Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes

Amyot, Marl; Mierle, Greg; Lean, D. R. S.; Queen, Donald J. Mc

doi:10.1016/s0016-7037(96)00390-0

Cited by 200 publications

(204 citation statements)

References 27 publications

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“…Photoreduction of Hg 2+ , caused by solar radiation, has been identified as the primary mechanism in the production of DGM in lake waters (Amyot et al 1994;O'Driscoll et al 2003a). Other studies have reported elevated DGM during summer in northern lakes (31-80 pg L 21 , Amyot et al 1997; 76 pg L 21 , O 'Driscoll et al 2003a). Modest differences were observed in average specific conductivity (Sp.…”

Section: Hg Relationship With Doc Somentioning

confidence: 99%

“…Differences in time lag and rates of DGM production between different lakes may be controlled primarily by DOC content and structure. Amyot et al (1997) compared lakes with low and high DOC, and found DGM production was several-fold greater in low DOC lakes. In another study, for a similar range in DOC concentration DGM production was lower in lakes with clear-cut watershed compared to reference lakes, and DOC structure was found to be an important factor controlling this response (O 'Driscoll et al 2004).…”

Section: Hg Relationship With Doc Somentioning

confidence: 99%

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Mercury dynamics and transport in two Adirondack Lakes

Selvendiran

Driscoll

Montesdeoca

et al. 2009

Limnology & Oceanography

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We investigated the chemistry and fluxes of mercury (Hg) species for two Adirondack lakes with contrasting landscape, physical, and chemical attributes. Samples were collected monthly at the lake inlets and outlets over 2 yr, and evasion of elemental Hg was measured at one lake (Arbutus). Concentrations of total Hg (THg) and methyl Hg (MeHg) in watershed runoff were highly variable throughout the year, increasing markedly during summer months. The proportion of THg as MeHg ranged from ,5% at Arbutus Lake up to 10% at Sunday Lake. Concentrations of Hg species increased with increases in dissolved organic carbon concentrations and percentage wetland coverage. The estimated rate of volatilization loss of elemental mercury (Hg o ) from Arbutus Lake surface (7.8 mg m 22 yr 21 ) was comparable to the rate of direct atmospheric Hg deposition to the lake surface (8.6 mg m 22 yr 21 ). Dry deposition to Arbutus Lake amounted to ca. 26% of total wet THg deposition. Hydraulic residence time (HRT) played a critical role in controlling Hg dynamics in the lakes. Negligible removal of THg inputs was observed at Sunday Lake, which has a short HRT (0.02 yr), compared with approximately 60% removal at Arbutus Lake, which has a longer HRT (0.6 yr). This pattern of increasing net Hg retention in lakes with increasing HRT was consistent with other mass balance studies in the literature. Both Arbutus and Sunday lakes were net sinks of MeHg.

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Section: Hg Relationship With Doc Somentioning

confidence: 99%

Section: Hg Relationship With Doc Somentioning

confidence: 99%

Mercury dynamics and transport in two Adirondack Lakes

Selvendiran

Driscoll

Montesdeoca

et al. 2009

Limnology & Oceanography

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“…It is known to form exceptionally strong complexes with the oxidized mercuric species, Hg(II), due to its coordination with reduced sulfur (−S) or thiol (−SH) functional groups in DOM at relatively high DOM:Hg(II) ratios (11,(18)(19)(20)(21). Such complexation has been shown to limit Hg(II) availability for bacterial methylation (9, 22, 23); however, facilitated uptake and methylation are also reported, especially when Hg(II) is complexed with small molecular-weight thiol compounds such as cysteine (5,24).Although a large body of literature is now available on the interactions of oxidized Hg(II) species with DOM, reactions between reduced gaseous Hg(0) and DOM have rarely been examined in natural sediments and water where dissolved Hg(0) is also observed (16,17,(25)(26)(27)(28)(29)(30)(31). Hg(0) has a solubility of ∼56 μg/L in water (32).…”

mentioning

confidence: 99%

Mercury reduction and complexation by natural organic matter in anoxic environments

Bian

Miller

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

298

272

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Mercuric Hg(II) species form complexes with natural dissolved organic matter (DOM) such as humic acid (HA), and this binding is known to affect the chemical and biological transformation and cycling of mercury in aquatic environments. Dissolved elemental mercury, Hg(0), is also widely observed in sediments and water. However, reactions between Hg(0) and DOM have rarely been studied in anoxic environments. Here, under anoxic dark conditions we show strong interactions between reduced HA and Hg(0) through thiolate ligand-induced oxidative complexation with an estimated binding capacity of ∼3.5 μmol Hg/g HA and a partitioning coefficient >10 6 mL/g. We further demonstrate that Hg(II) can be effectively reduced to Hg(0) in the presence of as little as 0.2 mg/L reduced HA, whereas production of Hg (0) is inhibited by complexation as HA concentration increases. This dual role played by DOM in the reduction and complexation of mercury is likely widespread in anoxic sediments and water and can be expected to significantly influence the mercury species transformations and biological uptake that leads to the formation of toxic methylmercury.Hg-dissolved organic matter complex | environmental factors | methylation | redox M ercury (Hg) is well known to bioaccumulate and biomagnify as neurotoxic methylmercury (CH 3 Hg + ) in organisms, particularly fish (1-3). Biologically mediated production of CH 3 Hg + predominantly occurs under anaerobic conditions (4-8). However, the environmental factors that determine Hg availability to methylating bacteria and its transformation under these conditions remain poorly understood (1, 9-12). In particular, the coupled reactions between Hg redox transformation and complexation with natural dissolved organic matter (DOM) remain unclear, yet this process may critically control the speciation, biological uptake, and methylation of aqueous Hg in aquatic environments (9)(10)(11)(13)(14)(15)(16)(17). DOM occurs in all natural sediments and water, usually at concentrations much higher than Hg (1, 9). It is known to form exceptionally strong complexes with the oxidized mercuric species, Hg(II), due to its coordination with reduced sulfur (−S) or thiol (−SH) functional groups in DOM at relatively high DOM:Hg(II) ratios (11,(18)(19)(20)(21). Such complexation has been shown to limit Hg(II) availability for bacterial methylation (9, 22, 23); however, facilitated uptake and methylation are also reported, especially when Hg(II) is complexed with small molecular-weight thiol compounds such as cysteine (5,24).Although a large body of literature is now available on the interactions of oxidized Hg(II) species with DOM, reactions between reduced gaseous Hg(0) and DOM have rarely been examined in natural sediments and water where dissolved Hg(0) is also observed (16,17,(25)(26)(27)(28)(29)(30)(31). Hg(0) has a solubility of ∼56 μg/L in water (32). Its formation can be mediated biologically (25, 26, 33), chemically (34, 35), or photochemically in the aquatic environment (15-17, 27-31). However, the role pla...

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“…Approximately 10-30 % of the Hg exists as elemental Hg in ocean water , where Hg 0 is mainly formed from the reduction of Hg (II) by aquatic microorganisms (Mason et al 1995) and from photoreduction of Hg (II) (Amyot et al 1997;Costa and Liss 2000) followed by geotectonic activity (Ferrara et al 2003;Horvat et al 2003). Abiotic methylation may take place in an environment loaded with humic organic matter (Weber 1993).…”

Section: Mercurymentioning

confidence: 99%

Harmful Elements in Estuarine and Coastal Systems

Khan

Masiol

Hofer

et al. 2014

PHEs, Environment and Human Health

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Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities.

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Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes

Cited by 200 publications

References 27 publications

Mercury dynamics and transport in two Adirondack Lakes

Mercury dynamics and transport in two Adirondack Lakes

Mercury reduction and complexation by natural organic matter in anoxic environments

Harmful Elements in Estuarine and Coastal Systems

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