Air pollution has been defined as the presence in the air around us of& substances put there by the activities of man in concentrations sufficient to interfere directly or indirectly with our comfort, safety, or health, or with the full use and enjoyment of our property.
No single factor can be charged with full or principal responsibility for air pollution. Many common and essential activities contribute. While automobile exhausts may be significant in one community or in one part of town, industrial fumes and vapors may be disturbing elsewhere. In many large cities, garbage and refuse incinerators in apartment houses or even backyard incinerators have been major contributors. Municipal incinerators, powerplants, steel mills, ore smelters, and petroleum refineries are serious
sources when improperly operated or lacking devices to control dust, smoke, or other discharges. Certainly operations such as the burning of open garbage and refuse dumps and the uncontrolled burning of automobile bodies in metal salvaging operations are offensive practices. Although the effects of air pollution are generally subtle and difficult to measure, they can be
apparent and even disastrous.
Efforts to control air pollution have been hindered by the lack of technical knowledge concerning the causes, effects, and practical control measures, major emphasis has been placed on research. Some studies are designed to determine which air pollutants, if any, cause or intensify specific disease conditions or otherwise adversely effect the population. Through such studies, we may learn what pollutants must be removed from the air and what elements may be safely ignored. By observing the effects of polluted air in the laboratory and on human beings over a considerable period of time, sound conclusions can be reached. Significant leads have been uncovered. There is evidence of a relationship between air pollution levels and mortality rates from stomach and lung cancer, with allowance being made for smoking habits. We know that there are pollutants in urban air which can produce cancer in
& Air pollution effects from specific industrial or community activities, such as oil refining, burning of municipal wastes, and operation of motor vehicles, are being evaluated. Fundamental studies are being conducted of the relationship between weather conditions and the buildup of pollutants in the atmosphere. A method is being developed for forecasting weather conditions which permit the abnormal concentration of pollutants. An automobile exhaust test facility developed by this program is becoming recognized as one of the best in the country. It permits simultaneous study of divers factors concerned with fuel and engine variables as they relate to the effects of irradiated auto exhaust on plants and animals.
No modern city can hope to be completely free of air pollution. Industrial activities necessarily produce vapors, dusts, or gases which slip by the most effective control and retention devices now known. To require industry to establish absolute restraint of such byproducts can easily impose an intolerable economic burden. There is a need for health agencies to determine the maximum concentrations of pollutants permissible and to apply these standards. This degree of control undoubtedly will prove costly, but
it is no longer a question of whether we can afford to conserve the air. We cannot afford not to. It is the breath of life. It is for this reason that continued research into the effects of air pollution is so vital. New knowledge may show that the application of controls which on the surface appear expensive may actually save ag yet unmeasured costs of damage to life and property caused by air pollution.