INDEPENDENT ENVIRONMENTAL CONSULTANCY
ABN 62 713 622 437
MINING & MERCURY
Mercury is found in the environment both in inorganic and organic forms. The latter are more toxic and in many organisms 60 to 95% of the mercury is organically bound. The toxicology of mercury and its compounds has attracted long-term attention since the Minimata Bay pollution incident in Japan. Considerable effort was devoted up to the mid-1970s to establishing baseline mercury concentrations following high levels, now recognised to be natural, found in top predator fish such as tuna and sharks.
Mining has long been a source of mercury, either through the use of mercury in gold amalgamation or from environmental releases during the processing and treatment of ores containing high mercury levels.
Mercury entering aquatic environments has a high affinity for organic matter and suspended solids due to adsorption and coprecipitation processes. In the bottom sediments, the most important conversion is the bacterially mediated methylation of mercury involving the addition of methyl groups to the mercuric ion (Hg2+) by means of enzymatic activity.
Although both inorganic and organic forms of mercury can be taken up by aquatic organisms, methylated forms are more readily accumulated due to their high lipophilicity and normally account for greater than 80% of the total body burden. Food chain biomagnification of mercury, coupled with slow elimination rates, results in high mercury burdens in top predator organisms.
Mercury is used in gold mining as an amalgamate to separate fine gold particles from other mineral components in processed ore/gravel.
People engaged in small scale mining may be exposed to high concentrations of mercury by inhaling the fumes arising from the burning of the amalgam in pans or furnaces. Exposure of indigenous peoples to naturally elevated mercury levels in their aquatic food resources has also been shown, and attributed to high dietary intakes of top-of-the-food chain fish species.
Mercury analyses of multimedia can be carried out on effluents, water, soils, aquatic sediments, plants, fish, animals, and human scalp hair, urine, and blood.
EnviroGulf Consulting subcontracts ilocally or nternationally-registered analytical laboratories to conduct mercury analyses. The separate determination of inorganic from organic mercury compounds in environmental samples is required for assessing biotransformation and evaluating environmental fate, behaviour, and pathways:
The following types of mercury analysis can be undertaken:
EnviroGulf Consulting offers the following services:
The Principal of EnviroGulf Consulting has carried out numerous metal contamination surveys of natural environments and exposed human populations, for example:
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