Mercury global cycle

In this final section, the global cycles of two metals, mercury and copper, are reviewed. These metals were chosen because their geochemical cycles have been studied extensively, and their chemical reactions exemplify the full gamut of reactions described earlier. In addition, the chemical forms of the two metals are sufficiently different from one another that they behave differently with respect to dominant... 

Fig. 15-16 The (a) present day and (b) pre-industrial global cycles for mercury. Units are 10 g Hg (burdens) and 10 g Hg/yr (fluxes). Hgp refers to mercury in particles. Redrawn from Mason et al, 1994.

Chilvers D.C., Peterson P.J. Global cycling of arsenic. In Lead, Mercury and Arsenic in the Environment, T.C. Hutchinson, K.M. Meema, eds. New York John Wiley. 1987. 

Andren AW, Nriagu JO. 1979. The global cycle of mercury. In Nriagu JO, ed. The biogeochemistry of mercury in the environment. New York, NY Elsevier/North Holland Biomedical Press, 1-22. 

In this final section, the global cycles of two metals, mercury and copper, are reviewed. These metals... 

The global cycling of copper has been reviewed by Nriagu (1979) and is described schematically in Fig. 15-16. Like most heavy metals and in contrast to mercury, the flux of copper from terrestrial to oceanic reservoirs is dominated by transport in rivers. Copper reaching the oceans by atmospheric transport is of the same order of magnitude as that by three strictly anthropogenic sources direct discharge... 

SuKHENKO SA and Vasiliev OP (1996) A Re onal Mercury Budget for Siberia and the Role of the Region in Global Cycling of the Metal. I n Baeyens W, Ebinghaus R and Vasiliev O, eds, Global and Regional Mercury Cycles Sources, Pluxes and Mass Balances, pp. 123-133. Kluwer Academic Publishers, Dordrecht, Netherlands and Norwell, MA, USA. 

Chilvers DC and Peterson PJ (1987) Global cycling of arsenic. In Hutchinson TC and Meema KM, eds. Lead, mercury, cadmium and arsenic in the environment. SCOPE 31 279-301. John Wiley Sons New York. 

Ebinghaus R (ed.) (1997) Regional and Global Cycles of Mercury Source, Fluxes and Mass Balances. NATO Series, Amsterdam Kluwer Press. 

Though mercury (Hg) occurs naturally in the environment, anthropogenic activities have affected its global cycle in ways that mobiUze increasing amounts of this metal currently, such human-related activities mobilize more Hg than do natural... 

In the global cycle of mercury the accumulation in the aquatic food chain plays a predominant role [6]. Inorganic mercury species are methylated in the water chemically or by microorganisms. The organomercury compounds formed enter the food chain. Caused by bioaccumulation in any of the several steps of the aquatic food chain, the highest levels of mercury can be found in the tissues of large predatory fishes such as marine tuna, swordfish, shark, turbot, or halibut and... 

Volatilization is also a dominant transport mode for mercury, which is the most volatile metal in its elemental state. As with lead, a key reaction that can increase the volatility of mercury is formation of an organometallic compound. In this case, the reactions take place in water and are primarily biological, being mediated by bacteria commonly found in the upper levels of sediments. These reactions and their importance in the global mercury cycle are discussed in some detail later in the chapter. 

Fitzgerald WF, Mason RP. 1996. The global mercury cycle oceanic and anthropogenic aspects. In Baeyens W, Ebinghaus R, Vasihev O, editors. Global and regional mercury cycles sources, fluxes and mass balances, Dordrecht, the Netherlands Kluwer Academic Publishers, p. 85-108. 

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