Although thallium comes used in industry does not appear to create employment risks. The action of the thallium at the biochemical level is not yet known and all we can say is that its metabolism is linked to that of potassium. After a single dose of thallium salts occurs a gastrointestinal reaction that can pass unnoticed. After a couple of days, a burning sensation starts in the feet and hands with Muscle weakness, ataxia, and constipation. From a clinical point of view, poisoning. by thallium is more difficult to recognize than other poisonings.
Diagnosis and treatment
If left untreated, thallium poisoning can be fatal. Once the diagnosis is clear, potassium ferrocyanate can be administered. Thallium in this way is chelated in the intestines and excreted with feces. The metal that has already penetrated the tissues is protected by the antidote.
Source: Vadecum of poisoning therapy by Roy Goulding