- Email: [email protected]
Mercury contamination in the northern Pantanal region Mato Grosso, Brazil
42A
EXCAVATIONS:GROUNDWATER
This paper presents a critical analysis of the environmental responses to the releases of radionuclides and metals from the uranium mining and milling facilities of Pocos de Caldas into surface waters. An evaluation of groundwater contamination due to the migration of seepage water from the tailing dam was also performed. The study was based on monitoring data. It is shown that tailing effluent is the most important source of Mn and sulfate to the aquatic environment, while acid mine and waste rock drainage were found to be the main sources of 226Ra, 23SU, AI, and Fe. Results from groundwater under the tailing dam showed only sulfate contamination. (Authors) 961343 Mercury contamination in the northern Pantanal region Mato Grosso, Brazil W. Von Tumpling Jr, R.-D. Wilken & J. Einax, Journal of Geochemical Exploration, 52(I-2), 1995, pp 127-134. In gold mining areas around the world, mercury is used to separate gold by amalgamation. This often causes mercury contamination. Such a situation near the goldmines in the Pocone area, Mato Grosso, Brazil was investigated. Concentrations of mercury were determined in water, sediment and air. The results obtained in water showed elevated mercury concentrations of between 18 and 160 ng/l (filtered) compared to 25 _ 0.9 ng/l in a reference site. In sediments, total mercury concentrations were in the range from 23 to 198 ng/g (dw). In the ambient air near the gold mine region, concentrations of up to 6 ng/m 3 mercury were detected. Two meters above contaminated tailings, the values found were ten times higher. These results provide first information on transformations of mercury species and their pathways under tropical conditions. (from Authors) 961344 The effect of nickel mining and metallurgical activities on the distribution of heavy metals in Levisa Bay, Cuba H. Gonzalez & M. Ramirez, Journal of Geochemical Exploration, 52(1-2), 1995, pp 183-192. The distribution of Ni, Co, Fe, Mn, Cu, Pb and Zn was investigated in surface and core sediment samples and in the leaves of the red mangrove (Rhizophora mangle) from Levisa Bay, an area affected by nickel mining and metallurgical activities. The results revealed that these activities have seriously polluted the sediments, especially by Ni, Fe, Co and Mn, with concentrations decreasing with increasing distance from discharge sources. The concentrations of Fe (0.64-22.66%) and Co, Mn and Ni (7.7-324, 125-2957 and 694764 lag/g, respectively) were up to two orders of magnitude greater than those of non-polluted coastal areas in Cuba. Rhizophora mangle was shown to be a useful bioindicator of heavy metal pollution in the studied ecosystem. (Authors) 961345 Geochemistry of iron ochres and mine waters from Levant Mine, Cornwall R. J. BoweU & I. Bruce, Applied Geochemistry, 10(2), 1995, pp 237-250. The geochemistry of metal-rich mine waters and mineral precipitates from the Levant mine, Cornwall, has been examined. Sulphide oxidation at Levant mine has produced a wide range of secondary sulphides, oxides, chlorides, sulphates and carbonates in a gossan environment. The mine waters display a wide variation in alkalinity, pH, chloride, sulphate, sodium, potassium and heavy metal content which can be explained by variable degrees of mixing between acidic, metal-rich, rock drainage waters and neutral to alkaline sea waters. Where pools of mine drainage are stagnant native copper and cuprite are precipitated. Precipitation of iron oxhydroxides, caused by a pH increase, also occurs and leads to copreeipitation of other metals, including CA, Co, Pb, Mn, Ag and Zn, thus limiting the release of dissolved metals in solution from the mine. (from Authors)
961346 Geomorphology and pollution: the environmental impacts of lead mining Leadhills, Scotland J. S. Rowan, S. J. A. Barnes, S. L. Hetherington, B. Lambers & F. Parsons, Journal of Geochemical Exploration, 52(1-2), 1995, pp 57-65. The Glengonnar Water has experienced severe environmental degradation resulting from historic lead mining operations. Though now abandoned, the legacy of the mining era remains in the form of river and floodplain sediments grossly polluted with metals, particularly lead which exhibits surface concentrations in excess of 75 000 mg kg "l total-Pb. Geomorphological investigations link the most recent mining period to a major phase of floodplain aggradation, which acted as an efficient sink for particulate-bound metals. Preliminary evidence indicates that lateral and vertical variations of metals (both total and available) can be accounted for in terms of age of deposit, distance downstream and local hydraulic conditions. The effectiveness of floodplains to interrupt the delivery of sediment-bound contaminants was highlighted by a metals budget developed for the main channel length. This confirmed that channel-bank erosion of contaminated floodplains soils is now the major source of metals to the fluvial system. (from Authors) 961347 Downstream effects of mine drainage on benthos and fish in a Norwegian river: a comparison of the situation before and after river rehabilitation J. V. Arnekleiv & L. Storset, Journal of Geochemical Exploration, 52(1-2), 1995, pp 35-43. Parts of the Norwegian river Gaula are strongly polluted from former mining activity in the area. In the most polluted parts of the river the concentration levels of Cu and Zn in 1986-1987 were up to 155 lag 1-I and 186 lag 1-1, respectively. In 1989 the spoil heaps in the mining area were covered with protective layers of moss-covered plastic. In 1991-1992 the concentration levels of Cu and Zn had decreased by 75% and 65%, respectively. Animal life in the polluted area seemed to be strongly affected by the trace metals in 1986-1987. The 1991-1992 results showed a marked increase in the number of species and in the number of individuals of each species of Epbemeroptera and Plecoptera, compared with the results from 1986-87. In 1987 trout died after an exposure of one to two days on three test sites in the river, whereas in 1991-1992 40-75% of the trout survived an exposure period of several weeks at two of the sites. Electrofishing in 1991-1992 indicated recolonization of trout in the lower parts of the former affected and uninhabitable area. (from Authors) 961348 Lead and sulphur isotope dilution during dispersion from the Faluo mining area P. Ostlund, P. Torssander, C.-M. Morth & S. Claesson, Journal of Geochemical Exploration, 52(1-2), 1995, pp 91-95. Sulphur and lead isotopes in water and sediments have been measured in the river Dalalven system. The river receives sulphate from two principle sources; atmospheric deposition in the river drainage area and continuously weathered sulphide rich mine waste. Lead in the sediments originates from both the ambient geological materials, as well as from the mine waste. Mixing models were applied to both sulphur and lead isotopes. The results demonstrate that it is possible to define and quantify the emission sources and dispersions in a receiving water body and its sediments. (Authors) 961349 Distribution of 23°Th in milling wastes from the Zirovski vrb uranium mine (Slovenia), and its radioecological implications M. Krizman, A. R. Byrne & L. Benedik, Journal of Environmental Radioactivity, 26(3), 1995, pp 223-235. Thorium-230, together with 23SU and 226Ra, was determined in samples from the waste piles at Borst and Jazbec in the vicinity of the former uranium mine at Zirovski vrh, Slovenia.
EXCAVATIONS:GROUNDWATER
This paper presents a critical analysis of the environmental responses to the releases of radionuclides and metals from the uranium mining and milling facilities of Pocos de Caldas into surface waters. An evaluation of groundwater contamination due to the migration of seepage water from the tailing dam was also performed. The study was based on monitoring data. It is shown that tailing effluent is the most important source of Mn and sulfate to the aquatic environment, while acid mine and waste rock drainage were found to be the main sources of 226Ra, 23SU, AI, and Fe. Results from groundwater under the tailing dam showed only sulfate contamination. (Authors) 961343 Mercury contamination in the northern Pantanal region Mato Grosso, Brazil W. Von Tumpling Jr, R.-D. Wilken & J. Einax, Journal of Geochemical Exploration, 52(I-2), 1995, pp 127-134. In gold mining areas around the world, mercury is used to separate gold by amalgamation. This often causes mercury contamination. Such a situation near the goldmines in the Pocone area, Mato Grosso, Brazil was investigated. Concentrations of mercury were determined in water, sediment and air. The results obtained in water showed elevated mercury concentrations of between 18 and 160 ng/l (filtered) compared to 25 _ 0.9 ng/l in a reference site. In sediments, total mercury concentrations were in the range from 23 to 198 ng/g (dw). In the ambient air near the gold mine region, concentrations of up to 6 ng/m 3 mercury were detected. Two meters above contaminated tailings, the values found were ten times higher. These results provide first information on transformations of mercury species and their pathways under tropical conditions. (from Authors) 961344 The effect of nickel mining and metallurgical activities on the distribution of heavy metals in Levisa Bay, Cuba H. Gonzalez & M. Ramirez, Journal of Geochemical Exploration, 52(1-2), 1995, pp 183-192. The distribution of Ni, Co, Fe, Mn, Cu, Pb and Zn was investigated in surface and core sediment samples and in the leaves of the red mangrove (Rhizophora mangle) from Levisa Bay, an area affected by nickel mining and metallurgical activities. The results revealed that these activities have seriously polluted the sediments, especially by Ni, Fe, Co and Mn, with concentrations decreasing with increasing distance from discharge sources. The concentrations of Fe (0.64-22.66%) and Co, Mn and Ni (7.7-324, 125-2957 and 694764 lag/g, respectively) were up to two orders of magnitude greater than those of non-polluted coastal areas in Cuba. Rhizophora mangle was shown to be a useful bioindicator of heavy metal pollution in the studied ecosystem. (Authors) 961345 Geochemistry of iron ochres and mine waters from Levant Mine, Cornwall R. J. BoweU & I. Bruce, Applied Geochemistry, 10(2), 1995, pp 237-250. The geochemistry of metal-rich mine waters and mineral precipitates from the Levant mine, Cornwall, has been examined. Sulphide oxidation at Levant mine has produced a wide range of secondary sulphides, oxides, chlorides, sulphates and carbonates in a gossan environment. The mine waters display a wide variation in alkalinity, pH, chloride, sulphate, sodium, potassium and heavy metal content which can be explained by variable degrees of mixing between acidic, metal-rich, rock drainage waters and neutral to alkaline sea waters. Where pools of mine drainage are stagnant native copper and cuprite are precipitated. Precipitation of iron oxhydroxides, caused by a pH increase, also occurs and leads to copreeipitation of other metals, including CA, Co, Pb, Mn, Ag and Zn, thus limiting the release of dissolved metals in solution from the mine. (from Authors)
961346 Geomorphology and pollution: the environmental impacts of lead mining Leadhills, Scotland J. S. Rowan, S. J. A. Barnes, S. L. Hetherington, B. Lambers & F. Parsons, Journal of Geochemical Exploration, 52(1-2), 1995, pp 57-65. The Glengonnar Water has experienced severe environmental degradation resulting from historic lead mining operations. Though now abandoned, the legacy of the mining era remains in the form of river and floodplain sediments grossly polluted with metals, particularly lead which exhibits surface concentrations in excess of 75 000 mg kg "l total-Pb. Geomorphological investigations link the most recent mining period to a major phase of floodplain aggradation, which acted as an efficient sink for particulate-bound metals. Preliminary evidence indicates that lateral and vertical variations of metals (both total and available) can be accounted for in terms of age of deposit, distance downstream and local hydraulic conditions. The effectiveness of floodplains to interrupt the delivery of sediment-bound contaminants was highlighted by a metals budget developed for the main channel length. This confirmed that channel-bank erosion of contaminated floodplains soils is now the major source of metals to the fluvial system. (from Authors) 961347 Downstream effects of mine drainage on benthos and fish in a Norwegian river: a comparison of the situation before and after river rehabilitation J. V. Arnekleiv & L. Storset, Journal of Geochemical Exploration, 52(1-2), 1995, pp 35-43. Parts of the Norwegian river Gaula are strongly polluted from former mining activity in the area. In the most polluted parts of the river the concentration levels of Cu and Zn in 1986-1987 were up to 155 lag 1-I and 186 lag 1-1, respectively. In 1989 the spoil heaps in the mining area were covered with protective layers of moss-covered plastic. In 1991-1992 the concentration levels of Cu and Zn had decreased by 75% and 65%, respectively. Animal life in the polluted area seemed to be strongly affected by the trace metals in 1986-1987. The 1991-1992 results showed a marked increase in the number of species and in the number of individuals of each species of Epbemeroptera and Plecoptera, compared with the results from 1986-87. In 1987 trout died after an exposure of one to two days on three test sites in the river, whereas in 1991-1992 40-75% of the trout survived an exposure period of several weeks at two of the sites. Electrofishing in 1991-1992 indicated recolonization of trout in the lower parts of the former affected and uninhabitable area. (from Authors) 961348 Lead and sulphur isotope dilution during dispersion from the Faluo mining area P. Ostlund, P. Torssander, C.-M. Morth & S. Claesson, Journal of Geochemical Exploration, 52(1-2), 1995, pp 91-95. Sulphur and lead isotopes in water and sediments have been measured in the river Dalalven system. The river receives sulphate from two principle sources; atmospheric deposition in the river drainage area and continuously weathered sulphide rich mine waste. Lead in the sediments originates from both the ambient geological materials, as well as from the mine waste. Mixing models were applied to both sulphur and lead isotopes. The results demonstrate that it is possible to define and quantify the emission sources and dispersions in a receiving water body and its sediments. (Authors) 961349 Distribution of 23°Th in milling wastes from the Zirovski vrb uranium mine (Slovenia), and its radioecological implications M. Krizman, A. R. Byrne & L. Benedik, Journal of Environmental Radioactivity, 26(3), 1995, pp 223-235. Thorium-230, together with 23SU and 226Ra, was determined in samples from the waste piles at Borst and Jazbec in the vicinity of the former uranium mine at Zirovski vrh, Slovenia.