Mercury Exposure Research Articles

The mercury and low molecular-weight antioxidants levels in ungulates of the Republic of Karelia

The high toxicity of mercury (Hg) poses a danger to the environment and humans, but studies of the concentration of this metal in organisms of terrestrial ecosystems are few. Ecotoxicologists also pay little attention to studying the role of antioxidant vitamins in protecting cells from toxic metals. The Republic of Karelia is one of the northwestern regions of Russia, the biogeochemical features of which can contribute to an increase in the mobility and bioavailability of Hg in food chains. The purpose of the work was to determine the concentration of Hg in the liver, kidneys, muscle and hair of ungulate mammals of the Republic of Karelia (wild boar Sus scrofa L. and moose Alces alces L.) and to analyze the relationship between the level of this toxic metal and the content of low molecular-weight antioxidants – reduced glutathione, retinol and α-tocopherol. Species and tissue-specific of the studied parameters in wild boars and moose are noted. The observations discovered by other researchers that omnivorous species accumulate more Hg in their tissues compared to herbivores, and also that this toxic metal is predominantly accumulated in the kidneys, while muscles contain a minimal amount, have been confirmed. Hg concentrations in most samples of liver and kidney of wild boars and in all samples of these same organs of moose were within the limits recorded for domestic pigs and deer, respectively. The levels of Hg we recorded in the tissues and hair of wild boars and moose were generally comparable to or lower than the levels of this metal noted in animals from other regions of Russia and other countries of the world. In wild boars and moose of Karelia, no statistically significant relationships were found between the Hg level and the content of the studied antioxidants in the internal organs. Moose were characterized by a higher content of α-tocopherol in the body than wild boars, which is a feature of this type of herbivorous ungulate mammal. The results of the study indicate a relatively low level of mercury pollution in terrestrial ecosystems in Karelia.

Total mercury exposure through canned tuna in water sold in Quito, Ecuador.

Mercury is a toxic trace metal found in seafood products owing to its bioaccumulative and ubiquitous nature. Seafood and fish are frequently consumed, being necessary to assess its human health risk. Accordingly, this study quantified total mercury in samples of canned tuna in water from supermarkets in the Metropolitan District of Quito in Ecuador, in order to ensure that Hg content is within the maximum limits stablished in national and international regulations. Total mercury levels were measured through cold vapor atomic fluorescence spectrophotometry. Three of the most consumed tuna brands in Ecuador were analyzed, coded as A, B, and C, according to the price at which they are sold in the market (A < B < C). Results indicated that mean total mercury in different tuna brands were within the permissible limits. Total mercury concentrations were 0.14 ± 0.11mg kg-1; 0.41 ± 0.42mg kg-1; and 0.25 ± 0.22mg kg-1 for brands A, B, and C, respectively. However, for brand B the potential non-carcinogenic risk of mercury for consumers exceeded the threshold limit (> 1). When considering the highest total mercury content to which Ecuadorian population is exposed through the consumption of brand A, B, and C, the recommended weekly intake for children and adults were: A: 63g and 306g; B: 12g and 57g; C: 30g and 144g, respectively.

Multigenerational impact of global change: Increased mercury toxicity in a marine copepod.

A multi-generational experiment (F1-F4) was conducted for a marine copepod Tigriopus japonicus to investigate its physiological and molecular responses to mercury (Hg) pollution and/or its combination with ocean acidification (OA) plus ocean warming (OW). The projected future scenario, i.e., OA plus OW (AW) significantly increased methylmercury accumulation in copepods by 1.14 times, despite insignificant change for total Hg bioaccumulation. Transcriptomic analysis indicated that copepods initiated several detoxification defense processes, including reactive oxygen species metabolic process, glutathione metabolism, and protein refolding, in response to increased Hg toxicity under combined exposure of AW and Hg; meanwhile, inhibited energy metabolism was observed in this case, linking to reduced number of nauplii/clutch but accelerated development in copepods probably due to an energetic trade-off. Increased Hg toxicity due to AW could also be ascribed to the impairment in immune defense (e.g., lysosome and vitamin metabolism) and reproduction-related processes (e.g., growth factor activity). Collectively, this study reveals the multi-generational response mechanism of copepods to Hg pollution under global change, emphasizing an exacerbated adverse effect of Hg, and it provides a scientific basis for an accurate understanding of the potential impact of Hg pollution on marine ecosystems.

Mercury Levels in Hair of Pregnant Women in Tumbes, Peru: A Cross-Sectional Study.

Mercury, a potent toxin that poses serious risks to human health, particularly for pregnant women and young children, is widely present due to artisanal and small-scale gold mining (ASGM), which impacts water quality. The objective of this study was to evaluate methylmercury exposure among pregnant women in communities downstream from ASGM sites. We characterized hair total mercury (THg) concentrations among 148 pregnant women across 24 communities in the Tumbes region of Peru, downstream from ASGM sites in Ecuador. Using purposeful sampling, we classified communities into three exposure risk zones: Puyango-Tumbes River watershed, Coast, and Zarumilla. The mean THg concentration was 2.08 µg/g ± 1.36, with 45% of participants (67/148) exceeding UNEP/WHO exposure limits (>2.0 µg/g). The median was 1.84 with an interquartile range (IQR) from 1.01 to 2.83. Median THg levels were significantly higher in the Puyango-Tumbes River region (2.72 µg/g; IQR: 1.66-3.55) compared with Zarumilla (1.61 µg/g; IQR: 0.67-2.63; P = 0.001) and to the Coast (1.71 µg/g; IQR: 1.13-2.50; P = 0.01), suggesting that living close to the Puyango-Tumbes River may be associated with a higher mercury exposure risk. After controlling for potential confounders, individuals in the Puyango-Tumbes watershed exhibited a significant 57% higher expected geometric mean of hair THg compared with Zarumilla (95% CI: 0.1-146.2%). These findings underscore the importance of identifying high-risk regional populations and ongoing biomonitoring of the Puyango-Tumbes River watershed.

The Relationship Between Mercury Exposure and Membranous Nephropathy: Case Reports and Meta-Analysis.

To investigate the clinical characteristics of patients with membranous nephropathy (MN) and the therapeutic efficacy of Sodium Dimercaptosulphonate (DMPS), as well as the relationship between mercury (Hg) exposure and MN, we investigated the clinical manifestations and treatment outcomes of six patients with MN and searched the China National Knowledge Internet (CNKI), PubMed, Web Of Science, and Embase databases for relevant studies on Hg exposure and MN published from the inception of the databases to April 2024. Data analysis was performed using SPSS 26.0 and Stata 16.0. We found that (1) the clinical symptoms of MN patients were mainly characterized by proteinuria, edema, hypoproteinemia, and hyperlipidemia. Comparative analysis before and after DMPS treatment showed a decrease in 24-h urinary Hg, 24-h urinary protein, and total cholesterol levels, as well as an increase in serum albumin levels (p < 0.05). (2) Two MN patients received DMPS for sole Hg detoxification treatment, whereas four patients received Hg detoxification combined with hormone therapy, and all patients showed significant improvement in symptoms after treatment. (3) Among the 564 articles, four met the inclusion criteria. The results showed that Hg exposure increased the incidence of MN by 5.74 times (95% confidence interval [CI] = 2.57, 12.83). The clinical symptoms of MN patients are mostly manifested as proteinuria, edema, hypoproteinemia, and hyperlipidemia. DMPS Hg detoxification treatment is effective for Hg-induced MN. Hg exposure can increase the prevalence of MN, therefore making it necessary to take prudent measures to reduce the risk of Hg exposure.

Mitigating Mercury Accumulation and Enhancing Methylmercury Degradation in Rice: Insights from Zinc-Mercury Antagonism at Molecular Levels.

Zn as an essential element has the potential to protect against mercury (Hg) toxicity in rice. However, the antagonistic effects between Zn and Hg in rice and their mechanisms remain unknown. This study proposed a promising strategy for Zn application to mitigate Hg accumulation and toxicity in rice and revealed the underlying molecular mechanisms. The findings revealed that Zn supplementation significantly reduced the uptake and transportation of both IHg and MeHg in rice, thereby alleviating Hg phytotoxicity. In particular, Zn profoundly mitigated Hg-induced oxidative damage to rice, which was attributed to the redistribution of Hg and Zn in the root and Zn competing for binding sites on glutathione. The co-binding of Zn2+ and HgCH3+ within the same active sites of Zn transporters can promote the transfer of regions with a high charge density distribution at the highest occupied molecular orbital (HOMO) level. This process facilitates proton attack on the Hg-C bond, thereby enhancing MeHg demethylation in rice. By elucidating the molecular mechanisms of Zn, IHg, and MeHg interactions in rice, this study offers new insights for developing efficient strategies to mitigate Hg risks while boosting the Zn content in crops, thereby fortifying food safety.

Peptide-Based Rapid and Selective Detection of Mercury in Aqueous Samples with Micro-Volume Glass Capillary Fluorometer

Mercury, a toxic heavy metal produced through both natural and anthropogenic processes, is found in all of Earth’s major systems. Mercury’s bioaccumulation characteristics in the human body have a significant impact on the liver, kidneys, brain, and muscles. In order to detect Hg2+ ions, a highly sensitive and specific fluorescent biosensor has been developed using a novel, modified seven amino acid peptide, FY7. The tyrosine ring in the FY7 peptide sequence forms a 2:1 complex with Hg2+ ions that are present in the water-based sample. As a result, the peptide’s fluorescence emission decreases with higher concentrations of Hg2+. The FY7 peptide’s performance was tested in the presence of Hg2+ ions and other metal ions, revealing its sensitivity and stability despite high concentrations. Conformational changes to the FY7 structure were confirmed by FTIR studies. Simultaneously, we designed a miniaturized setup to support an in-house-developed micro-volume capillary container for volume fluorometry measurements. We compared and verified the results from the micro-volume system with those from the commercial setup. The micro-volume capillary system accommodated only 2.9 µL of sample volume, allowing for rapid, sensitive, and selective detection of toxic mercury (II) ions as low as 0.02 µM.

Green and Mild Fabrication of Magnetic Poly(trithiocyanuric acid) Polymers for Rapid and Selective Separation of Mercury(II) Ions in Aqueous Samples.

The removal and detection of highly toxic mercury(II) ions (Hg2+) in water used daily is essential for human health and monitoring environmental pollution. Efficient porous organic polymers (POPs) can provide a strong adsorption capacity toward heavy metal ions, although the complex synthetic process and inconvenient phase separation steps limit their application. Hence, a combination of POPs and magnetic nanomaterials was proposed and a new magnetic porous organic polymer adsorbent was fabricated by a green and mild redox reaction in the aqueous phase with trithiocyanuric acid (TA) and its sodium salts acting as reductive monomers and iodine acting as an oxidant. In the preparation steps, no additional harmful organic solvent is required and the byproducts of sodium iodine are generally considered to be non-toxic. The resulting magnetic poly(trithiocyanuric acid) polymers (MPTAPs) are highly porous, have large surface areas, are rich in sulfhydryl groups and show easy magnetic separation ability. The experimental results show that MPTAPs exhibit good adsorption affinity toward Hg2+ with high selectivity, rapid adsorption kinetics (10 min), a large adsorption capacity (211 mg g-1) and wide adsorption applicability under various pH environments (pH 2~8). Additionally, MPTAPs can be reused for up to 10 cycles, and the magnetic separation step of MPTAPs is fast and convenient, reducing energy consumption compared to centrifugation and filtration steps required for non-magnetic adsorbents. These results demonstrate the promising capability of MPTAPs as superior adsorbents for effective adsorption and separation of Hg2+. Based on this, the prepared MPTAPs were adopted as magnetic solid-phase extraction (MSPE) materials for isolation of trace Hg2+ from aqueous samples. Under optimized conditions, the extraction and quantification of trace Hg2+ in water samples were accomplished using inductively coupled plasma mass spectrometry (ICP-MS) detection after MSPE procedures. The proposed MPTAPs-based MSPE-ICP-MS method is efficient, rapid, sensitive and selective for the determination of trace Hg2+, and was successfully employed for the accurate analysis of trace Hg2+ in tap water, wastewater, lake water and river water samples.

Gut heavy metal and antibiotic resistome of humans living in the high Arctic.

Contaminants, such as heavy metals (HMs), accumulate in the Arctic environment and the food web. The diet of the Indigenous Peoples of North Greenland includes locally sourced foods that are central to their nutritional, cultural, and societal health but these foods also contain high concentrations of heavy metals. While bacteria play an essential role in the metabolism of xenobiotics, there are limited studies on the impact of heavy metals on the human gut microbiome, and it is so far unknown if and how Arctic environmental contaminants impact the gut microbes of humans living in and off the Arctic environment. Using a multiomics approach including amplicon, metagenome, and metatranscriptome sequencing, we identified and assembled a near-complete (NC) genome of a mercury-resistant bacterial strain from the human gut microbiome, which expressed genes known to reduce mercury toxicity. At the overall ecological level studied through α- and β-diversity, there was no significant effect of heavy metals on the gut microbiota. Through the assembly of a high number of NC metagenome-assembled genomes (MAGs) of human gut microbes, we observed an almost complete overlap between heavy metal-resistant strains and antibiotic-resistant strains in which resistance genes were all located on the same genetic elements.

Electrochemical Biosensor for Detecting both Pb2+ and Hg2+ in Human Blood

Many studies have demonstrated that lead ion ( Pb2+ ) and mercury ion ( Hg2+ ) are harmful to human health. Lead was found to accumulate in the kidney, leading to oxidative stress, apoptosis, and inflammation in the nephrons, and possess marked testicular toxicity. Mercury is well-known to produce nephrotoxicity, inflammatory responses and induce oxidative stress and apoptosis. These heavy metals can enter the human body in various ways, such as through skin or inhalation routes, or contaminated drinking water and food. But heavy metal poisoning is not easy to diagnose because existing detecting measures has many disadvantages cause them can’t widely spread. So, seeking an easy way to detect them in human blood to discover lead or mercury poisoning is an unmet need. This paper develops a new reusable biosensor for detecting both Pb2+ and Hg2+ in human blood. This work is based on the reaction between guanine and Pb2+ form of G-quadruplex and Hg2+ connect two thymines together cause the variation of electrochemical signal. The signal is magnified by methylene blue-gold nanoparticles (MB-AuNP) to increase the limit of detection Although the reuse part of sensor is still in theory, but this approach can make the cost of sensor low and create the feasibility of recycle. Overall, providing a new idea to make contributions to the prevention of heavy metal poisoning is the reason why this study is conducted.

Effects of mercury and magnetic fields on the activity of proteinases and glycosidases in the intestine of common carp Cyprinus carpio.

Aquatic ecosystems are increasingly affected by anthropogenic pollution, including heavy metals like mercury, which accumulate in organisms and cause harmful effects. At the same time, human activities such as industrial operations and the use of electric power lines also alter the magnetic background in natural water bodies. However, the interaction between mercury exposure and magnetic fields remains poorly understood. This study aimed to investigate the combined effects of mercury and magnetic fields on the digestive enzyme activity of common carp (Cyprinus carpio), focusing on the relevance of magnetic fields due to their increasing presence in industrialized environments. Two groups of fish were fed diets with low (0.02mg/kg) or high (0.27mg/kg) mercury content for 6months and exposed to extremely low-frequency magnetic fields or hypomagnetic conditions. Results showed significant differences in mercury accumulation between groups, with higher levels in carps fed with high-mercury content diets. These fish also exhibited increased body length and weight compared to those on a low-mercury diet. The amylolytic activity (total activity of enzymes hydrolyzing starch: α-amylase, glucoamylase, and maltase) and proteolytic activity (total activity of serine proteinases) in the fish intestine were assessed. Magnetic exposure had contrasting effects on enzyme activity, depending on mercury levels in the diet. Fish fed the low-mercury diet exhibited decreased amylolytic activity following magnetic field exposure, while fish on the high-mercury diet showed increased activity. Proteolytic activity followed a similar pattern, with opposite effects observed between the two dietary groups. These findings suggest that mercury accumulation alters the biological response to magnetic fields, possibly through compensatory biochemical mechanisms. Understanding the interactions between toxic substances and magnetic fields is critical for improving environmental risk assessments.

Unveiling mercury exposure sources in e-waste recycling with biomonitoring - A Portuguese case study

Abstract Background Mercury (Hg), a global pollutant, poses risks to both human and environmental health. The management and recycling of electrical and electronic waste (e-waste) is recognized as having the potential to promote workers’ exposure to this pollutant. Human biomonitoring (HBM) is a tool that can be used to evaluate exposure and monitor the health of workers. The objective of this study was to characterize exposure of workers from an e-waste recycling company and to analyze the relevance that HBM holds in the detailed characterization of exposure. Methods A cross-sectional observational study was conducted using data collected within the framework of the European Human Biomonitoring Initiative (HBM4EU). Data from environmental monitoring (settled dust) and biological monitoring (urine and hair) of 30 workers potentially exposed to Hg were analyzed in comparison with 12 unexposed workers from other occupational settings (controls). Results Exposed workers did not exhibit significantly higher concentrations of Hg in urine when compared to control workers. We found a significantly positive correlation between the concentration of Hg in urine (ρ = 0.688; p ≤ 0.001) and hair (ρ = 0.470; p ≤ 0.01) and the consumption of fish and shellfish. Conclusions Diet appears to be the most significant source of Hg in this context. These results suggest the importance of information and dietary habits to prevent mercury exposure. HBM stands out as an essential tool for identifying the most relevant exposure sources and risk management measures for workers and the general population. Key messages • Diet appears to be the most significant Hg source in workers from a Portuguese e-waste company. • HBM stands out as essential for identifying the most relevant exposure sources and risk management.

Viscoelastic Fluid Focusing Chip-ICP-MS Single-Cell Analysis Enables Elucidating the Effect of Extracellular Polymeric Substances on Bioaccumulation of Hg2+/HgS in Microcystis aeruginosa Cell.

Understanding the interactions between mercury and microalgae, especially the interactions between inorganic mercury (IHg) and extracellular polymeric substances (EPS, a protective barrier between cells and their external environment), is essential for elucidating mercury's toxicological mechanisms. Given the inherent cell heterogeneity, a novel analysis system of an online viscoelastic fluid focusing chip-time-resolved analysis inductively coupled plasma mass spectrometry has been developed to investigate the bioaccumulation of HgS nanoparticles and Hg2+ in single Microcystis aeruginosa (M. aeruginosa) cells, exploring the interaction mechanisms between HgS/Hg2+ accumulation in algal cells and EPS. The single-cell analysis results reveal minimal bioavailability of HgS within algal cells, with mercury's toxicity to M. aeruginosa being species-dependent. Notably, algal cells exhibited more heterogeneity in HgS uptake than in Hg2+ uptake. Under Hg2+/HgS stress, M. aeruginosa cells with EPS removed (EPS-R algal cells) showed an increased level of bioaccumulation of mercury compared to those with EPS (EPS-C algal cells), highlighting the critical role of EPS in mercury bioaccumulation. Overall, the designed viscoelastic fluid microfluidic focusing chip integrates focusing and cleaning functions, featuring easy fabrication, simple operation, low sample loss, and relatively high throughput. Under the optimal conditions, the sample throughput is 1195 min-1 and the cell recovery is 90%. Besides, this research offers novel insights into the interaction mechanisms between Hg2+/HgS and EPS in microalgal cells and unveils the specific toxic effects of Hg2+/HgS on M. aeruginosa at the single-cell level, contributing to a deeper understanding of mercury's ecological and toxicological impact in aquatic environments.

The functional activity of the brain in patients with occupational chronic mercury intoxication against background of the treatment of insomnia disorders

Introduction. In patients with chronic mercury intoxication, insomnia disorders are much more common than in the general population. Persistent emotional disorders in combination with severe sleep disturbances may contribute to the progression of cognitive dysfunction in patients in the late post-exposure period of chronic mercury intoxication. The purpose of the study was to analyze the trend in electroencephalography indices and study cognitive evoked potentials in patients with occupational chronic mercury intoxication to optimize the treatment of insomnia. Materials and methods. Two groups of 30 patients with occupational chronic mercury intoxication, who worked at the enterprises of Usolyekhimprom LLC and Sayanskhimplast OJSC, were examined. In the first group of patients received the first treatment option, the average age was 56±0.71 years, in the second group, cases received the second treatment regimen, were of 57.1±3 years. Before and after treatment, there were carried out neurophysiological studies including polysomnography, electroencephalography, and a study of cognitive evoked potentials P300. Results. After the implementation of the treatment regimen in the first group, positive changes in the main indices of polysomnography were revealed as follows: decrease in the time of falling asleep and time of wakefulness in the bed, increase in total sleep time and the representation of delta sleep, increase in the sleep efficiency index, etc., electroencephalography (decrease in the delta index – rhythm and an increase in the alpha rhythm index), and cognitive evoked potentials (decreased latency and increased P300 amplitude). In the second group, there were registered positive alterations only in three neurophysiological indices: a decrease in the latent period of the 1st stage of sleep, a decline in the delta rhythm index and a fall in P300 latency. Limitations. The results cannot be generalized to workers as the group included only men. Conclusion. According to neurophysiological studies, improvement in polysomnography parameters during the treatment of insomnia in patients in the late post-contact period of chronic mercury intoxication was accompanied by an improvement in concentration and an increase in the rate of psychomotor response.

Association between blood total mercury and psoriasis: The NHANES 2005-2006 and 2013-2014: A cross-sectional study.

An inflammatory skin condition called psoriasis results from immune system interactions that are out of balance. Reactive oxygen species are produced as a general mechanism of mercury toxicity. This study aimed to determine whether there was an association between blood total mercury and psoriasis in US adults. Utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 and 2013-2014. NHANES is a national research survey program every two years to assess the population's nutritional and physical health. The relationship between blood total mercury and psoriasis was studied using multivariable logistic regression models and smooth curve fitting. Subgroup analysis and interaction tests were used to investigate if this association was stable across populations. After adjusting for several factors, we found a positive association between blood total mercury and psoriasis in 6086 participants. According to the fully adjusted model, each 1-unit increase in blood total mercury was associated with an 8% increase in the prevalence of psoriasis [1.08 (1.03, 1.14)]. The favorable association seems to be more pronounced in non-diabetes. Our research shows a positive association between psoriasis and blood total mercury in US adults. The results of this study need to be supported by additional prospective research.

Rational Design of Regenerable Amino-Functionalized Fluorescent Covalent Organic Framework for the Exclusive Detection of Mercury(II).

Goal-oriented development of novel covalent organic frameworks (COFs) to construct a sensing platform for highly toxic mercury (II, Hg2+) is of tremendous significance. Recently, numerous COFs with sulfur-based ligands were developed for Hg2+ monitoring; however, strong binding of Hg2+ by sulfur makes their regeneration very tough. Herein, we designed and developed an amino-functionalized fluorescent COF (COF-NH2) through facile postmodification for Hg2+ detection in which the π-conjugation skeleton is the signal reader and the nitrogen-based side is the highly selective Hg2+ receptor. More importantly, this nitrogen-based receptor permits the reversible binding of Hg2+. As a sensing platform, the outstanding performance of COF-NH2 for Hg2+ detection was reached with respect to high sensitivity with an ultralow detection of 15.3 nM, real-time response with rapid signal change of 10 s, and facile visualization with significant fluorescence color change. Expectedly, COF-NH2 obtained facile recycling which still shows excellent response performance toward Hg2+ after six cycles based on the reversible interaction between amino groups and Hg2+. Our work not only shows an attractive foreground of fluorescent COF for Hg2+ detection but also emphasizes the easy construction of novel COF materials via the rational introduction of metal ligands for the recognition of other metal ions.

Effects of Gingko Biloba Extract and L-Ascorbic Acid on Some Hematological, Biochemical, and Hepatic-Architectural Alterations in Mercury Chloride Intoxicated Adult Wistar Rat.

The study investigated the effects of Ginkgo biloba and Ascorbic acid (A.A) on mercury chloride (HgCl2) toxicity in Wistar rats. Forty-two adult Wistar rats were randomly divided into seven groups (n=6). Group I served as control. Groups II–VII received 5 mg/kg of HgCl2. Groups III and IV received 100 mg/kg and 500 mg/kg of A.A respectively, while groups V and VI daily received 100 mg/kg and 500 mg/kg of EGB761 respectively. Group VII received 100 mg/kg of A.A and EGB761. All administration were done orally, once daily for 21 days. Mercury exposure caused significant (p&lt;0.05) decreases in RBC (3.62.00±0.75), hemoglobin (8.67±0.14), and PCV (32.93±0.47) in group II when compared to the control group, while significantly (p&lt;0.05) increasing white blood cell count (18.57±1.51). Liver function tests significantly (p&lt;0.05) increased Alanine transaminase (1.38±1.51), Aspartate Transaminase (10.11±4.21), and Alkaline Phosphatase (1.89±0.51) in group II when compared to Control. Biochemical analysis revealed a significant (p&lt;0.05) increase in malondialdehyde levels and a significant (P&lt;0.05) decrease in superoxide dismutase (3.86 ± 0.69), glutathione (10.08 ± 2.13), and catalase (3.65 ± 0.2) levels in group II. However, treatment with ascorbic acid and EGB761 significantly (P&lt;0.05) increased in Groups IV (6.15 ± 0.38); VI (6.28 ± 0.40), and VII (6.19 ± 0.41), SOD levels in Groups IV (6.15 ± 0.38); VI (6.28 ± 0.40) and VII (6.19 ± 0.41) and GSH level when compared to the HgCl2 group. Histological examination showed moderate hepatocyte necrosis in group II, while treatment with EGB761 and A.A showed moderate healing, binucleate nuclei, and a slight decrease of distorted sinusoids and normalization of liver structure. The study concludes that EGB761 and A.A have hepatoprotective effects on mercury-induced hepatotoxicity in a dose-dependent manner. The findings suggest that these antioxidants may be useful in mitigating the harmful effects of mercury exposure on the liver.

Monitoring of mercury ion in environmental media and biological systems using a red emissive fluorescent probe with a large Stokes shift

The development of practical fluorescent probe for detecting toxic mercury ions (Hg2+) is desirable for environmental assurance and public health. In this study, a new red emissive fluorescent probe (KJL) was designed and synthesized for monitoring trace Hg2+ both in vitro and in vivo with distinct features including ideal response rate (within 4 min), red emission (596 nm), large Stokes shift (162 nm), highly sensitivity (LOD = 4.79 nM) and excellent specificity. KJL also validated the good capability for accurately monitoring trace Hg2+ levels in actual samples (faucet water, drinking water, river water, lake water, urine and serum) and possessed the eye-catching ability in visualization of Hg2+ under environmental/biological conditions, which revealed the great potential of this red-emitting fluorescent probe for practical applications in complex environmental and biological systems.

Blood mercury concentrations in preschool children and potential risk factors in São Paulo, Brazil

Environmental exposure of preschool children to mercury can elevate blood mercury levels (BML) and negatively affect their health. This study aimed to determine BML in preschool children from Brazil's largest city and explore potential associated risk factors. Blood samples were collected in 2013 from 2436 children (age 1–5 years) attending 50 daycare centers (DCC) located in São Paulo, Brazil. Parents or guardians answered questionnaires collecting information on sociodemographics and potential risk factors. BML was determined by Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and categorized using a cutoff point of 2.77 μg L⁻1, corresponding to the 75th percentile. Multiple logistic regression was performed (p < 0.05). Data were georeferenced and associations with air pollution, wind frequency and direction were evaluated. The results showed a geometric mean for BML of 1.65 μg L⁻1 (95% CI: 1.60–1.70), arithmetic mean of 2.15 μg L⁻1 (95% CI: 2.09–2.22), 75th percentile of 2.77 μg L⁻1 (95% CI: 2.67–2.91) and 95th percentile of 5.51 μg L⁻1 (95% CI: 5.18–5.92). DCCs located in the Northwest and East zones (p < 0.001) and fish consumption in the past two days (p = 0.04) were associated with high BML. The elevated BML observed in children living in the eastern zone might be attributed to the southeasterly winds passing through a petrochemical complex located nearby. The 95th percentile of BML in this study exceeded the U.S. 95th percentile by five times. BML in São Paulo preschool children was associated with individual and environmental risk factors. This finding highlights the need to identify and control hot spots in São Paulo, Brazil, especially in peripheral and surrounding areas, where individuals are more vulnerable. Further research is needed in Latin America to identify additional sources of urban environmental mercury exposure and guide interventions for protecting the environment and safeguarding children's health.

Unexpected anthropogenic emission decreases explain recent atmospheric mercury concentration declines.

Anthropogenic activities emit ~2,000 Mg y-1 of the toxic pollutant mercury (Hg) into the atmosphere, leading to long-range transport and deposition to remote ecosystems. Global anthropogenic emission inventories report increases in Northern Hemispheric (NH) Hg emissions during the last three decades, in contradiction with the observed decline in atmospheric Hg concentrations at NH measurement stations. Many factors can obscure the link between anthropogenic emissions and atmospheric Hg concentrations, including trends in the reemissions of previously released anthropogenic ("legacy") Hg, atmospheric sink variability, and spatial heterogeneity of monitoring data. Here, we assess the observed trends in gaseous elemental mercury (Hg0) in the NH and apply biogeochemical box modeling and chemical transport modeling to understand the trend drivers. Using linear mixed effects modeling of observational data from 51 stations, we find negative Hg0 trends in most NH regions, with an overall trend for 2005 to 2020 of -0.011 ± 0.006 ng m-3 y-1 (±2 SD). In contrast to existing emission inventories, our modeling analysis suggests that annual NH anthropogenic emissions must have declined by at least 140 Mg between the years 2005 and 2020 to be consistent with observed trends. Faster declines in 95th percentile Hg0 values than median values in Europe, North America, and East Asian measurement stations corroborate that the likely cause is a decline in nearby anthropogenic emissions rather than background legacy reemissions. Our results are relevant for evaluating the effectiveness of the Minamata Convention on Mercury, demonstrating that existing emission inventories are incompatible with the observed Hg0 declines.