Methylmercury in water

Ahmed, R. and M. Stoeppler. 1986. Decomposition and stability studies of methylmercury in water using cold vapor atomic absorption spectrometry. Analyst 111 1371-1374. 

Total mercury, inorganic mercury, and methylmercury in water were determined using a simple and ultrasensitive method, based on cold vapor generation (CVG), coupled to atomic fluorescence... 

Some key features relevant to mercury in the environment were established very early on (in the late 1960s). It was shown that it is present in fish as methylmercury, that there is an explanation of the methylation route (involving methylcobalamin, see below), and that analytical methods can be developed for methylmercury in water, sediment, or organisms at the ppm level. 

McLEAN The concentration in water and precipitation used in the models for global mercury transport and for mercury methylation and uptake into biota are too high. Some reassessment of these models is certainly necessary. In addition, the concentration of methylmercury in water for the fish to accumulate is also lower than was first considered. 

Domagalski J. (2001) Mercury and methylmercury in water and sediment of the Sacramento river basin, California. Appl. Geochem. 16, 1677-1691. 

Hu, G. L., Wang, X. R., Wang, Y. R., Chen, X., and Jia, L. (1997) Determination of methylmercury in waters using sodium tetraphenylborate derivatization/solvent extraction and gas chromatography-ion trap mass spectrometry. Anal Lett, 30,2579-94. 

Metals and metalloids that form alkyl compounds, eg, methylmercury and methylarsenic acid, tributjltin, deserve special concern because these compounds are volatile and accumulate in cells they are poisonous to the central nervous system of higher organisms. Because methylmercury or other metal alkyls may be produced at a rate faster than it is degraded by other organisms, it may accumulate in higher organisms such as fish. Hg species are also reduced to elementary Hg which is soluble in water but lost by volatilization to the atmosphere (40). 

Munthe J, Hultberg H, Lee Y-H, Parkman H, I verfeldt A, Renberg I. 1995a. Trends of mercury and methylmercury in deposition, run-off water and sediments in relation to experimental manipulations and acidification. Water Air Soil PoUut 85(2) 743-748. 

Munthe J, Hultberg H. 2004. Mercury and methylmercury in nm-off from a forested catchment — concentrations, fluxes and their response to manipulations. Water Air Soil Pollut Focus 4 607-618. 

Schwesig D, Ilgen G, Matzner E. 1999. Mercury and methylmercury in upland and wetland acid forest soils of a watershed in NE-Bavaria, Germany. Water Air Soil Pollut 113 141-154. 

Mercury (Hg) contamination is widespread in water, in surficial soils and sediments, and in the tissues of plants and animals in ecosystems around the globe. Once deposited to terrestrial and aquatic ecosystems, some inoiganic mercury is transformed into methylmercury (MeHg), a highly toxic compoimd that bioaccumulates efficiently in food webs (Wiener et al. 2003). As a result of the toxicity of MeHg to wildlife and humans, many nations are interested in reducing environmental mercury contamination and associated biotic exposure (UNEP 2002). 

Methylmercury in the marine environment may originate from industrial discharges or be synthesised by natural methylation processes. Fish do not themselves methylate inorganic mercury [62,64], but can accumulate methyl mercury from sea water [63]. Methylmercury has been detected in sea water only from Minamata Bay, Japan, an area with a history of gross mercury pollution from industrial discharge. It has been found in some sediments but at very low concentrations, mainly from areas of known mercury pollution. It represents usually less than 1% of the total mercury in the sediment, and frequently less than 0.1% [65-67]. Microorganisms within the sediments are considered to be responsible for the methylation [65,68], and it has been suggested that methylmercury may be released by the sediments to the sea water, either in... 

More research is needed on mercury removal technology. In the Florida Everglades, for example, using prototype wetlands of 1545 ha, removal of agricultural nutrients from stormwater reduced total mercury and methylmercury concentrations in water by as much as 70% in the first 2 years of operation moreover, total mercury concentrations in largemouth bass were about 0.1 mg Hg/kg FW muscle throughout the project site vs. 0.5 mg Hg/kg FW in adjacent areas (Miles and Fink 1998). 

Lansens, P., M. Leermakers, and W. Baeyens. 1991. Determination of methylmercury in hsh by headspace-gas chromatography with microwave-induced-plasma detection. Water Air Soil Pollut. 56 103-115. 

Wilken, R.D. and H. Hintelmann. 1991. Mercury and methylmercury in sediments and suspended particles from the River Elbe, North Germany. Water Air Soil Pollut. 56 427-437. 

S. Rio Segade and J. F. Tyson, Determination of methylmercury and inorganic mercury in water samples by slurry sampling cold vapor atomic absorption spectrometry in a flow injection system after preconcentration on silica C18 modified, Talanta, 71(4), 2007, 1696-1702. 

Jian, W. and McLeod, C.W. (1992) Rapid sequential determination of inorganic mercury and methylmercury in natural waters by flow-injection-cold vapour-atomic fluorescence spectrometry. Talanta, 39, 1537-1542. 

Laporte, J.M., F. Ribeyre, J.R Trachot, and A. Boudou. 1997. Combined effects of water pH and salinity on the bioaccumulation of inorganic mercury and methylmercury in the shore crab Carcinus maenas. Mar. Pollut. Bull. 34 880-893. 

The key decision is then whether the acceptable body burden in the target species is exceeded. Canada has derived Tissue Residue (i.e., body burden) Guidelines for the Protection of Wildlife Consumers of Aquatic Biota for several substances (e.g., DDT, methylmercury, PCBs), and the EU WFD permits the establishment for some substances of a body-burden EQS recalculated as an equivalent concentration in water (Lepper 2005), but there are few other approaches of this type. As indicated,... 

S. E. Methylmercury in a fresh--water food chain, p. 199-211, Internal. Conf on Hea Metals in Environment, Vol. II, Part I, Toronto, Canada, 1975-... 

---