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Registros recuperados: 106
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A description of mercury in fishes from the Madeira River Basin, Amazon, Brazil Acta Amazonica
Bastos,Wanderley Rodrigues; Rebelo,Mauro de Freitas; Fonseca,Márlon de Freitas; Almeida,Ronaldo de; Malm,Olaf.
Over the last 20 years several projects carried on the Madeira River basin in the Amazon produced a great amount data on total Hg concentration in different fish species. In this paper we discuss temporal trends in Hg contamination and its relation to body weight in some of those fishes, showing that even within similar groups, such as carnivorous and non-migratory fish, the interspecies variability in Hg accumulation is considerable.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Fish; Mercury; Biomagnification; Madeira River; Amazon.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672008000300006
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A first evaluation on the use of Ardea albus feathers as bioindicators of mercury burden in Amazonian ecosystems Acta Amazonica
Gomes,Andreza Lourdes; Vieira,José Luiz Fernandes; Pinheiro,Maria da Conceição Nascimento; Marceliano,Maria Luiza Videira.
We evaluated in this study the total mercury concentration in feathers of Ardea albus collected in a colony located in the city of Belem-PA, Brazil in a prospective trial for its use as bioindicators of mercury burden in Amazonia ecosystems. An Atomic absorption spectrophotometry with gold amalgamation was used for the metal determination. The total mercury average concentration in body feathers was 2.2 ± 1.5 µg.g-1 and 1.3 ± 0.9 µg.g-1 in wing feathers. No correlation was observed between total mercury concentration and the length of body or wing feathers. Total mercury concentration was above 5 µg.g-1 dry weight in only one body feather sample.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Mercury; Ardea albus; Birds; Feathers; Environmental.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672009000400025
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A Michaelis–Menten type equation for describing methylmercury dependence on inorganic mercury in aquatic sediments ArchiMer
Cossa, Daniel; Garnier, Cedric; Buscail, Roselyne; Elbaz-poulichet, Francoise; Mikac, Nevenka; Patel-sorrentino, Nathalie; Tessier, Erwan; Rigaud, Sylvain; Lenoble, Veronique; Gobeil, Charles.
Methylation of mercury (Hg) is the crucial process that controls Hg biomagnification along the aquatic food chains. Aquatic sediments are of particular interest because they constitute an essential reservoir where inorganic divalent Hg (HgII) is methylated. Methylmercury (MeHg) concentrations in sediments mainly result from the balance between methylation and demethylation reactions, two opposite natural processes primarily mediated by aquatic microorganisms. Thus, Hg availability and the activity of methylating microbial communities control the MeHg abundance in sediments. Consistently, some studies have reported a significant positive correlation between MeHg and HgII or total Hg (HgT), taken as a proxy for HgII, in aquatic sediments using...
Tipo: Text Palavras-chave: Mercury; Methylmercury; Aquatic sediment; Methylation; Demethylation.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00171/28220/26520.pdf
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Accumulation versus remobilization of mercury in sediments of a contaminated lagoon IPB - Escola Superior Agrária
Ramalhosa, Elsa; Pato, P.; Monterroso, Paulo; Pereira, Eduarda; Vale, C.; Duarte, A.C..
This work discusses the extent of sediment mercury retention in the most contaminated sites in the lagoon, and its exportation to the water column as well as transfer to biogenic suspended particles and to sea bass (Dicentrarchus labrax). Therefore,the main question, with important environmental management implications, was to assess if mercury is effectively retained in the sediments or is progressively released to the water column in considerable amounts.
Tipo: Article Palavras-chave: Mercury; Sediments; Accumulation; Remobilization.
Ano: 2006 URL: http://hdl.handle.net/10198/3956
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Allocation of CO2 Emissions Allowances in the Regional Greenhouse Gas Cap-and-Trade Program AgEcon
Burtraw, Dallas; Palmer, Karen L.; Kahn, Danny.
Cap-and-trade programs for air emissions have become the widely accepted, preferred approach to cost-effective pollution reduction. One of the important design questions in a trading program is how to initially distribute the emissions allowances. Under the Acid Rain program created by Title IV of the Clean Air Act, most emissions allowances were distributed to current emitters on the basis of a historic measure of electricity generation in an approach known as grandfathering. Recent proposals have suggested two alternative approaches: allocation according to a formula that is updated over time according to some performance metric in a recent year (the share of electricity generation or something else) and auctioning allowances to the highest bidders....
Tipo: Working or Discussion Paper Palavras-chave: Emissions trading; Allowance allocations; Electricity; Air pollution; Auction; Grandfathering; Generation performance standard; Output-based allocation; Cost-effectiveness; Greenhouse gases; Climate change; Global warming; Carbon dioxide; Sulfur dioxide; Nitrogen oxides; Mercury; Environmental Economics and Policy; Q2; Q25; Q4; L94.
Ano: 2005 URL: http://purl.umn.edu/10650
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Amazonian former gold mined soils as a source of methylmercury: Evidence from a small scale watershed in French Guiana ArchiMer
Guedron, Stephane; Grimaldi, Michel; Grimaldi, Catherine; Cossa, Daniel; Tisserand, Delphine; Charlet, Laurent.
Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L-1 and 1.84 ng g(-1), respectively) and sharply increased at the...
Tipo: Text Palavras-chave: Mercury; Methylmercury; Tropical watershed; Gold placers; Stream water; Oxisols; Hydromorphic soils.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00035/14628/12134.pdf
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An automated method for the assessment of mercury adsorption rates on particulate suspended matter OMA
Baeyens, W.F.J.; Decadt, G.; Dehairs, F.A.; Goeyens, L..
A continuous filtration system connected to a mercury auto-analyzer has been constructed for obtaining mercury adsorption rates on particulate suspended matter. The capabilities of this device have been demonstrated by carrying out a series of experiments under controlled physicochemical parameter conditions on samples of the Scheldt estuary. Duplicate measurements showed coefficients of variation ranging from 1 to 6 %. Depending on the physico-chemical conditions, the initial adsorption rate per unit of dissolved mercury concentration varied between 1.2 and 8.1 x 10<sup>-2</sup> mn<sup>-1</sup>.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Adsorption; Mercury; Methodology; Particulates; Suspended matter.
Ano: 1982 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3413
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Analyse du compartiment mésozooplanctonique et écologie alimentaire printanière de la sardine, Sardina pilchardus (Walbaum, 1782), et de l’anchois, Engraulis encrasicolus (Linné, 1758) adultes dans le Golfe de Gascogne ArchiMer
Dessier, Aurélie.
Dietary studies of marine species constitute an important key to improve the understanding of its biology and of its role in the ecosystem. Thus, prey-predator relationships structure and determine population dynamics and the trophic network at the ecosystem scale. Among the major study sites, the marine ecosystem is submitted to natural and anthropogenic constraints. In the North-Eastern part of the Atlantic Ocean, the Bay of Biscay is a large open area surrounded South by Spain and East by France. This bay is an historic place of intense fishery activities for which the main small pelagic species targeted are the pilchard, Sardina pilchardus and the anchovy, Engraulis encrasicolus. The aim of this work is to analyze the trophic ecology of these two small...
Tipo: Text Palavras-chave: Petits poissons pélagiques; Traceurs écologiques; Isotopes stables; Parasites; Mercure; Communauté mésozooplanctonique; Qualité du régime alimentaire; Golfe de Chaînes; Zooplancton marin; Isotopes stables; Expérience d’alimentation; Poissons pélagiques -- Gascogne; Small pelagic fish; Ecological tracers; Stable isotopes; Parasites; Mercury; Mesozooplanktonic community; Diet quality; Feeding experiment.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00353/46447/46197.pdf
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Analysis for the presence of determinants involved in the transport of mercury across bacterial membrane from polluted water bodies of India BJM
Jan,Arif Tasleem; Azam,Mudsser; Choi,Inho; Ali,Arif; Haq,Qazi Mohd. Rizwanul.
Abstract Mercury, which is ubiquitous and recalcitrant to biodegradation processes, threatens human health by escaping to the environment via various natural and anthropogenic activities. Non-biodegradability of mercury pollutants has necessitated the development and implementation of economic alternatives with promising potential to remove metals from the environment. Enhancement of microbial based remediation strategies through genetic engineering approaches provides one such alternative with a promising future. In this study, bacterial isolates inhabiting polluted sites were screened for tolerance to varying concentrations of mercuric chloride. Following identification, several Pseudomonas and Klebsiella species were found to exhibit the highest...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Bioremediation; Mercury; Resistance determinants; Mercury transport.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822016000100055
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Analysis of genetic susceptibility to mercury contamination evaluated through molecular biomarkers in at-risk Amazon Ameridian populations. Repositório Alice
KLAUTAU-GUIMARÃES, M. de N.; D'ASCENÇÃO, R.; CALDART, F. A.; GRISOLIA, C. K.; SOUZA, J. R. de; BARBOSA, A. C.; CORDEIRO, C. M. T.; FERRARI, I..
bitstream/item/178083/1/ID-27813-1.pdf
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Amazon Amerindian; Glutathione S-transferase; Susceptibilidade genética; Biomarcador molecular; Contaminação; Mercúrio; Amazonia; Genetic polymorphism; Mercury.
Ano: 2005 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/188269
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Analysis of genetic susceptibility to mercury contamination evaluated through molecular biomarkers in at-risk Amazon Amerindian populations Genet. Mol. Biol.
Klautau-Guimarães,Maria de Nazare; D’Ascenção,Renata; Caldart,Fabiana A.; Grisolia,Cesar K.; Souza,Jurandir R. de; Barbosa,Antonio C.; Cordeiro,Célia M.T.; Ferrari,Iris.
We investigated Individual differences in susceptibility to methylmercury (MeHg) contamination and its relationship with polymorphisms of the detoxifying enzyme glutathione S-transferase (GST). In Brazil, some Amerindian tribes from the Amazon region have an increased level of mercury in their hair. Samples of hair and blood were taken from inhabitants of two villages in the Kayabi and Munduruku Amerindian communities to investigate mercury levels in association with genetic polymorphism of GSTs. Other molecular biological markers were also studied, such as hemoglobin, haptoglobin and glucose 6-phosphate dehydrogenase (G-6-PDH). Higher levels of mercury contamination were found in the Kayabi villagers, who had a null genotype (GSTM1 0/0, also denominated...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Amerindian; Genetic polymorphism; Glutathione S-transferase; Mercury.
Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500027
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Analysis of Mercury-Rich plants and mine tailings using the Hydride-Generation AAS method BABT
Moreno,Fábio Netto; Anderson,Christopher; Stewart,Robert; Robinson,Brett.
A hydride-generation atomic absorption spectroscopy (AAS) method was developed for the analysis of total Hg in liquid matrices of mercury-rich plants and mine tailings samples. The detection limit for this method was as low as 11.4 ng/mL. The reproducibility of the mercury signals (in terms of relative standard deviation) was 4.6%. Accuracy of the method was verified by analyses of deionised water samples spiked with HgCl2 and HgNO3. Recovery values for total mercury ranged from 88.5 to 94.3% for both mercury species added. An external certified laboratory validated the analytical method with a maximum discrepancy of 15 %. Optimal analytical response of the equipment for Hg analysis of plant samples was achieved when the sample volume added to the reaction...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Hydride-generation; Mercury; Plant and mine tailings; Sodium borohydride (NaBH4); Phytoextraction.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000400019
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Analytical methods for mercury speciation in several matrixes: a review IPB - Escola Superior Agrária
Ramalhosa, Elsa; Río-Segade, Susana.
Mercury is one of the hazardous contaminants that may be present in the environment. Moreover, its toxicological effects are strongly dependent on the chemical form of the element, being the organic species the most toxic. In spite of this, the determination of mercury compounds in environmental samples, such as water, soils, sediments and biological matrixes, is of great importance. This review examines the current state of the sample treatments that have been developed, during the last 18 years (1990-2007),previous to separation and detection of mercury compounds, namely acid lixiviation, distillation,alkaline digestion and supercritical fluid extraction, as well as of the chromatographic techniques (gas chromatography and high performance liquid...
Tipo: Article Palavras-chave: Mercury; Speciation; Analytical methods; Gas chromatography; Liquid chromatography.
Ano: 2008 URL: http://hdl.handle.net/10198/3605
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Antioxidant Status, Lipid Peroxidation and Testis-histoarchitecture Induced by Lead Nitrate and Mercury Chloride in Male Rats BABT
Bas,Hatice; Kalender,Suna.
ABSTRACT This study was done to evaluate the effects of lead nitrate and mercury chloride in testis tissues of Wistar rats. Lead nitrate and mercury chloride are widely used heavy metals in industry. Oral lead and mercury administrations to adult male rats at doses 45 mg/kg bw and 0.02 mg/kg bw, respectively for 4 weeks caused a significant increasing in MDA levels and antioxidant enzyme activities (SOD, CAT, GPx and GST). The MDA levels and acivities of antioxidant enzymes was lower in rats that were administrated by lead nitrate than mercury chloride treated group. Light microscopic analyses revealed that lead nitrate and mercury chloride induced numerous histopathological changes in testis tissues of rats. Histopathological observations of the testis...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Antioxidant enzymes; Lead; Mercury; Oxidative stress; Testis.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000100341
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Are Consumers Color Blind?: an empirical investigation of a traffic light advisory for sustainable seafood AgEcon
Hallstein, Eric; Villas-Boas, Sofia Berto.
This paper empirically investigates consumer response to a traffic light advisory for environmentally sustainable seafood, which was implemented in the seafood department of a regional supermarket chain in the United States. Green meant 'best choice'; yellow meant 'proceed with caution'; red meant 'worst choice'. Using a unique product-level panel scanner data set capturing sales information for 2 treatment stores and 8 nearby control stores, we apply a difference-in-differences identification strategy to estimate the impact of color-coded labels on consumers' purchases. We find that the advisory leads to no significant difference in total seafood sales. Green sales significantly increase an average of 29% per week; yellow sales significantly decrease an...
Tipo: Working Paper Palavras-chave: Sustainable seafood; Fisheries crisis; FishWise; Traffic light advisory; Mercury; Consumer/Household Economics.
Ano: 2009 URL: http://purl.umn.edu/120535
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Are red mullet efficient as bio-indicators of mercury contamination? A case study from the French Mediterranean ArchiMer
Cresson, Pierre; Bouchoucha, Marc; Miralles, F.; Elleboode, Romain; Mahe, Kelig; Marusczak, Nicolas; Thebault, Herve; Cossa, Daniel.
Mercury (Hg) is one of the main chemicals currently altering Mediterranean ecosystems. Red mullet (Mullus barbatus and M. surmuletus) have been widely used as quantitative bio-indicators of chemical contamination. In this study, we reassess the ability of these species to be used as efficient bio-indicators of Hg contamination by monitoring during 18 months Hg concentrations in muscle tissue of mullet sampled from 5 French Mediterranean coastal areas. Mean concentrations ranged between 0.23 and 0.78 μg g−1 dry mass for both species. Values were consistent with expected contamination patterns of all sites except Corsica. Results confirmed that red mullets are efficient bio-indicators of Hg contamination. Nevertheless, the observed variability in Hg...
Tipo: Text Palavras-chave: Mercury; Bio-indicator; Fish; Mullus spp.; Mediterranean.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00244/35514/34083.pdf
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Binding of Hg by bacterial extracellular polysaccharide: a possible role in Hg tolerance ArchiMer
Cruz, Kimberly; Guezennec, Jean; Barkay, Tamar.
Bacteria employ adaptive mechanisms of mercury (Hg) tolerance to survive in environments containing elevated Hg concentrations. The potential of extracellular polysaccharides (EPS) production by bacteria as a mechanism of Hg tolerance has not been previously investigated. The objectives of this study were to determine if bacterial EPS sorb Hg, and if so does sorption provide protection against Hg toxicity. Purified EPS with different chemical compositions produced by bacterial isolates from microbial mats in French Polynesian atolls and deep-sea hydrothermal vents were assessed for Hg sorption. The data showed that EPS sorbed up to 82% of Hg from solution, that this sorption was dependent on EPS composition, and that sorption was a saturable mechanism. Hg...
Tipo: Text Palavras-chave: Mercury; Bacteria; Sorption; Tolerance; Exocellular polysaccharides.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00382/49348/49786.pdf
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Bioaccumulation of mercury in some marine organisms from Lake Timsah and Bitter Lakes (Suez Canal, Egypt) OceanDocs
El-Moselhy, K.M..
The present work is devoted to determine the level of total mercury in the different tissues of fish Mugil seheli, crab Portunus pelagicus, shrimp Metapenaeus stebbingi, and bivalves Paphia undulata and Gafrarium pectinatum collected from Lake Timsah and Bitter Lakes during spring 2003. In addition, factors affecting the accumulation of mercury in these organisms were studied. Levels of Hg in the edible parts of the investigated organisms showed the ranges 2.62 – 25.45 and 0.94 – 7.94 ng/g wet wt. in fish, 16.02 – 117.26 and 9.86 – 64.18 ng/g wet wt. in crab, 4.55 – 14.67 and 5.76 – 15.58 ng/g wet wt. in shrimp, and 1.06 – 36.31 and 5.38 – 69.59 ng/g wet wt. in bivalves from Lake Timsah and Bitter Lakes, respectively. High accumulation of Hg was recorded...
Tipo: Journal Contribution Palavras-chave: Chemistry Studies; Mercury; Bioaccumulation; Marine organisms; Heavy metals; Bioaccumulation; Mercury; Http://aims.fao.org/aos/agrovoc/c_32389; Http://aims.fao.org/aos/agrovoc/c_4751.
Ano: 2006 URL: http://hdl.handle.net/1834/1451
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Biological and ecological factors related to trace element levels in harbour porpoises (Phocoena phocoena) from European waters ArchiMer
Lahaye, V; Bustamante, Paco; Law, J.r; Learmonth, J.a; Santos, M.b.; Boon, J.p.; Rogan, E; Dabin, W; Addink, M.j.; Lopez, A; Zuur, A.f.; Pierce, G.j.; Caurant, Florence.
Selected trace elements (Cd, Cu, Hg, Se, Zn) were measured in the kidneys and the liver of 104 harbour porpoises (Phocoena phocoena) stranded along the coasts of France, Galicia (Spain), Ireland, Scotland (UK), and the Netherlands. Generally, relatively low concentrations of toxic elements were encountered in the tissues of European porpoises, except for two individuals, which displayed high hepatic Hg concentrations. Also, elevated Cd levels obtained in Scottish porpoises could be related to their feeding preferences and this result suggests an increase of the proportion of cephalopods in their diet with latitude. Moreover, significant geographical differences were seen in hepatic Zn concentrations; the elevated Zn concentrations displayed by porpoises...
Tipo: Text Palavras-chave: Tracers; Multivariate analysis; Diet; Age; Marine mammals; Zinc; Cadmium; Mercury; Heavy metals.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2920.pdf
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Cadmium and mercury in Seine Estuary flounders and mussels: the results of two decades of monitoring ArchiMer
Nakhle, K; Cossa, Daniel; Claisse, Didier; Beliaeff, Benoit; Simon, S.
The flounder (Platichthys flesus) is a flatfish that inhabits marine coastal environments, especially estuaries. It is an alternative quantitative biological indicator to the common marine mussel (Mytilus spp.), which is currently used as a sentinel species to monitor chemical contamination in numerous monitoring programmes. Findings from two decades of monitoring cadmium (Cd) and mercury (Hg) using both sentinel species in the Seine Estuary (France) are reported. For comparison, time-series of water concentrations for the same two metals at the mouth of the River Seine are given. Cd concentrations in the liver of the fish and in the soft tissue of mussels show similar temporal trends, consistent with the major temporal variations of Cd concentrations...
Tipo: Text Palavras-chave: Platichthys flesus; Mussel watch; Monitoring; Mercury; Flounder; Estuary; Cadmium.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3028.pdf
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