Subcellular effects of imidazolium-based ionic liquids with varying anions on the marine bivalve Mytilus galloprovincialis.

Green Chemistry involves applying a set of principles aimed at minimizing the use of hazardous substances in the design, production, and application of chemical products. In recent decades, Ionic Liquids (ILs) have emerged as more environmentally friendly substitutes for traditional organic solvents. This preference is primarily due to their low vapor pressure, which results in minimal atmospheric pollution and enhanced industrial safety. However, existing literature highlights the toxicity of ILs towards aquatic invertebrates. Consequently, this study points to assess the biochemical effects of a selection of ILs through an in vitro approach. Specifically, digestive gland and gill cellular fractions (S9) of the marine bivalve Mytilus galloprovincialis were exposed to varying concentrations (0.05-2 µM) of three ILs featuring identical cations but different anions. The ILs tested were 1-ethyl-3-methylimidazolium octanoate ([EMIM][Oct]), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), and 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]). The results indicate that [EMIM][Oct] induces higher toxicity in both S9 tissues, highlighting a strong effect of the anion. Overall, antioxidant and biotransformation defenses were significantly altered for all three ILs assessed. While acetylcholinesterase activity was significantly inhibited of about half of control activity, indicating neurotoxic damage as part of the toxicity mode of action of these ILs, neither lipid peroxidation nor alterations to DNA integrity were observed (≥100 %). This study supports the use of in vitro techniques as important tools capable of generating reliable ecotoxicological data, which can be further considered as a screening before in vivo testing and used for in silico modeling.

Sensitivity assessment of Biomphalaria glabrata (SAY, 1818) using reference substance sodium dodecyl sulfate for ecotoxicological analyzes.

Sodium dodecyl sulfate (SDS) is a surfactant used and recommended by regulatory agencies as a reference substance in ecotoxicological analyzes. In this work, acute toxicity assays were performed with adults and embryos of the freshwater snail Biomphalaria glabrata, an endemic organism with environmental and public health importance, to evaluate the effects of the surfactant and establish a sensitivity control chart. The organisms were exposed to SDS for 24 h to a range of concentrations, as well as a control group. Six assays were performed to establish the control chart for adults (with a median LC50 of 36.87 mg L-1) and differential sensitivity was observed at each embryonic stage (EC50 = blastulae 33.03, gastrulae 35.03, trochophore 39.71 and veliger 72.55 mg L-1). The following behavioral responses were observed in exposed adult snails: release of hemolymph and mucus, body outside the shell, and penile overexposure. Embryos at the blastulae and gastrulae stages were more sensitive, and teratogenic effects were accentuated in the trochophore stage. The difference in results obtained between adults and embryos underscore the importance of carrying out analyzes at different developmental stages. The serial assays established with SDS for B. glabrata demonstrated efficiency and constancy conditions in the assays with good laboratory practice standards. The wide distribution of Biomphalaria species in several countries, their easy maintenance and cultivation in the laboratory, in addition to ecological importance, make them economical alternatives for ecotoxicological assays.

Insights into the molecular response of Dioithona rigida to selenium nanoparticles: de novo transcriptome assembly and differential gene expression analysis.

The impact of contaminants on Copepod sp. and its molecular response is least explored, despite their abundance and dominance among invertebrates in aquatic environments. In the present investigation, Dioithona rigida, a cyclopoid zooplankton, was treated with selenium nanoparticles (SeNPs) to determine the associated biochemical changes, and the chronic exposure effects were recorded using transcriptomic analysis. It was found that, SeNPs were acutely toxic with a lethal dose 50% of 140.9 mg/L. The de novo assembled transcriptome of the copepod comprised 81,814 transcripts, which underwent subsequent annotations to biological processes (23,378), cellular components (21,414), and molecular functions (31,015). Comparison of the expressed transcripts against the treated sample showed that a total of 186 transcript genes were differentially expressed among the D. rigida treatments (control and SeNPs). The significant downregulated genes are coding for DNA repair, DNA-templated DNA replication, DNA integration, oxidoreductase activity and transmembrane transport. Similarly, significant upregulations were observed in protein phosphatase binding and regulation of membrane repolarization. Understanding the impact of SeNPs on copepods is crucial not only for aquatic ecosystem health but also for human health, as these organisms play a key role in marine food webs, ultimately affecting the fish consumed by humans. By elucidating the molecular responses and potential toxicological effects of SeNPs, this study provides key insights for risk assessments and regulatory policies, ensuring the safety of seafood and protecting human health from the unintended consequences of nanoparticle pollution.

The toxicity analysis in Dioithona rigida is the first of its kind as a copepod model for analysis on dietary fixation of metal toxicity at the trophic level. Since this copepod is a major zooplankton fed by fish and crustacean larvae in marine ecosystems, the toxicity analysis on this copepod will give us more insights of the trophic-level food transfer. As far as our knowledge, this is the first study that opted to construct the de novo transcriptomic pipeline for this copepod, treated with selenium nanoparticles. The effectiveness of this work may be further extrapolated to assess the effect of other metal nanoparticles in this model organism. Although the selenium toxicity in marine ecosystem is an established sector, through our combined approach of biochemical analysis and omics approach, the solid framework and comprehensive insight of the selenium toxicity in reproductive fitness and molecular changes has been studied. This study chose to seek a reliable alternative in the sense of new copepod model and omics approach to analyse the relevant metal nanoparticle toxicity in the marine ecosystem.

Comparing anticoagulant rodenticide exposure in barn owl (Tyto alba) and common kestrel (Falco tinnunculus): A biomonitoring study in an agricultural region of southeastern Spain.

Second-generation anticoagulant rodenticides (SGARs) are commonly used for rodent control, affecting various non-target wildlife species. Here, blood samples from common kestrels (Falco tinnunculus, n = 70 chicks) and barn owls (Tyto alba, n = 54 chicks and 12 adults) from Southeastern Spain were analysed using HPLC-TQ. SGAR prevalence was 68.6% in kestrel chicks, 50% in barn owl chicks and 100% in adult barn owls, with multiple SGARs in both species. Prothrombin time analysis in barn owls revealed a positive correlation with blood ΣSGARs, suggesting a potential adverse effect on coagulation. Analysis of variables potentially influencing SGAR prevalence indicated that, for kestrels, it was only related to the extent of artificial surface, showing no differences across study sites. In owlets, the highest prevalence occurred in the most urbanized study site, with human population density being a key factor. This study highlights species-specific differences in SGAR exposure, likely influenced by ecological traits. Barn owls probably encounter contaminated prey near anthropized areas, with widespread SGAR use and higher presence of target rodents. Conversely, kestrels, hunting a variety of prey often near human settlements, face consistently elevated exposure from multiple sources. Understanding these variations is crucial for effective conservation and minimizing SGAR impact on non-target wildlife.

Vanadium Toxicity Is Altered by Global Warming Conditions in Sea Urchin Embryos: Metal Bioaccumulation, Cell Stress Response and Apoptosis.

In recent decades, the global vanadium (V) industry has been steadily growing, together with interest in the potential use of V compounds as therapeutics, leading to V release in the marine environment and making it an emerging pollutant. Since climate change can amplify the sensitivity of marine organisms already facing chemical contamination in coastal areas, here, for the first time, we investigated the combined impact of V and global warming conditions on the development of Paracentrotus lividus sea urchin embryos. Embryo-larval bioassays were carried out in embryos exposed for 24 and 48 h to sodium orthovanadate (Na3VO4) under conditions of near-future ocean warming projections (+3 °C, 21 °C) and of extreme warming at present-day marine heatwave conditions (+6 °C, 24 °C), compared to the control temperature (18 °C). We found that the concomitant exposure to V and higher temperature caused an increased percentage of malformations, impaired skeleton growth, the induction of heat shock protein (HSP)-mediated cell stress response and the activation of apoptosis. We also found a time- and temperature-dependent increase in V bioaccumulation, with a concomitant reduction in intracellular calcium ions (Ca2+). This work demonstrates that embryos' sensitivity to V pollution is increased under global warming conditions, highlighting the need for studies on multiple stressors.

Persistent Organic Pollutants in Tagus Estuary Salt Marshes: Patterns of Contamination and Plant Uptake.

The presence of anthropogenic compounds, including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), was studied in three salt marshes within the Tagus estuary, Portugal, along an anthropogenic pressure gradient. Results revealed differences in OCPs and PCBs among the marshes, with differing concentration levels. Specifically, one marsh, with surrounding agricultural activity, showed the highest OCP concentrations, while another, with a historical industrial past, exhibited elevated PCB levels. In contrast, a third marsh, part of a natural reserve, displayed comparatively lower concentrations of both substances. Sediment concentrations, likely influenced by agricultural practices, were found to be comparable to or higher than those observed in other Portuguese estuaries. The halophyte Spartina maritima was found to absorb OCPs, particularly in its aboveground tissues, suggesting bioaccumulation within the plant. Additionally, PCB levels appeared to be influenced by industrial history, with one marsh displaying notably higher concentrations. In conclusion, the persistence of organochlorine compounds in the salt marsh ecosystems notwithstanding the regulatory prohibitions implemented in the 1990s highlights the need for continuous monitoring and study of such sites and the necessity of remediation practices, which are imperative to mitigate ecological and health risks in these polluted salt marshes.

Leveraging In Silico Structure-Activity Models to Predict Acute Honey Bee (Apis mellifera) Toxicity for Agrochemicals.

In the realm of crop protection products, ensuring the safety of pollinators stands as a pivotal aspect of advancing sustainable solutions. Extensive research has been dedicated to this crucial topic as well as new approach methodologies in toxicity testing. Hence, within the agricultural and chemical industries, prioritizing pollinator safety remains a constant objective during the development of predictive tools. One of these tools includes computational models like quantitative structure-activity relationships (QSARs) that are valuable in predicting the toxicity of chemicals. This research uses bee toxicity data to develop artificial neural network classification models for predicting honey bee acute toxicity. Bee toxicity data from 1542 compounds were used to develop models; the sensitivity and specificity of the best model were 0.90 and 0.91, respectively. These in silico models can aid in the discovery of next-generation crop protection products. These tools can guide the screening and selection of next-generation crop protection molecules with high margins of safety to pollinators, and candidates with favorable sustainability profiles can be identified at the early discovery stage as precursors to in vivo data generation.

Multiple endpoints analysis of the effects of diesel oil on a commercial species, Carcinus maenas.

Fuel spills in marine environments pose significant threats to aquatic ecosystems, evidencing the intricate relationship between fuel utilization and its impact on benthic species of commercial value for human consumption. This interconnectedness of human, animal and environmental welfare falls within the One Health framework. The aim of the present study was to evaluate the toxicological effects of diesel oil on the green crab Carcinus maenas, and make a parallelism between tested concentrations and petrogenic hydrocarbon levels in natural environments. Mortality, locomotion and feeding behavior, molting, somatic growth, morphological malformations, stress biomarkers, and nutritional variables were analyzed in three different bioassays. In Bioassay 1, prepuberal females were exposed to diesel oil water accommodated fraction (WAF) to determine the median lethal concentration (LC50) at different periods. In Bioassay 2, prepuberal females were exposed to 168 h LC50 and LC25 of diesel oil WAF for 7 days, and were subsequently exposed to clean water. In Bioassay 3, prepuberal females were exposed to 168 h LC12 and LC6 of diesel oil WAF for 30 days. Petrogenic hydrocarbon levels in the field were quantified at a port and a nature reserve, with concentrations of aromatic hydrocarbons being 1.92 µg/g in the former and below 0.01 µg/g in the latter. In Bioassay 1, the 168 h LC50 was estimated to be 1.04 % of diesel oil. The results obtained in Bioassays 2 (LC50 and LC25) and Bioassays 3 (LC12 and LC6) suggest that environmental exposure to petrogenic hydrocarbons produces high mortality or interferes with the molting process of crabs, leading to reduced growth and developmental abnormalities. Such malformations were observed in chelipeds, pereiopods, gills chambers and eye peduncles, and affected feeding and locomotion behaviors. Overall, this could impact on population size and health, and consequently alter the ecological role and commercial exploitation of economically important species like C. maenas.

Side effects of semi-synthetic insecticide spinetoram on the whitefly parasitoid Encarsia formosa.

BACKGROUND: Insecticide risk assessment for biological control agents is essential for implementing integrated pest management (IPM) programs. Spinetoram is a naturally derived insecticide used to control a variety of agricultural sap-sucking insect pests, and Encarsia formosa Gahan (Hymenoptera: Aphelinidae) plays a key role in the biocontrol of greenhouse whiteflies. Despite its presumed safe ecotoxicological profile, the side effects of spinetoram on E. formosa are partially unknown, especially at sublethal doses. In the laboratory, we estimated the lethal concentrations (LC) of spinetoram on E. formosa by topical exposure of pupae and 48 h residual contact exposure of emerged adults. Afterwards, we assessed the impact of spinetoram LCs on the life history traits (juvenile development, adult longevity, parasitism, adult emergence) and population growth parameter (the instantaneous rate of increase, ri) of the parasitoid. RESULTS: Probit analysis allowed the estimation of LC10 = 0.10 mg/L, LC50 = 0.56 mg/L, and LC90 = 3.28 mg/L. Spinetoram at LC10 had no impact on the observed parameters of E. formosa. Conversely, spinetoram at LC50 and LC90 significantly reduced adult longevity by 19.2% and 40.6%, total parasitism by 33.4% and 38.7%, and total adult emergence by 29.6% and 39.1%, respectively. Also, the ri of E. formosa was significantly affected by spinetoram LC50 and LC90 with a reduction of 8.17 and 29.83%, respectively. CONCLUSION: Our results suggested that spinetoram significantly threatens the effectiveness of E. formosa when applied at the field recommended rate. However, further validation of spinetoram under greenhouse conditions is required for a comprehensive risk assessment for E. formosa in IPM programs. © 2024 Society of Chemical Industry.

Transformative nanobioplasmonic effects: Toxicological implications of plasmonic silver nanoparticles in aquatic biological models.

Silver nanoparticles (AgNPs) present unique properties, such as the induced localized surface plasmon resonance (LSPR) provoked under illumination with a proper wavelength, allowing these nanomaterials to be applied in fields such as catalysis and biomedicine. The study of AgNPs is also highly relevant from the environmental pollution viewpoint due to their high production and application in commercial products. Consequently, AgNPs reach aquatic environments and can be plasmonically stimulated under natural light conditions. This study investigates the toxic effects promoted by AgNPs under plasmonic excitation on the survival and physiology of the crustacean Daphnia similis. Two AgNP shapes (spherical and triangular) with plasmon bands absorbing in different spectral regions in the visible range were studied. The organisms were exposed to different AgNP concentrations under five different light conditions. Survival and changes in enzymatic biomarkers of oxidative stress and lipid storage were evaluated. Under LSPR conditions, we observed increased lethality for both AgNP shapes. LSPR effects of AgNPs showed mortality 2.6 and 1.7 times higher than the treatment under dark conditions for spherical and triangular morphologies respectively. The enzymatic assays demonstrated that plasmonic treatments triggered physiological responses. Significantly decreased activities were observed exclusively under LSPR conditions for both AgNP shapes. Considering all treatments, spherical AgNPs showed lower LC50 values than triangular ones, indicating their higher toxic potential. Our results demonstrate that LSPR AgNPs can induce biological responses associated with oxidative stress and survival. Therefore, this study highlights the potential risks of environmental contamination by plasmonically active metallic nanomaterials. These materials can enhance their toxicity when light-excited, yet the results also indicate promising opportunities for light-based therapies.

Does exposure timing of macrolide antibiotics affect the development of river periphyton? Insights into the structure and function.

Discharged sewage is the dominant source of urban river pollution. Macrolide antibiotics have emerged as prominent contaminants, which are frequently detected in sewage and rivers and pose a threat to aquatic microbial community. As a typical primary producer, periphyton is crucial for maintaining the biodiversity and functions of aquatic ecosystem. However, effects of antibiotic exposure time as well as the recovery process of periphyton remain undetermined. In the present study, five exposure scenarios of two typical macrolides, erythromycin (ERY) and roxithromycin (ROX) were investigated at 50 µg/L, dose to evaluate their potential detrimental effects on the structure and function of periphyton and the subsequent recovery process in 14 days. Results revealed that the composition of periphytic community returned to normal over the recovery period, except for a few sensitive species. The antibiotics-caused significant photodamage to photosystem II, leading to continuous inhibition of the photosynthetic capacity of periphyton. Furthermore, no significant difference in carbon metabolism capacity was observed after direct antibiotic exposure, while the amine carbon utilization capacity of periphyton remarkably increased during the recovery process. These results indicated that periphyton community was capable of coping with the periodic exposure of antibiotic pollutants and recovering on its own. However, the ecological functions of periphyton can be permanently disturbed due to macrolide exposure. Overall, this study sheds light on the influence of macrolide exposure on the development, structure and function of the periphytic microbial community in rivers.

Cellular uptake of multi-walled carbon nanotubes is associated to genotoxic and teratogenic effects towards the freshwater diatom Nitzschia linearis.

The increase in industrial production of multi-walled carbon nanotubes (MWCNTs) raises concerns about their potential adverse effects associated to environmental releases, especially in aquatic environments where they are likely to accumulate. This study focuses on the environmental impact of MWCNTs, specifically on a benthic freshwater diatom (Nitzschia linearis), which plays a major role in the primary production of water bodies. The obtained results indicate that exposure to MWCNTs in the presence of natural organic matter (NOM) inhibits diatom's growth in a dose-dependent manner after 72 h of exposure. Interestingly, the photosystem II quantum yield (PSIIQY) in diatoms remains unaffected even after exposure to MWCNTs at 10 mg/L. After 48 h of exposure, MWCNTs are found to bind preferentially to extracellular polymeric substances (EPS) produced by diatoms, which could decrease their toxicity by limiting their interaction with this organism. However, measurement of genotoxicity and teratogenicity in diatoms exposed to MWCNTs revealed that the exposure to MWCNTs increased the occurrence of cells with micronuclei and abnormal frustules. Microscopy analyses including two-photon excitation microscopy (TPEM) revealed the internalization of MWCNTs. Investigations of the diatom's frustule structure using Scanning electron microscopy (SEM) indicated that the presence of pore structures constitutes a pathway allowing MWCNTs uptake. The presence in the diatom's cytoplasm of MWCNTs might possibly induce disturbances of the cellular components, leading to the observed genotoxic and teratogenic effects. In view of previous studies, this work underscores the need for further studies on the interaction between nanomaterials and different diatom species, given the species-specific nature of the interactions.

Widespread exposure to anticoagulant rodenticides among common urban mesopredators in Chicago.

Anticoagulant rodenticides (ARs) are currently the most common method to control rats in cities, but these compounds also cause morbidity and mortality in non-target wildlife. Little attention has been focused on AR exposure among mesopredators despite their ecological role as scavengers and prey for larger carnivores, thus serving as an important bridge in the biomagnification of rodenticides in food webs. In this study, we sampled liver tissue from raccoons (Procyon lotor; n = 37), skunks (Mephitis mephitis; n = 15), and Virginia opossums (Didelphis virginiana; n = 45) euthanized by pest professionals and brown rats (Rattus norvegicus; n = 101) trapped in alleys in Chicago, USA to evaluate how often these species are exposed to ARs. We tested whether mesopredators had a higher prevalence of ARs and to more AR compounds compared to rats and calculated biomagnification factors (mean concentration in mesopredators/rats) as indicators of biomagnification. Of 93 sampled mesopredators, 100 % were exposed to at least one AR compound, mainly brodifacoum (≥80 %), and 79 % were exposed to multiple AR compounds. We also documented teal stomach contents consistent with the consumption of rat bait and altricial young tested positive to the same AR as their mother, suggesting mammary transfer. Of the 101 rats, 74 % tested positive to at least one AR compound and 32 % were exposed to multiple AR compounds. All mesopredator species had biomagnification factors exceeding 1.00 for brodifacoum (6.57-29.07) and bromadiolone (1.08-4.31). Our results suggest widespread exposure to ARs among urban mesopredators and biomagnification of ARs in mesopredators compared to rats. Policies that limit AR availability to non-target species, such as restricting the sale and use of ARs to licensed professionals in indoor settings, education on alternatives, and more emphasis on waste management may reduce health risks for urban wildlife and people in cities around the world.

Elevated temperature exacerbates pharmaceutical-induced oxidative stress in zebrafish (Danio rerio) larvae.

There is growing evidence that rising global temperatures resulting from climate change may exacerbate the toxic effect of pollutants and heterotherms, including fish, in which homestatic mechanisms are directly influenced by environmental temperature will be most affected. Pharmaceuticals discharged into the environment are potentially harmful to wildlife as many of their drug targets are conserved across divergent phyla. Oxidative stress (OS) is a major mechanism by which many pharmaceutical contaminants can induce toxicity but this has received little consideration in the context of effects in wildlife. Further, these mechanisms are relatively poorly understood, particularly regarding multiple stressor interactions. We used transgenic TG(EpRE:mCherry) zebrafish, developed in our laboratory for detecting OS, as our experimental model. We show that the oxidative effects of high concentrations of pharmaceuticals from three different therapeutic classes (paracetamol, diclofenac and doxorubicin) are increased at temperatures elevated by 2-5 °C above those for zebrafish standard husbandry and relevant to their current natural environment (and predicted under the IPCC 2023 scenarios for intermediate to very high greenhouse gas emissions). These OS responses were primarily seen in the pronephros, liver, and gastrointestinal tract. The increase in OS at the increased water temperature may have resulted from the elevated temperature acting as a direct additive physiological stressor to the OS imposed by the drugs and/or via the temperature increasing the chemicals oxidative effect. For paracetamol, it appeared that the elevated responses at the higher temperature of 33 °C were in part due to an increase in uptake of the drug. Our data illustrate that risk assessments for chemicals inducing OS in fish (and likely other heterotherms) should consider the influence of temperature to ensure environmental protection in future environments.

Dynamics of Bactrocera dorsalis Resistance to Seven Insecticides in South China.

Bactrocera dorsalis is a highly invasive and destructive pest distributed worldwide. Chemical insecticides remain the primary measure for their control; however, this species has already developed resistance to several insecticides. In recent years, there have been several reports of monitoring B. dorsalis resistance in China, but continuous monitoring results are lacking and do not even span a decade. In this study, we monitored the dynamics of resistance to seven insecticides among 11 geographically distinct Chinese populations of B. dorsalis (2010-2013; follow-up in 2023). The 11 populations were found to adapt rapidly to antibiotic insecticides (spinosad, emamectin benzoate, and avermectin), reaching high levels of insecticide resistance in several areas. Overall, a decreasing trend in resistance to organophosphorus insecticides (chlorpyrifos and trichlorfon) was observed, whereas pyrethroid (beta-cypermethrin and cyhalothrin) resistance trends were observed to both increase and decrease. The monitoring of field resistance among different B. dorsalis populations over the duration of this study is important for improving the efficiency and sustainability of agricultural pest management, and the results provide a scientific basis for the development of more effective resistance management strategies.

Salinization and Low-dose Levels of Pesticides alter Brain Shape of Larval Amphibians.

Wetland communities are increasingly threatened by multiple stressors simultaneously, such as pesticides and salinization. We examined the effects of ecologically-relevant exposures to broad-spectrum insecticides and salinization on amphibian neurodevelopment, which is strongly linked to how organisms respond behaviorally to environmental change. Prior research showed that exposure to trace concentrations of an organophosphate pesticide (chlorpyrifos) altered the brain shape and behavior of larval and metamorphic amphibians. It is unknown whether brain shape is altered by additional pesticides and road salt. Using outdoor mesocosms, we tested whether salt (NaCl) and representatives from three pesticide families (organophosphates, pyrethroids, and neonicotinoids) altered tadpole (Lithobates pipiens) brain shape. Of the two organophosphates, chlorpyrifos induced relatively longer telencephalon lengths relative to body mass, consistent with previous studies, but malathion had no effect on brain shape. Of the two pyrethroids, permethrin, but not cypermethrin, increased telencephalon length. For the neonicotinoids, there were marginally significant effects of imidacloprid and thiamethoxam on telencephalon length. Thus, the impacts of pesticides on brain shape was not dictated by pesticide family. Exposure to relatively high concentrations of salt resulted in brains that were less wide but had longer optic tecta. Although we failed to find strong interactive effect of salt with pesticides, there was some weak, nonsignificant, evidence that exposure to salt masked responses to pesticides. Together, our results indicate that environmentally realistic levels of pesticides and salinization can alter larval brain shape. Our study highlights the importance of studying the impacts of naturally-occurring levels of pesticides and salinization on vertebrate neural development.

Tolerance and phytoremediation capacity of atrazine and S-metolachlor by two duckweeds.

The phytotoxicity and removal of atrazine and S-metolachlor in sterile duckweed systems were estimated in this study. Herbicides were added at environmentally relevant ranges: 0-400 µg/L for atrazine or 0-200 µg/L for S-metolachlor in systems with Spirodela polyrhiza or Lemna minor. Toxicity biomarkers, i.e., changes in plant biomass, surface area, chlorophyll fluorescence parameters, pigments, lipid peroxidation, protein concentration, and antioxidative enzyme activities in plants were estimated after 7 days. S. polyrhiza (RGRbiomass-EC50 = 164.8 µg/L) was more tolerant to atrazine than L. minor (RGRbiomass-EC50 = 101.0 µg/L). Atrazine caused damage to photosystem II (ΦM), a reduction in electron transport between PSII and PSI (Φ'M), as well as disruption in energy distribution pathways (decrease in qPrel and increase in UQFrel), most prominently in L. minor. However, L. minor (RGRbiomass-EC50 = 128.9 µg/L) was more tolerant to S-metolachlor than S. polyrhiza (RGRbiomass-EC50 = 15.5 µg/L). The highest sensitivity of S. polyrhiza to S-metolachlor was attributed to a decrease in absorbed energy used in photochemistry (qPrel) and an increase in lipid peroxidation, indicating that S. polyrhiza plants were experiencing oxidative stress. Residual pesticide analysis in the water after seven days allowed us to conclude that plants were responsible for reducing up to 16.5% of atrazine and 28.7% of S-metolachlor in the duckweed system. S. polyrhiza showed higher atrazine phytoremediation capacity than L. minor. S. polyrhiza was more efficient at an environmentally relevant concentration of S-metolachlor (25 µg/L) and L. minor at higher concentrations (200 µg/L).

Autophagy and PPARs/NF-κB-associated inflammation are involved in hepatotoxicity induced by the synthetic phenolic antioxidant 2,4-di-tert-butylphenol in common carp (Cyprinus carpio).

The synthetic phenolic antioxidant 2,4-di-tert-butylphenol (2,4-DTBP) is an emergent contaminant and can disrupt the delicate balance of aquatic ecosystems. This study aimed to investigate 2,4-DTBP-induced hepatotoxicity in common carp and the underlying mechanisms involved. Sixty common carp were divided into four groups and exposed to 0 mg/L, 0.01 mg/L, 0.1 mg/L or 1 mg/L 2,4-DTBP for 30 days. Here, we first demonstrated that 2,4-DTBP exposure caused liver damage, manifested as hepatocyte nuclear pyknosis, inflammatory cell infiltration and apoptosis. Moreover, 2,4-DTBP exposure induced hepatic reactive oxygen species (ROS) overload and disrupted antioxidant capacity, as indicated by the reduced activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). In addition, transmission electron microscopy revealed that 2,4-DTBP exposure induced autophagosome accumulation in the liver of common carp. Western blot analysis further revealed that 2,4-DTBP exposure significantly decreased the protein levels of mTOR and increased the LC3II/LC3I ratio. Furthermore, 2,4-DTBP exposure inhibited lysozyme (LZM) and alkaline phosphatase (AKP) activity; decreased immunoglobulin M (IgM), complement 3 (C3), and complement 4 (C4) levels in the serum; increased the mRNA levels of proinflammatory cytokines (NF-κB, TNF-α, IL-1ß and IL-6); and increased the mRNA levels of three types of proliferator-activated receptors (PPARs) (α, ß/δ and γ). Molecular docking revealed that 2,4-DTBP directly binds to the internal active pocket of PPARs. Overall, we concluded that 2,4-DTBP exposure in aquatic systems could induce hepatotoxicity in common carp by regulating autophagy and controlling inflammatory responses. The present study provides new insights into the hepatotoxicity mechanism induced by 2,4-DTBP in aquatic organisms and furthers our understanding of the effects of 2,4-DTBP on public health and ecotoxicology.

Ecotoxicological insights into the effects of triflumezopyrim on P. fuscipes fitness, detoxification pathways, and gene expression.

The primary objective was to evaluate the toxicity of triflumezopyrim (TFP) on P. fuscipes larvae and adults at lethal and sublethal levels through topical application. Sublethal effects were assessed by examining developmental period, fecundity, life-table parameters, and fitness parameters. Enzymatic and transcriptional analyses were conducted to determine the impact of TFP on P. fuscipes physiology and gene expression. The LC50, LC30, and LC10 of TFP against P. fuscipes larvae and adults were lower than the field-recommended dose (48.75 mg a.i. L-1), indicating direct toxicity and sublethal effects during immature stages. Exposure to LC30 of TFP extended developmental periods for 2nd-instar larvae and pupae, reduced oviposition, larval predation efficiency, and body weight in both sexes. Sublethal concentrations affected antioxidant, detoxification, and energy reservoir enzymes significantly. Transcriptional analysis revealed impacts on insecticide detoxification, resistance, and stress-related genes. KEGG analysis showed glycerolipid metabolism is the most regulated pathway, and UGT2B10 regulated several detoxification-related pathways under TFP stress. These findings prompt reconsideration of the role of TFP in paddy field IPM due to its adverse effects on P. fuscipes, emphasizing the importance of assessing its ecological impacts before widespread application in agricultural practices.

Morphophysiological and Histopathological Effects of Ammonium Sulfate Fertilizer on Aporrectodea trapezoides (Dugès, 1828) Earthworm.

The present study used the adult earthworm Aporrectodea trapezoides as a bioindicator species to look into the possible dangers of ammonium sulfate (AS) fertilizer. Two complementary toxicity tests were conducted to determine the LC50values, growth rate inhibition, morphological alterations, and histopathological texture of worms. The lethality test included four increasing concentrations of AS fertilizer (ranging from 2500 to 7500 mg/kg of dry soil weight (d.w.)), while sub-lethal concentrations were based on 10%, 30%, 40%, and 50% of the 14-day median lethal concentration (LC50), with a control group included for both tests. The LC(50) values for AS fertilizer were significantly higher at 7 days (4831.13 mg/kg d.w.) than at 14 days (2698.67 mg/kg d.w.) of exposure. Notably, earthworms exhibited significant growth rate inhibition under exposure to various concentrations and time durations (14/28 exposure days). Morphological alterations such as clitellar swelling, bloody lesions, whole body coiling and constriction, body strangulation, and fragmentation were accentuated steadily, with higher concentrations. Histopathological manifestations included severe injuries to the circular and longitudinal muscular layers, vacuolation, muscle layer atrophy, degradation of the chloragogenous tissue in the intestine, collapsed digestive epithelium of the pharynx with weak reserve inclusion, and fibrosis of blood vessels. These effects were primarily influenced by increasing concentrations of fertilizer and time exposure. The study highlights the strong relationship between concentration and exposure time responses and underscores the potential of A. trapezoides earthworms as valuable biological control agents against acidic ammonium sulfate fertilizer. Importantly, this research contributes to the use of such biomarkers in evaluating soil toxicity and the biological control of environmental risk assessment associated with chemical fertilizers.