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Popular Science Monthly/Volume 87/September 1915/Four Points in the Indictment of the Smoke Nuisance



IN all papers and talks concerning the smoke nuisance, it has become customary to refer to the economic cost of the nuisance both to the public and to the smoke makers. This is the indictment which is supposed to strike home. When a speaker on this subject says

The abolition of the smoke nuisance, unlike many other social nuisances against which outcry has been, would result in direct and immediate gain both to the public at large and to those who are chiefly responsible for the nuisance itself,

he feels that he has said the last word.

There are other points in the indictment of the smoke nuisance to which attention may more properly be directed. It is the purpose of this paper to tell of the present knowledge on four of these points, namely:

1. The effect on building materials.
2. The effect on meteorological conditions.
3. The effect on vegetation.
4. The effect on health.

There has been much talk within the last few years concerning city planning. The principal idea that city planning seems to convey to most people is a beautiful and costly square, set in the center of an ugly city. All real city planning should have as one of its main objects the purification of the atmosphere. Some forty years ago, John Ruskin, speaking to the Society of British Architects, said:

All lovely architecture was designed for cities in cloudless air. . . . But our cities, built in black air, which, by its accumulated foulness, first renders all the ornament invisible in distance, and then chokes its interstices with soot; . . . for cities such as these, no architecture is possible.

An architect in a smoky city is forced to take atmospheric conditions into account. Drain pipes must be arranged with great care—that there may result no splashing of the soot-carrying water to discolor the sides of the building. Mouldings must be so designed that the rain will not wash over the face that soot which collects on top of the mouldings. Drips must be provided on all projections. Under-cutting, delicacy of incised line and sharpness of angular forms must be foregone, for the soot deposited will, in time, fill up the crevices and mar the beauty of the outline, causing considerable alteration of the original forms and making the building degenerate into a mere mass of dirty, shabby masonry.

It is rather interesting to note the vogue of such materials in buildings as glazed brick and terra cotta, in smoky cities. Stone, for which they are substitutes in many cases, is injured by smoke and the associated products of combustion in two ways:

1. The soiling of the surface, so that in the course of a few months all stone takes on the same gray, grimy color. This means either the loss of all artistic effect that may have been obtained by color contrast, etc., or the frequent cleaning of the building, which is an additional expense and at the same time aids in the destruction of the stone.

2. The actual destructive action on all stones by the acid products of the combustion of the coal. This is especially marked on any stone containing calcium or magnesium carbonates in larger or smaller quantities. Although there is some action on other constituents of the building stones, it is so slow in most cases as to be hardly noticeable.

A study was made in connection with the smoke investigation of the Mellon Institute as to the effect of smoke on outside painting.[1] Both the effect on paint as a protective coating and as a decorative covering was considered. It was found that some paints last comparatively longer in Pittsburgh than in many other cities. This is in part due to the protective action of the soot in preventing the destructive action of the active rays of the sun. This would also indicate that such paints might afford a lodging place for fungi, which grow in the absence of direct sunlight.

It was found that smoke darkens paint coatings very rapidly and renders the use of light colors unsatisfactory on account of the short time they retain their true color. Analyses of the surface of the paints showed that the darkening was due to sulphur dioxide gas and to the accumulation of soot, carbon and similar organic matter contained in smoke.

The effect of smoke on metals must be taken into consideration in connection with the other building materials. When soot containing tar comes in contact with a metallic surface, it is made to adhere more or less firmly by means of its tar content. The occluded acids, principally sulphuric and sulphurous, are thus brought in intimate contact with the metal, giving a much better chance for corrosive action to take place and for it to become complete quicker than if the same amount of acid dissolved in rain water came in contact with the metal. The acid in the rain water drains off readily, while the soot protects the occluded acid to a great extent, so that it remains in contact with the metal until it has all been used up.

Inquiry in Pittsburgh among metal workers developed the fact that metal work in a smoky city lasts only half as long as in one free from smoke.

It is hardly necessary to point out that smoke damages the interior decorations of a building or home, limits interior decorators in the use of colors and materials and in every way tends to render artistic effects gloomy and depressing.

Cities very properly hold favorable climatic conditions as a very desirable asset, as is evidenced by the records of rainfall, temperature, fog and hours of sunshine which appear in the year books of the chambers of commerce and boards of trade of the different cities. Cities which have smoky atmospheres are under a severe handicap in this regard.

In the first place, while smoke is not a cause of fog, it intensifies a fog when it is once formed and accordingly causes it to persist longer.[2] In consequence of this there are fewer hours of sunshine in smoky cities than in cities which are practically free from smoke. Again, the sunshine is less intense in smoky cities, the light of short wave lengths, or the blue light, suffering the greater depletion. Not only is this true, but daylight, which depends entirely upon diffused light from the sky, is depleted by the smoke in greater proportion than the direct sunlight.

Experiments carried on by the Smoke Investigation of the Mellon Institute in Pittsburgh and Sewickley, a small residential town on the Ohio River, about twelve miles northwest of Pittsburgh, during 1913, revealed that Pittsburgh had 25 per cent. less sunlight and 40 per cent. less daylight than Sewickley. It was also found that the limit of visibility in the business section of Pittsburgh was about one tenth the limit in the open country. It is well known that the frequency of intense fogs in London has decreased and the hours of sunshine increased since 1890, due to a mitigation of the smoke nuisance. The same was true of Pittsburgh between 1885 and 1895, when the use of natural gas for manufacturing and domestic purposes was quite general.

A number of studies have been made of the effect of soot on vegetation. Cohen and Euston, as a result of their researches in Leeds, England, declared that soot may exert a detrimental effect on the growth of plants in three ways, namely, by blocking up the stomata and thus impeding the process of transpiration; by coating the leaf and so reducing the intensity of sunlight, and at the same time affecting the assimilation of carbon dioxide; and lastly, by the corrosive effect of the acid it contains.[3] Experiments they carried on went to show that the power of assimilation of laurel leaves had a definite relation to atmospheric impurities, that crops of radishes and lettuce grown in different sections of Leeds show the possibility of correlating the known atmospheric impurities with the yield of the crop. They also found that as trees automatically keep a record of yearly growth, the presence of any inhibiting factor will make itself known by the narrowing of the annual rings.

In 1913, a study of the effct of city smoke on vegetation was made in Des Moines by A. L. Bakke, of the Iowa State College.[4] Mr. Bakke reached the following conclusions:

1. That gases and smokes have a deleterious action upon vegetation.

2. That the vegetation about a manufacturing concern may be mapped off, in the form of concentric belt demarcation, each belt being represented by a certain form or forms of plant life, since certain plants are more susceptible to smoke injury than others.

3. That an industrial city like Des Moines, in its plant elimination process, is governed by the same set of conditions as are in operation for a single manufacturing plant.

Mr. J. F. Clevenger, as a result of his studies in connection with the Smoke Investigation of the Mellon Institute, declared that the fact that smoke injures vegetation is evidenced not only by the general external appearance of many of the constituent plants, but also by their internal appearance, as shown by the size of annual rings and by lesions in the leaves.[5] Mr. Clevenger's studies were confirmed by controlled field experiments which he made. In these experiments growing plants enclosed in cases were subjected to small quantities of soot distributed uniformly over them. The leaves of the plants so treated displayed a tendency to drooping and many of the leaves began to die at the tips; a checking of growth of the plants was also apparent.

The effect of smoke on health has been a much-mooted question. For a long time it was held, and still is by some, that a smoky atmosphere is not injurious and at times even beneficial to public health. This supposition gained favor from an observation, largely erroneous, that coal miners are not prone to contract tuberculosis.

One of the most comprehensive studies of the direct effect of smoke upon the respiratory organs was made by Dr. Louis Ascher, of Königsberg. Dr. Ascher's statistical and experimental studies led him to the conclusion that the mortality of acute lung diseases is certainly increasing, especially among children and old people. The cause of this increase, he declared, is the impurification of the air by smoke, as the increase is greatest in industrial centers and not in agricultural districts. He further pointed out that within industrial districts a difference in mortality can also be noted, the death rate from acute lung diseases, in districts with much smoke, being higher than in other industrial centers with little smoke as textile districts.

The physicians who worked in cooperation with the Smoke Investigation of the Mellon Institute made valuable contributions to the question of the relation of smoke to health.[6]

Dr. W. L. Holman, investigating the bacteriology of soot, arrived at the following conclusions:

1. Soot has a definite bactericidal action on bacteria, due either to the absorption of moisture from the organisms or more probably to the action of its contained germicidal acids and phenols.

2. Soot, as it occurs in smoke, clouds, fogs and as a non-transparent covering for our streets and houses, protects microorganisms from the destructive action of sunlight.

Dr. Oskar Klotz, attacking the subject from the viewpoint of a pathologist, asserts that pulmonary anthracosis—a term applied to a condition in which carbon particles of extraneous origin are deposited in the lungs—is an urban disease and is proportionate to the smoke content of the air. His examination of the lungs of adult individuals resident in Pittsburgh shows that they have materially more carbon deposit than the lungs of individuals resident in a lesser manufacturing community.

Dr. Samuel E. Haythorn, attempting to determine whether or not excessive deposits of dust and coal pigment within the body tissues have or have not any "real disease" significance, arrived at the conclusions:

1. Moderate anthracosis in an otherwise normal lung is not in itself detrimental to health.

2. In tuberculosis, the anthracotic condition is either entirely passive or is active in assisting healing, in that it aids in the localization of the process through the obliteration of the lymph spaces.

3. In the case of pneumonia, the effect of carbon deposits in the lungs is quite different. The carbon blocks up the lymphatic spaces and causes obliteration of the lymph channels. This results in serious interference with the drainage system of the lungs and thus delays, if it does not make impossible, the resolution of the pneumonic process. An anthracotic lung has, therefore, less chance of recovery from pneumonia than a lung which has not undergone changes from the deposit of carbon.

Dr. William Charles White, from a study of the relation of the mortality from tuberculosis and pneumonia to the smoke content of the air, shows that, in Pittsburgh, pneumonia increases with the density of smoke irrespective of the density of the population or of poverty. Tuberculosis, on the other hand, he shows to he independent of the smoke density, following, as it does everywhere, the line of overcrowding and poverty.

In summarizing the results of all medical investigators whose opinions are based on other groups than theory, it can be asserted that smoke has a tremendous influence in increasing the incident severity and mortality of acute disease of the air passages. It would appear that this increased susceptability is, in part, the result of the lowering of our natural body resistance. In simple terms, the smokier the atmosphere, the more the colds and bronchitis, and the more money paid to doctors.

It would seem from a consideration of the four points that have been discussed that it is high time for the people to arouse themselves from the apathy that they have shown toward the smoke nuisance. The purification of the atmosphere should receive the same attention as pure food and pure water are receiving, for it is just as important. People should be educated as to the evils of the nuisance so that an active and intelligent public opinion could be brought to bear on those who are responsible for it. The demand should go out that the nuisance be abated as a menace to health, property and the things which make for civic betterment.

  1. Benner, Raymond C., Bulletin No. 6, "Papers on the Effect of Smoke on Building Materials," 1913. (Published by Mellon Institute.)
  2. Kimball, Herbert H., Bulletin No. 5, "The Meteorological Aspects of the Smoke Problem," 1913. (Published by Mellon Institute.)
  3. Cohen, Julius Berend, and Ruston, Arthur G., "Smoke: a Study of Town Air," 1912.
  4. Bakke, A. L., "The Effect of City Smoke on Vegetation," Bulletin 145, Iowa State College of Agriculture.
  5. Clevenger, J. F., Bulletin No. 7, "The Effect of the Soot in Smoke on Vegetation," 1913. (Published by Mellon Institute.)
  6. Klotz, Oskar, and White, Wm. Chas., Bulletin No. 9, "Papers on the Influence of Smoke on Health," 1914. (Published by Mellon Institute.)