Urine thallium

In another cohort study, no statistically significant clinical effects were found, even though urinary concentrations ranging up to 236pg/liter indicated exposures above the threshold limit value (TLV) of O.lmg/m A urine thallium concentration of lOOpg/1 corresponds approximately to a 40 hour/week exposure at O.lmg/m and normal values range between 0.6 and 2.0pg/l. ... 

Residents near thallium-emitting cement plants had elevated urine thallium concentrations up to 100-fold higher than unexposed persons [57]. Urinary thallium values for nearby residents actually exceeded those found in workers at the plants. The presumed route of exposure was ingestion of home-grown vegetables. Some of the thallium urine concentrations approached values clinically considered to be toxic (>50p.g/liter) [58] but no definite cases of toxicity were documented [11,57]. An increased incidence of headaches and sleeplessness was noted. An occupational study of 128 workers at these cement plants revealed no evidence of clinical toxicity [12]. Another study of workers manufacturing thallium-based alloys also found no clinical effects [59]. Oil refinery workers who had elevated levels of urine thallium (10-23 p.g/day) were noted to have a mild alopecia areata [60]. A report exists of ill-defined functional changes in the nervous systems of workers exposed to thallium carbonate in the USSR [61]. 

Tb allium, which does not occur naturaHy in normal tissue, is not essential to mammals but does accumulate in the human body. Levels as low as 0.5 mg/100 g of tissue suggest thallium intoxication. Based on industrial experience, 0.10 mg /m of thallium in air is considered safe for a 40-h work week (37). The lethal dose for humans is not definitely known, but 1 g of absorbed thallium is considered sufficient to kHl an adult and 10 mg/kg body weight has been fatal to children. In severe cases of poisoning, death does not occur earlier than 8—10 d but most frequently in 10—12 d. Tb allium excretion is slow and prolonged. For example, tb allium is present in the feces 35 d after exposure and persists in the urine for up to three months. 

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. 

After exposure to 137Cs or thallium salts, the approved adult dosage is 3 g orally three times a day the corresponding pediatric dosage (2-12 years of age) is 1 g orally three times a day. Serial monitoring of urine and fecal radioactivity... 

The treatment of thallium poisoning is rather ingenious. It takes three forms diuretics eliminate thallium through increased urine production Prussian blue dye traps thallium excreted into the gut, preventing its reabsorption and potassium chloride supplements displace the thallium that has already been absorbed into the tissues. These measures allowed the unfortunate child from Qatar to make a complete recovery. 

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. 

Thallium salts have some of the characteristics of the ideal poison, being tasteless and colourless, but detection of thallium, for example in urine, is straightforward and can occur even two months after a single dose. The metal remains in the body after death and is not destroyed or lost by burial or cremation. 

Gregus and Klaassen carried out a comparative study of fecal and urinary excretion and tissue distribution of eighteen metals in rats after intravenous injection. Total (fecal + urinary) excretion was relatively rapid (over 50% of the dose in 4 days) for cobalt, silver and manganese between 50 and 20% for copper, thallium, bismuth, lead, cesium, gold, zinc, mercury, selenium and chromium and below 20% for arsenic, cadmium, iron, methylmercury and tin. Feces was the predominant route of excretion for silver, manganese, copper, thallium, lead, zinc, cadmium, iron and methylmercury whereas urine was the predominant route of excretion of cobalt, cesium, gold, selenium, arsenic and tin. Most of the metals reached the highest concentration in liver and kidney. However, there was no... 

Thallium and thallium salts are readily absorbed by virtually all routes, with gastrointestinal exposure being the most common route to produce toxicity. Thallium also crosses the placenta freely. Thallium enters cells by a unique process governed by its similarity in charge and ionic radius to potassium. Unlike potassium, however, once thallium enters the cells, it is released slowly. It can concentrate in the liver and kidneys. Since it is soluble at physiological pH, it does not form complexes with bone. Most thallium is excreted in the urine, but it is excreted slowly and can be detected months after exposure. 

Stavinoha, IT. B., and J. B. Nash Extraction and Flame Spectro-photometric Estimation of Thallium in Urine. Analyt. Chemistry 32, 1965 (1960). 

The Rhodamine B method has been used for determining thallium in foods and minerals [22], zinc and cadmium [57] and lead [17]. The Brilliant Green has been utilized for determining thallium in sea water [58], urine [23], waters, sewage, and ores [59], cadmium [27,60], antimony [27], and indium [5]. 

Ariel M, Bach D. The determination of thallium in urine. Analyst 1963 88 30. 

A middle-aged woman came to the hospital with a history of repeated attacks of complete hairless over a period of ten months. She had diffuse pain in both legs and had experienced some gastrointestinal disturbance, with alternate diarrhoea and constipation. She had noticed a lack of sensation in her fingertips and also tingling and numbness in her feet. She also reported a slow progressive loss of vision which had started about six months after the first attack of alopecia. Traces of thallium were found in her urine and blood. It was later discovered that her husband had several times attempted to poison her with rat poison which contained thallium salts. After a follow-up examination six years later she still retained partial blindness. 

Extraction systems with following electrothermal atomic absorption spectroscopy (ET-AAS) may be useful in some cases. For example, Zendelovska and Stafilov (2001) used isoamyl acetate extraction with following ET-AAS for thallium analysis in sulfide minerals. Eleischer (1997) reported a detection limit of 0.8 JgL when using ET-AAS with matrix modification (uirmineralized urine, diluted 1 2). 

In work places, slight thallium intoxications with hair loss, visual disturbances, and unspecific symptoms have been observed, but no data on the dose-response relationship are available (Kazantzis 1986). Concentrations of up to 1 pg n L in whole blood and urine may be considered as normal (see Table 22.1). For thallium-exposed workers, a threshold limit of 50 pg L in urine has been proposed (Marcus 1985), but this high limit should be revised on the basis of new results. The substitution of thallium (e.g., by silver) in chemical processes is an important preventional measure. In Germany, a threshold limit for thallium at workplaces (until 1999,0.1 mgm ) has been dis-... 

Besides accidential or suicidal ingestion, there is occupational exposure of some groups of employees in the production and processing of heavy metal ores, manufacturing and use of thallium, its alloys and compounds, and in certain cement factories from roasting pyrites and ingestion of dust from the electric filter (Schaller et al., 1980). Whereas the excretion level in urine from persons without known occupational contact with thallium was found to be lower than 1.1 mg Tl/kg creatinine, it significantly increases upon exposure. No influence of the age of the person examined and the duration of employment, as well as no influence of alcohol and nicotine consumption was noted. 

Therefore, concentration of thallium in the urine can be considered a suitable parameter for the assessment of the presence of thallium in the body, without detection of further symptoms (Schaller et al., 1980). 

For thallium, the detection limits achieved in pure solutions at 276.8 nm are fairly good (about 0.3-0.5/Other cations in large excess, such as Fe and P, also depress the signal (Machata and Binder, 1973). Nitric acid soil extracts could be determined by platform atomization/standard addition without further separation (Hofer et al.. 1990). 

Urine, and saliva could be directly polarographed for thallium after addition of a EDTA/acetate supporting electrolyte (pH 4.7) on a mercury-film graphite electrode (Kauffmann et al., 1984), with a detection limit of 0.01 fig/L for 15 min deposition time (far above background levels). 

Collett. D.LN. and Jones, S.M. (1991). Determination of thallium in urine by graphite furnace atomic absorption spectrometry. At. Spectr., 12 (3), 69-73. 

There are medical tests available to measure levels of thallium in urine and hair. In addition, thallium can also be measured in blood however, this is not a good indicator of exposure since thallium only stays in blood a very short time. 

Once the capacity of quantitative FD for alkali and alkaline earth cations was established the investigations were expanded to a wide variety of metals. One focal point in this analytical expansion of the method represents the toxic, heavy metal thallium. This metal exerts a pronounced toxic effect on mammals. Poisonings by thallium ions normally proceed very slowly they are accompanied by loss of hair, severe polyneuritic symptoms and tachycardia, and can culminate in paralysis of the central nervous system. Atomic absorption is a common spectroscopic method for the determination of thallium concentrations down to a few ppm . The direct determination of thallium from human urine reveals a limit of detection of approximately 30 ppb, whereas direct estimation from plasma and brain tissue is not successful without pretreatment. 

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 ... 

Various values have been proposed as the upper limit of normal for the quantity of thallium in urine. Most published values for the upper limit of normal thallium concentration in urine are... 

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