THE SANITATION OF AIR 23 



deaths were charged to acute respiratory diseases and pulmonary tuber- 

 culosis. During that period the deaths from these causes numbered 

 14,091. In the corresponding period of the year before they aggre- 

 gated 10,890. 



When we compare the efforts of the sanitary corps in this particular 

 direction with the systematic and thorough work done in checking cer- 

 tain epidemics, we can not fail to note the lack of a comprehensive 

 system in fighting diphtheria, grip, pneumonia and other respiratory 

 diseases, which now claim a majority of victims. The situation seems 

 to be recognized, but is met only to a limited extent. Much good has 

 been accomplished through sanitary inspection, stricter enforcement 

 of the regulations against expectorating in public places, also by ex- 

 hibits and other educational work, but there are many other possible 

 lines of action which should be taken up as parts of an organized cam- 

 paign for the sanitation of the air. Since the most promising measures 

 must always be of the preventive order, we should, above all, study the 

 causes which lead to unwholesome atmosphere. 



The Causes of Impure Air 



Quantities of smoke, vapor, dust and other offensive waste products 

 are constantly discharged into the atmosphere of urban districts. The 

 emanation of all this matter is so rapid that it becomes visible within 

 a few hours whenever the purifying breezes die away, and yet the 

 gathering gloom is not generally recognized as pollution of the air, 

 but rather taken for a change in weather. According to the seasons, 

 the solid particles like soot and dust will cause a haze, or encourage 

 the formation of mist and fog, sometimes, during the winter, depriving 

 a city for days of the life-giving sun. 



The sources that contribute to this pollution of urban atmosphere 

 naturally increase with the population, while the dispersal of impure 

 matter by the natural air currents becomes more sluggish and uncertain 

 with the growing areas of urban settlements. The density of popula- 

 tion in certain metropolitan districts is easily ten times that of smaller 

 cities. The rate of vitiation of the air through smoke and other waste 

 matter must therefore be at least that much greater. Comparatively 

 speaking, the conditions of health in a crowded community are like 

 those prevailing on board ship. The living space is still smaller than 

 that of the average city dwelling, but the elements contributing to the 

 vitiation are about the same per capita, hence more concentrated and 

 more in evidence. We know that extra labor and care are necessary 

 on a vessel to maintain the air in a tolerable state, quite irrespective 

 of ventilation. In cities, where dwellings and shops are built not only 

 closer together, but are literally piled up on each other, the general 

 contamination is likewise bound to become unwholesome unless special 



