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smoke,visible gaseous product of incomplete combustion. Smoke varies with its source, but it usually comprises hot gas and suspended particles of carbon and tarry substances, or soot. To reduce the amount of smoke entering the atmosphere, air pollutionair pollution,
contamination of the air by noxious gases and minute particles of solid and liquid matter (particulates) in concentrations that endanger health. The major sources of air pollution are transportation engines, power and heat generation, industrial processes, and the
..... Click the link for more information. laws generally require that power plants, factories, and other large combustion facilities burn anthracite (hard) coal, natural gas, or low-sulfur fuel oil rather than bituminous (soft) coal or high-sulfur fuel oil, and that smokestacks be equipped with scrubbers or other devices. Proper firing techniques and equipment can eliminate or greatly reduce the smoke produced by any fuel. Wood gives little smoke if burned when dry and if the fire is given a good supply of air. Where it is necessary to use soft coal because of its lower cost or because other fuel is not available, the grate and flue must be built to insure maximum combustion, the coal supply must be carefully regulated, and adequate air must be supplied. There are various ways of reducing the amount of smoke escaping into the air. Some methods utilize electricity or sound waves for precipitation of the suspended particles, others employ chemicals; the method using an electric current at high potential is perhaps best known. Smoke precipitates may yield valuable byproducts; for example, fly ash can be used as a construction material. Among the evils of smoke are interference with sunlight, causing the most healthful rays of the sun to be filtered out and necessitating the use of artificial light; disfigurement of buildings, leaving deposits that are costly to remove and causing corrosion of stone and metalwork; destruction of plant life by shutting out sunlight and by clogging the stomata of leaves with oily deposits; and injury to the respiratory systems of humans and livestock. Tobacco smoke, in particular, is known to be related to cancer of the lungs and other organs (see smokingsmoking,
inhalation and exhalation of the fumes of burning tobacco in cigars and cigarettes and pipes. Some persons draw the smoke into their lungs; others do not. Smoking was probably first practiced by the indigenous peoples of the Western Hemisphere.
..... Click the link for more information. ). In addition to such damages, smoke also represents a waste of energy, as imperfect combustion dissipates potential heat into the atmosphere. Smoke particles and other air pollutants are often trapped in the atmosphere by a combination of environmental circumstances (see temperature inversiontemperature inversion,
condition in which the temperature of the atmosphere increases with altitude in contrast to the normal decrease with altitude. When temperature inversion occurs, cold air underlies warmer air at higher altitudes.
..... Click the link for more information. ), forming smogsmog
[smoke+fog], dense, visible air pollution. Smog is commonly of two types. The gray smog of older industrial cities like London and New York derives from the massive combustion of coal and fuel oil in or near the city, releasing tons of ashes, soot, and sulfur
..... Click the link for more information. . Paris early passed stringent laws in an effort to preserve architectural and sculptural monuments, and most U.S. cities had smoke-nuisance laws before air pollution regulations were put into effect. Smoke-nuisance laws are difficult to enforce and often are not applicable to existing residential heating units, although these are often important contributors to pollution. In order to comply with federal air pollution standards many cities have now adopted building codes that require minimally polluting heating units in new buildings and that forbid the use of incinerators.
a persistent dispersed system consisting of fine, solid particles in suspension in gases. Smoke is a typical aerosol with hard particles ranging from 10−7 to 10−5 m in size. As distinguished from dust (a more crudely dispersed system), smoke particles generally do not settle under the influence of gravity. Particles of smoke may serve as nuclei of condensation of atmospheric moisture, as a result of which fog develops. Smoke is produced, specifically, during combustion of fuel, for example, in furnaces of thermal electric power plants and various industrial units, and during fires, especially forest fires. Such smoke may contain large particles of unburned fuel and ashes, metallic oxides, soot, and tar. If flue gases are poorly cleaned, the immediate environment is polluted, the microclimate deteriorates, fog is formed, and natural illumination is reduced.
Smoke has a deleterious effect on man’s health, contributing to the development of such diseases as catarrhs of the upper respiratory tracts, bronchitis, and fibrous changes in the lungs. The presence of condensates of heavy metals (lead, mercury) in smoke causes blood changes and retardation in the physical development of children. Certain components of smoke contain carcinogenic substances, that is, those contributing to the development of tumors. Large particles, in entering the eye, damage the cornea and mucous membrane.
In order to combat smoke the heat and gas supply of enterprises and populated areas is centralized. In the USSR maximum permissible concentrations of noxious substances in the atmosphere have been established. Health-protection zones are being established, as are gas purification facilities. The decree of the Council of Ministers of the USSR of May 29, 1949, prohibits the operation of units that pollute the air without providing for purification of industrial emissions.
At the same time pesticide smoke is being employed in agriculture. Smoke produced in smoke generators is used in the curing of food products. Smoke is also utilized in military actions for smoke screens. Certain toxins are used in smoke form; special smoke filters are installed in gas masks for protection against these toxins.
REFERENCERukovodstvo po kommunal’noi gigiene, vol. 1. Edited by F. G. Krotkov. Moscow, 1961.
N. IU. TARASENKO
What does it mean when you dream about smoke?
To be surrounded by smoke in a dream indicates that the dreamer is suffering from confusion and anxiety. Often a dreamer will be choked and disoriented suggesting the need to “clear things up.”