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1.
ACS Appl Mater Interfaces ; 13(27): 31710-31724, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34213303

RESUMO

In this study, we have designed a three-fluorophore-labeled Y-shaped DNAzyme with a high catalytic cleavage activity and a three-dimensional (3D) MOF-MoS2NB (metal-organic framework fused with molybdenum disulfide nanobox), which was synthesized as an efficient quencher of the fluorescent biosensor. The synthesized porous 3D MOF-MoS2NBs and Y-shaped DNAzyme exhibited a good analytical response toward the simultaneous multiple detections of Hg2+, Ni2+, and Ag+ ions over the other coexisting metal ions. More specifically, the three kinds of enzyme aptamer and substrate aptamer (SA) were hybridized and annealed to form the Y-shaped DNAzyme structure and labeled with three different fluorophores such as FAM, TAMRA, and ROX over the 3'-end of SA. When the targets were induced, the DNAzyme was triggered to cleave the fluorophore-labeled SAs. Then, the cleaved SAs (FAM-SA, TAMRA-SA, and ROX-SA) were adsorbed on the 3D MOF-MoS2NB surface to quench the fluorescence signal due to a noncovalent interaction (van der Waals and π-π stacking interaction), which transmuted the fluorescence on-state to off-state. As a result, the fluorescence assay confiscated the high selectivity and sensitivity for the target analytes of Hg2+, Ni2+, and Ag+ ions achieved for the detection limits of 0.11 nM, 7.8 µM, and 0.25 nM, respectively. Accordingly, the sensitivity of the developed sensor was explored with a better lower detection limit than the previously reported biosensors. The utility of the designed Y-shaped DNAzyme may find a broad field of application in real water sample analysis with interfering contaminants.


Assuntos
Biocatálise , Técnicas Biossensoriais/métodos , DNA Catalítico/metabolismo , Dissulfetos/química , Corantes Fluorescentes/química , Estruturas Metalorgânicas/química , Metais Pesados/análise , Molibdênio/química , Adsorção , Catálise , DNA Catalítico/química , Limite de Detecção , Mercúrio/análise , Níquel/análise , Prata/análise
2.
Environ Monit Assess ; 193(8): 499, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34291327

RESUMO

Mercury in the Arctic originates from emissions and releases at lower latitudes and, to a lesser extent, from local and regional sources. The relationship between mercury (Hg) and polycyclic aromatic hydrocarbons (PAHs) in sediment can be applied as an indicator of the mercury source. This research examines the Hg contamination gradient from a land-based coal mine to the surrounding coastal environment to quantify the impact of local sources. Total mercury and PAH (Σ14PAH) were measured in terrestrial and marine sediments as well as in marine biota. Samples were collected at the mine and two reference sites. Mercury and Σ14PAH concentrations in samples collected at the mine site were significantly higher than those at the reference sites. This was also found in the biota samples, although less pronounced. This work addresses the complexities of interpreting data concerning very low contaminant levels in a relatively pristine environment. A clear correlation between PAH and Hg concentration in sediment was found, although a large number of samples had levels below detection limits. PAH profiles, hierarchical clustering, and molecular diagnostic ratios provided further insight into the origin of PAHs and Hg, showing that signatures in sediments from the nearest reference site were more similar to the mine, which was not the case for the other reference site. The observed exposure radius from the mine was small and diluted from land to water to marine biota. Due to low contamination levels and variable PAH profiles, marine biota was less suitable for tracing the exposure radius for this local land-based Hg source. With an expected increase in mobility and availability of contaminants in the warming Arctic, changes in input of PAHs and Hg from land-based sources to the marine system need close monitoring.


Assuntos
Mercúrio , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Regiões Árticas , Carvão Mineral , Monitoramento Ambiental , Sedimentos Geológicos , Mercúrio/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Rádio (Anatomia)/química , Poluentes Químicos da Água/análise
3.
Environ Monit Assess ; 193(8): 498, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34287720

RESUMO

Despite the general lack of studies that use reptiles as bioindicators, the value of freshwater turtles and crocodilians in ecotoxicology has been proven, due to their importance as sentinel species. The aim of this study was to compile information on the use of freshwater turtles and crocodilians as environmental biomonitors of inorganic element contamination. We searched for articles in databases using specific keywords. A total of 104 studies published between the years 1970 and 2020 were collected. We noted a general increase in the number of studies involving turtles and crocodilians during the study time period. The Order Testudines were the subjects of 46% of the analysed publications, and the Order Crocodylia accounted for 54%. Within these studies, we counted 39 species (turtles n = 29 and crocodilians n = 10). Forty chemical elements were evaluated in the analysed articles, of which the majority represented non-essential elements (Hg, Cd, Pb). Although internal organs constituted the main biological matrix chosen for each group (37%), we observed an increase in the use of non-destructive matrices in both groups (scale, blood, tail muscle, carapace). The majority of analysed studies used HNO3 for the sample decomposition, with the majority of analyses being performed using atomic absorption spectroscopy (53%). Mainly blank controls (19%), analyte recovery (18%) and replicates (18%) were used as methods of validating analytical procedures. Furthermore, the studies used certified reference materials, which measure the accuracy of the methods used. We conclude that the increase in the use of aquatic reptiles in environmental monitoring research is mainly due to their ability to reveal integrated changes in ecosystems, aiding in environmental public policy decision-making and effective management plans.


Assuntos
Mercúrio , Tartarugas , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Água Doce , Mercúrio/análise , Poluentes Químicos da Água/análise
4.
Cien Saude Colet ; 26(6): 2253-2270, 2021 Jun.
Artigo em Português | MEDLINE | ID: mdl-34231736

RESUMO

This study aimed to review studies of human biomonitoring (HBM) that evaluated exposure to lead (Pb), cadmium (Cd), mercury (Hg), nickel (Ni), arsenic (As) and manganese (Mn) in adults living close to industrial areas. A systematic review of studies was selected, without initial date limit through to December 2017, from the MEDLINE and BVS databases. Original studies in English, Portuguese or Spanish conducted among the adult population using blood and/or urine as biomarkers were included. The articles were evaluated according to methodological criteria, including studies with comparison groups and/or probabilistic sampling. Of the 28 studies selected, 54% were conducted in Europe, 36% in Asia, 7% in North America and 4% in Africa. Foundries, metal works and steel mills were the most frequently studied. Urine and blood were used in 82% and 50% of studies, respectively. The elements most investigated were Cd, Pb and As. Despite using heterogeneous methodologies, the results revealed higher metal concentrations, especially from As and Hg in general, than in the comparison group. This review highlights the need for more rigorous methodological studies of HBM, stressing the importance of public health vigilance among populations exposed to toxic metals, especially in developing countries.


Assuntos
Arsênio , Mercúrio , Adulto , Arsênio/análise , Cádmio/análise , Monitoramento Ambiental , Europa (Continente) , Humanos , Chumbo/análise , Mercúrio/análise
5.
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
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.
Artigo em Inglês | MEDLINE | ID: mdl-34068268

RESUMO

The biomonitoring of atmospheric mercury (Hg) is an important topic in the recent scientific literature given the cost-benefit advantage of obtaining indirect measurements of gaseous Hg using biological tissues. Lichens, mosses, and trees are the most commonly used organisms, with many standardized methods for some of them used across European countries by scientists and pollution regulators. Most of the species used the uptake of gaseous Hg (plant leaves), or a mixture of gaseous and particulate Hg (mosses and lichens), but no method is capable of differentiating between main atmospheric Hg phases (particulate and gaseous), essential in a risk assessment. The purpose of this work was to evaluate different uptake patterns of biological tissues in terms of atmospheric Hg compounds. To accomplish this, the feasibility of two plant tissues from a tree commonly found in urban environments has been evaluated for the biomonitoring of gaseous Hg species in a Hg mining environment. Sampling included leaves and barks from Platanus hispanica and particulate matter from the atmosphere of the urban area around Almadén (south-central Spain), while analytical determinations included data for total Hg concentrations in biological and geological samples, Hg speciation data and total gaseous Hg (TGM). The results allowed us to identify the main Hg compounds in leaves and bark tissues and in atmospheric particulate matter, finding that leaves bioaccumulated only gaseous Hg (Hg0 and Hg2+), preferably during daylight hours, whereas the barks accumulated a combination of TGM and particulate bound Hg (PBM) during the day and at night. Subsequent merging of the atmospheric Hg speciation data obtained from leaves and barks allowed indicative maps of the main sources of TGM and PBM emissions to be obtained, thereby perfectly delimiting the main TGM and PBM sources in the urban area around Almadén. This method complements TGM biomonitoring systems already tested with other urban trees, adding the detection of PBM emission sources and, therefore, biomonitoring all Hg species present in the atmosphere. Scenarios other than mining sites should be evaluated to determine the utility of this method for Hg biospeciation in the atmosphere.


Assuntos
Poluentes Atmosféricos , Mercúrio , Poluentes Atmosféricos/análise , Monitoramento Biológico , Monitoramento Ambiental , Europa (Continente) , Mercúrio/análise , Casca de Planta/química , Espanha
8.
Artigo em Inglês | MEDLINE | ID: mdl-34068387

RESUMO

Total mercury (Hg) was determined in 450 environmental samples (seawater, sediment plant and fish) from five Mahdia coastal areas (Tunisia). Tolerable Weekly Intake% (TWI) values, according to the European Food Safety Authority (EFSA), were calculated based on the average metal concentration in fish and the average weekly fish consumption rate. Hg was accumulated mainly in fish and in Posidonia oceanica leaves. Hg in sediment ranged from 1.88 µg/kg dry weight (d.w.) to 7.48 µg/kg d.w., while it was between 0.32 µg/kg and 0.19 µg/kg in seawaters. Our study showed high concentration in Posidonia oceanica in S3 (plant = 16.76 ± 4.48 µg/kg d.w.) as compared to those in S4 sites (plant = 5.33 ± 0.05 µg/kg d.w.). Concentrations for S. aurata and S. salpa in the Rejiche area exceeded the EC 1881/2006 legislation with values of 1.9 mg/kg and 2.5 mg/kg, respectively, and consumers may be exposed to high concentrations of Hg that exceeds the EFSA. The results showed that the fish species should be constantly monitored due to their TWI% of 154.5% for S. aurata and 209.8% S. salpa respectively.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Peixes , Mercúrio/análise , Tunísia , Poluentes Químicos da Água/análise
9.
Water Sci Technol ; 83(12): 2921-2930, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34185689

RESUMO

Hg(II) ions in wastewater are highly toxic to the environment and human health, yet many materials to remove the ions exhibit lower adsorption efficiency, and few studies report the reuse of Hg(II)-loaded waste materials. Here, a cheap and efficient adsorbent was prepared for the removal of Hg(II) based on corn bracts (CB) loading copper sulfide (CuS), and the Hg(II)-adsorbed material was reused as a photocatalyst. By changing the adsorption variables such as pH, adsorbent dosage, Hg(II) concentration, contact time and coexisting ions, the optimum adsorption conditions were obtained. The study indicated the adsorption capacity and removal rate of CB/CuS reached 249.58 mg/g and 99.83% at pH 6 with 20 mg CB/CuS, 50 mL Hg(II) concentration (100 mg/L) and 60 min, and coexisting ions did not affect the uptake of Hg(II). The adsorption behavior of CB/CuS toward Hg(II) followed pseudo-second-order and Langmuir models, with the theoretical maximum adsorption capacity of 316.46 mg/g. Finally, we explored an alternative strategy to dispose of spent adsorbents by converting the CB/CuS/HgS into a photocatalyst for the degradation of rhodamine B, with a removal rate of 98%. Overall, this work not only develops a promising material for the treatment of Hg(II)-containing wastewater, but opens up a new approach for the use of the waste adsorbent.


Assuntos
Mercúrio , Poluentes Químicos da Água , Adsorção , Cobre , Humanos , Concentração de Íons de Hidrogênio , Cinética , Mercúrio/análise , Sulfetos , Poluentes Químicos da Água/análise , Zea mays
10.
Chemosphere ; 280: 130654, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34162069

RESUMO

Mercury (Hg(II)) is the 16th rarest element present in the earth's crust. Due to rapid industrialization and urban expansions, the mercury concentration has been elevated in the environment. Hg(II) contamination in the aqueous environment has become a great challenge for human beings. The main source of Hg(II) in the aqueous phase is untreated effluent industries (such as the paper industry). Hg(II) is non-biodegradable in nature and even its trace amount in an aqueous environment can pose chronic threats among the humans (damage to the central nervous system, respiratory system, and cardiovascular system, mutation of DNA), animals, and aquatic creatures. Therefore, the removal of mercury from aqueous solutions is an urgent need of the modern era. The conventional techniques such as ion exchange, precipitation, membrane filtrations are costly and also generate byproducts in the environment. Bioremediation is a sustainable, environmentally sound, and cost-effective technique to remove Hg(II) from the aqueous solutions. In this process, naturally occurring microorganisms are utilized to remove the Hg(II) from the aqueous solutions. Lentinus edodes, U. lactuca, and Typha domingensis are found to have great potential to remove mercury from water ranged from ~100 mg g-1 to 337 mg g-1.


Assuntos
Mercúrio , Poluentes Químicos da Água , Purificação da Água , Animais , Biodegradação Ambiental , Humanos , Concentração de Íons de Hidrogênio , Mercúrio/análise , Soluções , Água
11.
Anal Chem ; 93(23): 8257-8264, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34077178

RESUMO

Despite increased interest in microplasma-induced vapor generation (µPIVG) over the past several years, applications in real sample analyses remain limited due to their relatively low vapor generation efficiency and ambiguous mechanism. In this work, a novel method using methanol for significantly enhancing the liquid electrode discharge µPIVG efficiency was developed for the simultaneous and sensitive determination of Hg, Cd, and Zn by atomic fluorescence spectrometry (AFS). It is worth noting that the possible enhancement mechanism was investigated via the characterizations of volatile products by AFS, microplasma optical emission spectrometry, online gas chromatography, and gas chromatography-mass spectrometry, which involved the reductive species such as electrons, hydrogen radicals (·H), methyl radicals (·CH3), and other intermediates in the argon plasma adding methanol. Under the optimized conditions, the limits of detection of 0.007, 0.05, and 0.5 µg L-1 were obtained for Hg, Cd, and Zn, respectively, with relative standard deviations of 3.1, 3.7, and 5.2% for these elements, respectively. Vapor generation efficiencies of 90, 83, and 55% were achieved for Hg, Cd, and Zn, respectively, and improved 2.7-, 4.8-, and 7.9-fold, respectively, compared to those obtained in the absence of methanol. The accuracy and practicability of the proposed method were validated by the determination of Hg, Cd, and Zn in a certified reference material (CRM, Lobster hepatopancreas, TORT-3) and crayfish samples collected from three different provinces of China.


Assuntos
Cádmio , Mercúrio , Cádmio/análise , China , Eletrodos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Mercúrio/análise , Metanol , Alta do Paciente , Zinco
12.
Ecotoxicol Environ Saf ; 220: 112404, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111660

RESUMO

Cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and arsenic (As) are potent toxicants to human health via dietary intake. It is imperative to establish accurate soil thresholds based on soil-plant transfer models and food safety standards for safe agricultural production. This study takes rice genotypes and soil properties into account to derive soil thresholds for five heavy metal(loid)s using the bioconcentration factors (BCF) and species sensitivity distribution (SSD) based on the food safety standard. The BCF generated from two paddy soils was calculated to investigate the sensitivity of heavy metal accumulation in nine rice cultivars in a greenhouse pot experiment. Then, empirical soil-plant transfer models were developed from a middle-sensitivity rice cultivar (Denong 2000, one selected from nine rice) grown in nineteen paddy soils with various soil properties under a proper exogenously metal(loid)s concentration gradient. After normalization, hazardous concentrations from the fifth percentile (HC5) were calculated from the SSD curves, and the derived soil thresholds were obtained from HC5 prediction models that based on the combination of pH and organic carbon (OC) or cation exchange capacity (CEC). The soil Cd threshold derived based on pH and organic carbon (pH < 7.5, OC ≥ 20 g kg-1) was 1.3-fold of those only considering pH, whereas the Pb threshold (pH > 6, CEC ≥ 20 cmolc kg-1) was 3.1 times lower than the current threshold. The derived thresholds for five elements were validated to be reliable through literature data and field experiments. The results suggested that deriving soil heavy metal(loid)s threshold using SSD method and local food safety standards is feasible and also applicable to other crops as well as other regions with potential health risks of toxic elements contamination in agricultural production.


Assuntos
Metais Pesados/normas , Oryza/crescimento & desenvolvimento , Poluentes do Solo/normas , Solo/normas , Arsênio/análise , Arsênio/normas , Cádmio/análise , Cádmio/normas , Cromo/análise , Cromo/normas , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/normas , Inocuidade dos Alimentos , Humanos , Chumbo/análise , Chumbo/normas , Mercúrio/análise , Mercúrio/normas , Metais Pesados/análise , Oryza/química , Oryza/genética , Solo/química , Poluentes do Solo/análise
13.
Ecotoxicol Environ Saf ; 220: 112354, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34116335

RESUMO

Hydropower generation, a renewable source of electricity, has been linked to elevated methylmercury (MeHg) concentrations in impoundments and aquatic biota. This study investigates the impact of water level fluctuations (WLF) on MeHg concentrations in water, sediment, and fish. Using a set of controlled microcosm experiments emulating the drawdown/refill dynamics and subsequent sediment exposure to air experienced in reservoirs, we demonstrate that less frequent WLFs, and/or increased exposure of sediment to air, can lead to elevated MeHg concentrations in sediment, and total mercury (THg) and MeHg concentrations in water. In examining the effects of WLF frequency (two-day, weekly, and monthly), the monthly treatment displayed the highest THg and MeHg water levels, while the weekly treatment was characterized by the highest MeHg levels in the sediment. Our work supports emerging evidence that longer duration between WLF creates a larger surface area of sediment exposed to air leading to conditions conducive to higher MeHg concentrations in sediments and water. In contrast, THg, MeHg, and fatty acid trends in fish were largely inconclusive characterized by similar among-treatment effects and minimal temporal variability over the course of our experiment. This result could partly be attributed to overall low mercury levels and simple "worm-forage fish" food web in our experiment. To elucidate the broader impacts of water fluctuations on aquatic chemistry and biota, other factors (e.g., longer WLF cycles, dissolved organic matter, temperature, more complex food webs) which modulate both methylation rates and food web dynamics must be considered.


Assuntos
Mercúrio/análise , Movimentos da Água , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Peixes/metabolismo , Cadeia Alimentar , Sedimentos Geológicos/química , Compostos de Metilmercúrio/análise , Água/química
14.
Molecules ; 26(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073792

RESUMO

This research aimed at developing an analysis method, which was optimized and validated to determine the content of mercury in skin lightening cream discovered in the market in Bandar Lampung, Indonesia, through the use of microwave plasma atomic emission spectroscopy (MP-AES). The optimization on the analysis method was conducted on pump rate, viewing position, and reductant concentration in order to obtain the highest mercury emission intensity, while the solution stability was optimized to know the stability of mercury in the solution. The result showed that the method developed had precision with a relative standard deviation of 2.67%, recovery value of 92.78%, and linearity with an r value of 0.993, respectively. The sensitivity of the instrument detection had a limit of analysis method detection and quantification of 0.59 and 1.98 µg/L, respectively. The results of the test of the lightening cream (8 of 16 samples) positively contained mercury in the range of 422.61-44,960.79 ng/g. Therefore the method of analysis developed may be used for routine analysis of chemicals in any cosmetics products.


Assuntos
Mercúrio/análise , Creme para a Pele/química , Preparações Clareadoras de Pele/química , Espectrofotometria Atômica/métodos , Limite de Detecção , Reprodutibilidade dos Testes
15.
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
16.
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
17.
Environ Sci Process Impacts ; 23(5): 756-775, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33970175

RESUMO

The goal of this project was to assess how anthropogenic legacy mercury (Hg) retained in streambed sediment may be remobilized to stream water. To do this, we performed sequential extractions and Hg isotope analyses on streambed sediment collected along the length of East Fork Poplar Creek, a point-source contaminated stream in Oak Ridge, Tennessee, USA. Legacy Hg within streambed sediment appears to have been isotopically fractionated by equilibrium isotope effects driven by isotope exchange between co-existing Hg(0) and Hg(ii) species, potentially over-printing fractionation patterns that would have been imparted by kinetic redox reactions. Weakly-bound and recalcitrant sediment Hg pools were isotopically similar to one another, suggesting that small amounts of recalcitrant Hg may be released and then rapidly and weakly re-adsorbed onto the sediment. This weakly-bound Hg pool appears to contribute dissolved Hg to the hyporheic pore water, which may subsequently enter the surface flow. The isotopic composition of the organically-bound sediment Hg pools, as well as biofilm and suspended particulates, converged with that of the weakly-bound and recalcitrant sediment Hg pools along the flow path. This appears to be indicative of both physical mixing with streambed sediment and the transfer of weakly-bound sediment Hg into biofilm and suspended particulates, followed by re-incorporation into the organically-bound sediment Hg pool. Overall, these results provide evidence that legacy Hg in the streambed is remobilized, enters the stream water as dissolved Hg, and may be incorporated into streambed biofilm, which constitutes a basal resource within the stream ecosystem.


Assuntos
Mercúrio , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Sedimentos Geológicos , Isótopos , Mercúrio/análise , Tennessee , Poluentes Químicos da Água/análise
18.
Sci Total Environ ; 779: 146261, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34030265

RESUMO

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change and intensive land-use practices (e.g. forest clear-cutting and peatland ditching), processes that potentially increase leaching of peat- and soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) to top consumers (piscivorous fish), in 19 subarctic lakes situated on a latitudinal (69.0-66.5° N), climatic (+3.2 °C temperature and +30% precipitation from north to south) and catchment land-use (pristine to intensive forestry areas) gradient. We first tested how the joint effects of climate and productivity influence mercury biomagnification in food webs focusing on the trophic magnification slope (TMS) and mercury baseline (THg baseline) level, both derived from linear regression between total mercury (log10THg) and organism trophic level (TL). We examined a suite of environmental and biotic variables thought to explain THg baseline and TMS with stepwise generalized multiple regression models. Finally, we assessed how climate and lake productivity affect the THg content of top predators in subarctic lakes. We found biomagnification of mercury in all studied lakes, but with variable TMS and THg baseline values. In stepwise multiple regression models, TMS was best explained by negative relationships with food chain length, climate-productivity gradient, catchment properties, and elemental C:N ratio of the top predator (full model R2 = 0.90, p < 0.001). The model examining variation in THg baseline values included the same variables with positive relationships (R2 = 0.69, p = 0.014). Mass-standardized THg content of a common top predator (1 kg northern pike, Esox lucius) increased towards warmer and more productive lakes. Results indicate that increasing eutrophication via forestry-related land-use activities increase the THg levels at the base of the food web and in top predators, suggesting that the sources of nutrients and mercury should be considered in future bioaccumulation and biomagnification studies.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Bioacumulação , Fatores Biológicos , Ecossistema , Monitoramento Ambiental , Peixes , Cadeia Alimentar , Lagos , Mercúrio/análise , Poluentes Químicos da Água/análise
19.
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
20.
Huan Jing Ke Xue ; 42(6): 3018-3027, 2021 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-34032102

RESUMO

To ascertain the impact of mercury mining on the surrounding soil environment and human health, 42 surface soil composite samples were collected around a mercury mining area in Youyang County, Chongqing, and the heavy metals (Cd, Hg, Pb, As, Cr, Cu, Zn, and Ni) contents and pH of the soil, the spatial distribution of heavy metals, pollution degree, and ecological risk were studied. The results show that the surface soil layer in the study area is significantly enriched in heavy metals. According to the soil environmental quality risk control standard for soil contamination of agricultural land (GB15618-2018), soil Cd, Hg, Pb, As, and Zn showed different degrees of excess. A certain degree of pollution and ecological risk was also identified in the studied soil. Moderate-to-severe pollution and strong ecological risk areas are distributed around the mining sites, indicating the impact of mining activities on the soil environment. The content of Cr, Cu, and Ni in the soil may be affected by weathering and soil formation from the parent rock; Hg, Pb, and Zn content may be affected by human activities such as mineral mining; and Cd and As content may be affected by both geological processes and human activities. Heavy metals pose less of a health risk for adults but have a greater probability of causing health risks for children. Soil As is the main contributor to human health risks, and the oral intake of the eight heavy metals has the highest contribution rate. The mining of mercury is the main cause of soil pollution and ecological risk in the study area.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Criança , China , Monitoramento Ambiental , Poluição Ambiental/análise , Humanos , Mercúrio/análise , Metais Pesados/análise , Mineração , Medição de Risco , Solo , Poluentes do Solo/análise
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