Environmental Toxicants Research Articles

Metabolic Effect of Acute Lead and Restraint Stress Exposure on Female Wistar Rats

Lead is a common environmental toxicant while restraint stress is primarily a psychological stressor. Lead exposure and psychological stressors, are known to exert adverse effects on metabolic health independently. The aim of this study is to investigate the metabolic effects of acute lead and restraint stress exposure in female Wistar rats. Twenty-four (24) female Wistar rats weighing 180 - 240 grams were randomly divided into four (4) groups (n=6): Control (CTL), Restraint stress alone (RSA), Lead acetate alone (LDA), Restraint stress + Lead acetate (RSL). The duration of the study was 21 days. The lead acetate alone group were orally administered 100mg/kg of lead acetate, the restraint stress alone group were restrained for 1 hour daily and the restraint stress + lead group were administered lead acetate and restrained for 1 hour daily. Twenty-four hours post last lead administration and restraint stress exposure, all animals were anesthetized and sacrificed. Blood was collected via cardiac puncture for biochemical analysis. Results showed serum low-density lipoprotein (LDL), triglycerides (TAG) and total cholesterol (CHO) levels in lead alone and restraint stress alone groups were significantly increased (p<0.05) compared with control. The restraint + lead group showed a significant increase in serum LDL, TAG and CHO levels when compared with control, lead alone and restraint stress alone groups. Serum HDL levels showed no significant difference across all groups. Serum glucose, insulin and cortisol levels in lead alone and restraint stress alone groups were significantly increased (p<0.05) when compared with control. The restraint + lead group showed a significant increase (p<0.05) in serum glucose, insulin and cortisol levels when compared with control, lead alone and restraint alone groups. In conclusion, this study showed that exposure to restraint stress and lead has a significant effect on the metabolic profile of female Wistar rats.

Impact of Benzodiazepine Delorazepam on Growth and Behaviour of Artemia salina Nauplii.

Benzodiazepines, a significant group of newly recognised water contaminants, are psychotropic medications prescribed for common anxiety symptoms and sleep disorders. They resist efficient degradation during sewage treatment and endure in aquatic environments. Their presence in aquatic matrices is increasing, particularly after the recent pandemic period, which has led many people to systematically use benzodiazepines to manage anxiety. In previous studies, an important interference of this class of drugs on both the larval and adult stages of some aquatic species has been demonstrated, with effects on behaviour and embryonic development. This study examined the influence of delorazepam, a diazepam metabolite, on Artemia salina development to gain insight into responses in naupliar larvae. Results demonstrated that treatments (1, 5, and 10 µg/L) increase the hatching percentage and induce a desynchronisation in growth. Mortality was only slightly increased (close to 10% at six days post-hatching), but lipid reserve consumption was modified, with the persistence of lipid globules at the advanced naupliar stages. Locomotory activity significantly decreased only at 10 µg/L treatment. No teratogenic effects were observed, though modest damages were noticed in the posterior trunk and eyes, two targets of environmental toxicity. The negative impact of delorazepam on Artemia salina adds to those already reported in other species of invertebrates and vertebrates, which are not yet considered targets of these drugs. This study underscores the need for further research and immediate attention to this class of contaminants and the importance of monitoring their presence during environmental risk assessments.

Development of a TBXT-EGFP iPS cell model for screening the early developmental toxicity of typical environmental pollutants

In our daily lives, we are inevitably exposed to a variety of environmental pollutants in numerous ways. Fortunately, recent years have witnessed significant advancements in the field of stem cell toxicology, which have provided new opportunities for research in environmental toxicology. Applying stem cell technology to environmental toxicology, overcomes some of the limitations of traditional screening methods and we can more accurately predict the toxicity of environmental pollutants. However, there are still several aspects of stem cell toxicology models that require improvement, such as increasing the throughput of detection and simplifying detection methods. Consequently, we developed an environmental pollutant toxicity detection model based on TBXT-EGFP iPS cells and screened the developmental toxicity of 38 typical environmental pollutants. Our results indicate that TBBPA-BDBPE, TBBPA-BHEE, DG, and AO2246 may interfere with the expression of TBXT, a critical marker gene for early human embryo development, implying that these environmental pollutants could lead to developmental abnormalities.

Cesarean birth is associated with lower motor and language development scores during early childhood: a longitudinal analysis of two cohorts

With global C-section rates rising, understanding potential consequences is imperative. Previous studies suggested links between birth mode and psychological outcomes. This study evaluates the association of birth mode and neurodevelopment in young children across two prospective cohorts, using repeated psychometric assessments. Data from the ELEMENT (Early Life Exposures in Mexico to Environmental Toxicants) and PROGRESS (Programming Research in Obesity, Growth, and Environment and Social Stress) cohorts, comprising 7158 and 2202 observations of 1402 children aged 2 to 36 months, and 726 children aged 5 to 27 months, respectively, were analyzed. Exclusion criteria for the cohorts were maternal diseases such as preeclampsia, renal or heart disease, gestational diabetes, and epilepsy. Neurodevelopment was gauged via Bayley’s Scales of Infant Development: 2nd edition for ELEMENT and 3rd edition for PROGRESS. Mixed-effects models longitudinally estimated associations between birth mode and neurodevelopment scores, adjusting for cofounders. In ELEMENT, psychomotor development composite scores were significantly affected by birth mode from ages 2 to 8 months; the largest estimate within this range was at 2 months (β =-1.93; 95% CI: [-3.64, -0.22], reference: vaginal delivery). For PROGRESS, a negative association was found with motor development composite scores over all the studied age range (β=-1.91; 95% CI: [-3.01, -0.81]). The association was stronger between ages 6 to 18 months, with the strongest estimate at 11 months (β=-2.58; 95% CI: [-4.37, -0.74]). A negative impact of C-section on language scores in girls was estimated for the PROGRESS cohort (β=-1.92; 95% CI: [-3.57, -0.27]), most marked in ages 22 to 25 months (largest β at 24.5 months=-3.04; 95% CI: [-5.79, -0.30]). Children born by C-section showed lower motor and language development scores during specific age windows in the first three years of life. Further research is necessary to understand the complexities and implications of these findings.

Dual-defect AgBiO3/DCN S-scheme heterojunction for booted photocatalytic removal of Norfloxacin: Interfacial charge transfer, mechanism and toxicity assessment insights

Antibiotics pollution may pose a great risk to ecosystem and human health. In this work, an innovative dual-defect AgBiO3/DCN S-scheme heterojunction was constructed to overcome the sluggish charge separation and transfer issue and showed exceptional photodegradation performance towards norfloxacin (NFL) pollution under the visible light. The degradation efficiency of NFL reached 95.30 % within 120 min respectively, the rate constant was 3.64 times higher than that of defective g-C3N4 (DCN). The systematically characterizations proved that the enhanced photocatalytic activity was benefited from optimized band structures, improved carrier separation efficiency, due to dual defects and S-scheme heterojunction in AgBiO3/DCN. the intermediate degradation products and degradation pathway of NFL were speculated by UPLC-HRMS, and the environmental toxicity degree of degradation products was analyzed according to the T.E.S.T software. The charge transfer pathway was confirmed as an S-scheme mechanism through a combination of band structure analysis, alongside electron paramagnetic resonance (EPR) experiments.The quenching experiments and ESR analyses indicated that h+ and O2•− radicals played predominant roles. The efficient and stable photocatalytic NFL degradation efficiency and broad environmental adaptability proved potential practical application. This work may shed light on designing new dual-defect heterojunction with photocatalytic antibiotic removal capability in the innovative water treatment process.

Tetra aniline-based polymers ameliorate BPA-induced cardiotoxicity in Sprague Dawley rats, in silico and in vivo analysis

AimsBisphenol A (BPA), xenoestrogen, is an environmental toxicant, that generates oxidative stress leading to cardiotoxicity. The oxidative stress can be neutralized by natural and synthetic antioxidants. The present study elucidates the highly selective antioxidative potential of synthetic tetra aniline polymers Es-37 and L-37 against Bisphenol A-induced cardiac cellular impairments and the role of miRNA-15a-5p in the regulation of different apoptotic proteins. Materials and methodsThe molecular docking of L-37 and Es-37 with three proteins (p53, Cytochrome c, and Bcl-2) were performed. The dose of 1 mg/kg BW of BPA, 1 mg/kg BW Es-37 and L-37 and 50 mg/kg BW N-acetyl cysteine (NAC) was administered to Sprague Dawley rats. The miRNA and target gene expression were confirmed by qRt-PCR and Immunoblotting. Key findingsIn our results, BPA administration significantly elevated the reactive oxygen species (ROS), p53, cytochrome c, and particularly miRNA-15a-5p expression; however: these changes were notably reversed by Es-37 and L-37 treatment. Additionally, molecular docking of synthetic polymers validated that L-37 has a greater binding affinity with the target proteins compared to Es-37, with the highest binding values reported for the enzymatic protein cytochrome c. SignificanceThese results suggest that both synthetic polymers Es-37 and L-37 have the potential to scavenge free radicals, boost-up antioxidant enzyme activities, and avert (BPA-induced) toxicity, thus, may serve as cardioprotective agents. Moreover, this study first time proposes that miRNA-15a-5p overexpression is associated with oxidative stress and coincides with BPA induced cardiotoxicity, thus may serve as potential therapeutic target in future.

Detection and Prediction of Toxic Aluminum Concentrations in High-Priority Salmon Rivers in Nova Scotia.

Elevated concentrations of toxic cationic aluminum (Ali) are symptomatic of terrestrial and freshwater acidification and are particularly toxic to salmonid fish species such as Atlantic salmon (Salmo salar). Speciated metal samples are rarely included in standard water monitoring protocols, and therefore the processes affecting Ali dynamics in freshwater remain poorly understood. Previous analysis of Ali concentrations in Nova Scotia (Canada) rivers found that the majority of study rivers had concentrations exceeding the threshold for aquatic health, but a wide-scale survey of Ali in Nova Scotia has not taken place since 2006 (Dennis, I. F., & Clair, T. A., 2012, Canadian Journal of Fisheries and Aquatic Sciences, 69(7), 1174-1183). The observed levels of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada have potential serious and harmful effects for aquatic populations. We present the findings of the first large-scale assessment of the Ali status of Nova Scotia rivers in 17 years; we measured Ali concentrations and other water chemistry parameters at 150 sites throughout the Southern Uplands region of Nova Scotia from 2015 to 2022. We found that Ali concentrations exceeded toxic thresholds at least once during the study period at 80% of the study sites and that Ali concentrations increased during the study period at all four large-sample study sites. Modeling of relationships between Ali concentrations and other water chemistry parameters showed that the most important predictors of Ali are concentrations of the dissolved fractions of Al, iron, titanium, and calcium, as well as dissolved organic carbon and fluoride. We developed a fully Bayesian linear mixed model to predict Ali concentrations from a test data set within 15 μg/L. This model may be a valuable tool to predict Ali concentrations in rivers and to prioritize areas where Ali should be monitored. Environ Toxicol Chem 2024;00:1-12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Iron metal-organic framework nanofiber membrane for the integration of electro-Fenton and effective continuous treatment of pharmaceuticals in water

In this study, an iron metal-organic framework (Fe-MOF) was synthesized and immobilized by electrospinning technique with the objective of obtaining a membrane composed of nanofibers of this material (Fe-MOF nanofiber membrane). The characterization performed by XRD, TEM, SEM, EDS mapping and FTIR confirmed the correct synthesis of Fe-MOF as well as its correct retention in the elaborated membranes. The usefulness and effectiveness of the Fe-MOF nanofiber membrane as a catalyst for the electro-Fenton process was evaluated by performing sulfamethoxazole degradation tests. Different parameters such as the effect of intensity (25 and 100 mA), the effect of the drug initial concentration (10–50 mg/L) and the reusability of membranes were studied. Then, the degradation of a drug mixture formed by sulfamethoxazole and antipyrine was evaluated, reaching a degradation of 92.10 % and 87.43 % respectively for each drug in 4 h at 25 mA. In addition, the identification of reactive oxygen species was ascertained by scavenger assays. The study of degradation products was also carried out and their toxicity was predicted by ECOSAR program, concluding that the environmental toxicity would disappear with mineralization. Finally, given the good results obtained in batch tests, the behavior of the process was studied in a system that works continuously, achieving a stable degradation of 83.10 % in the case of treatment with a mixture of drugs. This confirmed the stability of the Fe-MOF nanofiber membrane, as well as, its catalytic activity, making it suitable for long-term treatments.

Efficient biodecolorization of direct black 22 Azo Dye by Aspergillus tamarii Kita UCP1279 isolated from caatinga soil

The textile industry is a major consumer of water, generating large volumes of wastewater contaminated with harmful substances, particularly azo dyes, which contain aromatic rings, amines, and sulfonic groups that contribute to their environmental toxicity. The use of microbial agents for wastewater treatment offers a cost-effective and sustainable solution, minimizing sludge production. Fungi from the Caatinga biome have demonstrated potential for bioremediation, especially under extreme environmental conditions. This study explores the ability of Aspergillus tamarii Kita to decolorize the azo dye Direct Black 22 (DB22) under varying conditions, including the use of both active and inactive fungal biomass, in static and agitated systems (120 rpm), at a controlled temperature of 30°C. Dye concentrations of 50, 125, and 250 mg/L were evaluated over time intervals of 75, 180, and 180 minutes, respectively. The influence of dissolved oxygen concentration and redox potential on the decolorization process was also investigated to identify optimal treatment conditions. Decolorization efficiency was quantified via spectrophotometric analysis. Results revealed decolorization rates of 100%, 97%, and 63% for the respective dye concentrations, with active biomass in agitated conditions achieving the highest removal rates. The study further demonstrated that dissolved oxygen levels and redox potential are critical factors in enhancing dye decolorization. These findings underscore the bioremediation potential of Aspergillus tamarii Kita in treating textile dye effluents, offering a promising approach to sustainable industrial wastewater management.

Hydrochar produced from mixed feedstocks as efficient adsorbent for selenium and chromium removal from acidic wastewater

Selenium (Se) and chromium (Cr) in water might be harmful because of their high toxicity in the aquatic environment. Efficient removal of their hexavalent forms (Se(VI) and Cr(VI)) from extreme acidic wastewater is still challenging. Therefore, several new hydrochars suited for efficient removal of trace Se(VI) and Cr(VI) from acidic wastewater were fabricated from biomass through a hydrothermal method. Most functional groups were retained in the hydrochar, which gave it an excellent adsorption capacity (43.2 mg·g−1 and 132 mg·g−1 for Se(VI) and Cr(VI), respectively). After one batch treatment at exceptionally low pH and a hydrochar dose of 0.2 g·L−1, Se(VI) and Cr(VI) could be removed from 1 mg·L−1 to 6 μg·L−1 and 15 μg·L−1, respectively. The mechanism of adsorption at various pH was elucidated by Scanning Electron Microscopy, Thermogravimetry, Fourier Transform Infrared Spectrometer, X-Ray Photoelectron Spectroscopy and density functional theory (DFT) calculation. The adsorption mechanism for Se(VI) in acidic solution involved the binding of SeO42− with protonated amino groups (−NH3+) of Mix hydrochar. In the pH range of 6.5 to 7, Cr(VI) combined with −NH3+ functional groups primarily in the form of CrO42−. When the pH fell below 6.5, Cr(VI) bound with both −NH3+ and carbonyl groups (−C=O) in the form of HCrO4−. Fast kinetics were observed during the removal process of Se(VI) and Cr(VI). The hydrochar adsorbent showed good stability under acidic environments and during long-term adsorption cycles. These findings may provide theoretical basis for design of adsorption materials for acidic wastewater treatment.

Per- and poly-fluoroalkyl substances (PFAS) do not accumulate with age or affect population survival in ruddy turnstone (Arenaria interpres)

Per- and poly-fluoroalkyl substances (PFAS) may threaten wildlife due to their high environmental persistence, toxicity potential and potential to bioaccumulate. Bioaccumulation may be particularly profound in long-lived animals inhabiting higher trophic niches. To date, there is a paucity of data on PFAS bioaccumulation potential in individual wild birds over their lifetime. In this study, we analysed within-individual PFAS contamination in a declining long-distance migratory shorebird, the ruddy turnstone (Arenaria interpres), and the variation in PFAS contamination with age by repeatedly sampling 19 individuals throughout their lives between 2007 and 2022. We found blood-sampled turnstones on their non-breeding grounds in King Island, Tasmania, exhibited no variation of PFAS contamination with age, with low overall circulating PFAS concentrations (<0.015–25 ng/g, median: 0.78 ng/g). Moreover, irrespective of the increased PFAS usage along the East Asian Australasian Flyway over the past two decades, ruddy turnstone survival remained consistent throughout the 15-year sampling period, with no temporal trend in percentage of juveniles in the population. From a conservation perspective, low concentrations of PFAS found in this study are good news as they suggest PFAS alone do not seem to threaten turnstone survival. However, the unknown effects of exposure to mixtures of pollutants may yet threaten turnstones.

Molecular mechanisms for the nanoplastic heteroaggregation with multi-component crude oil

Nanoplastic (NP) and crude oil co-contamination can affect the environmental transport and toxicity of individual NP and oil, but little is known about NP-oil heteroaggregation mechanism so far. In this study, three stages were recognized during NP-oil coalescence process including unstable fluctuation stage, fast coalescense stage and slowly mixing stage. Polyethylene and polypropylene preferred to bind to the aliphatic oil zone, while polystyrene adsorption started on the aromatic zone formed by asphaltenes and aromatics. Polyethylene and polypropylene aggregated with oil via surface dispersing mode by continuously spreading on oil surface and penetrating inside the oil droplet, but polystyrene adsorbed by surface wrapping mode where the rigid polyethylene cluster twisted as a whole until wrapping the oil surface. Heteroaggregates formed by these two modes had different coalescense rate, hydrophobicity and mobility, which might influence the envrionmental transport pathways. Overall results provided theoretical basis for developing environmental fate models for NP-oil co-contaminants.

The effects of microplastics exposure on quail's hypothalamus: Neurotransmission disturbance, cytokine imbalance and ROS/TGF-β/Akt/FoxO3a signaling disruption

Microplastics (MPs) have become a major focus of environmental toxicology, raising concerns about their potential adverse effects on animal organs and body systems. As these tiny particles infiltrate ecosystems, they may pose risks to the health of organisms across diverse species. In this study, we attempted to examine the neurotoxic effects of MPs exposure on avian hypothalamus by using an animal model-Japanese quail (Coturnix japonica). The quails of 7-day-old were exposed to 0.02 mg/kg, 0.4 mg/kg and 8 mg/kg polystyrene microplastic (PS-MPs) of environmental relevance for 35 days. The results showed PS-MPs exposure did damages to hypothalamic structure characterized by neuron malformation, irregular arrangement and cellular vacuolation after 5-week exposure. PS-MPs exposure also induced Nissl body reduction and dissolution in the hypothalamus. Moreover, the decrease of acetylcholinesterase (AchE) activity and increasing acetylcholine (Ach) indicated that PS-MPs exposure caused hypothalamic neurotransmission disturbance. PS-MPs exposure also led to neuroinflammation by disrupting the balance between proinflammatory and anti-inflammatory cytokines. Moreover, increasing reactive oxygen species (ROS) and malondialdehyde (MDA) generation with reducing antioxidants indicated PS-MPs led to hypothalamic oxidative stress. Additionally, RNA-Seq analysis found that both transforming growth factor-β (TGF-β) signaling and forkhead box O (FoxO) signaling were disturbed in the hypothalamus by PS-MPs exposure. Especially, the increasing ROS led to TGF-β activation and then induced hypothalamic inflammation by nuclear factor κB (NF-κB) activation. The present study concluded that oxidative stress might be an important mechanistic signaling involved in MPs neurotoxicology.

Deep learning-assisted detection of psychoactive water pollutants using behavioral profiling of zebrafish embryos

Water pollution poses a significant risk to the environment and human health, necessitating the development of innovative detection methods. In this study, a series of representative psychoactive compounds were selected as model pollutants, and a new approach combining zebrafish embryo behavioral phenotyping with deep learning was used to identify and classify water pollutants. Zebrafish embryos were exposed to 17 psychoactive compounds at environmentally relevant concentrations (1 and 10 μg/L), and their locomotor behavior was recorded at 5 and 6 days post-fertilization (dpf). We constructed six distinct zebrafish locomotor track datasets encompassing various observation times and developmental stages and evaluated multiple deep learning models on these datasets. The results demonstrated that the ResNet101 model performed optimally on the 1-min track dataset at 6 dpf, achieving an accuracy of 65.35 %. Interpretability analyses revealed that the model effectively focused on the relevant locomotor track features for classification. These findings suggest that the integration of zebrafish embryo behavioral analysis with deep learning can serve as an environmentally friendly and economical method for detecting water pollutants. This approach offers a new perspective for water quality monitoring and has the potential to assist existing chemical analytical techniques in detection, thereby advancing environmental toxicology research and water pollution control efforts.

Biogenic Synthesis, Optimization, and characterization of zinc oxide nanoparticles using Rumex abyssinicus Jacq root extract for antioxidant and antibacterial activities

Nanoparticles may be synthesized through chemical, physical, and biological strategies, but the former strategies contain critical troubles, including environmental toxicity and cost-effectiveness. This work addresses adopting a green synthesis method for ZnO NPs using Rumex abyssinicus Jacq root extract for antibacterial and antioxidant programs. A UV–vis spectrophotometer optimized various factors, including temperature, pH, time, zinc acetate dihydrate attention, and the volume ratio of zinc acetate dihydrate to plant root extract. The biosynthesized ZnO NPs had been examined using exclusive characterization instrunments. ZnO NPs and Rumex abyssinicus Jacq root extract confirmed enormous inhibitory effects on pathogenic bacterial lines, inclusive of the gram-negative bacterial strains Escherichia coli and Staphylococcus typhi and the gram-positive bacterial pressure Staphylococcus aureus. ZnO NPs and Rumex abyssinicus Jacq root extract exhibited the best antioxidant sports. consequently, this has a look at confirmed that Rumex abyssinicus Jacq root extract is an effective decreasing agent for the synthesis of ZnO NPs, which exhibit antibacterial and antioxidant activities.

Lead Acetate Exposure and Cerebral Amyloid Accumulation: Mechanistic Evaluations in APP/PS1 Mice.

The role of environmental factors in Alzheimer's disease (AD) pathogenesis remains elusive. Mounting evidence suggests that acute and past exposure to the environmental toxicant lead (Pb) is associated with longitudinal decline in cognitive function, brain atrophy, and greater brain -amyloid () deposition. However, the nature of Pb-induced amyloid deposition and how it contributes to AD development remain unclear. This study investigates the role of Pb in the pathogenesis of cerebral amyloid angiopathy (CAA) and whether plasminogen activator inhibitor-1 (PAI-1) contributes to this process in the APP/PS1 mouse model. Female APP/PS1 mice at 8 wk of age were administered either Pb-acetate (PbAc) (i.e., ) or an equivalent molar concentration of sodium acetate (NaAc) via oral gavage once daily for 8 wk. Amyloid deposition and vascular amyloid were determined by immunostaining. In addition, perivascular drainage, vascular binding assay, and microglial endocytosis were examined to determine underlying mechanisms. Furthermore, magnetic resonance imaging demyelination imaging was performed invivo measure the level of demyelination. Finally, Y-maze and Morris water maze tests were assessed to evaluate the cognitive function of mice. APP/PS1 mice (an AD mice model) exposed to PbAc demonstrated more vascular amyloid deposition less neocortical myelination, and lower cognitive function, as well as greater vascular binding to , higher ratios, strikingly lower levels in the perivascular drainage, and microglial endocytosis. Importantly, exposure to a specific PAI-1 inhibitor, tiplaxtinin, which previously was reported to lower CAA pathology in mice, resulted in less CAA-related outcomes following PbAc exposure. Our findings suggest that PbAc induced CAA/AD pathogenesis via the PAI-1 signaling in the APP/PS1 mouse model, and the inhibition of PAI-1 could be a potential therapeutic target for PbAc-mediated CAA/AD disorders. https://doi.org/10.1289/EHP14384.

Studies to assess natural resource recovery and evaluate monitoring methods for restored bottomland hardwood forests.

The Natural Resource Damage Assessment and Restoration process assesses natural resource injury due to oil or chemical spills and calculates the damages to compensate the public for those injuries. Ecological restoration provides a means for recovering resources injured or lost due to contamination from oil or chemical spills by restoring the injured site after remediation, or acquiring or reconstructing equivalent resources off site to replace those lost due to the spill. In the case of restored forests, once restoration is implemented, monitoring of forest ecology helps keep recovery on track, with the maturation of forest vegetation, recovered soil conditions, and development of microbial, fungal, and faunal communities, necessary for ecologically functioning forests. This series of papers focuses on applying methods for monitoring restoration progress in forest vegetation and soils, and amphibian, avian, and mammalian communities, assessing strengths and weaknesses of different methods, and evaluating levels of effort needed to obtain accurate indications of forest ecological condition. Integr Environ Assess Manag 2024;00:1-5. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Proteome Changes Induced by Iprodione Exposure in the Pesticide-Tolerant Pseudomonas sp. C9 Strain Isolated from a Biopurification System

Iprodione is a pesticide that belongs to the dicarboximide fungicide family. This pesticide was designed to combat various agronomical pests; however, its use has been restricted due to its environmental toxicity and risks to human health. In this study, we explored the proteomic changes in the Pseudomonas sp. C9 strain when exposed to iprodione, to gain insights into the affected metabolic pathways and enzymes involved in iprodione tolerance and biodegradation processes. As a result, we identified 1472 differentially expressed proteins in response to iprodione exposure, with 978 proteins showing significant variations. We observed that the C9 strain upregulated the expression of efflux pumps, enhancing its tolerance to iprodione and other harmful compounds. Peptidoglycan-binding proteins LysM, glutamine amidotransferase, and protein Ddl were similarly upregulated, indicating their potential role in altering and preserving bacterial cell wall structure, thereby enhancing tolerance. We also observed the presence of hydrolases and amidohydrolases, essential enzymes for iprodione biodegradation. Furthermore, the exclusive identification of ABC transporters and multidrug efflux complexes among proteins present only during iprodione exposure suggests potential counteraction against the inhibitory effects of iprodione on downregulated proteins. These findings provide new insights into iprodione tolerance and biodegradation by the Pseudomonas sp. C9 strain.

The Allium cepa comet assay for environmental sample assessment: a scoping review.

The purposes of this review were to investigate the application of the comet assay in Allium cepa root cells to assess the genotoxicity of environmental samples and to analyse the experimental procedures employed. A literature search was performed selecting articles published between January 2000 and October 2023 from online databases using the combined search terms 'comet assay' and 'A. cepa'. Only 18 papers met the inclusion criteria. None of these were published in the first eight years (2000-2007), highlighting the increasing interest in using the comet assay on A. cepa to analyse environmental samples over the last decade. The majority of the selected studies (15/18, 83%) were performed on samples belonging to the water compartment on onion bulbs. Half of the selected studies (9/18) were conducted to demonstrate the DNA damaging effect of the sample, while the other half of the studies not only recognized the presence of genotoxic agents but also addressed possible remediation measures. Detailed analysis of the experimental procedures revealed heterogeneity in many key steps, such as exposure time, test controls, nuclei isolation solutions, duration of electrophoresis, and number of nuclei scored. This literature review has shown that the comet assay on A. cepa, although recognized as an appropriate tool, is underutilized in environmental toxicology. Greater standardization could lead to its more widespread use, providing valuable information on the genotoxicity of environmental samples and the ability of different processes to mitigate their negative effects on plants.

Do Crops Grown at Urban Dumpsites Contain Metals at Levels that Pose Unacceptable Health Risks to Consumers?

Excessive dietary metal intake from crops grown on contaminated urban dumpsites poses a global health risk to consumers. We evaluated the health risk to adult and child consumers from dietary exposure to metals and metalloids in crops cultivated at the Mbale (Uganda) dumpsite centre. Thirteen crop types grown on the dumpsite soil were sampled and analyzed for concentrations of 11 metals: Fe, Al, Zn, Mn, Cu, Pb, Cr, Hg, Co, Ni, Cd, and two metalloids: Se and As. Different proportions of the crops were combined into 12 meal classes to simulate the diets of residents and estimate noncancer and cancer risks. The findings indicated that most individual crop types and simulated diets lacked sufficient selenium for bodily functions. Furthermore, their metal accumulations exceeded the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) permissible limits (mg/kg) for Al (20), Fe (100), Ni (10), Cu (20), Mn (10), Pb (0.3), Se (0.05), and Zn (99.4). The four most abundant metals in the various crop types and diets were Al, Fe, Mn, and Zn. A positive correlation between the metals in the crops indicated a common origin, which could possibly be the dumpsite soil. The chronic dietary intake (CDI) of metals was higher in children, and thus children faced higher noncancer and cancer risks compared with adults. The overall CDI values for each metal ranged from 0.000718 to 2.171 in adults, and 0.00125 to 3.781662 in children, which is approximately 1.74 times higher in children than in adult consumers. The noncancer and cancer risks ranged from moderate to high with Co, Cr, Fe, Mn, and Zn being mostly responsible for the high noncancer risks, and Al being the predominant contributor to cancer risks. The total noncancer risk levels equally ranged from moderate (1.4-3.3) for adults, and moderate to high (2.4-5.7) for children; the cancer risks were moderate to high in adults, with Al contributing to between 68% and 92% of the total risks across the 12 meal classes. Overall, CDI values and noncancer and cancer risks were all higher in children than in adults. The vegetables Amaranthus hybridus, Vigna unguiculate, Amaranthus dubius, and Cucurbita maxima significantly contributed to the high noncancer risk to both adults and children, particularly when they constituted 40% or more of the meal. Four additional vegetables (Cocorhrous olitorous, Brassica oleracea, Amaranthus cruentus, and Gynandropsis gynandra) also posed a high risk to children when consumed in large quantities. Our results highlight the urgent need to develop regulatory frameworks and/or rigorously enforce existing land and food governance policies to protect consumers' health from unsafe metal concentrations in crops grown on dumpsites. Environ Toxicol Chem 2024;00:1-17. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.