Thallium is a rather rare and scattered metal on our planet. But, despite this, quite often there are cases of poisoning with this element. The course of intoxication with thallium is severe, and deaths occur quite often. By its toxicity, it is similar to arsenic and lead.
Below will be considered the physico-chemical properties of this metal, the field of application, the toxic effect on the human body, as well as signs and clinic of thallium poisoning, therapy and existing antidotes.
Physical and chemical properties of thallium
The substance is a soft powder having different colors depending on the compound. Thallium in its pure form has a bluish tint and belongs to the transition metals of group III of the periodic table. It is monovalent and trivalent, and monovalent thallium compounds are more toxic.
This element exists in nature in a scattered form (1 gram per 1 cubic meter), so its extraction is carried out in production or in the processing of heavy metal salts (lead, zinc).
Thallium compounds are poorly soluble in water and fats. The element exists mainly in the form:
- nitrous oxide;
- halide salts (iodide, bromide, chloride);
- Clerici solution.
Thallium refers to elements found in the human body, but the significance of which is still unknown. Presumably thallium enters the human body with plant foods.
In addition to plants, its sources are:
- tobacco smoke;
- industrial smoke;
- dust in the room.
In humans, thallium is distributed evenly. It is found in fats in an insoluble form, in muscles, its minimum amount is found in adipose and connective tissue, as well as in teeth, hair, and colon. Normal is the content of thallium in the body 0.1 mg, with a large muscle mass - 0.5 mg.
Thallium and its compounds are used:
in infrared night vision devices;
- in optical glasses;
- in geological studies of ore and rocks;
- in low-temperature thermometers;
- in Cherenkov counters;
- as part of complex conductors;
- in the production of poison for rodents, insecticides and pesticides;
- as part of fluorescent paints;
- in the manufacture of artificial gems.
Workers in many industries have direct contact with this substance. Therefore, its toxic effect is of great interest.
Thallium poisoning are acute and chronic. Chronic poisoning occurs in production workers in contact with this metal. Acute poisoning is the largest percentage of the total number of intoxications. Children who have accidentally swallowed pesticides, or insecticides, or rodents are often affected. Fatal poisoning with thallium can be the result of his deliberate taking for the purpose of suicide or murder.
Symptoms of poisoning
Acute poisoning often occurs when a dose of thallium containing drugs is taken in excess of 1 gram. But the substance can enter the body through the skin and respiratory tract. The element is absorbed within an hour almost completely. It penetrates the bloodstream and spreads throughout the body. Fatal poisoning with thallium, possibly from a dose of 600 mg.
More waistline settles in the kidneys, since it is the main organ of excretion. The salivary glands secrete more thallium, but with saliva it is again swallowed and absorbed in the intestine. In the liver and myocardium is also determined by its high content. For thirty days, only half of the consumed dose is eliminated from the body.
Acute and chronic poisonings with this metal differ in time, but they have common clinical manifestations.
In the next 3-4 hours, the first symptoms of thallium poisoning appear, characteristic of most intoxications:
- intestinal bleeding.
During the following week, symptoms of the nervous system appear:
- paresthesia (numbness) of the limbs;
- muscle pains;
- ataxia (impaired coordination);
- cranial nerve damage;
- vision loss
In addition to the above symptoms, there are later signs of thallium poisoning from other body systems.
Respiratory system - cough, shortness of breath, possible pulmonary edema or paralysis of the respiratory muscles.
- Heart and blood vessels - pain in the heart, tachycardia, increased blood pressure.
- Skin - rash, alopecia (alopecia), dermatosis, white blotches on the nail plates.
- Vision - atrophy of the retina.
- Kidneys - possibly a decrease in glomerular filtration rate, an increase in the level of urea in the blood, a decrease in the amount of urine.
Deadly thallium poisoning begins suddenly. Symptoms may appear simultaneously or sequentially at short intervals. Subfebrile or fever, nausea, vomiting, diarrhea, intestinal bleeding can be supplemented by acute bronchitis, pulmonary edema, psychosis, loss of consciousness, or even coma. Death in acute poisoning with a lethal dose occurs within 7–10 days.
In chronic thallium poisoning, the symptoms are erased, the latent period lasts longer, and the clinical picture appears only in the latter stages. Signs of disruption of the gastrointestinal tract are practically absent.
The first manifestations can be:
- muscle weakness;
- vision loss;
- impotence development.
Diagnosis of poisoning
Diagnosis of thallium poisoning is very difficult, as tallotoksikoz disguises as a third-party disease. Especially carefully you need to ask the patient about his work, about what he was taking for the last week, whether he was in contact with pesticides or insecticides.
All patients with suspected poisoning with thallium salts take a urine test, it is possible to detect the output element in it.
In addition, thallium is well detected using X-rays and X-ray examination can be used for diagnosis. On the x-ray will be seen eaten substance. The level of its location in the lumen of the gastrointestinal tract can be judged on the duration of use.
Treatment of poisoning with thallium for a long time, requires hospitalization. Therapy is based on:
- on breeding unchanged;
- on binding substances and removing it from the body;
- neutralization with antidotes.
In the case of acute intoxication, treatment should begin with gastric lavage. It is desirable to carry out this procedure still at home, because until the patient enters the hospital, most of the thallium is already absorbed into the blood. Washing can be carried out with activated carbon, ipecac solution, sodium thiosulfate or potassium iodide. At the same time, even at home, you can drink magnesia, mannitol or salt for the British laxative effect and diuretics to enhance urination.
In a hospital, hemodialysis is repeated.
Recommended intake of potassium chloride 3–9 grams per day intravenously or intravenously. It prevents the reabsorption of thallium in the renal tubules.
If breathing is impaired, lubeline hydrochloride should be injected; in case of tachycardia and arrhythmias, cardiac drugs should be administered.
B vitamins are recommended to relieve symptoms of the nervous system.
An antidote for thallium has been sought for a long time. Many studies have been conducted with various substances and as a result the most suitable has been found. This is Prussian blue or as it is also called, Prussian blue. She is known to many since the school chemistry course. This substance contains potassium, which replaces thallium in the body. The most effective Prussian blue in the form of a solution. She removes thallium with feces.
Prevention and consequences of poisoning
Workers who are in contact with thallium in production should:
use personal protective equipment (special shoes, clothing, gloves, respirators);
- take a shower immediately after work;
- not to eat food and any drinks in the workplace;
- regularly undergo preventive medical examinations;
- eat full.
The consequences of thallium poisoning depend on the dose, the duration of the contact and the general body resistance. Intoxication can later threaten impotence, infertility, an increase in the number of congenital defects, chronic diseases of the gastrointestinal tract and respiratory system, mental and hormonal disorders. Death can occur from heart attack and stroke.
If the treatment was started on time, the dose was small, then after a few months it will be completely removed from the body.
Let's sum up. Thallium is a highly toxic element. Poisoning them often ends in death. Intoxication with this substance is possible both at home and at work. All body systems are affected, especially muscular and nervous. Treatment activities should be started as early as possible. It is desirable to introduce an antidote - Prussian blue. Workers in contact with thallium at work should not ignore the precautions and should regularly pass urine for analysis.