Thallium is a chemical element frequently used in infrared detectors, electronic and pharmaceutical industry and production of glass. Sometimes, thallium is also used to poison insects and other animals. This is a highly toxic element, mostly forbidden in many countries all over the world. Even the smallest dose of 1g is fatal for humans. Thallium is not a selective poison, so it is often called “poisoner’s poison”.
This is a soft, silver metal, usually found as byproduct of copper, lead or zinc production. People can be poisoned by inhaling or ingestion of thallium and also by penetration through the skin. Water containing this element was often used for murder, because it doesn’t have any taste or smell.
This element was discovered in 1861, in England. For many years, it was used to treat various health conditions, because people weren’t aware of its toxicity. After some time, it was used as an efficient insecticide and rodenticide, but since the 1973 many countries stopped that use, too.
Everything that contains thallium is toxic material. People handling this metal should always avoid direct contact with the skin and work in well-ventilated area. There are some rules for people dealing with thallium: they must not be exposed to more than 0.1mg of thallium per m2 of their skin and mustn’t work more than 40 hours per week. Thallium is water soluble and really easily absorbed through the skin. This element is known to be a threat, because it can provoke cancer in people.
Person poisoned by thallium can experience vomiting, diarrhea, weakness, hair loss and also multiple organ failure. First symptoms usually appear several days after the exposure to thallium. This poison is known to affect the heart, lungs, liver and kidneys.
There have been cases that people lived for 14 days after ingesting a fatal dose of this toxic material.
To diagnose thallium poisoning, toxicologists will use hair follicles. Prussian blue pigment can help people poisoned with thallium, but only if it was applied at time.
Whenever toxicologists find that someone died because of thallium poisoning, they will always suspect on murder. Accidental poisoning is extremely rare, since thallium and its products are banned or restricted in many countries.
Thallium is highly toxic but, it's still used for something. It can be used to make fake diamonds, infrared devices, sensors and some eyeglasses. Thallium is also used in medicine, as a stress test known as myocardial perfusion imaging test.