From Big Medical Encyclopedia

TRYTIY (Tritium, T) — radioisotope of hydrogen; it is applied in medicobiological researches. Mass number 3, an atomic nucleus of hyzone consists of one proton and two neutrons. Hyzone was for the first time received in 1934

by E. Rutherford, Olifant (M. L. Oliphant), P. Harteck. Radioactivity of T. it was found in 1939 by L. Alvarez and R. Cornog. Mass of atom T. — 3,017, half-life — 12,34 years, the maximum energy P ~ from spearing — 18,6 kev, mean energy — 5,7 kev, specific activity pure T. — 9600 curies/g (35,52*1013 Bq/g). Maximum and average run (3-cha-stits in air respectively apprx.

6 mm and 1 mm, in a soft biol. fabrics apprx. 6 microns and 1 micron.

T. it is continuously formed in the nature as a result of nuclear reactions of space radiation with elements of the atmosphere. Annual production kosmogenny T. — 1,5 — 3 Mkyuri (5,55*1010 — 11,1» 1010 MBK), its total quantity on the planet — 25 — 50 Mkyuri (92,5-Yu10 — 185,0-1010 MBK), at the same time 65% of T. 27% — in reservoirs of continents and a lithosphere, apprx. 8% — in the atmosphere are held in the ocean. During test thermonuclear explosions in 1952 — 1962 came to the atmosphere apprx. 5000 Mkyuri (185-1012 MBK) of T. In 1962 — 1963 concentration of an oxide of T., so-called tritium water (TNO), in surface waters of continents of the Northern hemisphere made about 3 nkyuri/l (111 Bk1l), after the termination of tests in 1963 this size considerably decreased and in 1973 — 1983 remained at the level apprx. 0,2 nkyuri/l (7,4 Bq/l). Annual exposure dose of the population from the radiation of T. is in limits 0,04 to 0,1 mrem.

In prokhmyshlenny conditions of T. receive as a result of radiation by neutrons of the lithium enriched with isotope 6Li3. Hyzone is used as a component of fuel mixture In reactions of thermonuclear fusion — explosive (see. Nuclear weapon) and managed. In the industry of T. use as the activator of a luminescence of phosphors in svetoznaka and svetosostava of constant action. Tritium radiators apply to ionization of air and neutralization of static electricity. In scientific research of T. sate targets for nuclear reactions, enter T. as a radioactive label in composition of organic compounds (see. Marked connections).

In medicine by means of an oxide of T. determine water volume in a body of the person for diagnosis of disturbances of water exchange (see the Water salt metabolism), use a tritium tag at diagnosis of malignant new growths (see Radioizotop-naya diagnosis), researches of the chromosomal device of cells (see. Radio isotope research), etc. Metabolism of T. in an organism physical depends from its. - chemical forms and a way of receipt to an organism. Connection T, most widespread in the biosphere. — oxide of T., it is absorbed from the environment with food. Under production conditions couples of oxide of T. can be inhaled and get through skin. At any way of receipt an oxide of T. it is quickly soaked up in blood and evenly distributed in an aqueous medium of a body, then it is replaced with water of food and brought out of an organism with urine and then (an average elimination half-life of 10 days). Apprx. 1% of hyzone steadily communicates with biol. fabrics.

Radiation of T. can cause the acute and remote beam effects in an organism: oppression of a hemopoiesis, a hemorrhagic syndrome, defeat of the hereditary device, malignant new growths (see. Post-radiation effects).

For decrease in level of radiation of the persons working with T., apply means of protection (see. Antiactinic protection). Works with T., having activity more than 10 curies (37*1010 Bq), carry out in rooms

of 1 class with a zone design equipped with boxes and cameras (see P adiologichesky protective processing equipment). For prevention of receipt of T. through skin the personnel shall wear overalls (see Clothes special) and rubber gloves. During the work with powders T. it is necessary to use respirators (see).

Important condition of safety is radiation control (see), to-ry includes measurement of concentration of T. in air, pollution of surfaces and receipt of T. in an organism of personnel. Activity T.v air is determined by flowing ionization chambers or method of selection of water vapors. Size of pollution of surfaces of T. measure by method of smears. Maintenance of an oxide of T. in an organism determine by concentration of T. in tests of urine by a liquid scintillation method (see Dosimetry of ionizing radiation). In case of detection of receipt in an organism of a significant amount of T. for decrease in a fabric dose it is necessary to increase consumption and removal of water.

Minimum significant activity of T. in a workplace, not demanding registration or obtaining permission of bodies state a dignity. supervision, 100 mkkyur.

See also Hydrogen.

Bibliography: Balonov M. I. Dozi

metriya and rationing of hyzone, M., 1983, bibliogr.; Lensk L. A. Fizika and chemistry of hyzone, M., 1981, bibliogr.;

An oxide of hyzone, under the editorship of Yu. И® Moskalyova, M., 1968; Okladnikova N. D., Hokhryakov V. F. and Odintsovo. B. The radial illness caused

by hyzone, Medical radio-gramophones., t. 14, No. 6, page 8, 1969; Evans E. Hyzone and its connections, the lane with English, M., 1970; Alvarez L. W. a. Corno g R. Helium and hydrogen of mass 3, Phys. Rev., v. 56, p. 613, 1939; Oliphant M. L., Harteck P. I. a. Ruterford, Transmutation effects observed with heavy hydrogen, Nature (Lond.), v. 133, p. 413, 1934 * M. I. Balonov, V. F. Zhuravlev.