Mercury bioaccumulation

Wang and Wai [43] showed that bioaccumulated mercury in plants can be recovered using a methanol-modified supercritical-fluid carbon dioxide containing a dichromate liquid. 

S Wang, CM Wai. Supercritical fluid extraction of bioaccumulated mercury from aquatic plants. Environ Sci Technol 30 3111-3114, 1996. 

Fig. 15-8 The mercury cycle, demonstrating the bioaccumulation of mercury in fish and shellfish. Reprinted with permission from An Assessment of Mercury in the Environment" (1978) by the National Academy of Sciences, National Academy Press, Washington, DC.

A number of environmental issues have received widespread publicity (Table 7.1), from major accidents at plants (e.g., Seveso and Bhopal) to the global and regional impacts associated with energy utilization (e.g., carbon dioxide, acid rain, and photochemical oxidants), the improper disposal of chemical waste (e.g., Love Canal and Times Beach), and chemicals that have dispersed and bioaccumulated affecting wildlife (e.g., PCBs and DDT) and human health (e.g., cadmium, mercury, and asbestos). 

In a report from the U.S. EPA (1980), fish contained between 10,000 and 100,000 times the concentration of methyl mercury present in ambient water. In a study of methyl mercury in fish from different oceans, higher levels were reported in predators than in nonpredators (see Table 8.2). Taken overall, these data suggest that predators have some four- to eightfold higher levels of methyl mercury than do nonpredators, and it appears that there is marked bioaccumulation with transfer from prey to predator. 

In a laboratory study (Borg et al. 1970), bioaccumulation of methyl mercury was studied in the goshawk (Accipiter gentilis). The details are shown in Table 8.3 below. 

Thus, chickens bioaccumulated methyl mercury to about twice the level in their food, whereas goshawks bioaccumulated methyl mercury to about four times the level present in the chicken upon which they were fed. The period of exposure was similar... 

Mercury, tin, lead, arsenic, and antimony form toxic lipophilic organometallic compounds, which have a potential for bioaccumulation/bioconcentration in food chains. Apart from anthropogenic organometallic compounds, methyl derivatives of mercury and arsenic are biosynthesized from inorganic precursors in the natural environment. 

There is a vast range of aqueous organic pollutants with a wide toxicity profile. Some, e.g. polychlorinated biphenyls, certain herbicides, fungicides and pesticides, and organo-mercury compounds, are persistent and may bioaccumulate in the food chain. Trace contaminants such as sodium chloride, iron and phenols (especially if chlorinated) may also impart a taste to water. Typical consent levels for industrial discharges are provided in Table 13.10. 

Heavy metals may also be concentrated in passage up the food chain. Other pollutants, e.g. fungicides, pesticides, biocides, polychlorinated biphenyls or organic mercury compounds, are persistent and can therefore also bioaccumulate. 

FIGURE 1.1 Conceptual diagram of mercury cycling and bioaccumulation in the environment. 

Policy makers would benefit from a combination of strong field evidence of trends and well-established models to draw upon when assessing the benefits of past or future policy decisions. Models of mercury cycling and bioaccumulation are not yet adequately predictive across a range of conditions and landscapes. Results from a national mercury monitoring program, if carefully designed, offer the potential to... 

Brumbaugh WG, Krabbenhoft DP, Helsel DR, Wiener JG, Eehols K. 2001. A national pilot study of mercury contamination of aquatic ecosystems along multiple gradients bioaccumulation in fish, U.S. Geological Survey Water-Biological Science Report BSR-2001-009. 

Historical data on the indicator. Existing information on the statistical variation, bias, and other interpretational attributes of potential biological indicators should be examined and considered in the design of a sampling program for assessing trends in mercury bioaccumulation. 

Bodaly RA, St. Louis VL, Paterson MJ, Fudge RJP, Hall BD, Rosenberg DM, Rudd JWM. 1997. Bioaccumulation of mercury in the aquatic food chain in newly flooded areas. In Sigel A, Sigel H, editors, Metal ions in biological systems, Vol. 34 Mercury and its effects on environment and biology. New York (NY) Marcel Dekker Inc., p. 259-287. 

Bowles KC, Apte SC, Maher WA, Kawei M, Smith R. 2001. Bioaccumulation and biomagnification of mercury in Lake Murray, Papua New Guinea. Can J Fish Aquat Sci 58 888-897. 

Downs SG, Macleod CL, Lester JN. 1998. Mercury in precipitation and its relation to bioaccumulation in fish a literature review. Water Air Soil Pollut 108 149-187. 

Gorski PR, Cleckner LB, Hurley JP, Sierzen ME, Armstrong DE. 2003. Factors affecting enhanced mercury bioaccumulation in inland lakes of Isle Royale National Park, USA. Sci Total Environ 304 327-348. 

Hill WR, Stewart AJ, Napolitano GE. 1996. Mercury speciation and bioaccumulation in lotic primary producers and primary consumers. Can J Fish Aquat Sci 53 812-819. 

Johnston TA, Leggett WC, Bodaly RA, Swanson HK. 2003. Temporal changes in mercury bioaccumulation by predatory fishes of boreal lakes following the invasion of an exotic forage fish. Environ Toxicol Chem 22 2057-2062. 

Morel FMM, Kraepiel AML, Amyot M. 1998. The chemical cycle and bioaccumulation of mercury. Annu Rev Ecol Systematics 29 543-566. 

Odin M, Feurtet-Mazel A, Ribeyre F, Boudou A. 1994. Actions and interactions of temperature, pH and photoperiod on mercury bioaccumulation by nymphs of the burrowing mayfly Hexagenia rigida, from the sediment contamination source. Envhon Toxicol Chem 13 1291-1302. 

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