Page:Popular Science Monthly Volume 87.djvu/252

248 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.

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.