Search Results (182)

Currently, water pollution is one of the major global environmental sustainability and public health issues that requires efficient and viable remediation technologies, as existing decontamination methods face limitations. In this sense, this review aims to highlight the potential of multifunctional aerogel-based magnetic nanocomposites as a novel strategy for water decontamination by integrating magnetic nanostructures into aerogel matrices that promote high adsorption capacity, selective catalysis, and facile magnetic recovery. In this regard, providing a comprehensive analysis of their functional design, contaminant-removal mechanisms, and multifunctional performance is crucial for developing and optimizing a system capable of addressing complex pollutants through multiple mechanisms (e.g., adsorption, photocatalysis, and reductive pathways). However, ecotoxicological evaluations focus on the potential for nanoparticles to leach, induce oxidative stress, and cause aquatic toxicity, supporting the development of strategies that comply with safety principles. Additionally, this review examines the aerogels’ capabilities for regeneration, operational stability, and scalability across repeated-use cycles, as well as their potential for real-world wastewater applications. Moreover, future directions for these aerogels include the development of smart, stimuli-responsive aerogels, machine-learning-based modeling, and the use of green synthesis approaches to enable sustainable water remediation strategies. Full article

Plastic pollution is a growing environmental crisis, with millions of tons of plastic entering the ocean each year and breaking down into microplastics and nanoplastics. These tiny particles pose a serious threat to marine life, particularly to zooplankton, which are essential to aquatic ecosystems. This study investigated the distribution and toxicity of polystyrene nanoplastics in Artemia salina (brine shrimp), a key model organism in ecotoxicology. Using specialized imaging and spectroscopy techniques, we tracked the presence of nanoplastics in A. salina and examined their effects on survival, behavior, and body structure. The results showed that nanoplastics accumulated in the gut and, at higher concentrations, caused gut deformities. The toxicity assay revealed that after 48 h of exposure, lethal concentrations decreased by nearly half compared with 24 h, demonstrating a time-dependent toxic effect. The estimated concentration that caused 50% mortality was 30.21 ± 6.44 mg/L. Additionally, these findings suggest that nanoplastics may impair the salt gland, affecting osmoregulation and energy allocation, leading to reduced feeding and pigmentation. These results highlight the potential risks of nanoplastics to marine organisms and emphasize the need for further research to understand their broader ecological and health impacts. Full article

The aim of this study was to evaluate the impact of fluoxetine, a widely used selective serotonin reuptake inhibitor, on two aquatic plants: Lemna minor and Spirodela polyrhiza. Additionally, the effect of exogenous serotonin on the level of fluoxetine-induced stress in duckweed will be studied. Increasing presence of antidepressants in surface waters poses ecological risks, and the duckweed species are ideal model organisms for ecotoxicological studies due to their rapid growth and ability to accumulate pollutants. For 14 days, plants were exposed to fluoxetine (0.001–150 mg L⁻¹), followed by a recovery phase in a drug-free medium or a medium supplemented with exogenous serotonin. We analysed morphological/physiological parameters (frond length and area, fresh and dry mass, hydration, stomatal size), the activity of antioxidant enzymes (catalase, ascorbate peroxidase, superoxide dismutase), cell viability, and the level of heat-shock proteins. The plants’ ability to remove fluoxetine from the medium was also assessed. High fluoxetine concentrations (50–150 mg L⁻¹) significantly reduced fresh mass (by 63–98% in L. minor and 56–97% in S. polyrhiza), frond area (by 21–48% in L. minor and 11–25% in S. polyrhiza), and cell viability (by 36–94% in L. minor and 49–94% in S. polyrhiza), and induced oxidative stress. Despite this, both species showed high regeneration potential after the stressor’s removal. Serotonin supplementation did not affect morphology but increased antioxidant enzyme activity, improved cell viability, and elevated heat-shock proteins levels. Crucially, serotonin significantly increased the efficiency of fluoxetine removal. The data can provide a basis for predicting fluoxetine removal efficiency in plants with different levels of endogenous serotonin. L. minor and S. polyrhiza exhibit substantial tolerance to fluoxetine, and antioxidative enzymes are sensitive markers of this stress. Full article

Silver nanomaterials (Ag NMs) are widely used, including in consumer products, and they inevitably enter the environment, with the soil compartment acting as a major sink. However, most available toxicity data focus on the reference Ag NM300K and rely on standard tests, even though long(er)-term exposure tests are recognized as particularly important for assessing the risks to soil invertebrates. Hence, the aim of the present study was to investigate the toxicity of commercial Ag NPs (Ag-Sigma, NPs < 150 nm) to the soil ecotoxicology model Folsomia candida (Collembola). Effects were assessed based on the standard OECD reproduction test (28 days) and beyond, with exposure prolonged for a second generation (56 days). Results showed that, based on the standard test (50% reproduction effect concentration—EC50 = 988 mg Ag/kg soil), the commercial Ag NPs were less toxic than the reference Ag NM300K and the ionic form AgNO₃ (from literature). However, the toxicity dramatically increased (ca. 4 times) during the second-generation exposure (EC50(56d) = 234 mg Ag/kg soil), surpassing the toxicity of Ag NM300K. The decrease in adults’ size indicates that moulting might be affected. Overall, increased toxicity in prolonged exposure was not expected based on the available and standard test results, which highlights the importance of long(er)-term exposures to fully assess the risks of NMs to soil communities. Full article

The increasing emphasis on green chemistry and environmentally responsible organic synthesis highlights the need to evaluate not only the biological activity but also the ecological safety of bioactive molecules. Xanthone, cinnamic acid, and chalcone scaffolds are widely explored in pharmaceutical and cosmetic research, yet their environmental profiles remain insufficiently characterized. This study assessed the ecotoxicity of simple derivatives from these three structural classes using the Microtox assay with the bioluminescent bacteria Aliivibrio fischeri. Test compounds were synthesized or obtained commercially, dissolved in dimethyl sulfoxide (DMSO), and evaluated at two exposure times (5 and 15 min), with half maximal effective concentration (EC₅₀) values calculated based on luminescence inhibition. The results revealed substantial differences between the investigated groups: chalcone derivatives exhibited uniformly high ecotoxicity, whereas cinnamic acid derivatives showed the most favorable environmental profile with low variability in EC₅₀ values. Xanthone derivatives displayed the widest ecotoxicity range, with toxicity strongly dependent on substituent type and substitution position. Notably, chloro-substitution in cinnamic acid derivatives correlated with lower toxicity, while positional effects were critical in the xanthone series. A comparison with in silico predictions generated using the ADMETlab platform showed poor correlation with the experimental outcomes. The predictive model did not distinguish the differing ecotoxicological behavior of α,β-unsaturated systems in chalcones versus cinnamic acids and systematically flagged halogenation as a toxicity-driving feature, contrary to several of our in vitro observations. Together, these findings provide new insights into structure–ecotoxicity relationships and underscore the need to complement computational predictions with validated experimental assays when designing bioactive compounds with improved environmental safety. Full article

Zinc oxide (ZnO) nanoparticles are widely used in cosmetics, coatings, and industrial formulations due to their UV-absorbing and antimicrobial properties; however, their increasing release into aquatic systems has raised concerns about potential ecological risks. This study evaluates the acute toxicity of pure and silver-doped ZnO (Ag-ZnO) nanoparticles using Artemia salina as a marine model organism. Nanoparticles were synthesized via a reflux-assisted method and characterized by UV–Vis spectroscopy, HRTEM, ED, FTIR, and EDX analyses, confirming a crystalline wurtzite structure, particle sizes of 10–30 nm, and successful incorporation of 5% Ag. Silver doping produced a slight blue shift in the absorption edge and minor lattice distortions, indicating modifications in the electronic structure. Toxicity assays revealed clear concentration- and time-dependent decreases in nauplii survival. Dose–response modeling showed LC₅₀ values of 358 ppm (24 h) and 64 ppm (48 h) for pure ZnO, whereas Ag-ZnO exhibited LC₅₀ values of 607 ppm (24 h) and 28 ppm (48 h). These results indicate that Ag doping does not enhance short-term toxicity but markedly increases toxicity after prolonged exposure. Overall, the findings highlight the need to consider both nanomaterial composition and exposure duration in ecotoxicological assessments and provide relevant data for evaluating the environmental impact of doped nanomaterials in marine systems. Full article

Mining activities have led to contamination of natural resources by heavy metals (HMs). Biomagnification studies of HMs within food webs are necessary for understanding the progressive increase in metal burdens across trophic levels and their potential ecotoxicological consequences. This study examined the trophic transfer of Cd, Cu, Pb, and Zn in a tri-trophic model involving maize plants (Zea mays), their herbivore, the grasshopper Sphenarium purpurascens, and their predator, the spider Neoscona oaxacensis, under controlled conditions. Samples from all individuals were collected in Huautla, Morelos, Mexico, where three tailing deposits are present, containing approximately 780,000 tons of waste rich in HMs. We evaluated the body biomass of the grasshopper and the percentage of maize leaf material consumed with and without HMs. HM bioaccumulation in maize, grasshopper, and spider tissues was analyzed, and the enrichment process, along with gender related effects on HM bioaccumulation in females and males of S. purpurascens, was studied. The results revealed enrichment of Pb, Cd, and Cu in maize leaf tissue, except for Zn. Grasshoppers exhibited biomagnification of the same metals, except for Cd. Metal bioaccumulation resulted in a reduced biomass of female and male grasshoppers, accompanied by an increased leaf consumption compared to grasshoppers fed maize leaves without HMs. The HMs’ bioaccumulation levels differed between genders, with males recording significantly higher concentrations of Zn and Pb. The excretion of HMs in feces and their bioaccumulation in exoskeletons are two efficient metal detoxification strategies in grasshoppers. This study revealed biomagnification in the spider N. oaxacensis, confirming metal biomagnification to higher trophic levels and providing critical insight into exposure pathways, risks to wildlife and humans, and how metal pollutants may disrupt ecosystem integrity. Full article

Green microalgae are widely used as model organisms in ecotoxicology due to their sensitivity to environmental stressors and their critical role in aquatic ecosystems as primary producers at the bottom of the food web. Pulse-Amplitude Modulated (PAM) chlorophyll fluorometry is a non-destructive, rapid and informative method for assessing photosynthetic efficiency and culture health, particularly through parameters such as the maximum photochemical activity of PSII (F_v/F_m) and effective PSII activity (Φ_PSII). Despite the growing number of studies utilizing PAM as an indicator rather than as a direct tool to evaluate microalgal stress responses, there remains a lack of standardized, accessible data for these key photosynthetic indicators. In this review, we analyze 38 sources, including 35 original research articles and 3 foundational references, to compile and compare reported values of F_v/F_m and Φ_PSII across various green microalgae species exposed to a wide range of chemical and environmental stressors. We highlight species-specific differences in sensitivity, identify underrepresented contaminants such as ionic liquids and artificial sweeteners, and emphasize the need for systematic numerical reporting in future research. PAM is an excellent and reliable technique for rapidly assessing culture health of green microalgae and their photosynthetic performance in various culture conditions and the vast array of chemical and physical stressors. Full article

Backgrounds: The marine diatom Ditylum brightwellii has been widely used as a model species for ecotoxicological assessments in marine environments. Heat shock proteins (Hsps) function as molecular chaperones that protect cells under diverse stress conditions. Of them, Hsp104 participates in the protein restoration system by reversing protein aggregation. Methods: In the present study, we determined the full-length sequence of DbHsp104 in D. brightwellii using transcriptome sequencing and gene cloning. Results: The open reading frame (ORF) was 2745 bp in length, encoding a protein of 915 amino acids (101.15 kDa). Phylogenetic and domain structural analysis revealed that DbHsp104 possesses conserved features of eukaryotic Hsp104. In addition, transcriptional responses of the gene were evaluated after exposures to thermal stress at 20, 25, and 30 °C, and heavy metals and endocrine-disrupting chemicals (EDCs) for 24 h. Relative gene expression analysis showed that DbHsp104 was significantly up-regulated under thermal stress and copper exposures, peaking at 4.87- and 5.55-fold (p < 0.001) increases, respectively. In contrast, no significant changes were observed in response to nickel, bisphenol A (BPA), polychlorinated biphenyl (PCB), and endosulfan (EDS) treatments. Conclusions: These results suggest that DbHsp104 is specifically responsive to acute stress induced by thermal stress and copper, highlighting its potential as a molecular biomarker in marine environments. Full article

The ubiquitous presence of microplastics across environmental compartments presents a formidable ecotoxicological and risk assessment challenge, fundamentally complicated by the link between microplastic morphology and differential toxicological outcomes. Current analytical methods face a significant measurement bottleneck, hindering the precise, high-throughput characterization needed for robust mechanistic and exposure studies. To address this, we introduce MNv4-Conv-M-fpn, a novel deep learning model specifically engineered for multi-class microplastic segmentation and morphological characterization from microscopic images. This model is designed to provide the toxicologically-relevant granularity required for rigorous risk assessment, segmenting images into six classes: five distinct microplastic categories (fiber, fragment, sphere, foam, and film) and the background. By incorporating advanced architectural features—including transfer learning, a Feature Pyramid Network, and a Feature Fusion Module—our approach achieves high accuracy, computational efficiency, and near real-time inference speed. Comprehensive validation using a diverse dataset demonstrates that MNv4-Conv-M-fpn outperforms existing segmentation methods while maintaining low computational load. This makes the model well-suited for high-throughput deployment in environmental laboratories and resource-constrained monitoring efforts. This approach offers a valuable tool for environmental monitoring, enabling more precise and scalable analysis of microplastic pollution in various ecosystems. Full article

Microorganisms such as methanogenic archaea play a key role in wastewater treatment plants (WWTPs) by breaking down organic matter and pollutants and producing methane, a potential renewable energy source. However, sulphate-reducing bacteria (SRB) compete with archaea for the same substrates under anaerobic conditions, lowering methane production and generating harmful hydrogen sulphide (H₂S). Inhibiting SRB is therefore crucial to enhance methane yield and reduce toxic by-products. By means of manual screening of public databases (KEGG, BRENDA, PDB, PubChem) 12 potential inhibitors of SRB were found. After computational ecotoxicological assessment, four candidates were selected, and one of them experimentally increased methane production, demonstrating that SRB inhibition favours the anaerobic digestion of sludges. In order to further explore new candidates, Quantitative Structure–Activity Relationship (QSAR) models were developed showing reliable predictive performance. These models enabled the virtual screening of COCONUT, a natural product database, identifying 73 potential SRB inhibitors. After an ecotoxicological assessment, five commercially available compounds remained. The identified candidates may reduce competition between SRB and methanogenic archaea, leading to higher methane production and supporting WWTPs in generating their own biogas. This would contribute to a circular economy and help mitigate greenhouse gas emissions. Full article

The synergistic effects of stratospheric ozone depletion and climate change are intensifying surface ultraviolet-B (UVB) radiation, posing a severe threat to amphibians—one of the most endangered vertebrate groups globally. Xenopus laevis, with its cutaneous respiration and limited photoprotective mechanisms, exhibits high sensitivity to UVB, making it a suitable model for ecotoxicological studies. While UVB is known to cause DNA damage, immune suppression, and microbial dysbiosis, its mechanisms in multi-organ interactions, dose–response thresholds, and host–microbiome regulatory networks remain poorly understood. This study employed a gradient UVB exposure regime integrated with histopathology, oxidative stress assays, and 16S rRNA sequencing to systematically evaluate the effects of UVB on (1) cascade damage across skin, liver, and intestinal barriers; (2) immune cell distribution; (3) redox dynamics; and (4) microbial community structure and function. Our findings demonstrate that low-dose UVB activated compensatory antioxidant defenses without structural disruption, whereas exposure beyond a critical threshold induced nonlinear redox collapse, microbial dysbiosis, and multi-organ barrier failure, collectively exacerbating ecological adaptation risks. These results reveal a cross-scale mechanism by which UVB impairs amphibian health via disruption of host–microbe homeostasis, providing a conceptual and empirical framework for assessing species vulnerability under ongoing climate change. Full article

In this study, we evaluated the cytotoxicity and antioxidant activity of the soil ciliate Rigidohymena tetracirrata (Gellért, 1942) Berger 2011, exposed to single and bimetallic mixtures of heavy metals (HMs) for 24 h. Ecotoxicological tests showed LC₂₀ values of 0.16, 19.86 and 0.68 mg L⁻¹ to Copper (Cu), Zinc (Zn), and Cadmium (Cd), respectively, and LC₅₀ values of 0.25, 44.12 and 1.12 mg L⁻¹, respectively. Furthermore, it was observed that the mixture of Cd and Zn exhibited antagonism in comparison to other mixtures, (Cd + Cu and Cu + Zn). In the total phenolic content (TPC) assay, a higher phenolic content was observed for the LC₂₀ of extracellular Cu (p ≤ 0.01) and the LC₂₀ of intracellular Cd (p ≤ 0.001). The LC₅₀ values for Cd and Zn in both extracellular and intracellular contents demonstrated increased α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging activity with significant values of p ≤ 0.05, respectively. Regarding hydroxyl scavenging activity (HRSA), the LC₅₀ of extracellular Cd (p ≤ 0.001) and LC₅₀ of intracellular Cu (p ≤ 0.001) exhibited higher antioxidant activity. Therefore, the present study suggests that R. tetracirrata holds considerable potential as bioindicators and could be used as a model organism in ecotoxicological studies of soil polluted by HMs. Full article

Anatoxin-a (ANTX-a), a potent neurotoxin produced by various cyanobacterial species, poses a serious threat to aquatic organisms. This study investigated the neurotoxicity of ANTX-a on juvenile Chinese mitten crab (Eriocheir sinensis). Different from previous studies on vertebrate models or fish liver toxicity, we focused on the microbiota–intestine–brain axis. Results demonstrated that ANTX-a exposure induced significant neurotoxicity, marked by the upregulation of apoptosis-related genes and disruption of neurotransmitter homeostasis. Transcriptomic analysis of thoracic ganglia revealed significant dysregulation of metabolic pathways, characterized by upregulated histidine metabolism (elevated histidine decarboxylase-like) and downregulated lipid metabolism (suppressed sphingomyelin phosphodiesterase-like). Additionally, increased intestinal histamine levels and elevated serum diamine oxidase activity indicated intestinal barrier damage. Intestinal microbiota analysis revealed that the abundance of nerve-related bacteria Tyzzerella and Clostridium sensu stricto 1 changed significantly. In summary, these findings indicate that ANTX-a induced neurotoxicity by affecting neurotransmitter systems and gut health, implicating the microbiota–intestine–brain axis. The results underscore the role of microbiota–intestine–brain communication in cyanotoxin toxicity within aquatic invertebrates and provide new insights into the ecotoxicological risks of cyanobacterial blooms in aquatic invertebrates. Full article