Gold Mining in Siberia as a Source of Mercury Contamination of the Environment
367
observed in the area of the Itaka settlement near the GRC building, resulted from
the use of metallic mercury, its careless storage and transportation. Elevated mercury concentrations (1.24 mg/kg) were also detected in sandy soil in the area of the
Baleyzoloto GEP, exceeding the background values of the town of Baley by 20 times.
In the area of the Lyubov mine, which is characterized by the maximum air
contamination among other settlements, the highest level of mercury concentration in the soil surface (0.03-0.57 mg/kg) was registered with an average of
0.20 mg/kg. A threefold increase in mercury content level was observed in
cultivated soils in comparison with the background values.
Very intensive soil contamination was determinated around refining plants in
Novosibirsk (Roslyakov and Kirillova 1995). A contrast technogenic mercury
halo, extended according to the wind and occupying an area of about 1 km\ was
formed around the plant. Mercury concentrations in the soils are high and lie in
the range of 0.03-18.9 mg/kg, average 0.5 mg/kg. Values exceeding MPC (2.1 mg/
kg) are registered. Mean background mercury content in the soils of Novosibirsk
accounts for 0.08 mg/kg and for soils of the Novosibirsk Oblast 0.03-0.04 mg/
kg. In conjunction with mercury, high lead concentrations are registered in the
soils around the refining plant: 10-478 mg/kg, average 140 mg/kg, local city
background value 41 mg/kg and regional 24 mg/kg. In solid snow fraction,
sampled in the area of soil anomaly, the mercury content reaches 6.8 mg/kg, and
lead content up to 100 mg/kg, when local background accounts for 0.04 and
15 mg/kg, respectively. Hence, refining plants are significant sources of mercury
and other toxic metal contamination of the environment.
Soils strongly bound mercury due to complexing with humus functional
groups, and half-life of such complexes is estimated at 250 years (Trachtenberg
and Korshun 1988). Thus, mercury pollution of soils is of a stable durable
character and may result in pollution of the atmosphere, waters, plant and
animal biocenosis, thus affecting the health of man.
5.4
Natural and Technogenic Waters
Mercury contamination of natural and industrial water streams and reservoirs in
the areas impacted by processing of placer and ore gold deposits may be caused
by: (1) direct emission of metallic mercury into the water in the process of sluice
amalgamation; (2) contaminated wastes of GDP and GEP; (3) emission of
dissolved and suspended mercury forms from processed gravels and rocks;
(4) precipitation from the atmospheric air in the form of vapour, aerosols, dust
and rainfall. High mercury contamination of water objects may take place in the
process of erosion of tailing dumps and heaps of GDP and GEP with flood water
and rainfall (Table 1).
Dissolved forms of mercury have low migratory ability due to their active
sorption on suspended particles of clay and organic materials. Therefore,
for the correct estimation of mercury contamination extent in water objects,
levels of mercury concentration in dissolved and suspended condition have to be
determined.
367
observed in the area of the Itaka settlement near the GRC building, resulted from
the use of metallic mercury, its careless storage and transportation. Elevated mercury concentrations (1.24 mg/kg) were also detected in sandy soil in the area of the
Baleyzoloto GEP, exceeding the background values of the town of Baley by 20 times.
In the area of the Lyubov mine, which is characterized by the maximum air
contamination among other settlements, the highest level of mercury concentration in the soil surface (0.03-0.57 mg/kg) was registered with an average of
0.20 mg/kg. A threefold increase in mercury content level was observed in
cultivated soils in comparison with the background values.
Very intensive soil contamination was determinated around refining plants in
Novosibirsk (Roslyakov and Kirillova 1995). A contrast technogenic mercury
halo, extended according to the wind and occupying an area of about 1 km\ was
formed around the plant. Mercury concentrations in the soils are high and lie in
the range of 0.03-18.9 mg/kg, average 0.5 mg/kg. Values exceeding MPC (2.1 mg/
kg) are registered. Mean background mercury content in the soils of Novosibirsk
accounts for 0.08 mg/kg and for soils of the Novosibirsk Oblast 0.03-0.04 mg/
kg. In conjunction with mercury, high lead concentrations are registered in the
soils around the refining plant: 10-478 mg/kg, average 140 mg/kg, local city
background value 41 mg/kg and regional 24 mg/kg. In solid snow fraction,
sampled in the area of soil anomaly, the mercury content reaches 6.8 mg/kg, and
lead content up to 100 mg/kg, when local background accounts for 0.04 and
15 mg/kg, respectively. Hence, refining plants are significant sources of mercury
and other toxic metal contamination of the environment.
Soils strongly bound mercury due to complexing with humus functional
groups, and half-life of such complexes is estimated at 250 years (Trachtenberg
and Korshun 1988). Thus, mercury pollution of soils is of a stable durable
character and may result in pollution of the atmosphere, waters, plant and
animal biocenosis, thus affecting the health of man.
5.4
Natural and Technogenic Waters
Mercury contamination of natural and industrial water streams and reservoirs in
the areas impacted by processing of placer and ore gold deposits may be caused
by: (1) direct emission of metallic mercury into the water in the process of sluice
amalgamation; (2) contaminated wastes of GDP and GEP; (3) emission of
dissolved and suspended mercury forms from processed gravels and rocks;
(4) precipitation from the atmospheric air in the form of vapour, aerosols, dust
and rainfall. High mercury contamination of water objects may take place in the
process of erosion of tailing dumps and heaps of GDP and GEP with flood water
and rainfall (Table 1).
Dissolved forms of mercury have low migratory ability due to their active
sorption on suspended particles of clay and organic materials. Therefore,
for the correct estimation of mercury contamination extent in water objects,
levels of mercury concentration in dissolved and suspended condition have to be
determined.