Blood thallium

A. Specific levels. Urinary thallium is normally less than 0.8 mcg/L. Concentrations greater than 20 mcg/L are evidence of excessive exposure and may be associated with subclinical toxicity during workplace exposures. Blood thallium levels are not considered reliable measures of exposure, except after large exposures. Hair levels are of limited value, mainly in documenting past exposure or in forensic cases. 

There are no recommended means for monitoring exposure to thallium. However, it is suggested that thallium in urine is a better indicator of recent exposure than blood thallium. The ACGIH TLV for soluble thallium compounds is 0.1 mg/m ... 

Thallium 0.0005 0.002 Hair loss changes in blood kidney, intestine, or liver problems Leaching from ore-processing sites discharge from electronics, glass, and pharmaceutical plants. 

Exercise tolerance (stress) testing (ETT) is recommended for patients with an intermediate probability of CAD. Results correlate well with the likelihood of progressing to angina, occurrence of acute MI, and cardiovascular death. Ischemic ST-segment depression during ETT is an independent risk factor for cardiovascular events and mortality. Thallium myocardial perfusion scintigraphy may be used in conjunction with ETT to detect reversible and irreversible defects in blood flow to the myocardium. 

Thallium has been determined in 10 ml of ashed serum or in urine by extracting with sodium diethyldithiocarbamate into MIBK n°). More recently, Savory and co-workers 1131 described a wet digestion procedure for 50 ml of urine or 5 ml of serum in which the thallium is separated by extracting the bromide into ether, evaporating the ether and then taking up in dilute acid for aspiration. As little as 0.1 ppm is determined in urine. Curry et al.114) determined less than 1 ng of thallium in 200 /d of urine by using the tantalum sample boat technique. The sample in the boat is dried by holding the boat 1 cm from the flame and then it is inserted into the flame where it is vaporized. A similar procedure is used for >3 ng of thallium in 50-100/al of blood, except that the blood is preashed with 3 drops of nitric acid. Since the tantalum boat method is susceptible to interelement interferences, the method of standard additions is used for calibration. 

The prosecution argued that Curley had planned to poison her husband, Robert, in cold blood for his life insurance money. She seized the opportunity when Robert Curley took a job that involved remodeling the labs in the chemistry building at Wilkes University. Joann began to add thallium to the ice tea that Robert took to work each day in a thermos, thinking that even if the authorities eventually made a diagnosis of thallium... 

Silver, lead, copper(l). and thallium(I) thiocyanates are insoluble and mercuiy(II), bismuth, and tm(II) thiocyanates slightly soluble. All of these, are soluble in excess of soluble (e.g., ammonium) thiocyanate, forming complexes. Iron(III) thiocyanate gives a blood-red solution, used in detecting either Fe(lll) or thiocyanate in solution, and is extracted from water by amyl alcohol. It is not formed in the presence of fluoride, phosphate and other strongly complexing ions,... 

The effect of this silatrane on the acid resistance of erythrocytes has been examined using a model anaemia induced by a heavy metal salts8). For this purpose 2 ml of 0.001% thallium nitrate and 2 ml of 0.1% or 0.01% l-(0,0-diethylphosphone-methyl)-3,7,10-trimethylsilatrane solution were added to the blood of rats. Then the blood was incubated for 1 hour at 37 °C. 

The availability of strongly chelating extractant reagents for a number of metals has lead to the development of procedures in which the metal is extracted from minimally treated blood or urine and then quantified by atomic absorption analysis. The metals for which such extractions can be used include cobalt, lead, and thallium extracted into organic solvent as the dithiocarbamate chelate, and nickel extracted into methylisobutyl ketone as a chelate formed with ammonium pyrro-lidinedithiocarbamate. 

Repeat the procedure with 5 ml of each of the diluted standard solutions, and with 5 ml of water (blank). Plot the absorbance of each standard solution against the concentration of thallium, and read off the concentration in the sample. The calibration curve should be linear in the range 0 to 4 ag/ml. Method for Urine. The method is the same as that given for blood, above, except that the pH of the... 

Concentrations of thallium in the blood or urine of unexposed subjects are usually less than 0.01 iLig/ml. Clinical symptoms of intoxication are associated with blood concentrations of about 0.1 iLig/ml values of 8 to 10 LLg/ml have been reported. Urinary concentrations of up to 20 LLg/ml may be seen in exposed subjects. Thallium salts are highly toxic and doses of about 12 mg/kg of a soluble salt may be fatal. 

OSHA PEL TWA 0.1 mg(Tl)/m3 (skin) ACGIH TLV TWA 0.1 mg(Tl)/m3 (skin) -(Proposed (inhalable fraction) 0.1 mg/m Not Classifiable as a Human Carcinogen) SAFETY PROFILE Poison by ingestion and subcutaneous routes. Human systemic effects blood pressure lowering, change in motor activity, muscle weakness. When heated to decomposition it emits very toxic fumes of Tl and I . See also IODIDES and THALLIUM COMPOUNDS. 

The sources of ionizing radiation are nuclear power plant, nuclear material processing, and radionuclide generation for nondestructive purposes. Medical and chemical laboratories use these radionuclides—for example, iodine, thallium, and barium—as tracers. The danger of mishandling these materials could cause release of these materials into the environment. Other than medical diagnostic tests for fracture of bones and constriction of blood vessels, these are used for the treatment of cancers. 

Thallium diphenyl trinitro-a-naphthoxide.— This salt crystallises in brilliant orange needles, which melt to a blood-red liquid at 282° C. With the exception of its complete solubility in hot alcohol, it resembles the corresponding ethyl derivative. 

Thallium is a rather uncommon element. Still, some of its compounds have important applications. For example, thallium sulfate (TI2SO4) has long been used as a rodenticide (rat and mouse poison). One form of thallium is sometimes used to study the flow of blood in the body. It shows how well the heart is working. 

The use of cobalt radiation treatments for cancerous tumors was described in Example 26-3. Several other nuclides are used as radioactive tracers in medicine. Radioisotopes of an element have the same chemical properties as stable isotopes of the same element, so they can be used to label the presence of an element in compounds. A radiation detector can be used to follow the path of the element throughout the body. Modern computer-based techniques allow construction of an image of the area of the body where the radioisotope is concentrated. Salt solutions containing "iNa can be injected into the bloodstream to follow the flow of blood and locate obstructions in the circulatory system. Thallium-201 tends to concentrate in healthy heart tissue, whereas technetium-99 concentrates in abnormal heart tissue. The two can be used together to survey damage from heart disease. 

The principle of dipyridamole and adenosine thallium imaging is related to their coronary arteriolar vasodilator properties. Dipyridamole inhibits adenosine cellnlar renptake, resulting in increased concentrations of adenosine in the blood and tissues. Adenosine is a potent coronary artery vasodilator and can increase perfusion four to five times over baseline. Areas distal to a coronary artery obstruction will show a relative hypoperfnsion compared with normal coronary arteries because there is reduced perfusion pressure owing to preferential perfusion of normal segments over stenotic segments. Acutely, these areas will appear as cold spots, but on the redistribution scans, the defects will fill, indicating viable bnt jeopardized myocardium. 

Dobutamine, a synthetic catecholamine, increases heart rate and cardiac output, resulting in an increase in myocardial oxygen demand. Ischemia develops in areas where stenosis prevents the increase in oxygen demand from being met with increased blood flow. Ischemia is detected by ECHO as regional wall motion abnormalities or with thallium scanning. 

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