Mercury in the North Atlantic

Mason, Robert P.; Rolfhus, Kristofer R.; Fitzgerald, William F.

doi:10.1016/s0304-4203(98)00006-1

Cited by 205 publications

(224 citation statements)

References 45 publications

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“…The concentrations of THg (remaining THg + Hg(0)) in waters varied from 0.96 to 2.23 ng L −1 with mean concentrations of 1.40 ± 0.48 ng L −1 (n = 8). These concentrations were clearly higher than those in the open oceans, such as the North Atlantic Ocean (0.48 ng L −1 , Mason et al 1998) and the North Pacific Ocean (~0.2 ng L −2 , Laurier et al 2004), and comparable to those of coast, offshore, and estuary, such as the Yellow Sea (1-3 ng L −1 , Ci et al 2011b, d) and the Connecticut River Estuary (~2 ng L −1 , Rolfhus et al 2003). During 2003, Tseng et al (2012) studied the Hg distribution in air and water in the South East Asia TimeSeries Station (SEATS), which is located in the open water of the SCS and about 6.5°(~800 km) further east than our station (see Fig.…”

Section: Resultsmentioning

confidence: 72%

Air–sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China

Zhang

Wang

2016

Environ Sci Pollut Res

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The air-sea exchange of gaseous mercury (mainly Hg(0)) in the tropical ocean is an important part of the global Hg biogeochemical cycle, but the related investigations are limited. In this study, we simultaneously measured Hg(0) concentrations in surface waters and overlaying air in the tropical coast (Luhuitou fringing reef) of the South China Sea (SCS), Hainan Island, China, for 13 days on January-February 2015. The purpose of this study was to explore the temporal variation of Hg(0) concentrations in air and surface waters, estimate the air-sea Hg(0) flux, and reveal their influencing factors in the tropical coastal environment. The mean concentrations (±SD) of Hg(0) in air and total Hg (THg) in waters were 2.34 ± 0.26 ng m −3 and 1.40 ± 0.48 ng L −1 , respectively. Both Hg(0) concentrations in waters (53.7 ± 18.8 pg L −1 ) and Hg(0)/THg ratios (3.8 %) in this study were significantly higher than those of the open water of the SCS in winter. Hg(0) in waters usually exhibited a clear diurnal variation with increased concentrations in daytime and decreased concentrations in nighttime, especially in cloudless days with low wind speed. Linear regression analysis suggested that Hg(0) concentrations in waters were positively and significantly correlated to the photosynthetically active radiation (PAR) (R 2 = 0.42, p < 0.001). Surface waters were always supersaturated with Hg(0) compared to air (the degree of saturation, 2.46 to 13.87), indicating that the surface water was one of the atmospheric Hg(0) sources. The air-sea Hg(0) fluxes were estimated to be 1.73 ± 1.25 ng m −2 h −1 with a large range between 0.01 and 6.06 ng m −2 h −1 . The high variation of Hg(0) fluxes was mainly attributed to the greatly temporal variation of wind speed.

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Section: Resultsmentioning

confidence: 72%

Air–sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China

Zhang

Wang

2016

Environ Sci Pollut Res

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“…These values are in agreement with those reported in literature, as in the Mediterranean Sea (0.09 to 0.38 ng L -1 ), 58 in Long Island Sound, USA (0.26 to 0.90 ng L -1 ), 57 in the South and Equatorial Atlantic (0.10 to 1.4 ng L -1 ), 56 in the St. Lawrence Estuary, Canada (< 0.04 to 0.22 ng L -1 ) 5 and in the North Atlantic (0.16 ± 0.09 ng L -1 ). 78 During the dry season, the percent of reactive Hg relative to the total Hg concentrations presented an average of 54.8 ± 24.2% in flood and 9.0 ± 3.0% in ebb tide, whereas during the wet season averages of 14.2 ± 6.3% in flood and 23.4 ± 11.2% in ebb tide were observed. These values are also similar to those reported in the St. Lawrence Estuary, Canada (8 to 59%, with an average of 20%) 5 but lower than in other regions, as in the Mediterranean Sea (15 to 98%, with an average of 57%) 58 and in the Long Island Sound, USA (14 to 71%).…”

Section: Mercury Speciationmentioning

confidence: 89%

“…. 78 During the dry season, the percent of reactive Hg relative to the total Hg concentrations presented an average of 54.8 ± 24.2% in flood and 9.0 ± 3.0% in ebb tide, whereas during the wet season averages of 14.2 ± 6.3% in flood and 23.4 ± 11.2% in ebb tide were observed. These values are also similar to those reported in the St. Lawrence Estuary, Canada (8 to 59%, with an average of 20%) 5 but lower than in other regions, as in the Mediterranean Sea (15 to 98%, with an average of 57%) 58 and in the Long Island Sound, USA (14 to 71%).…”

Section: Mercury Speciationmentioning

confidence: 89%

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Paraquetti¹,

Lacerda²,

Almeida³

et al. 2007

J. Braz. Chem. Soc.

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Este estudo descreve as mudanças na especiação de Hg nas águas da Baía de Sepetiba, SE, Brasil, ao longo do gradiente estuarino, durante eventos de maré em diferentes estações. A avaliação química das águas da baía indicou uma exportação de material particulado em suspensão (MPS) pobre em carbono orgânico para a plataforma continental adjacente, principalmente durante a estação chuvosa e uma importação de MPS oceânico rico em carbono orgânico, provavelmente de origem fitoplanctônica, durante a estação seca. A especiação química do Hg demonstrou que a produção de Hg 0 na Baía de Sepetiba pode ser controlada pela produtividade primária, e que a baía atua como produtora e exportadora de formas orgânicas de Hg para as áreas adjacentes, já que as maiores concentrações de Hg não-reativo foram encontradas durante a maré vazante. Não foram observadas correlações significantes entre as concentrações de Hg não-reativo e carbono orgânico dissolvido ou particulado. Em geral, as frações de Hg particulado, Hg não-reativo e Hg reativo representam 55%, 35% e 9,5% do conteúdo total de Hg nas águas da Baía de Sepetiba, respectivamente.This work describes changes in Hg speciation in water along the transport from Sepetiba Bay, SE Brazil, to the adjacent continental platform during tide events and in different seasons. The chemical evaluation of Sepetiba Bay waters showed that the bay exports suspended particulate material (SPM) impoverish in organic carbon to adjacent continental platform areas, mainly during the wet season and imports SPM enriched in organic carbon from the ocean, probably of phytoplanktonic origin, during the dry season. The chemical speciation of Hg during the study period showed that Hg 0 production can be controlled by primary productivity and that the bay acts as a producer and exporter of organic species of Hg to adjacent areas, since the highest non-reactive Hg concentrations were observed during the ebb tide. No significant correlations were found between non-reactive Hg and dissolved or particulate organic matter concentrations. In general the particulate Hg, non-reactive Hg and reactive Hg fractions represents 55%, 35.5% and 9.5% of the total Hg content in Sepetiba Bay waters, respectively.Keywords: mercury speciation, coastal area, organic carbon, Sepetiba Bay IntroductionCoastal environments are complex and very dynamic systems showing a strong salinity gradient, high variation of suspended matter concentration and complex hydrodynamic processes. They act as links between the terrestrial and oceanic environments, present a large capacity to accumulate materials of continental and marine origin and are strongly affected by tidal events and continental hydrology. These environments are also characterized by land-sea gradients of physicochemical processes such as oxidation/reduction, sorption/desorption and precipitation/dissolution, which result in gradients of dissolved chemical species concentration, ionic force, pH and redox potential, which are responsible for the precipitation of the major part of ...

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“…Nessa Tabela o percentual de mercúrio elementar foi desconsiderado, entretanto sabe-se que essa fração pode apresentar valores importantes para a ciclagem de mercúrio no ambiente marinho 11 .…”

Section: Parte Experimentalunclassified

“…Mercúrio total -A oxidação de todo mercúrio restante em solução ao Hg 2+ , inclusive a destruição dos complexos organo-mercuriais fortes, foi realizada a partir da adição de 0,2 ml de solução de cloreto de bromo obtida a partir da mistura (1:1) de solução de bromato de potássio (1%) à solução de HCl (20%) 11,14,28 . Estudos realizados previamente demonstraram que a oxidação com cloreto de bromo é adequada somente para águas com baixo teor de material em suspensão 31 .…”

Section: Determinação Das Espécies Hgunclassified

Alternativa analítica para especiação físico-química de mercúrio em águas costeiras tropicais

2002

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Recebido em 5/2/01; aceito em 24/10/01 ANALYTICAL ALTERNATIVE FOR THE PHYSICAL-CHEMICAL SPECIATION OF MERCURY IN TROPICAL COASTAL WATERS. The determination of the physical-chemical mercury speciation in tropical coastal waters using the derivatization technique with CVAFS detection was optimized. This methodology is able to separate the elementary, reactive, organic and total mercury phases with low operational costs. The importance of bromide chloride solution, the diluted aqua regia, used as the oxidative solution, and different compositions of the reductive solution of stannous chloride were tested and the better results for coastal waters are presented. The recuperation of the sum of the different phases ranges from 80 to 94% of the total Hg content in duplicates of different marine samples. The optimized methodology permits important studies on the mercury cycle in the coastal environment.Keywords: mercury; physical-chemical speciation; coastal waters; CVAFS. INTRODUÇÃOA compreensão dos processos biogeoquímicos, sejam eles precipitação/dissolução, adsorção/dessorção, bioconcentração, desgazeificação/deposição atmosférica, dos quais participam os metais-traço nas regiões estuarinas e no oceano aberto necessita da determinação das diferentes espécies físico-químicas dos metais presentes. A especiação de um elemento é a determinação das formas físico-químicas individuais do elemento que somadas são iguais à concentração total desse elemento 1 .Diferentes formas de distinguir espécies físico-químicas são empregadas em estudos ambientais 2 . A derivatização é um método de caráter operacional que define as formas dos elementos traço através do uso acoplado de técnicas analíticas de baixo custo operacional e técnicas de seleção física de espécies. A derivatização promove a separação entre as fases orgânicas e inorgânicas nas fases dissolvido e particulado de águas naturais. A modelagem matemática fundamentada em variáveis termodinâmicas e constantes de equilíbrio também é utilizada como estimativa acurada para a determinação das espécies de metais-traço em águas naturais 3,4 .As regiões costeiras, zonas de alta atividade reacional devido às rápidas mudanças das condições ambientais que ocorrem devido à mistura das águas doces com as águas salinas, promovem modificações de importantes parâmetros tais como a força iônica, razões entre os maiores componentes, pH, potencial de oxi-redução, turbidez, etc. Esses parâmetros vão modificar não somente a físico-química da solução aquosa como também modificar a biodisponibilidade dos metais-traço, que dependerá da especiação química desses elementos. A despeito dessas evidências tem sido dada pouca importância à especiação química, sendo determinadas somente espécies organometálicas individuais 2 . Técnicas de derivatização podem ser de grande interesse por relacionarem ciclos de especiação de grande interesse ambiental.Em região costeira subtropical foi observado que, embora haja grande capacidade de imobilização de mercúrio em sedimentos de fundo, esta retenção pode repres...

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Mercury in the North Atlantic

Cited by 205 publications

References 45 publications

Air–sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China

Air–sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Alternativa analítica para especiação físico-química de mercúrio em águas costeiras tropicais

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