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Topic: Thallium

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 Thallium - Wikipedia, the free encyclopedia
Thallium is highly toxic and is used in rat poisons and insecticides but since it might also cause cancer (although the EPA does not class it as carcinogen), this use has been cut back or eliminated in many countries.
Although the metal is reasonably abundant in the Earth's crust at a concentration estimated to be about 0.7 mg/kg, it exists mostly in association with potassium minerals in clays, soils, and granites and, thus, is not generally considered to be commercially recoverable from those forms.
Thallium was once an effective murder weapon before its effects became understood and an antidote (prussian blue) discovered.
en.wikipedia.org /wiki/Thallium   (1111 words)

 THALLIUM - LoveToKnow Article on THALLIUM   (Site not responding. Last check: 2007-11-07)
But the hydroxide of thallium, in most of its properties, comes very close to the alkali metals; it is strongly basic, forms an insoluble chloroplatinate, and an alum strikingly similar to the corresponding potassium compounds.
The best raw materials for the preparation of thallium are the flue-duits produced industrially in the roasting of thalliferous pyrites and the chamber muds accumulating in vitriol-chambers wrought with such pyrites; in both it is frequently associated with selenium.
Thallium forms two series of salts: thallous, in which the metal is monovalent; and thallic, in which it is trivalent.
80.1911encyclopedia.org /T/TH/THALLIUM.htm   (1681 words)

Thallium is an enigmatic element to study because of its highly divergent properties predicated upon its oxidation status.
Among the growing uses for thallium are in the semiconductor and laser industry, in fiber (optical) glass, in scintillographic imaging, in superconductivity, and as a molecular probe to emulate the biological function of alkali-metal ions.
Recycling of thallium in commercial products is not yet a serious business, and one has to be concerned about the long-term environmental effects of the growing technological applications of one of the most toxic and eccentric metals known to humankind.
pubs.acs.org /cen/80th/thallium.html   (808 words)

 Thallium (PIM 525)
Thallium is mainly excreted in the faeces (Barclay et al, 1953; Lund, 1956a, 1956b) though this may be decreased significantly by paralysis of the small intestine, a characteristic feature of thallium poisoning.
Thallium poisoning has a characteristic feature:the symptoms sign and indicate that the longest nerve fibers, both sensory and motor, are affected first, while shorter nerve fibers, such as those proximal to the limbs and in the cranial nerves, may be affected several days later.
It was non-toxic in the rat, with an LD of 17 mg/kg.
www.inchem.org /documents/pims/chemical/pim525.htm   (9148 words)

 Thallium   (Site not responding. Last check: 2007-11-07)
Thallium is suspected of carcinogenic potential for man. Thallium sulfate has been widely employed as a rodenticide and ant killer.
The electrical conductivity of thallium sulfide changes with exposure to infrared light, and this compound is used in photocells.
Thallium has been used in treating ringworm and other skin infections; however, its use has been limited because of the narrow margin between toxicity and therapeutic benefits.
www.scescape.net /~woods/elements/thallium.html   (401 words)

 ATSDR - ToxFAQs™: Thallium
Pure thallium is a bluish-white metal that is found in trace amounts in the earth's crust.
Thallium is used mostly in manufacturing electronic devices, switches, and closures, primarily for the semiconductor industry.
Thallium enters the environment primarily from coal-burning and smelting, in which it is a trace contaminant of the raw materials.
www.atsdr.cdc.gov /tfacts54.html   (920 words)

 Thallium   (Site not responding. Last check: 2007-11-07)
Thallium, Tl, is a metallic main group element, found in Group IIIb of the periodic table.
Thallium is occurs in the ores of zinc.
Thallium is used in photography to increase the sensitivity of the photosensitive silver halide emulsions.
www.ucc.ie /ucc/depts/chem/dolchem/html/elem/elem081.html   (82 words)

 thallium. The Columbia Encyclopedia, Sixth Edition. 2001-05   (Site not responding. Last check: 2007-11-07)
Thallium is a soft, malleable, lustrous silver-gray metal with a hexagonal close-packed crystalline structure.
Thallium is widely distributed in nature, but the only minerals rich in the element are crooksite and lorandite.
Thallium is used in low-melting alloys with other metals and in compounds.
www.bartleby.com /65/th/thallium.html   (236 words)

 Thallium (EHC 182, 1996)
Concentrations of thallium in the tissues of farm animals correlate with concentrations in the fodder.
An important aspect of thallium intoxication is the significant increase in lipid peroxidation and in the activity of the lysosomal enzyme ß-galactosidase.
The limited accumulation of thallium in the sediment was attributed in part to the short duration of the study and to the absence of organic matter and clay in the sand.
www.inchem.org /documents/ehc/ehc/ehc182.htm   (13742 words)

 EPA Ground Water & Drinking Water > breadcrumb? > Consumer Factsheet on: THALLIUM
Thallium is a metal found in natural deposits as ores containing other elements.
The leaching of thallium from ore processing operations is the major source of elevated thallium concentrations in water.
Thallium is a trace metal associated with copper, gold, zinc, and cadmium.
www.epa.gov /OGWDW/dwh/c-ioc/thallium.html   (815 words)

 Thallium (Tl) - Chemical properties, Health and Environmental effects
Due to accumulation of thallium in the bodies of humans, chronic effects consist, such as tiredness, headaches, depressions, lack of appetite, leg pains, hair loss and disturbances of the sight.
Thallium is partially water-soluble and consequentially it can spread with groundwater when soils contain large amounts of the component.
Thallium is very toxic to rats and is applied as a rat pesticide because of this.
www.lenntech.com /Periodic-chart-elements/Tl-en.htm   (372 words)

 USGS Minerals Information: Thallium
Thallium, a soft, bluish-gray, malleable heavy metal, was discovered by Sir William Crookes in 1861 while he was making spectroscopic determinations for tellurium on residues from a sulfuric acid plant.
Several thallium minerals, containing 16% to 60% thallium, occur in nature as sulfide or selenide complexes with antimony, arsenic, copper, lead, and silver but are rare and have no commercial importance as sources of this element.
Thallium also is recovered as a byproduct from the flue dust and residues generated during the roasting and smelting steps in the processing of these ores.
minerals.usgs.gov /minerals/pubs/commodity/thallium   (260 words)

 RAIS: Thallium (7440-28-0)   (Site not responding. Last check: 2007-11-07)
The subchronic RfDs are 8.00E-04 (thallium sulfate, chloride, and carbonate) or 9.00E-04 mg/kg/day (thallium nitrate and acetate) (EPA, 1994a), and the chronic RfDs are 8.00E-05 (thallium sulfate, chloride, and carbonate) or 9.00E-05 mg/kg/day (thallium nitrate and acetate) (EPA, 1994b-f).
Thallium isotopes are used in imaging procedures for the evaluation of myocardial disease (Hui, 1983; Kazantzis, 1986).
Subcutaneous injections of 7.8-15.5 mg/kg of thallium as thallium acetate were associated with degenerative changes in mitochondria and increased glycogen deposition in the liver (Herman and Bensch, 1967).
risk.lsd.ornl.gov /tox/profiles/thallium_f_V1.shtml   (4689 words)

 eMedicine - Toxicity, Thallium : Article by Igor Boyarsky, DO   (Site not responding. Last check: 2007-11-07)
Thallium is quickly distributed from the blood to the tissues with an apparent blood half-life of less than 5 minutes.
Thallium toxicity initially was described when thallium was used for ringworm infection because of a high incidence of adverse effects, primarily alopecia.
Laboratory evidence of thallium poisoning is limited because of the paucity of toxicology laboratories that perform a thallium assay.
www.emedicine.com /emerg/topic926.htm   (2628 words)

 Thallium acetate (CASRN 563-68-8), IRIS, Environmental Protection Agency
Thallium (I) salts were not mutagenic in reverse mutation assays using Salmonella typhimurium strains TA98, TA100, TA1535,and TA1538 and Escherichia coli strains B/r WP2 try and WP2 hcr try; use of hepatic homogenates was not specified (Kanematsu et al., 1980).
Negative results were obtained in a screening of thallium nitrate for induction of mitotic gene coversion and reverse mutation in the yeast, Saccharomyces cerevisiae (Singh, 1983).
Thallium carbonate (0.5-0.005 ug/kg/day) was positive in a dominant lethal test in male white rats (Zasukhina et al., 1983).
www.epa.gov /iris/subst/0111.htm   (1925 words)

 Medical Encyclopedia: Thallium and sestamibi stress tests (Print Version)
Thallium and sestamibi stress tests are nuclear imaging methods that provide a view of the blood flow into the heart muscle.
The thallium and sestamibi tests are also called “MIBI stress test” and “myocardial perfusion scintigraphy”, and are used to evaluate how well your heart is perfused (supplied with blood) at rest as compared with activity.
This is due to interference with the heart image from non-heart tissues such as the diaphragm (diaphragm attenuation), and, in women, the breast tissue ("breast attenuation").
www.nlm.nih.gov /medlineplus/print/ency/article/007201.htm   (1341 words)

Thallium was discovered spectroscopically in l861 by Crookes.
Thallium has been used, with sulfur or selenium and arsenic, to produce low melting glasses which become fluid between 125 and 150 deg C. These glasses have properties at room temperatures similar to ordinary glasses and are said to be durable and insoluble in water.
The mean abundance of thallium in the earth's crust is approximately 1 ppm.
www.speclab.com /elements/thallium.htm   (999 words)

 Thallium Stress Test
When the patient reaches his or her maximum level of exercise, a small amount of a radioactive substance called thallium is injected into the bloodstream.
The thallium mixes with the blood in the bloodstream and heart's arteries and enters heart muscle cells.
If no thallium is seen in some part of the heart muscle, the cells in this part of the heart are dead from a prior heart attack.
www.americanheart.org /presenter.jhtml?identifier=4743   (433 words)

 009. Poisoning by Thallium: Anil Aggrawal's Forensic Toxicology Page
Fatal dose of a poison is the average dose which is enough to kill an adult human being, while fatal period is the average period taken by the poison to kill.
She expressed her doubt to the doctors and on subsequent examination, she was indeed found to be suffering from thallium poisoning.
On detailed discussion with the child's parents it seemed that the most likely source of thallium was domestic poison used to eliminate cockroaches and rodents in the drains and septic tank of their home.
members.tripod.com /~Prof_Anil_Aggrawal/poiso009.html   (3393 words)

 Thallium definition - Medical Dictionary definitions of popular medical terms
Thallium: A metallic element having the symbol Tl and the atomic number 81 and an atomic weight of about 204.
A small amount of a radioactive form of thallium is used in the thallium scan of the heart to determine if the heart muscle is receiving an adequate flow of blood.
The word "thallium" is a Latinized version of the Greek "thallos" meaning "green stalk" because of a characteristic bright green line in the spectrum of the element.
www.medterms.com /script/main/art.asp?articlekey=18758   (401 words)

 Environmental Protection Agency
Acute exposure to thallium sulfate may include itching, burning, or tingling of the skin, muscular pain, headache, cranial nerve damage, convulsions, delirium, and coma.
If elapsed time since ingestion of thallium sulfate is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step 4.
Warning: Ingestion of thallium sulfate may result in sudden onset of seizures or loss of consciousness.
yosemite.epa.gov /oswer/CeppoEHS.nsf/firstaid/10031-59-1?OpenDocument   (710 words)

The chosen IDLH has been estimated from the data given by; ACGIH [1971] that LD values for different thallium compounds, by various routes of administration and for several species of animals ranged from 3 to 92 mg/kg [Downs et al.
Further support for the chosen IDLH can be gained from the statement by Deichmann and Gerarde [1969] that a dose of 0.2 gram (inorganic salts of thallium) may be lethal unless treatment if started promptly.
Therefore, the revised IDLH for soluble thallium compounds is 15 mg Tl/ m
www.cdc.gov /niosh/idlh/thallium.html   (345 words)

 RAIS: Thallium (007440-28-0)   (Site not responding. Last check: 2007-11-07)
Humans who ingested large amounts of thallium over a short time have reported vomiting, diarrhea, temporary hair loss, and effects on the nervous system, lungs, heart, liver, and kidneys as well as death.
Thallium sulfate, selenite, nitrate, chloride, carbonate, acetate, and thallic oxide have been placed in EPA's weight-of evidence Group D, not classifiable as to human carcinogenicity based on inadequate human and animal data.
The Dermal Chronic Reference Doses for Thallic Oxide, Thallium Acetate, and Thallium Carbonate are based on a gastrointestinal absorption factor of 0.5000.
risk.lsd.ornl.gov /tox/profiles/thallium_ragsa.shtml   (645 words)

 Chemistry : Periodic Table : thallium : key information
Here is a brief summary of the isolation of thallium.
Thallium metal would not normally be made in the laboratory as it is available commercially.
Crude thallium is present as a component in flue dust along with arsenic, cadmium, indium, germanium, lead, nickel, selenium, tellurium, and zinc.
www.webelements.com /webelements/elements/text/Tl/key.html   (221 words)

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