A New Frontier: Air-pollution Control

Activity in the field of air pollution in the United States has reached tremendous proportions. Any attempt to summarize this effort, even superficially, would require space beyond the present limits. As an illustration, the proceedings of only one three-day meeting (United States Technical Conference on Air Pollution, 1950) at which ninety-seven technical papers were presented occupies a book of almost 850 pages. Since that meeting, the amount of technical thought and effort devoted to the problem of air pollution has grown apace, so that the developments and accomplishments in the field occupy the complete attention of several special publications, as well as resulting in frequent articles in the general technical Press.

Therefore, the present discussion will attempt to cover only those areas in the United States and Canada where definite accomplishment or significant developments have been made in air-pollution control. In addition, its scope is limited by the special interests and opportunities of the author.

The legislative developments of the important areas are treated rather fully, because in most instances of reduced air pollution it was an effective ordinance backed by public opinion which brought about the result.

The influence of meteorological factors upon the dispersion or accumulation of air pollutants has long been apparent, but an understanding of the fundamental factors, other than wind, is just being reached. These principles are discussed generally, and in specific application.

The highlights of the Donora (Pennsylvania) smog of 1948 are covered, primarily to illustrate how the present warning system has been developed. A description of the control procedures and equipment presently in use there is given, together with a statistical analysis of the air sampling and meteorological data which had been collected.

In the light of recent findings on the synergic effect upon laboratory animals of sulphur dioxide and sulphuric acid mist, both of which are believed to be frequent air pollutants, some speculative thoughts are presented. If further research bears out these findings, there will then be available the basis for an explanation of the physiological mechanisms acting in acute smog episodes such as Donora and London. Controls to prevent the emission of sulphur gases would then become necessary.

The current air-pollution activity has stimulated the development of instrumental methods for the detection, determination, analysis and recording of atmospheric contaminants, and factors influencing their accumulation or dispersal, many of which are described or illustrated. A corresponding stimulation in the control-equipment field has resulted from stringent local demands. Specific examples of successful application are given, but emphasis is placed upon the enormous cost and technical difficulties which such installations present.

A concluding section deals with the socio-economic aspects of the air-pollution problem in which an attempt is made to visualize the future of the air-pollution control movement.