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Concentrations of toxic metals (Hg, Pb, and Cd) were determined in the muscles of Lepomis macrochirus, Barbus callensis, and Barbus nasus caught from the Moulouya River of Morocco by graphite furnace (for Pb and Cd) and cold vapour (for Hg) atomic absorption spectrometry, after acid digestion. Although the concentration of metals in some species was relatively high, no health risk has been identified in comparison to the maximum limits as set by the European Commission. The order of increasing concentrations was Cd < Hg < Pb. Calculated Target Hazard Quotients and Hazard Indices were below 1, indicating that the intake of metals via consumption of the muscles of both fish species does not represent a hazard to human health. [ABSTRACT FROM AUTHOR]

Skin whitening is a practice that is used to obtain lighter skin tone and is most prevalent in Africa and Asia. Substances used for this procedure, such as hydroquinone or mercury have a variety of side effects and are banned in several countries. This study examined the popularity of internet searches for terms related to skin whitening and bleaching creams with the use of GoogleTrends (GT). GT was searched globally for the topic “skin whitening” and two terms “hydroquinone cream” and “mercury cream” throughout a 10-year period (01.09.2013–31.08.2023). The popularity of searches increased during the analyzed period. The topic “skin whitening” was most popular in Sudan, Vietnam, and Sri Lanka. The searches were higher for “hydroquinone cream” than “mercury cream” in almost all countries, besides the Philippines and Indonesia. Our study confirms that skin whitening practices are popular, especially among populations with darker skin tone. Despite potentially toxic side effects, creams with hydroquinone and mercury are increasingly searched worldwide. Education about skin whitening and the usage of bleaching substances should be implemented, especially in the regions of Africa and Asia. [ABSTRACT FROM AUTHOR]

Soil contamination by toxic metals threatens global public health, highlighting the need for cost-effective and ecologically sound site remediation. In this study, we assessed phytoremediation of Hg-contaminated soils by Emilia fosbergii Nicolson (Asteraceae). Pot experiment was conducted using a substrate of sand and vermiculite (1:1 volume ratio), treatments consisted of five Hg concentrations (0, 1, 3, 5, and 7 mg kg−1). Metal transfer rates were calculated, including accumulation (BAF), translocation (TF) and bioconcentration (BCF) factors. E. fosbergii roots exhibited greater Hg accumulation than other tissues, but biomass production and plant health were not significantly affected at the concentrations tested, as indicated by elongation factors and tolerance index. The results revealed BAF values between 2.18 and 7.14, TF values ranged between 0.15 and 0.52, and the BCF index varied between 8.97 and 26.58. Treatments with Hg content of 5 mg kg−1 and 7 mg kg−1 recorded the highest total Hg concentrations of 66 mg kg−1 and 65.53 mg kg−1 (roots), and 9.18 mg kg−1 and 33.88 mg kg−1 (aerial), respectively. E. fosbergii demonstrated promise for Hg phytoremediation due to its high accumulation capacity, indicated by regular TF and high BCF and BAF indexes, thus classifying it as a high Hg accumulator. Phytoextractor and phytostabilizer plant, high accumulator of Hg. Weed with great capacity for proliferation and adaptability. E. fosbergii showed tolerance to Hg in the substrate. Promising plant for phytoremediation of soils contaminated by Hg. Novel species for recovery of soils degraded by Hg exposure. [ABSTRACT FROM AUTHOR]

Illegal gold mining causes mercury and trace metal contamination in many Colombian territories. The government has been requested by several ethnic communities to monitor and evaluate the state of mercury contamination in strategic ecosystems. The work aimed to evaluate mercury and trace metal contamination in a mining area located in Afro-descendant communities in the department of Cauca, Colombia. The study estimated the Hg content in different environmental compartments, such as soil, water, sediments, and trees. The level of trace metals in soil samples was assessed. It also estimated the human health risk associated with Hg from fish consumption. The concentration of T-Hg was measured using atomic absorption, and the trace element content was measured using inductively coupled plasma mass spectrometry (ICP-MS). Two out of three watersheds examined had a mean T-Hg concentration in water that exceeded the international standard limit of 2.0 µg/L set by the United States Environmental Protection Agency (USEPA). The Rattlesnake River had the highest mean concentration of T-Hg in sediments at 1.05 µg/g. The community of La Toma exceeded the maximum permissible value for T-Hg in soil. While T-Hg concentrations in C. macropomum were low at 0.02 µg/g, they were surprisingly high in Prochilodus sp. at 0.53 µg/g. F. luschnathiana trees had the highest T-Hg levels at 18.3 ± 2.3 ng/g. The soil samples analyzed showed levels of As (21.4 µg/g), Cr (148.5 µg/g), V (205.0 µg/g), and Zn (146.5 µg/g) that exceeded the maximum levels established internationally. The presence of mercury and trace elements in the communities indicates a potential risk to human and environmental health. [ABSTRACT FROM AUTHOR]

The consumption of camel milk is gaining popularity in Algeria. This study aimed to determine the concentrations of Lead (Pb), Cadmium (Cd), Nickel (Ni) and Mercury (Hg) in camel milk sold in Southeast Algeria and assess the potential health risks associated with its consumption. 120 samples of camel milk were collected from 10 farms located near the roads in the south of Algeria. Metals were measured using an atomic absorption spectrophotometer with a graphite furnace and Target Hazard Quotients (THQs) were calculated. The mean concentrations were 0.026 ± 0.013 mg/kg, 0.001 ± 0.0002 mg/kg, 0.017 ± 0.002 mg/kg and 0.0005 ± 0.0002 mg/kg for Pb, Cd, Ni and Hg. The THQ was higher for children, suggesting health risks associated with consumption of camel milk for this age group (p <.001). The primary contribution of this study is the establishment of a database on toxic metal levels in camel milk, which can be valuable to manage possible risk associated with metals in milk. [ABSTRACT FROM AUTHOR]

This study aimed to analyse the concentrations of mercury in fish samples available in the Algerian market and evaluate the potential health risks associated with their consumption. A total of 135 fish samples, representing the species Sardina pilchardus, Merluccius merluccius, Sparus aurata and Auxis rochie, were collected and analysed. Mercury levels were determined using thermal decomposition amalgamation Atomic Absorption Spectrophotometry. Health risks were evaluated by calculating hazard quotients. The overall mean concentration was 0.19 ± 0.11 mg/kg across all species. Individual species concentrations were recorded as 0.17 ± 0.08 mg/kg for Sardina pilchardus, 0.26 ± 0.19 mg/kg for Merluccius merluccius, 0.27 ± 0.18 mg/kg for Sparus aurata and 0.23 ± 0.13 mg/kg for Auxis rochei. Hazard quotients were below 1, indicating low health risk for fish consumers. Nevertheless, it is recommended to conduct periodic monitoring of heavy metal levels in fish, coupled with ongoing risk assessments, to ensure continued consumer protection. [ABSTRACT FROM AUTHOR]

We studied δ13C, δ15N and δ18O values, and total mercury (THg) concentrations in muscle samples from deep-sea predators – five beaked whale species and sperm whales – stranded along the coast of Hokkaido, in the north of Japan in 2010 and 2019. The δ13C, δ15N and δ18O values, THg concentrations, and body length (BL) of Stejneger’s beaked whales were similar to those of Hubbs’ beaked whales, which belong to the same genus. In contrast, δ13C values, THg concentrations, and BL of Sato’s beaked whales were markedly different from those of Baird’s beaked whales, which belong to the same genus. Stejneger’s and Hubbs’ beaked whales living around Hokkaido may compete in their ecological niches, whereas Sato’s and Baird’s beaked whales may segregate their ecological niches. Although Cuvier’s beaked whales and sperm whales belong to different genera and their BLs were significantly different, their δ13C and δ15N values were similar, probably because they can dive and stay in deeper waters than other beaked whale species. The δ13C values in combined samples from all whales increased with increasing BL, probably owing to the larger whale species’ dietary preference for squid. The δ13C values in combined samples from all whales were positively correlated with THg concentrations, whereas the δ15N values in the combined samples were negatively correlated. The δ18O values in combined samples from most whales tended to be positively correlated with THg concentrations. These correlations may be explained by a higher THg load from deep-sea feeding than from pelagic feeding and by a feeding shift towards lower trophic levels. [ABSTRACT FROM AUTHOR]

Annually, a tremendous amount of mercury is emitted due to anthropogenic activities. As a consequence, occupational and environmental exposure to mercury has drawn broad concern all over the world, and attempts have been sustained to progress analytical methods. The main limitation in exposure assessment is the complexity of biological and environmental samples. Environmental and biological samples need sample preparation to eliminate matrix interferences as well as pre-concentration of the ultra-trace analyte. Among sample preparation methods, considerable attention is devoted to solid-phase extraction (SPE). Porous materials play a vital role in the solid phase extraction procedure for the adsorption and desorption of the target analytes. In this paper, porous materials that were applied for inorganic mercury solid phase extraction were reviewed from 2009 until 2023. Through this study, porous materials were classified and the extraction parameters of each analytical method, including the type of solid phase extraction, porous adsorbent, adsorbent amount, extraction efficiency, real matrices, and detection technique, were clarified. Ultimately, novel attitudes toward green analytical chemistry and innovative ideas were discussed in order to open new horizons. [ABSTRACT FROM AUTHOR]

The voltammetric characterisation and determination of insecticide flonicamid (N-cyanomethyl-4-(trifluoromethyl)nicotinamide) were performed for the first time using a simple electrochemical sensor, renewable silver-amalgam film electrode (Hg(Ag)FE). During the development of the direct cathodic square wave voltammetric method (SWV) for the determination of flonicamid, a voltammetric behaviour of a target analyte in aqueous Britton-Robinson buffer solution from pH 2.0 to pH 11.98 was examined. In the investigated pH range, the peak which appeared in the potential span between −0.86 V and −1.56 V vs. saturated calomel electrode depending on the applied pH value was chosen for analytical purposes. As optimal pH for the determination of flonicamid, pH 2.5 was selected. Cyclic voltammetric measurements at pH 2.5 confirmed that the electrode reaction mechanism is an irreversible reduction controlled by the diffusion of flonicamid at Hg(Ag)FE. The optimised Hg(Ag)FE-SWV method resulted in good linearity in the concentration range of 1.96–41.2 µg mL−1 while the relative standard deviation of the method was 0.30%. Flonicamid was successfully determined in commercial formulation Teppeki 500 WG® and spiked river water sample by the developed method using the standard addition procedure. The average value of flonicamid amount found in a commercial formulation based on three repetitions was 497.8 ± 0.9 g kg−1, which is in good agreement with the manufacturer's declaration (500 ± 25 g kg−1) and with comparative high-performance liquid chromatographic measurements with diode array detection where a found average value of flonicamid content was 497.5 ± 11.5 g kg−1. The obtained results also indicate that the developed SWV procedure using Hg(Ag)FE was appropriate for the determination of flonicamid in a spiked river water sample with the recovery of 92.86% and RSD of 6.19%. [ABSTRACT FROM AUTHOR]

Soil systems are commonly regarded as receptors of anthropogenic mercury contamination and play an essential role in the containment or dispersion of pollution to surface water, groundwater and the atmosphere. Mercury fate and transport are simulated using a local scale model to evaluate mercury dynamics in a soil system impacted by anthropogenic mercury pollution from artisanal and small-scale gold mining. The model assumes first-order differential equations that describe losses principally by evasion and leaching simulated on a yearly time step from thirty years ago to the present and into the future, where two different scenarios are considered. The model predicts that topsoil mercury concentrations may more than double in the next 50 years. Soil mercury is currently a source of mercury to the atmosphere and water but the leaching flux is less than the evasion flux. The soil would accumulate mercury until emission is curtailed and may require more than 500 years for levels to decrease to background values. If current emission rates are maintained, mercury contents of contaminated soil will keep increasing and will reach levels that poses risk to ecological and human health. [ABSTRACT FROM AUTHOR]

Foliage uptake of atmospheric elemental mercury (Hg0) and subsequent translocation by the phloem is the main pathway for Hg accumulation in tree rings. Tree rings have been used as the emerging natural archive to directly reconstruct centennial trends of atmospheric Hg0 level. The tree-ring Hg records in remote regions have successfully reconstructed the peak of anthropogenic Hg emissions in Europe and North America in 1960s − 1970s and the distinct increase of Hg emissions in Asia since 1980s. Combining the Hg concentrations and isotopic signatures would provide historical atmospheric Hg trends and Hg emission source shifts. The mechanisms for Hg translocation, specifically the radial translocation and impacts of environmental and tree physiological factors, are yet to be clarified to explain the nonlinear relation between atmospheric Hg0 concentration and Hg signals in tree rings. Thus, we recommend to trace Hg accumulation and translocation processes and their Hg isotopic fractionation in tree rings, and examine the relationship between tree-ring Hg profile and atmospheric pollution level in specific tree species. Finally, we suggest to develop more statistical models to quantify environmental and tree physiological impacts on Hg accumulation and translocation in tree rings. [ABSTRACT FROM AUTHOR]

The agricultural ecosystem is moderately contaminated with mercury due to industries, mining, and farming activities. Mercury concentrations in agrarian lands depend on pH, organic matter, soil texture, vegetation cover, and land usage. The legume-rhizobia symbiosis is an effective rhizoremediation tool to lessen mercury and recover soil nitrogen. Mercury-resistant rhizobia in the roots of legumes assist the host by alleviating the phytotoxicity of Hg by stabilizing Hg in the roots and producing plant growth-promoting substances. The mechanisms of Hg resistance in rhizobia include reducing mercury to a volatile form (Hg0) and sequestering in the cell wall. Legume roots can phytostabilize mercury due to their high biomass. Thus, the translocation of mercury to shoot is low, with less than one translocation and bioaccumulation factor. Sulfur compounds, enzymes, amino polycarboxylic acids, and low molecular weight organic acids can enhance mercury phytoremediation by improving plant biomass and mercury uptake. Mercury stress increases free radical scavenging in nodules. Therefore, legumes and the associated rhizobia are sustainable tools for the remediation of polluted soil. However, Hg toxicity affects nodulation by rhizobia, nodule number, morphology, weight, and micro-community structure. Contemplating the harmfulness of mercury on rhizobia, effective rhizoremediation strategies can be developed to reduce mercury in agroecosystems. [ABSTRACT FROM AUTHOR]

Mercury (Hg) pollution has seriously threatened the crop productivity and food security. In the present research, experiments were conducted to assess the influence of nanoscale sulfur/sulfur nanoparticles and the corresponding bulk and ionic sulfur forms on the growth and Hg accumulation of oilseed rape seedlings grown on Hg-contaminated soil, as well as the transformation of soil Hg fractions. The results showed a significant reduction in fresh biomass for seedlings grown on 80–200 mg/kg Hg-polluted soil after 30 days. At 120 mg/kg Hg treatment, 100–300 mg/kg sulfur nanoparticles (SNPs) application counteracted Hg toxicity more effectively compared to the corresponding bulk sulfur particles (BSPs) and ionic sulfur (sulfate) treatments. The seedlings treated with 120 mg/kg Hg + 300 mg/kg SNPs gained 54.2 and 56.9% more shoot and root biomass, respectively, compared to those treated with Hg alone. Meanwhile, 300 mg/kg SNPs application decreased Hg accumulation by 18.9 and 76.5% in shoots and roots, respectively, relative to Hg alone treatment. SNPs treatment caused more Hg to be blocked in the soil and accumulating significantly less Hg in plants as compared to other S forms. The chemical fractions of Hg in the soil were subsequently investigated, and the solubility of Hg was significantly decreased by applying SNPs to the soil. Especially 200–300 mg/kg SNPs treatments caused the ratio of the soluble/exchangeable and the specifically absorbed fraction to be the lowest, accounting for 1.95–4.13% of the total Hg of soil. These findings suggest that adding SNPs to Hg-contaminated soils could be an effective measure for immobilizing soluble Hg and decreasing the Hg concentration in the edible parts of crops. The results of the current study hold promise for the practical application of SNPs to Hg-contaminated farmland for better yields and simultaneously increasing the food safety. The novelty of this study is the selection of oilseed rape and nanoscale sulfur (NS) or sulfur nanoparticles (SNPs) as nontoxic nanomaterial to counteract the Hg toxicity and accumulation. Oilseed rape was selected due to its wide adaptability to various environmental conditions and the high-value oil for human consumption and biofuels production. These advantages make oilseed rape a highly valuable crop for various applications. NS was selected due to its reported ability to limit the uptake of heavy metals in oilseed rape, rice, and wheat along with other crops and subsequently restrict the toxicity of heavy metals in these plants and improve food safety. In this study, we evaluated the growth, Hg accumulation, and the resulting toxicity in oilseed rape grown on Hg-contaminated soil, with or without amendments with NS. The outcomes from this study provided evidence of the significant potential of NS in preventing Hg bioaccumulation and improving crop yields in oilseed rape. This provides opportunity to use NS as an ideal non-GMO approach to limit toxic metals in crops. [ABSTRACT FROM AUTHOR]

The present study focused on the isolation and selection of identically similar bacteria from two different estuaries: polluted (KM186605) and marginally polluted (KM186603). The selected strains were tentatively identified as Bacillus anthracis using biochemical and molecular characteristics. The comparative assessments were performed based on their mercury and antibiotic resistance capabilities. The mercury removal percentages of KM186605 were 57.76, 40.88, 30.24 and 24.88%, while those of KM186603 were 45.92, 36.16, 28.15 and 21.69% respectively, at 25, 50, 75 and 100 mg−l concentrations of mercury. The antibiotic profile showed that KM186605 was susceptible to erythromycin, novobiocin, oxytetracycline, vancomycin, and amikacin. On the other hand, KM186603 was susceptible to oxytetracycline, erythromycin, novobiocin, and amikacin. The notable finding of the present investigation is that the strain screened from the polluted estuary (KM186605) showed higher mercury resistance but lower antibiotic resistance. The strain screened from a marginally polluted estuary (KM186603) exhibited lower mercury resistance and higher antibiotic resistance. Identically similar strains (Bacillus anthracis) were isolated from two different estuary ecosystems (polluted and marginally polluted estuaries). Phenotypical and genotypical similarities of the strains were characterized using biochemical analysis and genetic tools. Mercury removal efficiency and antibiotic resistance of the stains were analyzed and compared. The findings illustrated that the efficiency of the bacteria is influenced by the contaminant factors present in the respective environment. Based on the nature of pollutants, the resistance genes may be induced to develop their resistance capacity for their survival. [ABSTRACT FROM AUTHOR]

Accumulation of heavy metals in aquatic meat can have a destructive role in food safety and is also closely related to the water and feed consumed by animals. Thus, the aim of this study is to evaluate the heavy metals in three aquatic species and their relationship with water and food. Fresh samples included 65 trout, 40 carp, and 45 shrimp, and their water and food were collected from Kermanshah aquaculture. After the preparation phase, the concentration of heavy metals was determined by using inductively-coupled plasma-mass-spectrometry. Lead in carp, arsenic in shrimp, cadmium, and mercury in trout had the highest concentrations of toxic metals. The lead, arsenic, and mercury concentrations in all three farmed aquatic species were higher than the maximum permissible limits. A significant correlation coefficient was observed between the concentration of these metals in the meat and their consumed water and food (p≤0.001). Of the essential metals, except for selenium in trout, and zinc in all three aquatic species, the concentration of other metals was higher than that of the permissible consumption limit. There was also a significant correlation between the concentration of essential metals and their consumed feed (p<0.001). The target hazard quotient of toxic metals was less than 1, but the target cancer risk for arsenic and mercury was in the range of carcinogenicity. Thereby, it is vital to monitor the quality of aquatic meat and pay special attention to their water and feed sources in this region of Iran, which will consequently guarantee human health. [ABSTRACT FROM AUTHOR]

Mercury can travel over long distances, and bioaccumulate in the trophic chain thereby posing a threat to not only humans but also animals and plants. Mercury also causes neurological problems such as the Minamata diseases. Pollution and toxicity of mercury have become a global problem that requires immediate attention. In this study, a thermal-desorption technique using a Zeeman direct mercury (Hg) analyser (DMA) was employed for the quantification of Hg in river sediments as well as for Hg thermo-scanning to investigate the behaviour of Hg release from sediments. Thermal speciation was based on comparison of the temperatures at which Hg species in sediments were thermally released to the temperatures at which Hg in known standards were released. Moreover, total Hg concentrations in river sediments were measured using a DMA. The accuracy of the method for total Hg quantification was confirmed by the analysis of several standard reference materials of sediment (SRM2709a, NCS DC 73325, NCS DC 73374, NCS DC 73316 and NCS DC 73322) and quantitative percentage recoveries ranging from 84 to 99% were obtained. The total Hg concentrations in sediments ranged from 7.4 to 35.2 ng/g and 2.1 to 21.2 ng/g in the low and high flow seasons, respectively. Different forms of Hg associated with river sediments were successfully identified by thermo-desorption technique. The concentrations of Hg in the sediment samples were all below 200 ng/g which is the sediment quality guideline set by the United States Environmental Protection Agency (US EPA). Different species of Hg were present in the sediment samples, with humic acid and/or iron oxide being the most predominant forms of Hg associated with the sediments. [ABSTRACT FROM AUTHOR]

The present study examines the impact of pretreatment procedures on the metal concentrations in bags that are to be exposed. We examine Mn, Fe, Cu, Zn, Cd, and Pb amounts in Sphagnum fallax and Dicranum polysetum mosses using atomic absorption spectrometry. The concentration of Hg was also determined using a mercury analyzer. Two sample preparation ways were tested (with and without rinsing) and their influence was evaluated by determining the coefficient of variation (CV). Chlorophyll content was also determined in mosses collected from three habitats (deep woodland, forest road, and wood lot). The results indicate, that the concentration of elements deposited in mosses depends on the species and the habitat where they were collected (ANOVA, p < 0.001). Rinsing of mosses reduces the CV for Mn, Fe, Cu, and Zn and uniform the material prior to exposure (CV for the majority of metals <10%). Selected correlations were found for element concentrations with chlorophyll content. Photosynthetic activity of mosses decreased by about 80% during their one-month storage in the laboratory. Due to the varying concentration of metals in the collected samples, proper, and standardized preparation of mosses before exposure, they can be effectively used in active biomonitoring. Compared to other biomonitoring work the novel approach is the simultaneous study of two moss species, the analysis of three different habitats and the tie-in of accumulated trace elements by mosses and their vitality by measuring chlorophyll content and photosynthetic activity. [ABSTRACT FROM AUTHOR]

The structures and properties of Circumtrindene derivatives were studied at the M062X/6-31 + G(d,p) and M062X/LANL2DZ levels of theory in the gas phase and water as a solvent. Novel derivatives of Circumtrindene were designed by providing XH (X = NH, O, S) groups on the peripheral five-membered rings. Concave isomers were more stable (14.99–21.25 kcal/mol) than convex isomers. In these compounds, NH, OH, and SH groups were attached directly to the bowl and did not represent the proper size and flexibility to catch and hold ionic contaminants. Therefore, they could not be considered suitable for removing anions and cations. In the next series, the arms were extended to CH2XH (X = NH, O, S). In these flexibility derivatives, the average distances of heteroatoms were sufficient (0.99–1.26 Å) in removing anionic (Cl− and S2-) and cationic (Hg2+) contaminants. A comparison of removal equilibrium constants showed that the amine-containing derivative (X = NH) (K = 43192, 99.52% removal) was more effective than the alcoholic derivative (X = O) (K = 10, 73.49% removal) in removing Cl−. The alcohol derivative (X = OH) was more effective in removing S2− (K = 218530, 99.79% removal). On the other hand, the amine derivative (X = NH) possessed smaller energy barriers (ΔG#) of 7.44 and 8.91 kcal/mol for Cl− and S2− uptake, respectively compared to the corresponding alcohol derivative. The thiol derivative (X = S) was effective in trapping Hg2+ (K = 1.35 × 107), achieving a removal rate of 99.97%. Calculations in a PCM solvent (water) showed a decrease in Gibbs free energy barriers for ion removal, with values of 0.69 and 4.21 kcal/mol for Cl− and S2−, respectively, compared to the gas phase. [ABSTRACT FROM AUTHOR]

The study was carried out to define the distribution of mercury in surface soils in the Mitrovica region, Republic of Kosovo and to assess the level and extent of contamination. A total of 156 soil samples were collected from a depth of 5 cm at each grid point of 1.4 × 1.4 km in an area of 301.5 km2. The mercury content was found to be between 0.02 mg/kg and 11.16 mg/kg. The average Hg content (0.49 mg/kg) exceeded the mean content in European (0.037 mg/kg) and world (0.06 mg/kg) soils by 13.2 and 8.2 times, respectively. From the calculated enrichment factors (EF) and the geo-accumulation index (I-geo), as well as from the distribution map of Hg content, it is evident that the soils of the study area are highly contaminated with mercury, with extremely high enrichment of Hg in the soils of Zone I, which was classified as the most contaminated zone with Hg and other potentially toxic elements in the study area as well as in the towns of Zveçan and Mitrovica. The higher Hg content is of anthropogenic origin, mainly due to lead and zinc mining and metallurgical activities in the study area. The mercury levels were also found to exceed the New Dutch List target value (0.3 mg/kg) in 90 km2 of the study area. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a well know element due its toxicity to both environment and humans. Also, mercury has a high persistence in the environment, and therefore, it is essential to monitor its presence on environmental matrices, such as water, soils and sediments. Sediment cores can provide a useful tool when monitoring water bodies for the presence of mercury since, when coupled with geochronological techniques, it is possible to analyze the temporal variation of Hg during a certain period. Thus, the objective of this work was to perform a systematic review about papers that analyzed the presence of Hg in dated sediment cores in Brazil. The review was performed in the following databases: Scielo, PubMed, Science Direct and Scopus. We searched for papers published between 2011 and 2020. In total, we found 217 articles, that after the application of successive filtration criteria, were reduced to 13 articles. The majority of the papers showed a tendency of increase in the concentration of Hg. We also performed a risk assessment that indicates that some places have Hg concentrations above quality criteria established for sediments. Regarding the sources, all the papers that presented a tendency of increase in Hg concentrations considered this as consequence of anthropogenic activities, such as chlor-alkali industries and deforestation. [ABSTRACT FROM AUTHOR]

This study analyzed the rainwater collected in Central Taiwan during the near typhoon period. Mercury (Hg) was analyzed and the Hg volume weighted mean concentrations (VWM) and wet depositions were calculated during the near typhoon period. In addition, the Hg wet depositions, VWM and precipitation values obtained were compared with Plum rain and regular precipitation periods. The relationship between wet Hg depositions, VWM and precipitations were also discussed. Wet Hg depositions, VWM and precipitations were also compared with the precipitation collected from other parts of the world during 2009 to 2021. The results indicated that the precipitations, VWM and wet Hg depositions in the near typhoon period were 152.5 mm, 0.82 ng/L, and 0.29 μg/m2, respectively. The Hg precipitation ratio values of this study to the plum rain and regular precipitation periods were 3.70 and 6.63, respectively. The Hg VWM ratios values of this study to the plum rain and regular precipitation periods were 12,852.56 and 1.56, respectively. Moreover, the wet Hg deposition ratios values of this study to the plum rain and regular precipitation periods (near typhoon period) were 105.97 and 9.90, respectively. The results further indicated that the Hg VWM and wet depositions obtained in the near typhoon period showed the lowest values when compared with plum rain and regular precipitations periods. Compared with Hg(p) VWM and Fw values obtained from plum season, regular precipitation, this study (typhoon period) demonstrated it has the average lowest VWM and Fw values among these three sampling periods. The correlation coefficient of precipitation and the mercury wet deposition was 0.72051 which was significant in this study. The correlation coefficient for the VWM of mercury was 0.0826 which displayed insignificant relationship in this study. Finally, when comparing the Hg VWM, wet deposition and precipitation values from various studies, the results further indicated that the near typhoon period has the lowest average Hg VWM, wet deposition and precipitation values. [ABSTRACT FROM AUTHOR]

Katingan River has been contaminated by mercury from ASGM activities since the early 2000s. This study aims to assess the risk of mercury exposure from Katingan fish consumption and analyze relationships between exposure variables. We proposed two risk assessment scenarios based on mercury analysis of 74 fish samples and fish consumption questionnaire. The risk assessment result revealed that estimated daily intakes (EDIs) of Scenario 2 were generally 3–4 times higher than Scenario 1. The statistical test results showed significant differences (p < 0.05) in EDI values between scenarios, indicating that variations in fish consumption influenced the mercury intake. Three different health reference-based values (HRVs) were applied in estimating the hazard quotient (HQ) and it influenced the HQ results (p < 0.05), for both scenarios. The relationship analysis between variables presented a strong non-linear correlation between EDI and hair mercury level for both scenarios, but a weak relationship between age and hair mercury level. [ABSTRACT FROM AUTHOR]

To maintain a green and sustainable environment for human beings, rapid detection of potentially toxic heavy metals like mercury (Hg(II)) has attracted great attention. Recently, sensors have been designed which can selectively detect Hg(II) over other common available cations and give a naked eye or fluorometric response. In the last two decades, the trend is shifting from bulky organic chemosensors toward nanoparticles due to their rapid response, low cost, eco-friendly and easy synthesis. In this review, promising nanoparticles-based sensors for Hg(II) detection are discussed. The nano-sensors are functionalized with nucleotide or other suitable materials which coordinate with Hg(II) ions and give clear color or fluorescence change. The operational mechanisms are discussed focusing on its four basic types. The nanoparticles-based sensors are even able to detect Hg in three different oxidation states (Hg(II), Hg(I) and Hg(0)). Recently, the trend has been shifted from ordinary nanoparticles to magnetic nanoparticles to simultaneously detect and remove Hg(II) ions from environmental samples. Furthermore, the nano-sensors for Hg(II) are compared with each other and with the reported organic chemosensors. [ABSTRACT FROM AUTHOR]

The present study aimed to systematically review the concentration of different PTEs, including Arsenic (As), Mercury (Hg), Lead (Pb), and Cadmium (Cd) in cheese among some databases between 2000 and 2021 (from 57 included studies). Estimated concentrations of 160.78 (95% CI = 119.24–202.28), 15.68 (95% CI = 11.88–19.48), 16.94 (95% CI = 13.29–20.59), and 2.47 (95% CI = 1.70–3.23) µg/kg were calculated for As, Pb, Cd, and Hg, respectively. Most of the studies for PTEs are related to Pb, about 40% of the studies, compared to As, which has fewer studies. The results showed that As and Hg concentrations were lower than the Codex Alimentarius Commission standard limits. Nevertheless, Cd and Pb concentrations were higher than the standard limit values. Results showed that cheese making, the ripening period, fat content, and texture are influential factors in a high level of Pb and Cd in cheese samples. [ABSTRACT FROM AUTHOR]

Mercury is a ubiquitous environmental contaminant and can be found in inorganic (Hg0, Hg+ and Hg2+) and organic forms (chiefly CH3Hg+ or MeHg+). The main route of human, mammals and bird exposure occurs via predatory fish ingestion. Occupational exposure to Hg0 (and Hg2+) can also occur; furthermore, in gold mining areas the exposure to inorganic Hg can also be high. The toxicity of electrophilic forms of Hg (E+Hg) is mediated by disruption of thiol (-SH)- or selenol (-SeH)-containing proteins. The therapeutic approaches to treat methylmercury (MeHg+), Hg0 and Hg2+ are limited. Here we discuss the potential use of ebselen as a potential therapeutic agent to lower the body burden of Hg in man. Ebselen is a safe drug for humans and has been tested in clinical trials (for instance, brain ischemia, noise-induce hearing loss, diabetes complications, bipolar disorders) at doses varying from 400 to 3600 mg per day. Two clinical trials with ebselen in moderate and severe COVID are also approved. Ebselen can be metabolized to an intermediate with -SeH (selenol) functional group, which has a greater affinity to electrophilic Hg (E+Hg) forms than the available thiol-containing therapeutic agents. Accordingly, as observed in vitro and rodent models in vivo, Ebselen exhibited protective effects against MeHg+, indicating its potential as a therapeutic agent to treat MeHg+ overexposure. The combined use of ebselen with thiol-containing molecules (e.g. N-acetylcysteine and enaramide)) is also commented, because they can have synergistic protective effects against MeHg+. [ABSTRACT FROM AUTHOR]

Mercury is the most dangerous pollutant prone to the formation of the toxic forms. Therefore, the problem of cleaning mercury contaminated areas seems to be very relevant. Numerous works have been published on the study of mercury uptake depending on the type of plants and natural conditions, but less attention was paid to studying the influence of element's speciation on their accumulation ability. In the present work, the results of laboratory experiments on the assessment of accumulation efficiency of white mustard growing in medium with artificially introduced mercury species such as HgCl2, CH3Hg Cl and HgS are discussed and bioconcentration factors were evaluated while maintaining plant viability. It was shown that methylmercury is the most intensively accumulated specie while mercury sulphide is more imbibed than HgCl2 during 3 months experiment in spite of its negligible solubility in water. Based on the assumption that the cause of such a phenomenon is associated with the transformation of mercury species in the process of the plants growth, mercury speciation in the growing environment has been studied in dynamics and the results obtained confirmed this suppose. It appeared that HgCl2 and HgS are transformed into other chemical forms. [ABSTRACT FROM AUTHOR]

An on-line flow injection mercury analyser (FIMA) for inorganic mercury (Hg) analysis in environmental waters is presented. The FIMA is a portable dual-channel and purge-and-trap system combining aqueous reduction with stannous chloride (SnCl2), two-stage gold (Au) amalgamation, thermal desorption of Hg0 and final detection with cold vapour atomic fluorescence spectrometry (CVAFS). Simultaneous on-line operations of sample loading and analysis make analytical throughput and accuracy improved and contamination eliminated. Results of system optimisation and reliability regarding the determination of inorganic Hg2+ are described. Analytical performances of both channels were the same in terms of data reliability. Low procedural blanks were obtained from laboratory and field trip (≤5 pg, n = 30). Excellent calibrations (r2 > 0.99) with a high precision and good stability (RSD <5%, n = 30) were obtained. Detection limits and reproducibility of the methods have been estimated as ≤0.05 ng L−1 and <5% (0.5 ng L−1, n = 30). The system was finally validated by measurements comparison of the two channels (r2 > 0.98), and analysis of a certified reference material (coastal seawater BCR-579, recoveries 101 ± 4%, n = 10). Overall, a sample throughput of ~10 samples per hour with two-channel detections of FIMA can be achieved. The onboard analysis of inorganic Hg species (e.g. elemental, reactive, and total Hg) in surface seawaters of the East China Sea (ECS) are also successfully achieved. The portable FIMA is fast, easy, and robust for reliable monitoring of Hg in natural seawaters. [ABSTRACT FROM AUTHOR]

In this work, we have synthesised a mixture consisting of sodium calcium silicate and calcium silicate nanostructures in the presence and absence of the hydrothermal method. The synthesised products were identified utilising many techniques such as XRD, EDS, FT-IR, HR-TEM, and FE-SEM. The XRD demonstrated that the mean crystallite size of the product, which was synthesised in the absence of the hydrothermal method, is 72.71 nm. The average crystallite size of the products, which were synthesised using the hydrothermal method at 160℃ for 4, 8, and 16 h, are 44.85, 34.89, and 37.38 nm, respectively. HR-TEM confirmed that all the products consist of irregular and rod shapes. The product, which was synthesised after 8 h of hydrothermal treatment, was operated as an adsorbent for the efficient removal of toxic ions (Cd(II) and Hg(II)) from aqueous media. The maximum adsorption capacity of the adsorbent towards Hg(II) and Cd(II) ions are 177.94 and 199.20 mg/g, respectively. The removal process of the studied ions was fitted well with the pseudo-second-order kinetic model and Langmuir equilibrium isotherm. Thermodynamic parameters confirmed that the removal process of the studied ions was spontaneous, chemical, and endothermic. [ABSTRACT FROM AUTHOR]

A mixture risk assessment (MRA) for four metals relevant to chronic kidney disease (CKD) was performed. Dietary exposure to cadmium or lead alone exceeded the respective reference values in the majority of the 10 European countries included in our study. When the dietary exposure to those metals and inorganic mercury and inorganic arsenic was combined following a classical or personalised modified reference point index (mRPI) approach, not only high exposure (95th percentile) estimates but also the mean exceeded the tolerable intake of the mixture in all countries studied. Cadmium and lead contributed most to the combined exposure, followed by inorganic arsenic and inorganic mercury. The use of conversion factors for inorganic arsenic and inorganic mercury from total arsenic and total mercury concentration data was a source of uncertainty. Other uncertainties were related to the use of different principles to derive reference points. Yet, MRA at the target organ level, as performed in our study, could be used as a way to efficiently prioritise assessment groups for higher-tier MRA. Since the combined exposure to the four metals exceeded the tolerable intake, we recommend a refined MRA based on a common, specific nephrotoxic effect and relative potency factors (RPFs) based on a similar effect size. [ABSTRACT FROM AUTHOR]

Herein we describe the synthesis of a library of new mercury complexes, including some dimers and polymeric species. Initially, a phosphonium salt, [PPh3CH2C(O)C6H4–m-OCH3]Br (S), was synthesized from triphenylphosphine (PPh3) and BrCH2C(O)C6H4-m-OCH3 in acetone. We then reacted this phosphonium salt with an appropriate base to acquire a new phosphorus ylide monodentate, PPh3=C(H)C(O)C6H4-m-OCH3 (Y). Finally, we treated the synthesized ligand with mercury halides in dry CH3OH to form C-coordinated complexes of the form [HgX(PPh3C(H)C(O)C6H4-m-OCH3) (μ-X)]2 [X = Cl (1), Br (2), I (3)], [(PPh3=C(H)C(O)C6H4-m-OCH3)Hg(NO3)2]n (4). We characterized these compounds using CHN analysis, FT-IR, NMR (1H, 13C and 31P) and density functional theory. We elucidated the structure of 2 by single-crystal X-ray diffraction. The results establish that 1, 2 and 3 have dimeric structures, while a polymeric structure is suggested for 4. The antioxidant activity of all compounds in DMSO was assessed using a DPPH free radical scavenging method. Also, the nature of metal-ligand (C→Hg) bonding in 1, 2 and 3 have been investigated using natural bond orbital (NBO) and energy-decomposition analyses (EDA). [ABSTRACT FROM AUTHOR]

A simple and effective electrochemical sensor for cobalt using mercury nanodroplets supported on montmorillonite (MMT) was developed. Physical analyses allowed the identification of crystalline structure, morphology, and presence of mercury structures in MMT-Hg2+ with nanometric dimensions between 3 and 11 nm. Electrochemical responses obtained by differential pulse anodic stripping voltammetry (DPASV) using carbon paste electrode modified with montmorillonite decorated with mercury nanodroplets (CPEM-MT-Hg) toward cobalt (II) provide a limit of detection (LOD) of 3.4 × 10−6 mol L−1, limit of quantification (LOQ) of 1.1 × 10−5 mol L−1, and a linear dynamic range (LDR) from 3.5 × 10−5 to 2.9 × 10−4 mol L−1. The developed method was applied to the determination of cobalt ions in a commercial vitamin B12 sample. [ABSTRACT FROM AUTHOR]

The oceans, serving as some of the most extensive reservoirs of mercury (Hg) on Earth, play an essential role in the global Hg biogeochemical circulation, as a sink for atmospheric deposits and surface runoff while simultaneously emitting Hg to the atmosphere. Clarifying the mechanisms during cycling of Hg in marine ecosystems is a crucial segment in elucidating global Hg behavior and assessing its risks to wildlife and humans. The stable Hg isotope technique has emerged as a powerful tool for identifying potential sources and certain processes of Hg. Herein, the research advances in marine Hg biogeochemical cycling were reviewed from an isotopic tracing perspective, including sources of marine Hg, isotopic fingerprints across various marine media, and applications of Hg isotopes in pathways, transport, and transformation mechanisms associated with marine environments. The knowledge gaps and challenges were further discussed in the development of ultratrace level and species-specific isotopic analytical methods, the isotope fractionation mechanisms in reactions and processes, and the integration of multiple approaches and cross disciplines. These future studies would advance our understanding of Hg behavior in oceanic environments, its authentic function, and interactions with other ecosystems in the global Hg cycle, and evaluate its response to environmental changes. [ABSTRACT FROM AUTHOR]

The diagnosis and treatment of the diseases in a certain coordination is a subject that has been emphasized in recent years. Theragnostics approaches allow simultaneous diagnosis and treatment of chronic diseases such as cancer. An ideal theragnostic should be biocompatible and can be used safely in humans. Although several types of theragnostics have been developed, none of yet satisfied these criteria. Bioinspired materials with noble metal centers encapsulating therapeutic and imaging agents were shown to possess theragnostic activities. In this study, it was aimed to synthesize, characterize, and evaluate the cytotoxic and genotoxic effects of self-assembly of diphenylalanine (Phe–Phe) dipeptides presence of mercury (Hg2+) ions to be used for theragnostic. Cytotoxicity and genotoxicity studies were done in mouse fibroblast (NIH/3T3) cells by 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) and single cell gel electrophoresis (Comet) assays, respectively. It was found that cell viability decreased in a dose-dependent manner in 24-, 48-, and 72-h treatment. Also, Phe–Phe dipeptides did not cause any significant changes in DNA damage at the concentrations of 1, 2, and 5 mg/mL in 4- and 24-h exposures. In the 48-h exposure, Phe–Phe peptide exposure at concentrations of 2 and 5 mg/mL caused a significant increase in DNA damage and in the 72-h of exposure, a significant increase in DNA damage was observed at all studied concentrations. According to the results of the study, it can be said that Phe–Phe dipeptides presence of Hg2+ ions are biocompatible and can be used safely for theragnostic purposes. [ABSTRACT FROM AUTHOR]

Exposure to environmental metal pollutants is linked to oxidative stress and the subsequent development of neurological disease. In this study, the effects of copper, manganese, and mercury, were evaluated at X100 the World Health Organization safety limits for drinking water. Using a Sprague-Dawley rat model, following exposure for 28 days, the effects of these metals on biochemical blood parameters and tissue and cellular structure of the brain were determined. Biochemical analysis revealed no hepatocellular injury with minor changes associated with the hepatobiliary system. Minimal changes were found for renal function and the Na+ /K+ ratio was reduced in the copper and manganese (Cu + Mn) and copper, manganese, and mercury (Cu, Mn + Hg) groups that could affect neurological function. Light microscopy of the brain revealed abnormal histopathology of Purkinje cells in the cerebellum and pyramidal cells in the cerebrum as well as tissue damage and fibrosis of the surface blood vessels. Transmission electron microscopy of the cerebral neurons showed microscopic signs of axonal damage, chromatin condensation, the presence of indistinct nucleoli and mitochondrial damage. Together these cellular features suggest the presence and influence of oxidative stress. Exposure to these metals at X100 the safety limits, as part of mixtures, induces changes to neurological tissue that could adversely influence neurological functioning in the central nervous system. [ABSTRACT FROM AUTHOR]

Mercury is the only natural liquid non-ferrous metal that occurs under normal temperature. Cinnabar, also known as Chensha 辰砂 and Dansha 丹砂 in ancient China, is a natural ore of mercury sulphide that exists in mercury mines and is the most common source ore for refining elementary mercury. The largest cinnabar deposit in China is at the Wanshan mercury mine in Wanshan Town, Guizhou Province, which was an important centre for the mercury production industry since the Tang Dynasty (AD 618–907). An archaeological field survey of the area identified 36 locations related to cinnabar mining and mercury production spanning the period from the Tang and Song Dynasties (AD 960–1279) to the late 20th century. This survey was the first comprehensive archaeological investigation and exploratory research of these materials, and provides a fresh insight into the evolution of the Wanshan mercury mine and its secondary development as a unique industrial heritage site. [ABSTRACT FROM AUTHOR]

Tungsten and nitrogen co-doped carbon dots (W, N-CDs) with a high quantum yield of 51.08% were synthesized by a facile hydrothermal process. Doping of tungsten effectively enhanced luminescent properties of the carbon dots, and the quantum yield was increased by 10.3%. The surface composition and morphology of the synthesized W, N-CDs were characterized. W, N-CDs were employed as nanoprobes to develop a sensor for the selective and sensitive determination of Hg2+ and captopril. Under the optimal conditions, the linear response range for Hg2+ and captopril were 0.125 to 9.0 μM and 0.5 to 10 μM with detection limits of 40 nM and 300 nM, respectively. The developed sensor was successfully applied for the determination of Hg2+ in water and captopril in urine with recoveries from 95.50 to 105.50% and 96.33 to 105.13%, which demonstrates suitable accuracy and reliability. The fluorescence mechanisms of W, N-CDs toward Hg2+ and captopril were also evaluated. [ABSTRACT FROM AUTHOR]

This work has been performed to synthesize a new dithiooxamide/glutaraldehyde resin (R-DTGA) polymer, and to determine the adsorption behavior as well as the adsorption kinetics of the reaction of the synthesized polymer towards the removal of mercury (II) ions from contaminated aqueous and industrial waste media. The synthesized resin polymer has been characterized by using the X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier-Transform Infrared spectroscopy (FT-IR), the DTA, and the TGA measurements and techniques. The adsorption behavior of mercury ions and species was studied using the batch technique. The batch adsorption experiments were performed by using the synthesized polymer, and the effect of various parameters affecting the mercury (II) ions removal has been carefully investigated. The studied parameters are the solution pH, mercury ions concentration, and adsorption time. The obtained experimental results and data indicated the adsorption of mercury was maximum at the pH value (4.6). Also, it was found the adsorption of mercury ions onto the synthesized resin is best fitted by the Langmuir adsorption model, and the adsorption kinetics is best fitted by pseudo-second order kinetics model. The studied adsorbent polymer gave a superior maximum uptake (adsorption) capacity of 11 mmol/g. Based on the obtained results, the synthesized polymer provided extraordinary maximum capacity, selectivity, reusability, sensitivity, and fast adsorption kinetics to remove, extract, and recover mercury (II) ions from industrial, aqueous, and wastewater solutions. [ABSTRACT FROM AUTHOR]

Spiders are good bioindicators of ecological contamination by potentially toxic trace elements such as As, Cd, Hg, In, Ni, Pb, Se Zn and methylmercury (MeHg). Here, we investigated their bioaccumulation in an Indian tarantula, Theraphosidae spider Thrigmopoeus truculentus inhabiting mud embankments along a national highway in the Western Ghats mountains, and the soil contamination. Concentrations in soil were higher than the soil environmental quality criteria of different countries for Cd, Zn and Ni. Concentrations in whole-body of tarantulas (n = 7) were Zn > Se > [Cd, As, Pb, Ni] > In > total mercury (THg) > MeHg. Concentrations of Zn, Cd, Se, THg and MeHg were significantly higher (p < 0.05) compared to soil, suggesting biomagnification. Our work and the review of past data suggest that spiders can biomagnify Zn, Cd, Se, THg and MeHg; but not Pb, As, In and Ni. For As, Zn, Se, Cd, In and THg, correlations between concentrations in tarantula appendages and whole-body were significant (p < 0.05), suggesting that a non-lethal approach be explored where only appendages of larger tarantulas are analysed. Overall, the Theraphosidae species showed the potential to be used as an indicator of bioaccumulation, and their usefulness should be further explored. [ABSTRACT FROM AUTHOR]

Distinguishing the respective contributions of various microbes to methylmercury (MeHg) production is critical for predicting MeHg bioaccumulation and exposure risk. Metabolic inhibitors have been commonly used to block the activity of specific microbial groups and identify primary Hg methylating microbes. By reviewing literatures and our empirical data, we demonstrate how multiple factors, including (1) the addition of inappropriate amounts of inhibitors, (2) a tendency to overlook microbial syntrophy, and (3) the absence of comprehensive proxy systems of Hg methylation, would impact result interpretation of this approach. We thus suggest that the design of inhibition assays should consider the environmental properties, e.g., background levels of electron acceptors, concentrations of metabolic substrates, and abundances of Hg methylating microbes. We also recommend that inhibitors should be added at multiple concentrations and that observed changes in Hg methylation should be assessed with comprehensive indicators. Revealing the key factors responsible for the improper usage of this method and inadequate interpretation of the results would help optimize inhibition assays for robust predictions of MeHg production in nature. [ABSTRACT FROM AUTHOR]

Mercury has been described as been in daily household items such as soaps, skin-lightening creams (SLC), and topical disinfectants. Mercury exposure can reportedly cause damage to the optic nerve and retina. A 30-year-old Somali woman presented with decreased vision and was found to have bilateral optic atrophy. Neuroimaging and laboratory work-up for nutritional deficiencies, heavy metals, and syphilis were performed. Evaluation revealed normal neuroimaging and laboratory work-up except for elevated serum and urine mercury levels. Mercury levels at the initial blood test was 11.1 ug/L (normal limits < 10.0 ug/L) and was 15.7 ug/L on repeat testing. A 24-h urine test showed elevated mercury at 16 ug/24 h (normal limits < 2 ug/24 h). Evaluation of an unlabelled SLC that she was using showed the presence of mercury. It is worth testing for heavy metals in the work-up of bilateral optic atrophy. Clinicians should consider cosmetic products as a potential source of mercury exposure and recommend discontinuation if mercury is present. [ABSTRACT FROM AUTHOR]

Mercury (II) ions have significant ecological impacts. In the current study, magnetized iron oxide (Fe3O4) nanoparticles were green synthesized and encapsulated with alginate (ALG). The nanoparticles were converted into a composite (Fe3O4/ALG). The Fe3O4/ALG beads were used to remove Hg (II) from industrial wastewater. Characterization was performed by X-ray diffraction (XRD), scanning electron microscopy—energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis-differential thermal analysis (TGA-DTA). A central composite design (CCD) approach was performed to define the experimental conditions providing the highest global adsorption efficiency and to optimize the pH, temperature and adsorbent mass. Hg (II) concentrations were determined by flame and electrothermal atomic absorption spectrometry (FAAS and ETAAS). The limits of detection (LOD) and quantification (LOQ) were 1.2 mg L−1 and 3.5 mg L−1 for FAAS and 0.2 µg L−1 and 0.5 µg L−1 for ETAAS, respectively. Additionally, Langmuir, Freundlich, and Temkin isotherm models were employed to determine the adsorption mechanism. The adsorption capacity of Fe3O4/ALG was determined to be 49.18 mg g−1 by the Langmuir model. Kinetic studies revealed that the adsorption of Hg (II) best fitted the pseudo-second order model. The Gibb's free energy (ΔG°) values showed that the adsorption of Hg (II) on Fe3O4/ALG occurred spontaneously. [ABSTRACT FROM AUTHOR]

Heavy metals such as Mercury and Cadmium are highly cytotoxic metals when released into the environment and pose serious hazards to the ecosystem. The current study introduces CMC/Fe3O4 nanocomposite as an effective, magnetically recyclable, low-cost, and environment-friendly biopolymer-based adsorbent for removing these harmful contaminants from waste water. This nanocomposite was synthesized by ultrasonic assisted coprecipitation method and characterized using X-ray diffractometer, scanning electron microscope, BET surface area, Fourier-transform infrared spectroscopy, etc. Series of batch experiments were carried out at room temperature to determine the adsorption capacity of CMC/Fe3O4, which is found to be 243.52 mg g−1 and 414.04 mg g−1 toward Hg(II) and Cd(II), respectively, at optimum conditions. Optimum parameters for Hg(II) were pH 7, initial concentration 200 mg L−1, and 0.02 g of adsorbent loading, while for Cd(II) experiments were conducted using pH 6, initial concentration 500 mg L−1, and 0.03 g of adsorbent. The adsorption was well described by the Langmuir isotherm model and Pseudo-second order kinetic model, and the thermodynamic study reveals spontaneous and endothermic nature of adsorption. [ABSTRACT FROM AUTHOR]

This study was conducted in five randomly selected small-scale mining communities in the Amansie West District of Ashanti Region, Ghana to assess the impacts of small-scale mining activities on heavy metal presence in three different land use types (mined site, farmland and forest area). Using a random sampling design, a total of 60 soil samples were collected from 0–20 cm depth and analyzed for soil heavy metals: arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg) and copper (Cu) using Two-way ANOVA. Heavy metal concentrations for As (5.571 mg/kg), Cd (0.002 mg/kg), Cu (1.158 mg/kg), Pb (0.076 mg/kg) in the communities did not exceed the FAO/WHO permissible limits with the exception of Hg concentrations for the respective communities (0.68 mg/kg, 1.07 mg/kg, 1.26 mg/kg, 1.28 mg/kg, 17.03 mg/kg) whose levels were 2.3 to 56.8 times higher than FAO/WHO permissible limits (0.3 mg/kg). The distribution of heavy metals in the soil was not uniform across the different land use types in the mining landscape. Differences in heavy metal concentrations were significant (p < .05) at the community, land use and their interaction (community*land use) levels with the exception of As concentration at the land use level (p > .05). The study concludes that soils of the major land use types in the study area (mined sites, farmlands and forest area) are all contaminated by Hg accumulation. Therefore, effective rehabilitation of mined sites in mining-plagued-communities should include measures for removing mercury from the soil. [ABSTRACT FROM AUTHOR]

The K shell binding energies of lead, mercury, and tungsten in their pure elemental form and in some of their compounds have been measured for the first time by adopting a novel method. The method involves a weak beta source, an external bremsstrahlung converter, element and compound targets, and a high-resolution, high-purity germanium detector coupled to 16K multichannel analyzer. Continuous external bremsstrahlung photons produced by the interaction of beta particles from a 90Sr-90Y radioactive source with an iron foil are allowed to pass through the elemental and compound targets of lead, mercury, and tungsten. The spectrum of transmitted external bremsstrahlung photons is measured with a high-resolution high purity germanium detector spectrometer. The transmitted spectrum shows a sudden drop in intensity at K shell binding energy of the target. Such a sudden drop, which is due to the onset of the K shell photoelectric effect, has been used to determine the K shell binding energies. It has been investigated that the shifts in the K shell binding energies due to chemical environment of lead, mercury, and tungsten atoms is attributed to crystal structure. [ABSTRACT FROM AUTHOR]

Mercury contamination is a significant public health and environmental problem; thus, detection of Hg2+ at sensitive levels is very important for environmental protection. In this study, we report a noble green synthesis of copper nanoparticles (CuNPs) using Aegle marmelos fruit peel extract, characterising their catalytic properties for reduction of methylene blue (MB) and sensitive chemiluminescence (CL) detection of Hg2+ ions based on this reaction. The transformation of MB dye in the presence of sodium borohydride (NaBH4) was analysed by UV-visible spectroscopy, and kinetics of pseudo first order were found. Changes of CL were used for determination of Hg2+ in the presence of ethylenediamine. Interestingly, the formation of the ethylenediamine-CuNPs-Hg2+ complex increases the rate of H2O2-Luminol catalysis and the corresponding CL growth. The given effect was applied to determine the Hg2+ concentration in real water. The linear range of the calibration curve was from 0.01 pM to 1.0 pM of Hg2+, and 0.0062 pM was the detection limit. The assay selectivity was confirmed using other toxic metallic ions. The proposed approach may be qualified as cost effective, eco-friendly, sensitive and selective. [ABSTRACT FROM AUTHOR]

This study reports the concentrations of As, Cd, Hg, and Pb in commonly consumed crustaceans collected from South Korea. The samples were prepared by wet digestion using HNO3 and H2O2 by microwave-assisted combustion. For the determination of As, Cd, and Pb, inductively coupled plasma-mass spectrometry was used, while Hg was determined by gold amalgamation direct mercury analysis. The techniques were validated by determining quality parameters of correlation coefficients, limits of detection and quantification, coefficient of variance, recovery, and accuracy by analyzing an oyster tissue certified reference material (NIST CRM-1566b). The distribution of toxic metals was determined in whole, muscle, and digestive tracts of the crustaceans. Also, to provide information concerning consumer safety, risk assessment in terms of estimated dietary daily/weekly intake, target hazard quotient, and hazard index values was carried out. The concentration ranges (mg/kg) of the analyzed elements were in the decreasing order of As (4.0-25.2) > Cd (0.154-4.57) > Pb (0.033-0.128) > Hg (0.011-0.086). The estimated dietary daily/weekly intake, target hazard quotient, and hazard index values were compared with the standard limits set by United States Environmental Protection Agency and Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives. In general, the analyzed crustaceans were found not to cause any threat to consumers under normal circumstances. [ABSTRACT FROM AUTHOR]

Abstract Trimetazidine (TMZ) is a promising emerging therapeutic piperazine derivative for renal pathologies. However, the nephroprotective mechanism of TMZ against heavy metal-induced toxicity is unknown. This study, therefore, aimed to explore whether TMZ could mitigate mercury-induced nephrotoxicity in rats. Rats were injected TMZ (3 mg/kg bw) and/or mercury chloride (HgCl2) (4 mg/kg bw) for 4 days (n = 6 rats per group). The blood analysis revealed marked increases in creatinine, urea and uric acid levels in HgCl2 group compared to the control. HgCl2 induced prominent decreases in renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPx) activities compared to the control followed by marked increases in the levels of malondialdehyde (MDA), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), caspase-3 and caspase-9. Whereas the renal levels of anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) reduced considerably compared to the control. Contrarily, it was found that in the rats administered TMZ + HgCl2, levels of renal markers, MDA, TNF-α, IL-6 and caspases-3/-9 were prominently reduced compared to the HgCl2 group. The renal SOD, CAT, GPx, IL-4, and IL-10 were markedly elevated along with ameliorated histopathological lesions. On the whole, therefore, TMZ could be repurposed for blocking HgCl2 nephrotoxicity via inhibition of oxidative inflammation and apoptosis in rats. [ABSTRACT FROM AUTHOR]

An electrochemiluminescence (ECL) sensor for mercury (II) was developed based on the cation exchange reaction between Hg2þ and CdS due to the large difference in the sedimentation equilibrium constant. To fabricate the sensor, CdS nanowires (CdS NWs) serving as the emitter were introduced upon a glass carbon electrode (GCE). Gold nanoparticles (Au NPs) with excellent electrical conductivity were introduced on the surface of CdS NWs/GCE to enhance the sensor performance. In the presence of Hg2þ, the electrochemiluminescence of the sensor decreased. The electrochemiluminescence intensity was negatively correlated with the concentration of Hg2þ. The excellent performance of Au NPs:CdS NWs/GCE, combined with the difference in the CdS and HgS sedimentation equilibrium constants, endows the sensor with good selectivity and sensitivity for the analyte. A long linear range from 6.7x10-15 M to 1.0x10-8 M was obtained for Hg2þ with a detection limit of 5.0x10-15 M. The applicability of the method was validated by the analysis of water and lake water. [ABSTRACT FROM AUTHOR]

The artisanal and small-scale gold mining site (ASGM) located in the forest of Suwawa Timur District, Bone Bolango Regency, was found to be host to a number of unique problems. To solve those problems, we, the researchers, seek to endorse the implementation of transdisciplinary communities of practice (TDCOP). Through dialogue and discussion amongst stakeholders, the concept of "The Health Resilience Village" was derived. Furthermore, in order to solve the problems, our project is leading to ongoing discussions in villages near mines, the development of methods to reduce mercury emissions, and the creation of livelihoods, through TDCOP. [ABSTRACT FROM AUTHOR]

The first Cd-Hg 2,2′-bipyridine compound, [Cd(2,2′-bipy)3](Hg2Cl7)·H3O (1), (2,2′-bipy = 2,2′-bipyridine), has been solvothermally prepared and characterized by single-crystal X-ray diffraction. Compound 1 is characterized by an isolated structure, comprising [Cd(2,2′-bipy)3]2+ cations, (Hg2Cl7)3– anions and protontated lattice water molecules. Photoluminescence investigation discovers that compound 1 displays an emission in the yellow region. It has remarkable CIE (Commission Internationale de I'Éclairage) chromaticity coordinates of (0.5126, 0.4865). Its CCT (Correlated Color Temperature) is 2510 K. Time-dependent density functional theory (TDDFT) calculations reveal that the emission is attributed to ligand-to-ligand charge transfer (LLCT). The first Cd-Hg 2,2′-bipyridine compound has been solvothermally prepared and characterized by single-crystal X-ray diffraction. It is characterized by an isolated structure, comprising [Cd(2,2′-bipy)3]2+ cations, (Hg2Cl7)3– anions and protontated lattice water molecules. Photoluminescence investigation discovers that it displays an emission in the yellow region. TDDFT calculations reveal that the emission is attributed to ligand-to-ligand charge transfer (LLCT). [ABSTRACT FROM AUTHOR]