Mercury Exposure Research Articles

Chromoionophoric molecular probe infused bimodal porous polymer rostrum as solid-state ocular sensor for the selective and expeditious optical sensing of ultra-trace toxic mercury ions

This study presents a distinctive solid-state naked-eye colorimetric sensing approach by encapsulating a chromoionophoric probe onto a hybrid macro-/meso-pore polymer scaffold for fast and selective sensing of ultra-trace Hg(II). The customized structural/surface properties of the poly(VPy-co-TM) monolith are attained by specific proportions of 2-vinylpyridine (VPy), trimethylolpropane trimethacrylate (TM), and pore-tuning solvents. The interconnected porous network of poly(VPy-co-TM), inherent superior surface area and porosity, is captivating for the homogeneous/voluminous incorporation of probe molecules, i.e., 7-((4-methoxyphenyl)diazenyl)quinoline-8-ol (MPDQ), for the target-specific colorimetric detection. The structural morphology, surface topography, and phase characteristics of the bare poly(VPy-co-TM) monolith and MPDQ@poly(VPy-co-TM) sensor are examined using HR-TEM-SAED (High-Resolution Transmission Electron Microscopy - Selected Area Electron Diffraction), FE-SEM-EDAX (Field Emission Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), XPS (X-ray Photoelectron Spectroscopy), p-XRD (Powder X-Ray Diffraction), FT-IR (Fourier Transform Infrared Spectroscopy), UV-Vis-DRS (Ultraviolet-Visible Diffuse Reflectance Spectroscopy), and BET/BJH (Brunauer-Emmett-Teller / Barrett-Joyner-Halenda) analysis. The distinctive properties of the sensor reveal a constrained geometrical orientation of the MPDQ probe onto the long-range continuous monolithic network of meso-/-macropore template, enabling selective interaction with Hg(II) with peculiar color transfiguration from pale yellow to deep brown. The sensor demonstrates a linear spectral-color alliance in the 0–200 ppb concentration range for Hg(II), with quantification and detection limits of 0.63 and 0.19 ppb. The sensor efficacy is verified using certified contaminated water and tobacco samples, with excellent reusability, reliability, and reproducibility of ≥ 99.23 % (RSD ≤1.89 %) and ≥ 99.19 % (RSD ≤1.94 %) of Hg(II), respectively.

Prenatal mercury exposure and the secondary sex ratio: The Japan Environment and Children's Study

Prior research into the association between prenatal mercury (Hg) exposure and the secondary sex ratio has yielded inconclusive and conflicting results. Notably, no study has used cord blood Hg measurement in this context. Also, the differences in Hg species and the potential modifying role of selenium (Se) on this association remain unexplored. Using data from the Japan Environment and Children's Study, we analyzed mother–child pairs with available data for concentrations of total mercury (THg) and Se in maternal blood during late pregnancy, and THg, inorganic mercury (IHg), methylmercury (MeHg), and Se in cord blood. Logistic regression models were employed to examine the association between Hg and Se biomarkers and the secondary sex ratio. Out of the total sample of 3698 children, 1877 (50.8 %) were male, corresponding to an overall secondary sex ratio of 1.03. After adjusting for maternal age and parity, no significant associations were observed between THg concentrations of maternal blood and the secondary sex ratio. Nevertheless, we identified that two-fold increases in THg, IHg, and MeHg concentrations in cord blood were positively associated with increased odds of having a male child, yielding adjusted odds ratios of 1.13 (95 %CI: 1.04, 1.22), 1.12 (1.03, 1.21), and 1.12 (1.03, 1.22), respectively. When stratified by the median Se concentrations, no apparent differences were detected in the associations between Hg concentrations and the secondary sex ratio. In summary, elevated Hg concentrations in cord blood, but not maternal blood, were associated with an increased probability of male births.

Bismuth Film Electrodes: Characterization and Analytical Application

Bismuth film electrodes (BiFE) were first introduced more than two decades ago and have been regarded as a posible alternative to toxic traditional mercury electrodes, both for electro-synthesis and electro-analytical endeavors. However, despite all the associated benefits, there hasn’t been a proper characterization reported for this electrodes and their use is still limited.The present work shows the results of a physicochemical characterization of Bismuth film electrodes, as well as the application of BiFE for the detection and quantification of heavy metals (such as cadmium), which for years have been considered to be important pollutants and are toxic for humans and the environment at large; there for putting at risk the health of all organisms that come into contact with them. The analysis is carried out in a EtOH:H2O mixture at pH 5, simulating the matrix of a traditional mexican alcoholic beverage, Mezcal.The characterization includes: the calculation of the geometric area as well as the electro-active area of the electrode, the composition of the deposited film and it’s texture, and the electrical properties of the modified electrode.The analysis is carried out using Anodic Stripping Square Wave Voltammetry (ASSWV), this allows us to make use of the electrode’s ability to form strong interactions with the analyte, in a similar manner to that of mercury drop electrodes; along with the high sensitivity of this technique.

Bioremediation of heavy metals by an unexplored bacterium, Pseudoxanthomonas mexicana strain GTZY isolated from aerobic-biofilm wastewater system.

We prompted to characterize a wastewater bacterium, Pseudoxanthomonas mexicana GTZY, that efficiently transforms toxic mercury and arsenic, explores its bioremediation capability, and reveals their relevant gene resistance operons. The isolated strain was characterized by its phylogenetic, biochemical, and phenotypic properties. The strain GTZY potentially removed 84.3% of mercury and their mercury volatilization (Hg(II) to Hg(0)) was confirmed using the X-ray film method, and its respective merA gene was PCR amplified. In addition, strain GTZY efficiently removed arsenate (68.5%) and arsenite (63.2%), and showed resistance up to > 175 and > 55mM, respectively. Their genomic annotations disclosed the linkage of Tn2-transposon and int1 in both ends of mer operon (merAPTR). The co-existence of arsP and arsH proteins in its intrinsic ars operon (arsCPRH) was extremely diverse from its ancestral species. We believe that the mercury resistance-conferring mer operon of P. mexicana GTZY presumably derived horizontally from other species in the reactor, while the arsenic resistance-conferring intrinsic ars operon was highly diversified and evolved from its ancestral species. By considering the potential of the strain GTZY to transform heavy metals, this can be used to recover contaminated sites.

Determination of Heavy Metals in Some Selected Flavour Drinks in Nigeria

The level of heavy metals contamination in flavor drinks has not been investigated in Nigeria. This research was aimed at arsenic at the level of heavy metals contamination in five (5) different powdered flavor drinks commonly sold in Nigerian local markets using atomic absorption spectroscopy (AAS) after acid digestion (HNO3, H2SO4 &HCLO4) in the ratio 1:1:1. The results showed the presence of heavy metals that are considered toxic such cadmium, lead, mercury, nickel, and arsenic at concentrations range between 0.040-0.199, 0.075-0.260, 0.132-0.487, 0.091-0.1324 and 0.221-1.185 mg/L respectively and were found to be above the maximum contaminant level sets by USEPA (2011). Other heavy metals such as chromium, cobalt, copper, selenium, manganese, and iron that are considered essential and less toxic were also determined using this method.

Exploring the versatility of carbohydrate-capped green silver nanoparticles as multi-dimensional reagents for targeted applications

The present work describes the impact of the structural diversity of different carbohydrate molecules on the morphology and sensing ability of silver nanoparticles synthesized by a green protocol using Ocimum sanctum leaf extract, used as the reducing agent. Seven different monosaccharides were utilized as capping and stabilizing agents during the green synthesis of silver nanoparticles. The carbohydrate-capped nanoparticles were more stable in solution than the uncapped counterpart for at least three months. The formation and stability of the silver nanoparticles were analyzed using UV-visible, fluorescence spectroscopy, and X-ray diffraction studies, whereas the morphological characteristics were studied using scanning electron microscopic analysis. The different types of interaction of sugar molecules with silver atoms were studied using DFT calculation. Silver nanoparticles synthesized using d-galactose and l-arabinose, having an axial-OH group at the C-4 position, were found to have the smallest size with maximum efficacy as chemosensors for toxic mercury (II) ions in aqueous medium. The green silver nanoparticles were successfully employed as antimicrobial agents against different gram-positive and gram-negative bacteria. The catalytic activity of silver nanoparticles in the degradation of organic dyes was also evaluated for Congo red, methyl orange and reactive blue in the presence of sodium borohydride. The nanoparticles showed excellent dye degradation activity with a minimum time duration.

Surgical Management of Iatrogenic Mercury Poisoning From Subcutaneous Injection Into the Arm.

Mercury, an element with threats of severe toxic insult to humans and no biological function, has a surprisingly extensive record of human exposure. Regardless of hesitancies toward its harmfulness, it has been historically identified with an almost supernatural power to provide protection from evil and sickness, give good fortune, lend aid in athletic undertakings, or even allow one to achieve immortality. Mercury poisoning is an iatrogenic disease even today as people attempt to achieve these effects through volitional injections into their body by practitioners. Although an uncommon practice in the United States, awareness of patient presentation after volitional injections of elemental mercury is necessary for appropriate treatment of these patients. We aim to increase awareness of the cultural practice of subcutaneous injections of mercury, as it is uncommonly seen in the United States, to contribute a broader understanding to the patient's medical presentation and describe an approach and the impact of medical and surgical intervention. In this report, we describe a rare case of elemental mercury poisoning secondary to volitional subcutaneous injection to the arm. Initial management of care through chelation therapy and monitoring of renal and serum mercury levels in addition to symptoms of systemic spread was overseen by an internal medicine physician and poison control. Surgical intervention via full-thickness excision of the visible mercury to the right arm followed by local flap and skin grafting reconstruction was performed. Mercury poisoning from intentional subcutaneous administration is an uncommon patient presentation in the United States; however, knowledge of management of this rare condition is important for effective management of iatrogenic mercury toxicity.

Integrating Multi-Omics with environmental data for precision health: A novel analytic framework and case study on prenatal mercury induced childhood fatty liver disease

BackgroundPrecision Health aims to revolutionize disease prevention by leveraging information across multiple omic datasets (multi-omics). However, existing methods generally do not consider personalized environmental risk factors (e.g., environmental pollutants). ObjectiveTo develop and apply a precision health framework which combines multiomic integration (including early, intermediate, and late integration, representing sequential stages at which omics layers are combined for modeling) with mediation approaches (including high-dimensional mediation to identify biomarkers, mediation with latent factors to identify pathways, and integrated/quasi-mediation to identify high-risk subpopulations) to identify novel biomarkers of prenatal mercury induced metabolic dysfunction-associated fatty liver disease (MAFLD), elucidate molecular pathways linking prenatal mercury with MAFLD in children, and identify high-risk children based on integrated exposure and multiomics data. MethodsThis prospective cohort study used data from 420 mother–child pairs from the Human Early Life Exposome (HELIX) project. Mercury concentrations were determined in maternal or cord blood from pregnancy. Cytokeratin 18 (CK-18; a MAFLD biomarker) and five omics layers (DNA Methylation, gene transcription, microRNA, proteins, and metabolites) were measured in blood in childhood (age 6–10 years). ResultsEach standard deviation increase in prenatal mercury was associated with a 0.11 [95% confidence interval: 0.02–0.21] standard deviation increase in CK-18. High dimensional mediation analysis identified 10 biomarkers linking prenatal mercury and CK-18, including six CpG sites and four transcripts. Mediation with latent factors identified molecular pathways linking mercury and MAFLD, including altered cytokine signaling and hepatic stellate cell activation. Integrated/quasi-mediation identified high risk subgroups of children based on unique combinations of exposure levels, omics profiles (driven by epigenetic markers), and MAFLD. ConclusionsPrenatal mercury exposure is associated with elevated liver enzymes in childhood, likely through alterations in DNA methylation and gene expression. Our analytic framework can be applied across many different fields and serve as a resource to help guide future precision health investigations.

Tissue Distribution and Toxicological Risk Assessment of Mercury and Other Elements in Northern Populations of Wolverine (Gulo gulo)

Wolverines are facultative scavengers that feed near the top of terrestrial food chains. We characterized concentrations of mercury and other trace elements in tissues of wolverine from a broad geographic area, representing much of their contemporary distribution in northwestern North America. We obtained tissues from 504 wolverines, from which mercury was measured on muscle (n = 448), kidney (n = 222), liver (n = 148), hair (n = 130), and brain (n = 52). In addition, methylmercury, seven trace elements (arsenic, cadmium, chromium, cobalt, lead, nickel, selenium), and arsenic compounds were measured on a subset of samples. Concentrations of mercury and other trace elements varied between tissues and were generally highest in kidney compared to brain, liver and muscle. Mercury was predominately as methylmercury in brain and muscle, but largely as inorganic mercury in liver and kidney. Mercury concentrations of hair were moderately correlated with those of internal tissues (Pearson r = 0.51–0.75, p ≤ 0.004), making hair a good non-lethal indicator of broad spatial or temporal differences in mercury exposure to wolverine. Arsenobetaine was the dominant arsenic compound identified in tissues, and arsenite, arsenocholine and dimethylarsinic acid were also detected. A preliminary risk assessment suggested the cadmium, lead, mercury, and selenium concentrations in our sample of wolverines were not likely to pose a risk of overt toxicological effects. This study generated a comprehensive dataset on mercury and other trace elements in wolverine, which will support future contaminants study of this northern terrestrial carnivore.

Effect of Mercury Exposure on the Growth and Physiological Characteristics of Lowland Tomato (Solanum lycopersicum)

Effect of Mercury Exposure on the Growth and Physiological Characteristics of Lowland Tomato (Solanum lycopersicum)

Potential Combination of Phytoremediation Plants and Compost in Remediation of Hg in Ex-Gold Mine Soil Contaminated Mercury (Hg)

Heavy metal mercury pollution in the environment can have negative impacts on both surrounding ecosystems and human health. Sources of mercury pollution often come from mining activities, particularly from many unlicensed gold mines (PETI) that use the mercury amalgamation method to extract gold. Due to the persistent, bioaccumulative, and toxic nature of mercury, contamination in the soil has increased. One effort to reduce mercury toxicity is the application of absorption methods using phytoremediation plants and compost as regulating factors. The aim of this study is to review sources of information related to the use of phytoremediation plants and the application of compost as remediators to clean mercury (Hg)-contaminated soil. To reduce levels of heavy metal contamination, plants employ five phytoremediation mechanisms: phytoextraction, phytostabilization, rhizofiltration, phyto degradation, and phytovolatilization. Therefore, selecting hyperaccumulator plants that have the ability to accumulate mercury (Hg) at levels 100 times higher than ordinary plants is crucial for effective remediation. Additionally, the use of compost as a source of organic material can enhance mercury mobility. The addition of organic materials such as compost can increase C organic content, cation exchange capacity (CEC), pH, and Hg-chelate formation, thereby maximizing mercury absorption by plants. This combination has a positive impact on reducing mercury levels in the soil and is environmentally safe.

Acute toxicity of mercury to freshwater cultured milkfish Chanos chanos: Clinical symptoms and lethal concentration assessment

The increasing use of mercury in the industrial sector poses significant risks to freshwater ecosystems and aquatic organisms. Milkfish (Chanos chanos), a widely consumed species, is now being reared in freshwater environments, raising concerns about mercury bioaccumulation and food safety. This study aimed to determine the median lethal mercury concentration for milkfish at 96 hours (LC50) in freshwater using an experimental approach and probit analysis. Five mercury concentrations were tested: 0 (control), 0 .110 mg Hg/L, 0.195 mg Hg/L, 0.347 mg Hg/L, and 0.618 mg Hg/L. The results indicated that mercury is highly toxic to milkfish, with a 96-hour LC50 of 0.147 mg Hg/L. Clinical symptoms observed included loss of reflex movements, irregular swimming, frequent surfacing with widened mouth and operculum openings, convulsions, and ventilation of the ram before mortality. These findings highlight the acute toxicity of mercury in freshwater milkfish and underscore the potential health risks associated with mercury contamination in aquaculture systems.

Concentration and Distribution of Oligochaeta Worms in the Waters of Kejapanan, Pasuruan, Indonesia Polluted by Mercury Waste using DNA Barcode

Graphical Abstract Higlight Research Based on AAS test, results showed that the St2 sample has the highest concentration of mercury compared to other locations. St2 samples are samples taken right at the pollutant source. The results showed that the samples consist of the Nadidae family with two species, namely Limnodrilus hoffmeisteri and Branchiura sowerbyi. The COI gene that was successfully amplified had a length of approximately 700 bp using a 3000 bp DNA ladder as a comparison. Based on the results of the SEM-EDX test, the worm samples contained several elements. The majority of them are organic except Al, Si, and Ti. Aluminium (Al), Silicon (Si), and Titanium (Ti) are metals that are used by organisms. Abstract Physiological monitoring of mercury waste contamination can be carried out using the biota around the waters. This study aims to identify concentration of Hg and the types of worms in the waters of Kejapanan, Pasuruan, East Java with a molecular approach. Target gene amplification was carried out using the mitochondrial genome COI barcode primer. Analysis of molecular identification was performed with DNA analysis and phylogenetic, similarity, DNA sequence variation, genetic distance, and the BOLD System. The concentration Hg was analyzed using AAS and the distribution of mercury in the worms was analyzed using SEM Edax Mapping. The results showed that the pollutant source area (St2 sample) has the highest concentration of mercury compared to other locations. The results of molecular identification indicate the formation of two clusters. The amplified samples produced DNA bands according to the target (600-700 bp), and the process was continued with morphological-based-key identification. The results showed that they consist of the family Nadidae with two species, namely Limnodrilus hoffmeisteri and Branchiura sowerbyi. A DNA length of 709 bp as well as nucleotide composition. BLAST results showed that species L. hoffmeisteri and B. sowerbyi had similarity indexes of 99% and 86%, respectively. Based on the research results, it was found that there was an accumulation of mercury exposure in worms in polluted areas. For this reason, the results of this study can provide a novelty that worms can be used as biomonitoring of water pollution using the barcode data.

Methylmercury exposure and risk of wintering migratory birds in the Poyang Lake basin, China

Mercury (Hg), especially methylmercury (MeHg), is a pervasive contaminant that poses significant risks to birds occupying high trophic levels. However, we have little knowledge about the mercury exposure and its risks for birds in Poyang Lake basin, China. Therefore, during 2020–2021, we investigated MeHg concentrations in breast feathers of wintering migratory birds (n = 430 from 43 species belonging to 9 orders) in Poyang Lake Nanji Wetland and Jiangxi Nanfengmian National Nature Reserve, China. MeHg concentrations in breast feathers varied greatly by species, foraging guilds and taxonomic orders, among which the highest concentration was detected in great egret (8849 ± 5975 ng g−1 dw). Comparing with studies worldwide, high MeHg concentrations in feathers of Ardeidae from Pelecaniformes were found in this area. Moreover, herons migrating between northern and southern China had lower MeHg concentration than residents in southern China related to habitat Hg. Considering the applicability and sensitivity of the equations for the transformation of MeHg concentrations in feathers to blood-equivalent total Hg (THg) values, method CJ that the equation based on songbirds was used for the transformation of the songbirds and the equation based on seabirds for the others performed better than other three for risk assessment of bird Hg in this study. 23.1% of birds from Poyang Lake were at risk of Hg exposure based on the method CJ. Carnivorous birds from Pelecaniformes had the highest risk levels, with 37.2% categorized as no risk (≤200 ng g−1 ww), 48.9% as low risk (200–1000 ng g−1 ww), 11.1% as moderate risk (1000–3000 ng g−1 ww), 1.1% as high risk (3000–4000 ng g−1 ww), and 1.7% as severe risk (>4000 ng g−1 ww). These risks suggest long-term monitoring and further advanced studies about freshwater waterbirds Hg exposure is necessary.

A case of intravenous injection of mercury poisoning

There are few reports of poisoning caused by high-dose intravenous injection of mercury. Its clinical manifestations are diverse and the risk of mortality is high. Currently, the pathogenesis is not clear and the treatment experience is insufficient, leading to difficulties in clinical diagnosis and treatment. In this article, the data of a case of mercury poisoning caused by intravenous self-administration was analyzed and summarized. The patient developed multiple organ dysfunction syndrome after intravenous injection of high-dose mercury. After comprehensive treatment, such as mercury removal, organ support, and infection prevention, the condition was improved. This case suggests that intravenous injection of mercury can cause damage to the functions of multiple organs, such as the heart, lungs, and kidneys. Early treatment and intervention can bring benefits.

Natural mercury exposure of European insectivorous bats may exceed a recognized toxicity threshold

Heavy metals are an important group of toxic substances harmful for many organisms. Of these, mercury is one of the most monitored in the environment. Several matrices are used for the monitoring of environmental load, including a range of organisms; bats, however, have only been examined rarely. Insectivorous bats are apex predators threatened by several human interventions in their natural environment, including heavy metal pollution. The aim of this study was to analyze the content of total mercury in the fur, flight membrane, and pectoral muscle of greater mouse-eared bats (Myotis myotis). Total mercury concentrations were also measured in carabid beetles from the catch locality Zastávka u Brna. Samples were obtained from 43 bat carcasses at two different localities in the Czech Republic (Zastávka u Brna, Malá Morávka). Total mercury content varied between 1.76–72.20 µg/g in fur, 0.04–0.14 µg/g in skin, and 0.05–0.20 µg/g in muscle. Total mercury values in the fur of some individuals from Malá Morávka exceeded the recognized toxicity limit. Furthermore, there was a significant difference (p < 0.001) in content of total mercury in fur between localities, and there was a clear effect of age on concentrations in fur, skin, and muscle, the concentrations being significantly correlated (fur and skin rs = 0.783; fur and muscle rs = 0.716; skin and muscle rs = 0.884). These findings confirm the usefulness of fur samples from living bats for biomonitoring mercury burden in the environment.

Genome-Scale Screening of Saccharomyces cerevisiae Deletion Mutants to Gain Molecular Insight into Tolerance to Mercury Ions.

Mercury (Hg) is a global pollutant and a bioaccumulative toxin that seriously affects the environment. Though increasing information has been obtained on the mechanisms involved in mercury toxicity, there is still a knowledge gap between the adverse effects and action mechanisms, especially at the molecular level. In the current study, we screened a diploid library of Saccharomyces cerevisiae single-gene deletion mutants to identify the nonessential genes associated with increased sensitivity to mercury ions. By genome-scale screening, we identified 64 yeast single-gene deletion mutants. These genes are involved in metabolism, transcription, antioxidant activity, cellular transport, transport facilitation, transport routes, and the cell cycle, as well as in protein synthesis, folding, modification, and protein destination. The concentration of mercury ions was different in the cells of yeast deletion mutants. Moreover, the disruption of antioxidant systems may play a key role in the mercurial toxic effects. The related functions of sensitive genes and signal pathways were further analyzed using bioinformatics-related technologies. Among 64 sensitive genes, 37 genes have human homologous analogs. Our results may provide a meaningful reference for understanding the action mode, cellular detoxification, and molecular regulation mechanisms of mercury toxicity.

Leek (Allium ampeloprasum var. kurrat) aqueous extract loaded on selenium nanoparticles protects against testis and brain injury induced by mercuric chloride in rats.

Mercuric chloride (HgCl2) is poisonous to humans and animals and typically damages the nervous system and other organs. Mercuric chloride exposition disclosed to initiation of oxidative stress pathway can result in a defect in male fertility and testis tissue. Synthesized selenium nanoparticles (SeNPs) were characterized with a diameter range minimal than 100 nm, having the effective sets of the biological matter. The present study aimed to evaluate the effect of biosynthesized SeNPs, prepared by leek extract on Wistar rats' testicles and brain. Thirty-five Wistar male rats (120-150 g) were randomly split into five groups (n = 7), orally ingested with leek aqueous extract loaded on SeNPs, and then the animals were administered with mercury II chloride (HgCl2) to induce testis injury and damage the nervous system. The used dose of mercuric chloride led to oxidative stress damage in the testis of the rats which was evidenced by a decrease in testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and proliferating cell nuclear antigen (PCNA) levels, and an increase in nuclear factor-kappa B (NF-κB) and caspase-3. Also, HgCl2 decreased the levels of dopamine (DA), serotonin (5-HT), norepinephrine (NE) and brain-derived neurotrophic factor (BDNF) in the brains of rats. In addition, A decrease was observed in the levels of antioxidant markers, B-cell lymphoma-2 (Bcl-2), as well as an increase in malondialdehyde (MDA), nitric oxide (NO), NF-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and Bax in both testes and brains. Pre-treatment with leek extract loaded on SeNPs significantly ameliorated testosterone, LH, FSH, PCNA and caspase-3 levels in the testis and DA, 5-HT, NE and BDNF in brains. Although the contents of MDA, NO, TNF-α, IL-1β, NF-κB and Bax decreased significantly in both. glutathione, glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase and Bcl-2 levels were significantly improved in both organs. Our findings suggest that treatment with aqueous leek extract loaded on SeNPs may offer promising prospects for the advancement of anti-inflammation activity against testis injury and also have a very key role in neurobehavioral alterations as a result of mercury toxicity. © 2024 Society of Chemical Industry.

Mercury Exposure Is Associated with Urbanization but not Salmonella Status in White Ibis (Eudocimus albus).

Mercury (Hg) is a ubiquitous contaminant in wetlands that can cause immunosuppression in birds, which may increase susceptibility to colonization with Salmonella spp. Previously, we found that White Ibis (Eudocimus albus), a recently urbanized wading bird, shed Salmonella spp. at a higher prevalence when captured at urban sites, compared with natural sites. In this study, we sought to determine if Hg burdens in ibis are related to Salmonella status or degree of urbanization or both. We analyzed feathers from 94 ibis in Palm Beach County, Florida, USA, along an urbanization gradient (0-68% urbanization) and from individuals with confirmed Salmonella spp. status (shedding or not shedding). We detected Hg in all ibis feathers (0.22-8.47 mg/kg; mean=1.96 mg/kg; SD=1.94). The Hg concentration was not significantly correlated to Salmonella spp. shedding status (Wilcoxon rank sum test, W=1170; P=0.596) but was negatively associated with capture site urbanization level (R2=0.327; P=0.026). Our findings may suggest that the immunosuppressive effects of Hg do not affect Salmonella shedding in the ibis or that Hg burdens were too low to affect Salmonella shedding status. Further, ibis that were captured in high urbanization sites appeared to have a lower risk of Hg exposure than ibis that were captured within low urbanization sites.

Mercury exposure and trophic ecology of urban nesting black-legged kittiwakes from France

Seabirds are increasingly used as bioindicators for assessing the chemical contamination of marine ecosystems, including by mercury (Hg) worldwide. However, some geographical areas are still poorly documented, as metropolitan France that is home to 28 seabird species including the black-legged kittiwake Rissa tridactyla, in the part of the southern limit of the North Atlantic range of the species. Here, we investigated Hg contamination and trophic ecology of black-legged kittiwakes breeding in the harbour of Boulogne-sur-Mer, Northern France. Mean blood Hg concentration was 4.81 ± 1.20 μg g−1 dw (dry weight), 3.66 ± 0.75 μg g−1 dw and 0.43 ± 0.07 μg g−1 dw for adult males, adult females, and chicks, respectively. According to Hg toxicity benchmarks for avian blood, 30% of the sampled adults were considered to be at moderate risk to Hg toxicity. Stable isotope and food analyses showed that highest δ15N values (reflecting a higher trophic position) were related to highest blood Hg concentrations in adult birds, and that Atlantic herring (Clupea harengus) and Atlantic mackerel (Scomber scombrus) were the main prey. Adult kittiwakes from Boulogne-sur-Mer showed Hg levels three times higher than those found in Arctic nesting kittiwakes, where sublethal effects have been documented. This study provides a first description of Hg contamination of black-legged kittiwakes breeding in France and calls for future ecotoxicological research to assess the vulnerability of this species in the southern part of its distribution range.