Changes in thallium distribution in the scalp hair after an intoxication incident.

In cases of criminal thallium poisoning, forensic investigation is required to identify the amount and time of thallium exposure. Usually, blood and urine thallium levels are respectively used as biomarkers. Additionally, hair has the unique potential to reveal retrospective information. Although several studies have attempted to clarify how thallium is distributed in hair after thallium poisoning, none have evaluated the time course of changing thallium distribution. We investigated changes in the distribution of thallium in hair at different time points after exposure in five criminal thallotoxicosis patients. Scalp hair samples were collected twice, at 2.6 and 4.2-4.5months after an exposure incident by police. Results of our segmented analysis, a considerable amount of thallium was detected in almost all hair sample segments. The thallium exposure date estimated from both hair sample collections matched the actual exposure date. We found that determination of thallium amounts in hair samples divided into consecutive segments provides valuable information about exposure period even if a considerable time passes after exposure. Moreover, when estimating the amount of thallium exposure from a scalp hair sample, it is necessary to pay sufficient attention to individual differences in its decrease from hair.

Clinical evaluation of desferrioxamine (DFO) for removal of thallium ions in rat.

An investigation was conducted to evaluate the ability of DFO following the administration of thallium salt in male Wistar rats. Thallium was introduced to several groups of weanling male Wistar rats via different means, through drink, food and intraperitoneal injection. A control group was fed on a diet containing a normal level of iron. After a period of 30 days, all the rats administered thallium were severely anemic and showed toxicity symptoms through loss of hair, an increase in thallium and a decrease in iron levels in the blood. Chelation therapy was carried out to remove the toxic element from the body. The ability of desferrioxamine (DFO) in removing thallium was investigated by injection of this chelator for one week to the remaining rats of similar groups. The results showed that the thallium level present in the blood was significantly reduced and, at the same time, the iron concentration returned to the normal level. It was concluded that DFO chelator is able to remove thallium from the body and could be used for the treatment of complications and eradication of symptoms of thallium intoxication.

Uptake of thallium from naturally-contaminated soils into vegetables.

Thallium transfer from naturally (pedogeochemically) contaminated soils into vegetables was studied. Three different types of top-soil (heavy, medium, and light) were used for pot experiments. The soils were collected from areas with low, medium, and high levels of pedogeochemical thallium (0.3, 1.5 and 3.3 mg kg(-1)). The samples of vegetables were collected and analysed. The total content of thallium in soil and the type of soil (heavy, medium and light), plant species and plant variety were found to be the main factors influencing thallium uptake by plants. The uptake of thallium from soils with naturally high pedogeochemical content of this element can be high enough to seriously endanger the food chain. These findings are very important because of the high toxicity of thallium and the absence of threshold limits for thallium in soils, agricultural products, feedstuffs and foodstuffs in most countries, including the Czech Republic.

[Acute effects of the administration of potassium on the organ uptake of Tl+ in the rabbit]. / Efectos agudos de la administración de potasio sobre la captación orgánica del Tl+ en el conejo.

This paper describes the acute effects produced by administering potassium (2.7 and 5.5 mg.per kg of weight) to rabbits intoxicated with 10 and 30 mg.kg-1 of thallium. Acute capture (90 minutes) of thallium by skeletal muscle, left ventricle, liver and renal medulla and cortex is studied. Different doses of thallium were found to modify the organic capture in the studied organs with quantitative differences. The administering of potassium also modified the magnitude of capture, in different magnitudes, in the various organs. The modification produced depends more upon the studied organ than on the dose of potassium given. The skeletal muscle seems to manage the thallium-potassium interaction depending on the activation of sodium-potassium ATPase. The liver does not seem to be directly affected by the thallium-potassium interaction. The left ventricle captures thallium very rapidly, and also seems to depend on the activation of sodium potassium ATPase, and potassium increases thallium capture. The renal medulla captures 4 to 5 times more thallium than its cortex and the high dose of thallium seems to saturate the medulla's capture. The renal cortex's capture was not renal elimination of thallium is activated by potassium. The renal cortex uptake was not modified by potassium but the renal thallium elimination seems to be activated by potassium. The uptake by the renal medulla is diminished by potassium, suggesting a thallium-potassium interaction similar to the competitive inhibition described by McCall et al. (1985).