Dissolved and Total Thallium in Great Lakes Waters

Cheam, Venghuot; Lechner, J.; Desrosiers, R.; Sekerka, Ivan; Lawson, Greg; Mudroch, A.

doi:10.1016/s0380-1330(95)71049-8

Cited by 41 publications

(26 citation statements)

References 23 publications

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“…Dissolved Pb is about twice as concentrated as Tl, which was reported to be higher than dissolved Cd in Lakes Ontario and Erie [7]. Total Pb is about 7-times more concentrated than total Tl.…”

Section: Dissolved and Particulate Pb And Tlmentioning

confidence: 89%

“…A Laser-Excited Atomic Fluorescence Spectrometer (LEAFS) makes possible direct analysis of real substrates for various elements [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, thallium (Tl) is the least studied, least cited priority element even though it is next neighbor to those 3 elements in the periodic table and is known to be more toxic than Pb and Cd [8][9]. Cheam et al [7] attributed this dilemma to the possible historical difficulties with the detection of Tl compared to other toxic metals. They based this hypothesis on their unexpected finding that the concentration of Tl in Great Lakes waters is greater than that of Cd, yet there had been no published Tl data compared to much Cd data reported for this very important ecosystem.…”

Section: Introductionmentioning

confidence: 99%

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LEAFS determination and concentration of metals in Great Lakes ecosystem

Cheam

Lechner

Desrosiers³

et al. 1996

Analytical and Bioanalytical Chemistry

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A Laser-Excited Atomic Fluorescence Spectrometric (LEAFS) method for Tl determination has been extended to investigate the direct determination (without preconcentration nor acid digestion) of total Pb, for which the method validation was successfully achieved by using a standard reference material as well as many spike recoveries of digested and undigested unfiltered water samples. The method was applied to study total and dissolved Pb in many water columns collected from different stations in Lake Ontario. Dissolved Pb was found to be about twice as much as dissolved Tl, and total Pb about seven times higher than total Tl. Seventy five percent of Pb is in particulate form versus 11% for Tl. Also, a simple cold dissolution procedure using HNO(3) and HF (not a hot acid digestion) is proposed to "liquefy" sediments in a form suitable for LEAFS analysis and was used to analyze a sediment core, where pore water samples were also collected. The interaction dynamics of Tl within the natural environment of a water/pore water/sediment system from Lake Erie was assessed. The calculations of fluxes suggest a strong similarity between Tl and Cd geochemical transport. The paper also presents for the first time a genuine sediment pore water profile of Tl concentration, which ranged from sub- to 40 ng/l and which was directly determined by LEAFS.

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Section: Dissolved and Particulate Pb And Tlmentioning

confidence: 89%

“…A Laser-Excited Atomic Fluorescence Spectrometer (LEAFS) makes possible direct analysis of real substrates for various elements [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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LEAFS determination and concentration of metals in Great Lakes ecosystem

Cheam

Lechner

Desrosiers³

et al. 1996

Analytical and Bioanalytical Chemistry

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“…In fresh surface water (e.g., lake water, river water and stream water), thallium concentration varies in different localities. What is more interesting is that river water running through mining areas contains higher thallium concentration (Zitko et al, 1975), whereas high thallium in lake waters is due to the precipitates of thallium-bearing coal dust (Cheam et al, 1995).…”

Section: Distributions Of Thallium In Natural Watersmentioning

confidence: 99%

Environmental impact of thallium related to the mercury-thallium-gold mineralization in southwest Guizhou Province China

Xiao¹

2001

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Toxic metals associated with metal mineralization and mining are critical targets for environmental studies. Thallium, as a typical toxic metal, has received less attention from a geo-environmental perspective since thallium deposits are relatively rare.This study focuses on natural accumulation of thallium associated with Hg-Tl-(Au) mineralization in the Lanmuchang area in southwest Guizhou Province, China, as a case study for thallium hazard in a geo-environmental perspective. It aims at understanding of the occurrence, the transfer processes and the environmental impacts of thallium related to natural processes and human activity. The distribution and dispersion of thallium together with mercury and arsenic in bedrock, sulfide ore, coals, soil, sediment, ground and surface waters, crops and vegetation have been examined.This study shows that the Lanmuchang area can be characterized as a specific geological context of thallium, mercury and arsenic accumulations. The extensive occurrences of sulfide minerals, such as lorandite, cinnabar, realgar, orpiment and pyrite are the primary carriers of Tl, Hg and As in the rocks and ores. Thallium occurs either as isomorphous substitution in the structure of sulfide minerals of mercury ores, arsenic ores coals, or as a pure thallium mineral lorandite.Tl, Hg and As accumulations are characterized by their high concentrations in rocks/ores, soils, sediments, (sub)surface waters and various crops. The range of thallium concentrations are 33-35000 ppm in sulfide ores, 12-46 ppm in coals, 33-490 ppm in host rocks, 25-1100 ppm in secondary minerals, and 6-330 ppm in outcropped host rocks. Thallium concentrations in soils in the mineralized area range from 53 to 282 ppm, from 21 to 100 ppm in alluvial deposits or foundation soils, from 40 to 46 ppm in slope wash material, and from 2.2 to 29 ppm in undisturbed natural soil. A high concentration has also been observed in sediments, ranging from 10 to 3700 ppm. Thallium concentrations are also high in the deep groundwater of the thallium-mineralized area (13.4-1102 \lg/\), decreasing away from the area to a background level of less than 0.005 |ig/l. In stream water, thallium concentration ranges from 0.3 to 33 jig/1, with marked high contents in downstream sections which likely originated from an unidentified groundwater discharge. In the edible parts of various vegetables and cereals, thallium ranges from 0.21 to 494 ppm (dry weight). The uptake of thallium is more pronounced in vegetables than in cereals, and the highest accumulation occurs in green cabbage.The dispersion of thallium together with mercury and arsenic in the specific ecosystem of Lanmuchang is constrained by the original Tl-Hg-As sulfide mineralization, the specific topography and hydro-geomorphology, and by the disturbance of human activity. High values of thallium are concentrated in the mineralized and mining area; away from this area, thallium concentrations decreases gradually to a background level. Thallium from bedrocks is accumulated in soils, se...

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“…A recent study found that the average concentrations of Tl are higher than those of Cd in waters of the Great Lakes and that they occasionally exceed those of Pb in some contaminated areas. 6 In spite of the recognized potential hazards of the growing levels of pollution, little has been done to understand the chemistry of thallium in any of the environmental media.…”

Section: Introductionmentioning

confidence: 99%