Mercury lake sediment

Syers, J.K. Iskandar, I.K. Keeney, D.R. Distribution and Background Levels of Mercury in Sediment Cores from Selected Wisconsin Lakes. Water Air Soil Pollut. 1973 2, 105-118. 

Pak K-R, R Bartha (1998) Mercury methylation and demethylation in anoxic lake sediments by strictly anaerobic bacteria. Appl Environ Microbiol 64 1013-1017. 

Brndler R, Renberg I, Appleby PG, Anderson NJ, Rose NL. 2001. Mercury accumulation rates and spatial patterns in lake sediments from west Greenland a coast to ice margin transect. Environ Sci Technol 35 1736-1741. 

Engstrom DR, Polhnan CD, Fitzgerald WF, Balcom PH. 2003. Evaluation of recent trends in atmospheric mercury deposition in south florida from lake-sediment records. Tallahassee (FL) Florida Department of Environmental Protection, 27 pp. 

Lindestroem L. 2001. Mercury in sediment and fish communities of Lake Vaenem, Sweden recovery from contamination. Ambio 30 538-544. 

Lockhart WL, Wilkinson P, Billeck BN, Danell RA, Hunt RV, Brunskill GJ, DeLaronde J, St. Louis V. 1998. Fluxes of mercury to lake sediments in central and northern Canada inferred from dated sediment cores. Biogeochemistry 40 163-173. 

Bishop CA, Koster MD, Chek AA, HusseU DJT, Jock K. 1995a. Chlorinated hydrocarbons and mercury in sediments, red-winged blackbirds Agelaius phoeniceus) and tree swallows (Tachycineta bicolor) from wetlands in the Great Lakes-St. Lawrence River basin. Environ Toxicol Chem 14 491-501. 

Jensen and Jernelou [52] reported that both mono and dimethylmercury (CH3Hg+ and (CH3)2Hg) can be produced in lake sediments. The gases evolved from incubated sediment samples were analysed for monomethyl mercury by conversion to methylmercury halide by means of gas chromatography, using electron capture and mass spectrometric detection. 

Mercury Fluxes and Sediment Records. Our calculations of lakewide Hg fluxes from more than 80 dated sediment cores from seven small headwater lakes reveal a regionally consistent increase in Hg inputs from preindustrial times to the present the modern Hg flux to each of these lakes is about 3.7 times that of the early 1800s. Such increases are typical of that reported in other investigations of lake sediments from remote or rural sites in eastern North America (3, 6, 7,10, 23). Most researchers have concluded that the increase is anthropogenic and that the Hg must be transported through the atmosphere and deposited on the lake and its terrestrial catchment. 

Secular change in the global mercury cycle as a result of human activity is one of the major themes in this chapter and a focus of research currently. One of the most insightful research activities in pursuit of this theme has been the development of historical archives of mercury change. As of early 2000s, this development effort has focused on three archives peat bogs, lake sediments, and ice cores. All are used to reconstmct historical changes in the flux of mercury from the atmosphere. 

Although most research has been carried out with mercury, the possibility of a wider role for biomethylation of metals is suggested by reports of microbial formation of tetramethyl lead [(CH3)4Pb] in a number of lake sediments (Wong et al., 1975) and of methyl tin (CHjSn) by Pseudomonas sp. (Jemelov and Martin, 1975). 

Regnell O, Tunlid A. 1991. Laboratory study of chemical speciation of mercury in lake sediment and water under aerobic and anaerobic conditions. Appl Environ Microbiol 57(3) 789-795. 

Wren C. 1992. Relationship of mercury levels in sportfish with lake sediment and water quality variables. Toronto Ontario Environmental Research Program. Govt Reports Announcements and Index (GRA I) Issue 08. 

In order to understand the full extent of the mercury problem in these times, one has only to consider the enormous loss rates. From the total of 2865 tons of mercury purchased in the U.S. in 1968, 76% or 2160 tons were lost to the environment. According to calculations of Kemp et al. (1974), the Lake Ontario reservoir contained a mass of 500 to 600 metric tons of "excess" mercury, i.e. discharged from anthropogenic sources. With the improvements in the methods of chlor-alkali electrolysis and by subsequent purification of waste streams the mercury loss has been reduced from 100 g per metric ton of manufactured chlorine to approx. 2 g per ton or less (Anon., 1973). The effect of these measures can be seen from concentration profiles of mercury in sediment cores taken off the mouth of Niagara River by Mudroch (1983), where a very distinct decrease from formerly approx. 4-7 ug Hg/g to less than lug Hg/g in recent years has occurred (Figure 2-6). 

Figure 2-6 Concentration Profiles of Mercury in Sediment Cores from the Western Basin of Lake Ontario (Mudroch, 1983)...

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