of the red tide species Prorocentrum donghaiense

Bibliometric network analysis has revealed that the widespread distribution of microplastics (MPs) has detrimental effects on marine organisms; however, the combined effects of MPs and climate change (e.g., warming) is not well understood. In this study, Prorocentrum donghaiense, a typical red tide species in the East China Sea, was exposed to different MP concentrations (0, 1, 5, and 10 mg L^-1) and temperatures (16, 22, and 28 °C) for 7 days to investigate the combined effects of MPs and simulated ocean warming by measuring different physiological parameters, such as cell growth, pigment contents (chlorophyll a and carotenoid), relative electron transfer rate (rETR), reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), and adenosine triphosphate (ATP). The results demonstrated that MPs significantly decreased cell growth, pigment contents, and rETR_max, but increased the MDA, ROS, and SOD levels for all MP treatments at low temperature (16 °C). However, high temperatures (22 and 28 °C) increased the pigment contents and rETR_max, but decreased the SOD and MDA levels. Positive and negative effects of high temperatures (22 or 28 °C) were observed at low (1 and 5 mg L^-1) and high MP (10 mg L^-1) concentrations, respectively, indicating the antagonistic and synergistic effects of combined warming and MP pollution. These results imply that the effects of MPs on microalgae will likely not be substantial in future warming scenarios if MP concentrations are controlled at a certain level. These findings expand the current knowledge of microalgae in response to increasing MP pollution in future warming scenarios.

Humic acids alleviate the toxicity of reduced graphene oxide modified by nanosized palladium in microalgae

The use of graphene-family materials modified by nanosized palladium (Pd/GFMs) has intensified rapidly in various fields; however, the effects of environmental factors (e.g., natural organic matter (NOM)) on the transformation and ecotoxicity of Pd/GFMs remain largely unknown. In this study, reduced graphene oxide modified by nanosized Pd (Pd/rGO) was incubated with humic acid (HA) under light irradiation for 56 d to explore the effects of NOM on the physicochemical transformations (e.g., defects, surface charges and dispersity) and biological toxicity (e.g., growth inhibition, oxidative stress and ultrastructural damage on algae cells) of Pd/GFMs. The results revealed that HA increased the defects and dispersity of Pd/rGO. Growth inhibition, damage to cellular ultrastructures, and oxidative stress in microalgae cells were induced by Pd/rGO, and corresponding defense responses (e.g., superoxide dismutase, peroxidase and glutathione) were activated. HA diminished the above defense responses in microalgae triggered by Pd/rGO by regulating GSH metabolism and the alanine biosynthesis pathway. In the presence of HA, cell wall damage (i.e., hole formation) caused by exposure to Pd/rGO was restored, and the plasmolysis area was reduced by 28.6 %. In addition, growth inhibition, lipid peroxidation, loss of mitochondrial membrane potential and ROS formation induced by 1.0 mg/L MoS₂NPs were decreased by 1.4-65.6 %, 13.9-26.1 %, 21.8-58.3 % and 9.6-16.1 %, respectively. These findings highlight the need to consider the effects of HA on the environmental transformation and biological toxicity of Pd/GFMs, which presents significant implications for the management of Pd/GFMs.

Induced aging, structural change, and adsorption behavior modifications of microplastics by microalgae

The effects of microalgal biofouling on microplastic (MP) may differ from bacterial biofouling. In this study, the influence of microalgae on MP surface alteration, structural change, and adsorption of organic micropollutants was evaluated. Virgin polyethylene (PE), polyvinyl chloride (PVC), and polyamide (PA) were each immersed in algal photobioreactor and river freshwater for 30 days to simulate algal and river microbe biofouling respectively. Consequently, their physicochemical changes and adsorption potential of a mixture of six bisphenol analogues (BPA, BPS, BPE, BPB, BPF, BPAF) and two parabens (propyl-paraben, benzyl-paraben) were investigated. Owing to the algal bioactive compounds, major microalgae-induced biofouling and more MP aging than the river microbe aging were observed through fractures, pits, cracks, and algal attachments. Intrusion of algal organic matter and scission of polymeric functional groups were revealed during microalgal immersion and the potential MP aging pathways were proposed. Algal biofouling considerably altered the intrinsic properties of the MPs, consequently the adsorption capacity of PE and PVC was enhanced by 3.04-6.72 and 2.14-8.72 times, respectively. Adsorption process onto algal-aged MPs was pH-dependent, endothermic, non-spontaneous, and favored by hydrogen bonds. Meanwhile, the amide group in PA structure was conducive to organic micropollutant adsorption, which was likely reduced by algal aging and the erosion of the N-H stretching. Moreover, higher adsorption capacities of organic micropollutants were shown by the algal-biofilm PE and PVC than virgin and river microbial biofilm MPs. This study discloses that, biofouling and aging of MPs by microalgae through their bioactive components would engender more incidences on MP properties, organic micropollutants adsorption with associated environmental and health hazards.

Physiological and transcriptomic responses of Chlorella sorokiniana to ciprofloxacin reveal molecular mechanisms for antibiotic removal

Microalgae-based technology is an effective and environmentally friendly method for antibiotics-contaminated wastewater treatment. To assess the tolerance and removal ability of Chlorella sorokiniana to ciprofloxacin (CIP), this study comprehensively revealed the responses of C. sorokiniana to CIP exposure and its degradation processes through physiological and transcriptomic analyses. Although the photosynthetic system was inhibited, the growth of C. sorokiniana was not negatively affected by CIP. Dissolved organic matter was analyzed and indicated that humic-like substances were released to alleviate the stress of CIP. In addition, the maximum removal of CIP was 83.3% under 20 mg L-1 CIP exposure. HPLC-MS/MS and RNA-Seq analyses suggested that CIP could be bioaccumulated and biodegraded by C. sorokiniana through the reactions of hydroxylation, demethylation, ring cleavage, oxidation, dehydrogenation, and decarboxylation with the help of intracellular oxidoreductases, especially cytochrome P450. Collectively, this research shows that C. sorokiniana have a great potential for removing CIP from wastewater.

Microplastics decrease the toxicity of sulfamethoxazole to marine algae (Skeletonema costatum) at the cellular and molecular levels

Microplastics (MPs) and sulfamethoxazole (SMX) are ubiquitous in various aquatic environments, but little is known about their joint toxicity mechanism on marine organisms. This study investigated the individual and joint toxicity of SMX and five MPs, including polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS) and bioplastic polylactic acid (PLA), on Skeletonema costatum. The inhibition rates (IR) of the single MPs systems (50 mg/L) followed the order of PP > PE > PLA > PS > PET, while the addition of 0.3 mg/L SMX significantly decreased the toxicity of PP, PE and PLA in the joint system due to the "shelter" effect from MPs adsorption. As for the PS and SMX joint system, the malondialdehyde (MDA), reactive oxygen species (ROS) levels and superoxide dismutase (SOD) activity were higher than those of the other joint systems. The metabolomic results showed that SMX downregulated glycerophospholipid and amino acid metabolism. PS caused the downregulation of glycerophospholipids, carbohydrates and amino acid via the hetero-aggregation with algae. The co-exposure of SMX and PS alleviated the perturbation of alanine, aspartate and glutamate metabolism of algae compared with SMX. These findings enhance our understanding of the potential mechanisms of the MPs and organic pollutants joint toxicity in the marine environment.

Microplastics impacts in seven flagellate microalgae: Role of size and cell wall

The toxicity of microplastic particles (MPs) on aquatic environments has been widely reported; however, their effects on protists are still contradictory. For example, it is unclear if cell size and cell wall have a role in shaping the response of flagellates to MPs. In this study, seven marine flagellated microalgae (six Dinoflagellates and one Raphidophyceae) were incubated with 10 mg L^-1 MPs (polystyrene plastic micro-spheres, 1 μm diameter) to address the above question by measuring different response variables, i.e., growth, optimal photochemical efficiency (F_v/F_m), chlorophyll-a (Chl-a) content, superoxide dismutase (SOD) activity, and cell morphology. The effect of MPs on growth and F_v/F_m showed species-specificity effects. Maximum and minimum MPs-induced inhibitions were detected in Karenia mikimotoi (76.43%) and Akashiwo sanguinea (10.16%), respectively, while the rest of the species showed intermediate responses. The presence of MPs was associated with an average reduction of Chl-a content in most cases and with a higher superoxide dismutase activity in all cases. Seven species were classified into two groups by the variation of Chl-a under MPs treatment. One group (Prorocentrum minimum and Karenia mikimotoi) showed increased Chl-a, while the other (P. donghaiense, P. micans, Alexandrium tamarense, Akashiwo sanguinea, Heterosigma akashiwo) showed decreased Chl-a content. The MPs-induced growth inhibition was negatively correlated with cell size in the latter group. SEM images further indicated that MPs-induced malformation in the smaller cells (e.g., P. donghaiense and K. mikimotoi) was more severe than the bigger cells (e.g., A. sanguinea and P. micans), probably due to a relatively higher ratio of the cell surface to cell volume in the former. These results implicate that the effect of MPs on marine flagellated microalgae was related to the cell size among most species but not cell wall. Thus plastic pollution may have size-dependent effects on phytoplankton in future scenarios.

Enhanced microalgal toxicity due to polystyrene nanoplastics and cadmium co-exposure: From the perspective of physiological and metabolomic profiles

As important emerging contaminants, nanoplastics can act as vectors for other environmental pollutants, resulting in their migration throughout ecosystems and altering their toxicity. In this study, the fluorescent dye label aggravated the toxicity of polystyrene (PS) nanoplastics (100 nm diameter particles) to microalgae Euglena gracilis. Therefore, the toxicity of non-fluorescent labelled PS alone and in combination with divalent cadmium (Cd²⁺) on Euglena gracilis in the environmentally relevant concentrations was investigated. Results revealed that co-exposure to 50 μg/L (1.1 × 10¹⁰ particles/L) PS and 50 μg/L Cd²⁺ resulted in synergistic effects, significantly inhibiting microalgal growth by 28.76%. Superoxide dismutase, peroxidase and extracellular polymeric substances were distinctly enhanced in co-exposure treatments compared to the control, indicating that cellular antioxidant defense responses were activated. LC-MS-based metabolomic analysis suggested that PS and Cd²⁺ exposure alone or in combination induced significant disruption to carbohydrate and purine metabolism-related pathways, as compared to controls. As part of the PS and Cd²⁺ stress response, differential metabolites involved in lipid metabolism and amino acid metabolism provide antioxidants and cell membrane protective molecules. Overall, this combined physiological and metabolomic analysis approach provides a better understanding of the potential risks posed by nanoplastics and heavy metal pollution in aquatic ecosystems.

Exposure to trace levels of metals and fluoroquinolones increases inflammation and tumorigenesis risk of zebrafish embryos

Exposure to trace-level heavy metals and antibiotics may elicit metabolic disorder, alter protein expression, and then induce pathological changes in zebrafish embryos, despite negligible physiological and developmental toxicity. This study investigated the single and combined developmental toxicity of fluoroquinolones (enrofloxacin [ENR] and ciprofloxacin [CIP]) (≤0.5 μM) and heavy metals (Cu and Cd) (≤0.5 μM) to zebrafish embryos, and molecular responses of zebrafish larvae upon exposure to the single pollutant (0.2 μM) or a binary metal-fluoroquinolone mixture (0.2 μM). In all single and mixture exposure groups, no developmental toxicity was observed, but oxidative stress, inflammation, and lipid depletion were found in zebrafish embryos, which was more severe in the mixture exposure groups than in the single exposure groups, probably due to increased metal bioaccumulation in the presence of ENR or CIP. Metabolomics analysis revealed the up-regulation of amino acids and down-regulation of fatty acids, corresponding to an active response to oxidative stress and the occurrence of inflammation. The up-regulation of antioxidase and immune proteins revealed by proteomics analysis further confirmed the occurrence of oxidative stress and inflammation. Furthermore, the KEGG pathway enrichment analysis showed a significant disturbance of pathways related to immunity and tumor, indicating the potential risk of tumorigenesis in zebrafish larvae. The findings provide molecular-level insights into the adverse effects of heavy metals and antibiotics (especially in chemical mixtures) on zebrafish embryos, and highlight the potential ecotoxicological risks of trace-level heavy metals and antibiotics in the environment.