THALLIUM

From Big Medical Encyclopedia

THALLIUM (Tl) — chemical element III of group of a periodic system of elements of D. I. Mendeleyev; at. number 81, at. weight (weight) 204,39. It is open in 1861.

T. silver-white soft metal. In the nature meets in polymetallic ores, pyrites. Average content in crust (Clark) 4,5*10 - 5  % on weight. Is oxidized on air at the room temperature. Reacts with chlorine, bromine, iodine. Receive T. in parallel with receiving lead, zinc and other metals from waste and semi-products of polymetallic ores, transferring them to soluble salts, to-rye then process and clear.

T. and its connections find application in instrument making, in production of optical glasses, semiconductors, at division of diamonds, in chemical and other industries; is a part of a number of alloys with magnesium, selenium, zinc. Also salts T have wide use.: haloid, sulfate, sulfide, carbonate of T., tellurides, selenides, ant molo - new acid T. (liquid of Klerichi), etc.

Radioisotopes T are known. with mass numbers from 184 to 210, behind an exception 203Tl and 205Tl, to-rye are stable. In medicine use 199Tl, 204Tl and it is the widest — 201Tl. At radio-diagnostic testings 199Tl and 201Tl enter intravenously in fiziol. solution. Being bpol. an analog of potassium, these isotopes quickly and actively accumulate a myocardium. Drugs of thallium chloride, 199Tl or 201Tl use in radio isotope diagnosis (see) for a stsintigrafiya of a myocardium, a research of disturbances of cardiovascular system, including microcirculation, for a venografiya. Researches are conducted by means of the gamma camera or the high-speed scanner which is adjusted on fo-toppk radiations 60 — 80 kev with a width of power window of 15 — 20%. The obtained data process on the computer.

204Tl apply in the form of applicators (see. Radioactive drugs ).

204Tl-applicators apply in dermatology and ophthalmology to treatment of diseases with superficial localization of process — neurodermatitis, eczema, a hemangioma, a sclerite, a keratitis, etc.; they are imposed directly on the center of defeat. The maximum run [] - particles 204Tl in fabrics — 3,4 mm. Total doses of local radiation at various diseases — from 600 to 4500 I am glad (6 — 45 Gr). Absorbed doses at intravenous administration 201Tl on all body make 0,17 — 0,24 is glad! mkyur (4,6-10-11 — 6,5-10 ~ and Grbk) and counting on one kidney (critical body) — 0,39 — 0,65 I am glad / mkyuri (10,5*10 - 11 — 17,6*10 - 11 Gr/Bq). At use 199Tl these sizes it is much less. During the work with drugs of radioactive thallium it is necessary to be guided by «Health regulations of work with radioactive materials and sources of ionizing radiation».

Professional harm

During the receiving and use of T. the main professional vrednost are aerosols of disintegration and condensation of T. During the work with T. pollution of integuments and clothes working, the equipment and building constructions, production rooms can take place. T. and its connections are highly toxic. On the nature of toxic action remind lead (see) and arsenic (see). At the same time direct dependence of toxicity of connections T is not revealed. from their rastvorikhmost in water.

In an organism of T. arrives through a respiratory organs, went. - kish. path, unimpaired skin. T. possesses the expressed cumulative action, it is long is late in an organism (preferential in a thyroid gland, sialadens and hair) and it is slowly allocated from an organism through kidneys, intestines, to a lesser extent through sweat and mammary glands. The elimination half-life with urine reaches 10 — 12 days. Content of thallium in urine 10 ~ is normal of 6 mg of %, in hair of 10_3 mg of %.

At hit of T. in an organism depending on a dose and duration of influence development of acute, subacute and chronic poisoning is possible. Existence of stage of latency from several hours to several weeks is characteristic. To number of the main manifestations of toxic action of T. in an acute stage refer defeats went. - kish. path (vomiting, diarrhea, abdominal pains) and nervous system (frustration of a dream, concern, ataxic gate, etc.). Hron. poisoning is shown by onychalgias, spasms in gastrocnemius muscles, weakness in extremities. In the subsequent development of a polyneuritis, sharp emaciation, damage of a liver and kidneys, a visual disturbance, damage of skin (a peeling, dermatitis) is possible. The most characteristic sign of both acute, and chronic poisoning of T. the alopecia is (see).

Acute management at poisoning of T.: a gastric lavage water with active coal (see the Gastric lavage) and 0,3% solution of sodium thiosulphate, purpose of salt laxative. The artificial diuresis and a long hemodialysis is effective (see Poisonings, treatment of a thallotoxicosis). At acute and hron. poisonings of T. depending on a condition of the patient carry out a symptomatic treatment.

Examination of working capacity — see St. Examination .

Maximum allowable concentration in air of a working zone for bromide and iodide T. — 0,01 mg/m 3 .

Preventive actions include a zone design of rooms with allocation of a «dirty» and «pure» zone, a continuity of technological process, its distance steering, tightness of the equipment. Elimination of direct contact with T is necessary. and its connections by means of mechanization and automation of the main working operations. All operations which are followed by allocation in air of aerosols of thallium or pollution of skin of ii of the equipment (packing of finished goods, in time a cut destruction of ampoules with T is possible., sorting or processing of the material containing T., etc.), it is necessary to carry out in boxes or cameras. Production rooms and the equipment shall be provided with effective local and all-exchange ventilation (see). Working shall be provided with individual protection equipment of a respiratory organs (see Respirators), and at the increased concentration it is necessary to use a LIZ-4 pneumohelmet, antidust overalls (see Clothes special), kerchiefs or hats, gloves two-layer, acid-resistant, protective footwear (see). Repair work and cleaning of the equipment needs to be carried out in pneumosuits. Strict observance of measures of personal hygiene (see), the equipment of sanitary inspection rooms is obligatory (see). Performing preliminary and periodic medical examinations (at least 1 time a year is very important, and at the operations connected with crystals growing, 1 time in 6 months). For all working with T. monthly determination of content of T is obligatory. in urine. The food allowance, protein-rich, is recommended by amino acids, microelements and vitamins.

Thallium in the medicolegal relation

thallous sulfate, acetate and thallous carbonate are Most toxic. Poisonings develop at intake and receipt through skin.

At court. - a medical research of a corpse find hemorrhages in a mucous membrane of a stomach, in initial department of a small bowel, tissues of a liver, thyroid gland; hypostasis and a hyperemia of a mucous membrane of a stomach and duodenum, dystrophic changes in a liver up to necroses; phenomena of nephrite, hemorrhage.

Court. - chemical determination of T. in internals, hair and bones make by a fractional method in the miner the lysate received at oxidation of cadaveric material concentrated sulfuric and nitric to-tami during the heating. For detection of T. chromogenic reactions are recommended: it forms with diamond or malachite green the complex connection painted in blue color which is well taken by toluene. In alkaline condition at pH 11,0 — 14,0 forms monosubstituted diti-zonat T. — pink or crimson color the complex which is easily taken by chloroform. For a full complex formation of the cations which are contained in natural state in human organs it is necessary to enter potassium cyanide into reaction. Undesirable influence of trivalent iron is eliminated with introduction to reaction of a gidroksilampn and citrate (tartrate) - ions.

Use of reaction of formation of a ditizonat of thallium allows to otdifferentsirovat thallium from antimony.

Quantitative determination of T. make photometric: maximum of light absorption of a chloride complex T. with tetraethyl-diamino-triphenyl-carbohydride sulfate of 635 — 640 nanometers, a monosubstituted ditizonat of T. — 505 nanometers. Minimum defined number of T. — 0,1 mg in 100 g of body.

T. the long time remains in a corpse in this connection court. - the chemical proof of poisoning of T. perhaps on remains of the exhumed corpse in many years after death.



Bibliography: Harmful substances in the industry, under the editorship of N. V. Lazarev and I. D. Gadaskina, t. 3, page 423, L., 1977; Kosharko K. A., etc. Treatment of trophic ulcers and decubituses radioactive applicators with P32, Tl and Sr90, Medical radio-gramophones., t. 19, No. 3, page 33, 1974; Krylova A. N. Judicial and chemical detection and definition of thallium in biological material by a fractional method, Court. - medical examination, t. 14, No. 3, page 38, 1971; Fundamentals of forensic medicine, under the editorship of N. V. Popov, M. — L., 1938; T and x about in and T. S. Tally and his connections, in book: New data on toxicology of rare metals and their connections, under the editorship of 3. I. Israelson, page 24, M., 1967; Eventov A. Z., etc. Stsintigrafiya of a myocardium with chloride 201Tl, Medical radio-gramophones., t. 25, No. 7, page. And, 1980; In e n d of 1 V. J. Thallium poisoning, Arch. Derm, v. 100, p. 443, 1969; Special communication, thallium poisoning, Clin. Toxicol., v. 5, p., 89, 1972; Taraszkiewicz F. Rzadki obraz kliniczny ostrego zatrucia talem u dziecka, Arch. Med. Sad., t. 16, s. 61, 1964; Thrall J. o. Non cardiac organ perfusion imaging with thallium 201, J. nucl. Med., v. 19, p. 708, 1978; T o n a m i N. o. Clinical tumor scanning with TL-201 chloride, ibid., v. 18, p. 617, 1977; Wei-nig E. u. Schmidt G. Zur Vertei-lung des Thalliums im Organismus bei todlichen Thalliumvergifftungen, Arch. To-xikol., Bd 21, S. 199, 1966.


H. Yu. Tarasenko; V. F. Rubtsov (court.), A. B. Malinin, V. V. Sedov (I am glad.).

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