Thallium poisoning occurs due to an exposure to a large amount of this highly toxic metallic element. Its compounds are also toxic, and they can adversely affect several vital organs of the body.
Thallium is the chemical element, represented by the symbol TI. It can be found in trace amounts in the Earth’s crust. Earlier, it was obtained mainly as a byproduct from the smelting of lead, copper, and zinc ores. This metallic element is usually soft-gray in color and resembles tin. But it discolors and becomes bluish-gray in color, when exposed to the air.
This metallic element and its compounds are known for being highly toxic, and they can be easily absorbed by the skin. Thallium poisoning can occur, if someone inhales or ingests a large amount of this toxic element. Even skin contact can be dangerous, for which a lot of precautions need to be maintained while handling this toxic element and its compounds.
An exposure to a high level of this metallic element can produce several harmful effects. The toxicity of this element is mainly attributed to the resemblance of the univalent thallium ions to potassium ions in an aqueous solution. Due to this resemblance, this toxic element can easily enter the body through the potassium uptake pathways. This however, disrupts many vital cellular processes taking place within the body.
The long-term exposure to this element in large amounts can eventually affect the nervous system. On the other hand, the ingestion of a high level of thallium even for a short period of time can affect the vital organs, like the heart, lungs, liver, and the kidneys, along with the nervous system. However, the effects of ingesting a small amount of this element and its compounds for a prolonged period of time are not known with certainty.
The following are some of the most common signs and symptoms of this poisoning:
- Nausea and vomiting
- Severe abdominal pain
- Blood in stool
- Numbness of the extremities like the fingers and the toes
- Temporary hair loss
- Loss of reflexes
- Shortness of breath
- Muscle wasting
Chronic poisoning on the other hand, can cause hair loss, headaches, loss of appetite, excessive tiredness, leg pain, vision disturbances, and depression.
Thallium poisoning can be treated with Prussian blue, an antidote for this toxic element. Prussian blue is administered orally to prevent the absorption of thallium in the intestine. Prussian blue absorbs this metallic element, while releasing potassium inside the body. The thallium-contaminated Prussian blue then comes out in the stool. This treatment option is effective if Prussian blue is administered within 6 hours, following the ingestion of this toxic element or its compounds.
Other treatment options available for this condition are dialysis, and the administration of certain medications that can help treat the poisoning by increasing the excretion of this metallic element. Diuresis and potassium chloride are also used to increase its excretion. Sometimes, EDTA (ethylenediaminetetraacetic acid), penicillamine, sodium iodide, thiouracil, and dimercaprol are also used for treating this condition.
Despite its toxicity, thallium was widely used in ant killers and rodenticides. Today, it is used for producing low melting glasses, specialized eyeglasses, transmission devices, photoelectric sensors, imitation diamonds, and electronic devices. A very small amount of this element is also used in myocardial perfusion test, which is a diagnostic test employed for evaluating certain heart conditions.
To prevent poisoning, it is very important to handle this metallic element and its compounds carefully. In this regard, government has set certain guidelines related to the exposure to this toxic element in workplaces. The Occupational Safety and Health Administration (OSHA) has established the exposure limit of thallium at 0.1 mg per cubic meter of air in workplaces. On the other hand, the National Institute for Occupational Safety and Health (NIOSH) has suggested that the presence of 15 mg thallium per cubic meter of air be considered dangerous for life.
Disclaimer: This article is for informative purposes only, and should not be replaced for the advice of a medical professional.