METHANE

From Big Medical Encyclopedia

METHANE (synonym: marsh, rattling, natural, firedamp) — the elementary saturated hydrocarbon — CH 4 , the first member of a homologous number of saturated aliphatic hydrocarbons, in a human body is formed in intestines as a result of metane fermentation, allocated with intestinal gases and at breath with expired air; possesses weak narcotic action, in high concentration it is poisonous. The m is the main component of the natural gas which is widely used in the national economy and in life.

The m represents the colorless gas possessing a slight smell of onions; pier. weight (weight) 16,04; 1 l of methane weighs 0,717 g, t ° pl 182,5 °, t ° kip 161,55 °.

The m from water solutions well gets through skin of the person (3 — 13 ml/hour/cm 2 ). At concentration of 5,1 — 16% in mix with air M. ignites with explosion.

M.'s maintenance in air is determined by a spectrophotometric method, method of burning, a hromatograficheska.

In natural, or miner, gas there are at a type of impurity M.'s homologs — the ethane, propane, butane strengthening narcotic action of M. and giving it toxic properties. Content of these impurity in natural gas makes to 30 about. the % also depends on a depth of coal layers, character of gas fields etc. In natural gas of purely gas fields M.'s maintenance reaches 97 — 98 about. %.

Poisoning with methane

Long inhalation of the gas mixtures containing 80% of methane and normal amount of oxygen (20%) causes headaches, disturbance of color sensation and visual acuity, delay of breath, emergence of drowsiness. M.'s influence in gas mixture, free of oxygen, leads to development of an acute hypoxia with a hypocapny that is followed by a bystry loss of consciousness (on 5 — the 6th breath), an apnoea and the termination of cordial activity (on 4 — the 6th minute).

On character a wedge, manifestations from c. the N of page, cardiovascular system, a respiratory organs and blood are allocated three severity of defeat of an organism of M. Easy degree (consciousness is kept, the lungs which are quickly passing funkts, disturbances from c are noted. N of page and cardiovascular system; working capacity is completely recovered on 2 — the 3rd days).

Average degree (a long loss of consciousness, to 2 — 3 hours, deeper funkts, disturbances from c. N, page and cardiovascular system, than at poisoning of easy degree, increase in quantity of leukocytes in peripheral blood to 10 — 14 thousand in 1 mkl; working capacity is recovered in 8 — 15 days). Heavy degree (extremely long loss of consciousness, organic lesions of a brain, tissues of heart, went. - kish. a path, a fluid lungs, the expressed leukocytosis — to 16 — 20 thousand leukocytes in 1 mkl; disability to 11/2 — 2 months, demanding the subsequent out-patient and sanatorium therapy and discharge from former work for up to 2 months, in hard cases the question of disability can be raised).

M.'s poisonings are possible in coal mines. Danger decreases the fact that the fainted person, falling, gets to the atmosphere richer with oxygen since M. is easier than air.

Treatment

First aid consists in immediate carrying out of the victim on fresh air. The victim needs to be exempted from the clothes constraining a body, to warm, having imposed a body with hot-water bottles. At disturbance of breath to give oxygen. In the absence of breath immediately (before arrival of the doctor!) artificial respiration by method from a mouth in a mouth or from a mouth in Nov. At a serious poisoning hospitalization is necessary.

In a hospital the oxygenobarotherapy, dehydrational therapy, administration of the cardiovascular medicines and means normalizing a metabolism according to indications — hormonal therapy, vitamin therapy, prevention of infections is applied.

Labor protection

is provided by Safety regulationss the size of M.'s concentration, safe for coal and slate mines, in the descending current of air. This concentration shall not exceed 0,5%, and local accumulation of M. in clearing faces, preparatory and other developments shall not exceed 2%. Systematic control of a gaseous fluid includes continuous measurements for the purpose of determination of content of M. in air. At the content in air of the mine M. in dangerous concentration shutdown of all electric devices is made. The prevention of emissions of M. consists in the organization of service of the seismoacoustic forecast, vent well-drilling, forcing in coal layer of a suspension of metanookislyayushchy bacteria, solutions of urea-formaldehyde resins, salt to - you that sharply reduces a metanoopasnost of coal layers. Shaking detonation of coal layers is widely used for prevention of emissions of M. The equipment of miners and the zashchitnospasatelny equipment of mines is constantly improved. Since danger consists in a lack of oxygen of air, use of the filtering gas masks is useless. Therefore apply helmets with air delivery through a hose or the isolating respiratory devices supplied with a reserve of oxygen (self-rescuers of various brands, oxygen apparatuses of KIP-5, RKK-1, RKK-2M, the Urals-1, etc.).

See also Gas industry , Gas-rescuing service , Ore mining industry .



Bibliography: Harmful substances in the industry, under the editorship of N. V. Lazarev and E. N. Levina, t. 1, page 12, L., 1976; V. G Deynega. Features of a clinical current and treatment of the diseases caused by emission of coal and firedamp in mines, the Doctor, business, No. 11, page 121, 1975; In about n d J. H., E and g e 1 R. R. a. L e at i t t M. D. Factors influencing pulmonary methane excretion in man, J. exp. Med., v. 133, p. 572, 1971.


V. G. Deynega.

Яндекс.Метрика