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1.
Sci Total Environ ; 784: 147252, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088049

RESUMO

Atmospheric deposition of mercury (Hg) to terrestrial and aquatic ecosystems has significant implications for human and animal exposure. Measurements of Hg isotopic composition can be utilized to trace sources of Hg, but outside of the Arctic there has been little Hg isotopic characterization of snow. To better understand deposition pathways at mid-latitudes, five time series of snowfall were collected at two sites (Dexter and Pellston, Michigan, USA) to investigate the Hg isotopic composition of snowfall, how it changes after deposition, and how it compares to rain. The Hg isotopic composition of a subset of fresh snow samples revealed the influence of reactive surface uptake of atmospheric Hg(0). The first time series collected at Dexter occurred during a polar vortex, demonstrating Hg isotopic fractionation dynamics similar to those in Arctic snow, with increasingly negative Δ199Hg as snow aged with exposure to sunlight. All other time series revealed an increase in Δ199Hg as snow aged, with values reaching up to 3.5‰. This characterization of Hg isotopes in snow suggests a strong influence of oxidants and binding ligands in snow that may mediate Hg isotope fractionation. Additionally, isotopic characterization of Hg in snow deposited to natural ecosystems at mid-latitudes allows for better understanding of atmospheric mercury sources that are deposited to lakes and forests and that may become available for methylation and transfer to food webs.


Assuntos
Mercúrio , Idoso , Animais , Regiões Árticas , Ecossistema , Monitoramento Ambiental , Humanos , Mercúrio/análise , Isótopos de Mercúrio/análise , Michigan , Neve
2.
Environ Monit Assess ; 193(7): 416, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34120239

RESUMO

Spatial variations and mobility of mercury (Hg) and Hg associations with other potentially toxic elements (PTEs) were studied in soil samples from Alaba, the largest e-waste recycling site in Nigeria and West Africa. Total Hg concentration was determined in surface soil samples from various locations using cold vapour atomic absorption spectrometry (CVAAS) following microwave-assisted acid extraction, while sequential extraction was used to determine operationally defined mobility. The concentrations of the PTEs arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) metals were determined using inductively coupled plasma mass spectrometry (ICP-MS) following microwave-assisted digestion with aqua regia. Total Hg concentration ranged from < 0.07 to 624 mg/kg and was largely dependent on the nature and intensity of e-waste recycling activities carried out. Mobile forms of Hg, which may be HgO (a known component of some forms of e-waste), accounted for between 3.2 and 23% of the total Hg concentration, and were observed to decrease with increasing organic matter (OM). Non-mobile forms accounted for >74% of the total Hg content. In the main recycling area, soil concentrations of Cd, Cd, Cu, Hg, Mn, Ni, Pb and Zn were above soil guideline values (Environment Agency in Science Report, 2009; Kamunda et al., 2016). Strong associations were observed between Hg and other PTEs (except for Fe and Zn) with the correlational coefficient ranging from 0.731 with Cr to 0.990 with As in April, but these correlations decreased in June except for Fe. Hazard quotient values > 1 at two locations suggest that Hg may pose health threats to people working at the e-waste recycling site. It is therefore recommended that workers should be investigated for symptoms of Hg exposure.


Assuntos
Resíduo Eletrônico , Mercúrio , Metais Pesados , Poluentes do Solo , África Ocidental , Monitoramento Ambiental , Humanos , Mercúrio/análise , Metais Pesados/análise , Nigéria , Medição de Risco , Solo , Poluentes do Solo/análise
3.
Analyst ; 146(12): 3852-3857, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34075934

RESUMO

A method for the rapid screening of toxic elements in fruits and vegetables is of significant importance to prevent human exposure to these elements. In this work, a simple method used for microplasma-induced vapor generation (µPIVG) was developed for the rapid screening and quantification of mercury in fruits and vegetables without sample preparation. A stainless-steel capillary was partly inserted into a juice droplet from the tested fruits and then the sample liquid automatically moved to the end of the capillary with the assistance of inherent capillary driving force. Subsequently, a high voltage was applied between the capillary and a tungsten electrode to generate microplasma wherein the juice was sprayed and the mercury ions contained in the juice were converted to mercury cold vapor (Hg0). The Hg0 was finally separated from the liquid phase and swept to an atomic fluorescence spectrometer (AFS) for rapid screening. A standard addition method coupled with µPIVG atomic fluorescence spectrometry was further used for the quantitative analysis of the suspected sample. Under the optimized conditions, the limits of detection (LODs) of 0.3, 0.5, and 0.4 µg L-1 were obtained for the tested tomato, lemon, and orange samples, respectively. The proposed technique provides a simple and cost-effective tool for the rapid screening of mercury in fruits and vegetables by atomic spectrometry.


Assuntos
Mercúrio , Frutas , Gases , Humanos , Mercúrio/toxicidade , Espectrometria de Fluorescência , Verduras
4.
Environ Sci Technol ; 55(12): 8203-8214, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34081443

RESUMO

Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.


Assuntos
Resíduo Eletrônico , Mercúrio , Nanopartículas , Taquicardia por Reentrada no Nó Atrioventricular , Idoso , Arritmias Cardíacas/induzido quimicamente , Nó Atrioventricular , Humanos , Resíduos Industriais , México , Titânio
5.
Chemosphere ; 279: 130470, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134398

RESUMO

Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of differential foraging may be especially important for generalist species that exhibit high plasticity in foraging habitats, locations, or diet. Here, we investigate whether foraging habitat, sex, or fidelity to a foraging area impact blood mercury concentrations in western gulls (Larus occidentalis) from three colonies on the US west coast. Cluster analyses showed that nearly 70% of western gulls foraged primarily in ocean or coastal habitats, whereas the remaining gulls foraged in terrestrial and freshwater habitats. Gulls that foraged in ocean or coastal habitats for half or more of their foraging locations had 55% higher mercury concentrations than gulls that forage in freshwater and terrestrial habitats. Ocean-foraging gulls also had lower fidelity to a specific foraging area than freshwater and terrestrial-foraging gulls, but fidelity and sex were unrelated to gull blood mercury concentrations in all models. These findings support existing research that has described elevated mercury levels in species using aquatic habitats. Our analyses also demonstrate that gulls can be used to detect differences in contaminant exposure over broad geographic scales and across coarse habitat types, a factor that may influence gull health and persistence of other populations that forage across the land-sea gradient.


Assuntos
Charadriiformes , Mercúrio , Animais , Organismos Aquáticos , Ecossistema , Cadeia Alimentar
6.
Chemosphere ; 279: 130631, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134422

RESUMO

The Hg isotopic composition of 1-year-old Norway spruce (Picea abies) shoots collected from Saarland cornurbation Warndt, Germany, since 1985 by the German Environmental Specimen Bank, were measured for a better understanding of the temporal trends of Hg sources. The isotopic data showed that Hg was mainly taken up as gaseous element mercury (GEM) and underwent oxidation in the spruce needles; this led to a significant decrease in the δ202Hg compared with the atmospheric Hg isotopic composition observed for deciduous leaves and epiphytic lichens. Observation of the odd mass-independent isotopic fractionation (MIF) indicated that Δ199Hg and Δ201Hg were close to but slightly lower than the actual values recorded from the atmospheric measurement of the GEM isotopic composition in non-contaminated sites in U.S. and Europe, whereas observation of the even-MIF indicated almost no differences for Δ200Hg. This confirmed that GEM is a major source of Hg accumulation in spruce shoots. Interestingly, the Hg isotopic composition in the spruce shoots did not change very significantly during the study period of >30 years, even as the Hg concentration decreased significantly. Even-MIF (Δ200Hg) and mass-dependent fractionation (MDF) (δ202Hg) of the Hg isotopes exhibited slight decrease with time, whereas odd-MIF did not show any clear trend. These results suggest a close link between the long-term evolution of GEM isotopic composition in the air and the isotopic composition of bioaccumulated Hg altered by mass-dependent fraction in the spruce shoots.


Assuntos
Mercúrio , Picea , Monitoramento Ambiental , Europa (Continente) , Alemanha , Mercúrio/análise , Isótopos de Mercúrio/análise , Noruega
7.
Environ Monit Assess ; 193(7): 412, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34114120

RESUMO

Arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), beryllium (Be), nickel (Ni), selenium (Se), and thallium (Tl) are reportedly notorious toxic contents of make-ups, with potential to cause cancer and chronic kidney disease, warranting investigation on their toxic effects. One hundred female university students were randomly selected as consistent users of make-ups for upward of 3 years. The serum/urine levels of the 8 elements were regressed against the kidney functions (estimated glomerular rate, eGFR) of the subjects. At coefficient of - 0.009, As had insignificant (0.518) level. The coefficient for Cd was - .155 and insignificant (0.423). At coefficient of - 039, Pb level was insignificant (0.595). The coefficient, 0.061, for Hg was insignificant (0.462). At - 1.585, the coefficient of Be was insignificant (0.292). The coefficient for Ni, 1.384, was insignificant (0.354). At - .002, the coefficient of Se was insignificant (0.635). The coefficient, 0.039, for Tl was significant at 5% (0.015). This finding internally validated the mean serum Tl level, 201.4900 ± 20.63316 µg/L, which was much higher than the normal level of < 2 µg/L and within the toxic range of > 200 µg/L. A policy is needed to address the use of make-ups containing Tl.


Assuntos
Arsênio , Mercúrio , Selênio , Oligoelementos , Arsênio/análise , Cádmio/análise , Cádmio/toxicidade , Monitoramento Ambiental , Feminino , Humanos , Mercúrio/análise , Mercúrio/toxicidade , Nigéria , Estudantes , Oligoelementos/análise , Oligoelementos/toxicidade , Universidades
8.
Artigo em Chinês | MEDLINE | ID: mdl-34074076

RESUMO

Objective: To screen and identify plasma differentially expressed genes and related signal pathway by human gene expression profile array and fluorescent quantitative PCR. Methods: From September 2018 to October 2019, 291 workers from a Mercury-in-glass thermometer factory in Jiangsu Province were selected for an occupational health examination, a total of 60 persons were divided into two groups: high and low mercury exposure groups (30 persons in each group) . Plasma total RNA samples from the high exposure group and the low exposure group (10 cases each) were detected by gene expression microarray, and differentially expressed genes (DEGs) with fold change >2 were selected. DEGs were submitted to David and Metascape for gene function clustering, pathway and protein interaction network analysis. Finally, fluorescence quantitative PCR was performed to verify the changes in the expression levels of key DEGs in the high exposure group and the low exposure group (another 20 cases in each group) . Results: A total of 269 DEGs, of which 203 up regulated and 66 down regulated were identified in the differential expression analysis of gene expression microarray. Bioinformatics analysis suggested that, DEGs were involved in forebrain development, glial cell fate determinants of GO biological process and PID NF-KB, PTEN signal pathway. NFE2L1, SOX8, SOX6 and RNF2 (P<0.05) were confirmed down regulated in high level group by fluorescent quantitative PCR compared with the low level group (fold changes were 2.10, 11.52, 2.19, and 4.38 respectively) . Conclusion: The plasma NFE2L1, SOX8, SOX6 and RNF2 gene expressions are significantly altered in occupa tional high mercury exposure population. PTEN signaling pathway and fate of glia cells determines the biological process may be closely related to the body injury caused by mercury exposure.


Assuntos
Biologia Computacional , Mercúrio/efeitos adversos , Exposição Ocupacional/efeitos adversos , Biomarcadores , Análise por Conglomerados , Perfilação da Expressão Gênica , Humanos , Fator 1 Relacionado a NF-E2/sangue , Neuroglia/efeitos dos fármacos , PTEN Fosfo-Hidrolase/metabolismo , Complexo Repressor Polycomb 1/sangue , Fatores de Transcrição SOXD/sangue , Fatores de Transcrição SOXE/sangue , Transdução de Sinais
9.
J Hazard Mater ; 415: 125653, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088177

RESUMO

This research experiment was conducted to investigate the potential of Brevundimonas species IITISM22 to remove mercury by using live biomass of bacterial cells at 298, 308, and 318 K. Characterization of bio-sorbent was done by FT-IR and SEM-EDX. The prime functional groups accountable for binding Hg were OH, -NH2, -CH, -SH and -COO. The deformed bacterial structure was seen after Hg adsorption over the bacterial cell. Influences of different experimental factors, such as pH, temperature, contact time, Hg concentration, and biomass dose was examined. IITISM22 exhibited the highest Hg absorption at pH 6.5, contact time of 4 h, and showed an increased adsorption capacity while increasing the concentration of Hg. Kinetics were recommended by pseudo-second-order for adsorption process and isotherm was adequately defined by the Linear Langmuir isotherm model (KL) = 1.4, 1.2, 0.9 mg/l; (RL) = 0.020, 0.015, 0.013, respectively than Freundlich isotherm model. The Activation energy (Ea) of biosorption calculated were (131.10 KJ/mole) by using Arrhenius equation, and the thermodynamic parameters were ΔG⸰ (-41.03, -16.33, -16.12 KJ/mol), ΔH⸰ (-36.87 KJ/mol) and ΔS⸰ (-194.03 J/mol), respectively. These findings suggest that the removal process was based on chemisorption and the biosorption was exothermic. The result of the current experiment indicated that the IITISM22 could be an authentic biosorbent for Hg detoxification.


Assuntos
Mercúrio , Poluentes Químicos da Água , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
10.
J Hazard Mater ; 415: 125712, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088194

RESUMO

Mercury is an anthropogenic toxic heavy metal found in the environment. It is highly desirable to develop a fluorescence probe that can selectively and sensitively detect mercury ions using a turn-on response. This paper reports the successful development of a peptide fluorescence probe, TP-2 (TPE-Trp-Pro-Gln-His-Glu-NH2), which uses aggregation-induced emission effects and high selectivity to detect Hg2+. After fluorescence was activated, Hg2+ was efficiently detected using the change in fluorescence intensity. The detection limit for Hg2+ in the buffer solution was 41 nM (R2 = 0.9952). Owing to its high sensitivity, high cell permeability, and low biotoxicity, the probe could perform live cell imaging under biological conditions. This study demonstrated that TP-2 can detect Hg2+ in complex biological environments.


Assuntos
Mercúrio , Corantes Fluorescentes , Íons , Mercúrio/toxicidade , Peptídeos , Espectrometria de Fluorescência
11.
Mar Pollut Bull ; 168: 112426, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33940372

RESUMO

Mercury (Hg) is an important environmental indicator of anthropogenic pollution. In this study, the Hg content in the bottom sediments of the East Siberian Sea was observed to range from 13 to 92 ppb, with an average of 36 ppb. Facies dependence was also observed and expressed as an increase in the Hg concentration in fine-sized sediments on the shelf edge and continental slope, compared to that in the sandy silts and sands of the inner shelf. The Hg accumulation in bottom sediments of the eastern part has increased over the past 150 years due to an increase in global emissions of anthropogenic Hg, which is caused by the transboundary transport of Hg to the Arctic. Moreover, changes in the Hg value, which occur due to the plankton arriving at the bottom sediments because of changes in hydrology and primary production, are thought to be associated with global warming.


Assuntos
Mercúrio , Poluentes Químicos da Água , Regiões Árticas , Monitoramento Ambiental , Sedimentos Geológicos , Hidrologia , Mercúrio/análise , Poluentes Químicos da Água/análise
12.
Mar Pollut Bull ; 168: 112400, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33957494

RESUMO

Higher levels of persistent pollutants (Σ16PCB, Σ6PBDE, ΣHCH, ΣDDT, ΣCHL) were detected in fresh eggs of Common Terns Sterna hirundo from Rockabill Island near Dublin (Ireland's industrialised capital city) compared to Common and Arctic Terns S. paradisaea from Ireland's west coast. Intra-clutch variation of pollutant levels in Common Terns was shown to be low, providing further evidence that random sampling of one egg may be an appropriate sampling strategy. Significant differences in pollutant concentrations were detected between fresh and abandoned eggs on Rockabill. However, abandoned eggs can still provide a useful approximation of pollutants in bird eggs if non-destructive sampling is preferred. Levels of p,p' -DDE in tern eggs have decreased over time according to this study, in concurrence with worldwide trends. Results in this study fall below toxicological thresholds for birds and OSPARs EcoQO thresholds set for Common Tern eggs, except for mercury and HCH in the west coast.


Assuntos
Charadriiformes , Poluentes Ambientais , Mercúrio , Animais , Poluentes Ambientais/análise , Irlanda , Ilhas , Mercúrio/análise
13.
Mar Pollut Bull ; 168: 112408, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33965692

RESUMO

Mercury (Hg) concentrations have significantly increased in oceans during the last century. This element accumulates in marine fauna and can reach toxic levels. Seafood consumption is the main pathway of methylmercury (MeHg) toxicity in humans. Here, we analyzed total Hg (T-Hg) concentrations in two oceanic squid species (Ommastrephes bartramii and Thysanoteuthis rhombus) of an increasing commercial interest off Martinique, French West Indies. Stable isotope ratios reveal a negative linear relationship between δ15N or δ13C in diamondback squid samples. No significant trend was observed between δ34S values and T-Hg concentrations, contrasting with the sulfate availability and sulfide abundance hypotheses. This adds to a growing body of evidence suggesting Hg methylation via sulfate-reducing bacteria is not the main mechanism driving Hg bioavailability in mesopelagic organisms. All squid samples present T-Hg levels below the maximum safe consumption limit (0.5 ppm), deeming the establishment of a commercial squid fishery in the region safe for human consumption.


Assuntos
Cefalópodes , Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Região do Caribe , Monitoramento Ambiental , Humanos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oceanos e Mares , Poluentes Químicos da Água/análise , Índias Ocidentais
14.
Arch Environ Contam Toxicol ; 81(1): 25-35, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34027570

RESUMO

Dragonflies (Order Odonata) often are considered to be biosentinels of environmental contamination, e.g., heavy metals and/or persistent organic pollutants (POPs). Dragonflies (n = 439) belonging to 15 species of 8 genera were collected from an abandoned mercury (Hg) mining region in China to investigate the bioaccumulation of total Hg (THg) and methylmercury (MeHg). THg and MeHg concentrations in dragonflies varied widely within ranges of 0.06-19 mg/kg (average: 1.5 ± 2.2 mg/kg) and 0.02-5.7 mg/kg (average: 0.75 ± 0.65 mg/kg), respectively. THg and MeHg were positively correlated with bodyweight (THg: r2 = 0.10, P = 0.000; MeHg: r2 = 0.09, P = 0.000). Significant variations were observed among species, with the highest MeHg value (in Orthetrum triangulare) was fivefold higher than the lowest (in Pantala flavescens). These variations were consistent with those of nitrogen isotope (δ15N) values, indicating that increased δ15N, i.e., trophic levels, may reflect increased exposure and uptake of biomagnifying MeHg in dragonflies. A toxicological risk assessment found hazard quotients for specialist dragonfly-consuming birds of up to 7.2, which is 2.4 times greater than the permissible limit of 3, suggesting a potential toxicological risk of exposure.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Odonatos , Poluentes Químicos da Água , Animais , China , Monitoramento Ambiental , Cadeia Alimentar , Mercúrio/análise , Mineração , Poluentes Químicos da Água/análise
15.
Environ Pollut ; 283: 117397, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34030063

RESUMO

Hg is a global concern given its adverse effects on human health, food security and the environment, and it requiring actions to identify major local Hg sources and to evaluate pollution. Our study provides the first assessment of Hg stock trends on the entire Majorca surface, identifying major Hg sources by studying the spatiotemporal soil Hg variation at two successive times (2006 and 2016-17). The Hg soil concentration ranged from 14 to 258 µg kg-1 (mean 52 µg kg-1). Higher concentrations (over 100 µg kg-1) were found in two areas: (i) close to the Alcudia coal-fired power plant; (ii) in the city of La Palma. During the 11-year, the total Hg stock in Majorcan soil increased from 432.96 tons to 493.18 tones (14% increase). Based on a block kriging analysis, soil Hg enrichment due to power plant emissions was clearly detectable on a local scale (i.e. a shorter distance than 18 km from the power plant). Nonetheless, a significant island-wide Hg increase due to diffuse pollution was reported. This result could be extrapolated to other popular tourist destinations in the Mediterranean islands where tourism has increased in recent decades In short, more than 60 tons of Hg have accumulated on Majorca island in 11 years.


Assuntos
Mercúrio , Poluentes do Solo , Carvão Mineral/análise , Monitoramento Ambiental , Humanos , Ilhas , Ilhas do Mediterrâneo , Mercúrio/análise , Centrais Elétricas , Solo , Poluentes do Solo/análise , Espanha
16.
Chemosphere ; 274: 129959, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33979911

RESUMO

This work describes a novel fluorescent chemoprobe that uses carbon dots and silver nanoparticles (AgNPs) to monitor mercury ions in aqueous samples attributed to the principle of inner filter effect. The fluorescent response signal of the carbon dots is diminished by AgNPs, attributed to inner filter effect, and is restored with the addition of Hg2+. The fluorescent chemoprobe was specific over the range from 0.01 to 2.5 µM and a high sensitivity of 3.6 nM. The chemoprobe was validated using real local aqueous samples, and the spike recoveries of 97.4%-103% were excellent and satisfied. The data indicated that the developed fluorescent chemoprobe was sensitive, selective, stable and reliable. This fluorescent chemoprobe provides a sensitive tool with broad prospects for mercury detection in aqueous samples and the work will offer ideas for designing and constructing novel fluorescent probes.


Assuntos
Mercúrio , Nanopartículas Metálicas , Pontos Quânticos , Carbono , Corantes Fluorescentes , Prata
17.
J Hazard Mater ; 414: 125529, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34030407

RESUMO

Atmospheric Hg is a highly toxic heavy metal with bioaccumulative properties. However, relatively few studies have focused on the distribution of Hg in cellular and subcellular structures of plants and factors influencing its accumulation. In this study, we selected Tillandsia usneoides, which is a widely used bioindicator for Hg, to analyze the concentration of Hg in different cells (foliar trichomes, epidermal cells, mesophyll cells, and vascular bundle cells), different subcellular structures (cell wall, cell membrane, vacuoles, and organelles) and different cell wall components (pectin, hemicellulose 1, and hemicellulose 2). It was determined that Hg was present in different types of cells, but there was no significant difference, suggesting that atmospheric Hg circulates dynamically in the surface and internal structural cells of T. usneoides leaves. Subcellular analysis showed that as Hg concentration increased, more Hg accumulated in the vacuoles and cell wall through the compartmentalization mechanism. Hemicellulose had the highest content of Hg, indicating that it is the primary Hg-binding component of the cell wall. The FTIR analysis results showed that after the Hg treatment, the cell wall -OH and COO- absorption peaks changed most significantly, indicating that these functional groups play a vital role in the Hg accumulation process.


Assuntos
Mercúrio , Tillandsia , Folhas de Planta
18.
Food Chem ; 358: 129844, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33940287

RESUMO

Considering food safety and limitations of biorecognition elements, this study focused on the development of a novel method for predicting mercury (Hg2+) in fish and water samples using surface-enhanced Raman scattering (SERS) coupled wavenumber selection chemometric method. Herein, core-shell Au@Ag nanoparticles (Au@Ag NPs) were synthesized as SERS substrate, and rhodamine 6G (R6G) was used as signaling probe for Hg2+. In the presence of Hg2+, citrate ion of Au@Ag NPs induced complexation and become amalgam causes desorption of R6G occurred, resulted in decreased SERS signal intensity. Compared to surface Plasmon resonance method, SERS coupled genetic algorithm-partial least squares realized good correlation coefficient (0.9745 and 0.9773) in their prediction over the concentration ranges 1.0 × 102 to 1.0 × 10-3 µg/g. The recovery (88.45 - 94.73%) and precision (coefficient of variations, 3.28 - 5.76%) exhibiting satisfactory results suggested that the proposed method could be employed to predict Hg2+ in fish and water samples towards quality and safety monitoring.


Assuntos
Análise de Alimentos , Mercúrio/análise , Nanopartículas Metálicas/química , Rodaminas/química , Análise Espectral Raman/métodos , Calibragem , Ouro , Prata , Ressonância de Plasmônio de Superfície
19.
Nat Commun ; 12(1): 3035, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031414

RESUMO

Mercury is a potent neurotoxin that poses health risks to the global population. Anthropogenic mercury emissions to the atmosphere are projected to decrease in the future due to enhanced policy efforts such as the Minamata Convention, a legally-binding international treaty entered into force in 2017. Here, we report the development of a comprehensive climate-atmosphere-land-ocean-ecosystem and exposure-risk model framework for mercury and its application to project the health effects of future atmospheric emissions. Our results show that the accumulated health effects associated with mercury exposure during 2010-2050 are $19 (95% confidence interval: 4.7-54) trillion (2020 USD) realized to 2050 (3% discount rate) for the current policy scenario. Our results suggest a substantial increase in global human health cost if emission reduction actions are delayed. This comprehensive modeling approach provides a much-needed tool to help parties to evaluate the effectiveness of Hg emission controls as required by the Minamata Convention.


Assuntos
Atmosfera/análise , Saúde Global , Mercúrio/análise , Clima , Ingestão de Alimentos , Ecossistema , Meio Ambiente , Monitoramento Ambiental , Política Ambiental , Avaliação do Impacto na Saúde , Humanos , Cooperação Internacional , Mercúrio/efeitos adversos , Neurotoxinas
20.
Sci Total Environ ; 787: 147374, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34045077

RESUMO

Beginning in the late-1800s, gold mining activities throughout Nova Scotia, eastern Canada, released contaminants, notably geogenic arsenic from milled ore and anthropogenic mercury from amalgamation, to local environments via surface water flows through tailings fields. We investigated recovery from and legacy effects of the tailings field at the Montague Gold District (~1863-1940) on nearby urban lake ecosystems using geochemical measures and zooplankton remains archived in dated sediment cores from an impact (Lake Charles) and a reference (Loon Lake) lake. Sedimentary levels of total arsenic and total mercury were used to assess mining-related inputs. Arsenic concentrations remain elevated at nearly 300 times above sediment guidelines in Lake Charles surface sediments, due to its upward mobilization from enriched sediment intervals and sequestration by iron oxyhydroxides in surficial sediments. Peak mercury concentrations at Lake Charles were eight times above sediment guidelines during the mining period, and since ~1990 have recovered to levels observed before mining began. Legacy mining impacts at Lake Charles and non-mining related environmental changes in the post-1950 sediments at both lakes have thus combined to structure assemblage compositions of primary consumers. At both lakes, assemblages of pelagic-dominated Cladocera differed (p ≤ 0.05) during the mining period compared to periods before and after mining. Taxon richness differed (p ≤ 0.01) only between the pre- and post-mining periods at mining-impacted Lake Charles and reflects long-term declines of substrate-dwelling littoral taxa. Geochemical and biological recovery have not completely occurred at Lake Charles despite the mine district's closure ~80 years ago. Our findings demonstrate that impacts of ore processing and amalgamation from historical gold mining, combined with recent watershed stressors, continue to affect sedimentary arsenic geochemistry and intermediate trophic levels of nearby, downstream aquatic habitats.


Assuntos
Arsênio , Mercúrio , Poluentes Químicos da Água , Arsênio/análise , Ecossistema , Biomarcadores Ambientais , Monitoramento Ambiental , Sedimentos Geológicos , Ouro , Mineração , Nova Escócia , Poluentes Químicos da Água/análise
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