COBALT (With) — the element VIII of group of a periodic system of D. I. Mendeleyev, subgroup of iron, is a constant component of vegetable and animal organisms and is among the major microelements; it is physiologically active — influences a hemopoiesis and a metabolism. Isotopes (radionuclides) To. are widely used in medicine for radiation therapy, radiation sterilization of medical materials, products and pharmaceuticals and in radio diagnostic testings. Salts K. are applied as the pharmaceuticals promoting digestion of iron and stimulating its exchange in an organism. To. is a part of many antianemic medicines. To. and its connections are widely used in electronics, in metallurgy during the receiving alloys of metals and separate brands staly, as catalysts at production of dyes, and also for coloring of glass, paper and so forth. Long-living isotope 60Co is widely used in science, the equipment and agriculture as radio tracer and as the gamma-emitter in various radio isotope devices, installations for gamma-radiography, in plants for radiation. Organic compounds K. apply as a sikkativ and the accelerator in production of polyester plastics (stearate K.), tetracarbonyl K. use as the catalyst at various sinteza and for drawing cobalt coverings.
Sequence number To. 27, at. weight (weight) 58,933 2. To. it is a little widespread in the nature, its content in crust makes only 0,002 weight. %. He represents brilliant metal of silvery color with a pink shade, in chemical reactions shows the valency +2, and in the majority of the steadier complex connections valency + 3. Its t pl ° 1493 °, t kip ° 3100 °. In usual conditions To. it is chemically resistant on air and in water.
To. contains in trace amounts in river, lake and sea water, in sea plants, in organisms of fishes and other marine animals. From foodstuff most of all To. contains in peas (apprx. 15,0 mkg of %), beef liver (13,53 mkg of %), beet (12,1 mkg of %), a wild strawberry (9,8 mkg of %), a Siberian salmon (5,6 mkg of %), Dutch cheese (4,32 mkg of %).
Daily need of the person in To. it is definitely though there are data that it is equal to 40 — 70 not defined. In a human body and animals To. collects in a liver, kidneys, limf, nodes and ferruterous bodies. With urine at healthy people 6,0 — 6,2 mkg are every day removed To.
Influence To. on a metabolism at the person it is extremely diverse. In fiziol, doses it stimulates processes of a hemopoiesis, activating formation of erythrocytes, reticulocytes, leukocytes and hemoglobin (high doses To., on the contrary, oppress an erythrogenesis). According to V. N. Shustov (1967), K. causes oppression of tissue respiration with the subsequent formation of the erythropoietic factors providing normal synthesis of hemoglobin and strengthening of maturing of erythrocytes in marrow. It is established that the globin of hemoglobin of the person contains about 60 — 100 mkg of % of K. Aktivnost of the enzymes connected with membranes (generally hydrolytic), first of all phosphatases of intestines and a bone tissue, increases under the influence of ions of Co 2+ , especially at simultaneous action on enzyme of ions Mg 2+ .
The major role belongs To. at endogenous synthesis of polyneuramin 12 (see. Cyanocobalamine ).
Many reactions in a human body and animals are catalyzed by enzymes which prosthetic group includes Co atom (so-called B 12 - dependent and CoB 12 - dependent enzymes). In some cases To. instead of other bivalent cations (Mn 2+ , Mg 2+ , Zn 2+ etc.) undertakes a role of the activator of some enzymatic reactions.
Disturbance of a blood coagulation under the influence of K. Vozmozhno is established that change under influence is the reason of it To. structures of a molecule of fibrinogen.
Organic compounds K. have hypotensive and coronarodilator effect. According to experimental data of N. G. Leontyeva (1971), at long inhalation effect of vapors metal To. in blood serum concentration of the general cholesterol, lipidic phosphorus increases and size lecithin - cholesteric coefficient decreases. Oxides K. oppress activity of a thyroid gland, cause its hypoplasia, and also promote decrease in intensity of gas exchange. Some authors note communication between content To. in blood and an immune responsiveness of an organism.
Diseases of page are known - x. animals, caused by insufficiency To. in an organism (enzootic marasmus, a coastal disease, a shrubby disease, etc.). Diseases have local character and arise in the areas differing in low contents To. in the soil and in plants. Introduction of additional quantities To. in a forage of animals leads to their recovery.
The medicines containing To., promote digestion of iron, stimulating processes of its transformation in an organism. During the use of salts K. in therapeutic doses the hemoglobin content, number of erythrocytes, reticulocytes, leukocytes increases, in marrow there is strengthening of speed of oxygen consumption, intensity of phosphorylation increases.
There are experimental data on ability of some connections K., in particular Co 2 EDTA and Na 3 Co (NO 2 ) 6 , to prevent toxic effect of sodium cyanide (NaCN).
To. is a part of many antianemic means — Coamidum (see), ferkovena (see), cyanocobalamine (see). The drugs containing To., apply to treatment of patients with hypochromia anemias, hypoplastic anemia, etc.
Natural To. consists of one stable isotope 59 Co. 12 radioisotopes K are known., including 2 isomers, with mass numbers from 54 to 64. From them four — ultrashort-lived, with second and minute half-lives (cobalt-54, 62, 63, 64), four — short-lived, with hour half-lives (cobalt-55, 58 m, 60 m, 61) and four — with longer half-lives (cobalt-56, 57, 58, 60). From artificial radio-active isotopes K. have the greatest practical value 60 Co, and also 57 Co and 58 Co. In medicine 60 Co is widely applied at radiation therapy (see) and at radiation sterilizations (see) medical materials, products and pharmaceuticals; 57 Co and 58 Co are used in radio diagnostic testings.
Cobalt-60 (T 1/2 = 5,26 g) it was for the first time received on a cyclotron on nuclear reaction 59 Co (d, p) 60 Co (see. Nuclear reactions ). However further its began to receive radiation natural To. neutrons in the nuclear reactor on reaction 59 Co (n, scale) 60 Co. Cobalt-60 breaks up with emission of a difficult range of the beta radiation consisting of two components from which main component has the maximum energy E beta = 0,31788 MEV (99,88%), and a weak component — E beta = 1,4911 MEV (0,12%). Disintegration is followed by gamma radiation with E gmma = 1,1732 MEV (99,88%); 1,3325 MEV (100%).
For medical use various types of sources 60so are issued: for charging of the domestic gamma and therapeutic «Beam» installations and Rokus intended for a telecurietherapy use sources activity in 4000 curies; for intracavitary radiation therapy use sources in a type of the sterzhenk from a kobanik (alloy of cobalt with nickel) placed in hollow nylon or metal tubes (a radio cobalt beads, applicators of the different sizes in the form of the pins from a kobanikovy wire concluded in a cover from stainless steel); for interstitial therapy — the needles from stainless steel containing inside a thin kobanikovy wire with 60 Co, various sizes and with various distribution of activity on length of needles; for a contact therapy use flat and a special form (e.g., ophthalmologic) applicators, plastobalt (plastic with the cobalt balls which are contained in it) and other products with activity from shares to tens of millicuries (see. Radioactive drugs ).
Cobalt-57 (T 1/2 = 270 days) receive on a cyclotron, irradiating iron targets with deuterons on nuclear reactions 56Fe (d, n) 57Co and 57Fe (d, 2n) 57Co or nickel targets protons on reaction 60 Ni (p, alpha) 57 Co. Cobalt-57 breaks up electron capture (e. h. = 100%) with emission of 10 gamma lines from which the main four have energy E scale (MEV): 0,0144 (9,5%), 0,122 (85,6%), 0,136 (10,6%) and 0,692 (0,15%). Disintegration 57 Co is followed by also characteristic x-ray emission of iron with energy 6,46 kev (54%).
Cobalt-58 (T 1/2 = 71,3 days) can be received as in a cyclotron, irradiating with deuterons a target from iron on reaction 57 Fe (d, n) 58 And in the nuclear reactor, irradiating with Co a nickel target on reaction 58 Ni (n, p) 58 With that more simply is also more productive. Cobalt-58 breaks up by positron radiation with E beta + = 0,474 MEV (15%) and electron capture (85%) with simultaneous emission of annihilation gamma radiation with E scale =0,511 MEV (30%) and three gamma lines with energy (MEV): 0,8106 (99,44%), 0,8636 (0,69%) and 1,6748 (0,53%). Disintegration 58 Co is followed by also characteristic x-ray emission of iron with energy 6,47 kev (25,7%).
Radiofarm. drugs with 57 Co and 58 Co release in the form of marked them vitamin B 12 (cyanocobalamine) in penicillinic bottles also apply orally or parenterally, entering the patient 0,5 — 5 mkkyur of drug on one research. Drugs are used with the diagnostic purpose at identification of disturbances of absorbability of polyneuramin 12 at anemias, a disease of the operated stomach, diseases of a liver and intestines. 57 Co in the form of a complex with Bleomycinum apply to establishment of localization of tumors.
Activity of drugs with a telecobalt-57, 58, 60 is measured on them to 7 radiation; at relative measurements use model radioactive solutions and spectrometer gamma sources (see. Radiators exemplary ). Radioisotopes To. treat group of average radio toxicity. In a workplace without the permission a dignity. - epid, services there can be no more than 10 mkkyura of drug.
Professional harm and occupational health
In spite of the fact that To. is the bio-element participating in implementation of important exchange reactions of substances in an organism, in the raised doses it has toxic properties and treats group of industrial poisons of the second class of danger (see. Poisons industrial ).
In the course of receiving and use To. and its connections their receipt in an organism through a respiratory organs is possible (in the form of aerosols), partially through went. - kish. a path, and also through skin. Content To. in air in some cases can exceed maximum allowable concentration, especially at such operations as unloading, unloading and having sunk the loose materials containing To. At the enterprises of powder metallurgy during the receiving tungsten-cobalt hard alloys the dust of the mixed structure containing To can be emitted in air. to 3,33 mg/m 3 . Mix K., tungsten and titanium each of these metals separately has more expressed toxicity, than. The prof. contact with To. workers in the asbestos-cement industry, plasterers, concreters and another, working with liquid cement, and also painters and kolershchik have during the work with various colorants. To influence To. also nurses of rooms for medical procedures at injections of polyneuramin can be exposed 12 . Possess the most expressed toxic action well water soluble and biol, environments of salt K. (chloride To., etc.), and also metal To. All-toxic action To. it is shown by defeat preferential of a respiratory organs, systems of a hemopoiesis, tissue respiration, a nervous system and digestive organs. There are data that the elevated temperature of air (higher than 30 °) strengthens toxic action To.
At impact To. on an organism poisonings are possible acute and hron. Under production conditions at workers poisonings can preferential be observed hron, To., at the same time complaints to cough, disturbance of appetite, dispepsichesky frustration and disturbance of sense of smell are characteristic. Changes in upper respiratory tracts develop (hron, rhinitises, laryngitis, pharyngitises). At long contact with connections K. the phenomena hron, bronchitis, pneumonia and a pneumosclerosis are noted. Cases of bronchial asthma are described. At influence To. and its connections observed emergence cardiomyopathy (see). Changes of blood are found: increase in a hemoglobin content, increase in quantity of erythrocytes, a reticulocytosis, decrease in coagulability, at severe forms — anemia. Changes from a liver come to light patol, and symptoms of irritation of kidneys. In emergencies chances of acute poisonings To. Against the background of the expressed vegetovascular dysfunction and funkts. disturbances of a condition of c. the N of page noted scattered microfocal symptomatology.
Connections K. have the expressed sensibilizing properties, they can be the cause of development of the prof. of dermatitis, eczemas and giperkeratoz; there are instructions on development of allergic myocarditis. Toxic influence of connections K is established. on the course of pregnancy, childbirth and on fetation and the newborn.
Methods of definition To. in air are based on interaction of an ion of CO 2+ with nitrozo - R - I will merge also the subsequent colorimetry of the painted complex connection (test-sensitivity of 0,5 mkg in the analyzed volume). Definition is possible To. in urine and blood after their mineralization on reaction To. with nitrozo - R - I will merge or nitrozonaftoly.
Maximum allowable concentration metal To. and to its oxide for a working zone of production rooms it is equal to 0,5 mg/m 3 ; for tetracarbonyl and a karbonilgidrid To. and products of its disintegration — 0,01 mg/m 3 (on To.). For all inorganic compounds K. maximum allowable concentration is equal in water of reservoirs to 1 mg/l. Average daily maximum allowable concentration To. for free air — 0,5 mg/m 3 (To. and its connections) and 0,01 mg/m 3 (To. hydrocarbonyls).
Measures of the prevention
Due to the high toxicity To. and its connections at contact with them strict observance a dignity is required. - a gigabyte. norms and rules. Consecutive holding the preventive actions directed to the prevention of hit To is necessary. in air of rooms. The processes which are followed by a pylevydeleniye need to be transferred to wet technology, and to pressurize the raising dust equipment with the device of filters.
Control and management tekhnol. it is necessary to carry out by process by means of remote devices. Manual, heavy and dangerous works shall be mechanized. Before repair of the equipment its prerefining from is necessary To. Special attention shall be paid to sanitary and household devices and individual protection equipment. Protection of a respiratory organs and integuments and observance of rules of personal hygiene is required.
Contraindication to employment with connections K. are: sharply expressed rinolaringofaringita, hron, bronchitis, a pneumosclerosis, emphysema of lungs, bronchial asthma, organic diseases of c. N of page, the expressed endocrine and vegetative diseases, eczemas.
In the presence of persistent bronchitis with respiratory insufficiency, the bronchial asthma recuring eczemas, and also the expressed and permanent changes in lungs transfer into the work excluding contact with toxic connections K is required. (especially irritant action). Persons at whom dispepsichesky frustration, the easy phenomena of bronchitis come to light need observation and treatment without discharge for work. Treatment of patients symptomatic. At damage of upper airways appoint oil inhalations, at bronchitis — anti-spastic means, at a complication consecutive infection — antibiotics. If necessary — cardiacs. At anemia drugs of Ferrum reductum, fortifying means are used.
Are of great importance to lay down. - the prof. of an action. For prevention of occupational diseases during the receiving and use To. and its connections it is necessary to carry out medical examination at revenues to work and periodic survey of 1 times in 12 months. In medical examination participation of the therapist and according to indications — the stomatologist, the neuropathologist, the oculist and the dermatovenerologist is necessary. Blood test (hemoglobin, leukocytes, ROE) and X-ray inspection of bodies of a thorax is obligatory.
Bibliography: Brichenko V. S. Kliniko-elektroentsefalograficheskaya the characteristic of damages of a brain of the person at acute intoxication hydrocobalt carbonyls, Saturday. nauch. works Angarsk, nauch. - issled, in-that a gigabyte. work and the prof. having got sick., century 6, page 41, M., 1975; Harmful substances in the industry, under the editorship of N. V. Lazarev and I. D. Gadaskina, t. 3, page 531, L., 1977; Gadaskina I. D., and d and with to both N and N. D. and Filov V. A. Definition of industrial inorganic poisons in an organism, L., 1975; Levin V. I. Receiving radioisotopes, page 152, M., 1972; Lopukhova K. A. and Antonyev A. A. About a role of cobalt in emergence of a professional dermatosis at workers of the asbestos-cement industry, in book: Vopr, neuroendocrinal dysfunctions and allergology, under the editorship of Yu. K. Skripkin, page 60, M., 1971; Mashkovsky M. D. Pharmaceuticals, p. 2, page 100, M., 1977; Sinitsyn V. I. Telecobalt of So60, M., 1967, bibliogr.; With p and-ridonovav.s. ishabalinal.p. Pilot study of toxicity of tetracarbonyl of cobalt, Gigabyte. and dignity., No. 1, page 97, 1973; Toxicology of rare metals, under the editorship of 3. I. Iz-raelsona, page 164, 227, M., 1963; Shustov V. Ya. Microelements in hematology, page 13, M., 1967; Examination of working capacity at occupational diseases, under the editorship of K. P. Molokanov, etc., page 106, M., 1968.
N. Yu. Tarasenko; V. V. Bochkaryov (I am glad.), V. P. Fisenko (pharm.).