APPROPRIATE INTENSITY OF THE USE OF LAND 29 



" Quite as important as the volume of air taken into buildings is 

 its cleanliness. One of the difficulties in cities is to obtain proper air 

 inlets for ventilation systems. The amount of smoke and dust, foul 

 odors on the streets, bad smells from buildings, from passing ve- 

 hicles, from exposed refuse and from other sources are matters 

 properly subject to the control of the health department but the con- 

 centration of dust and smoke and foul odors is greatly influenced 

 by street ventilation. The regulation of buildings is a regulation of 

 the amount of dilution of colors and is therefore a public health 

 factor." 



Exposure to a vitiated atmosphere, especially if it is of long duration, 

 tends to break down the individual's power to resist disease. The suscepti- 

 bility to respiratory affections, tuberculosis, pneumonia and colds, is par- 

 ticularly increased. In the treatment of disease pure air is of the greatest 

 curative value. The importance of direct sunlight on health is hard to 

 over-estimate. It serves as a beneficial stimulant to the nervous system. In 

 the destruction of bacteria it is better than many artificial disinfectants. An 

 increased supply of sunshine in an apartment means decreased dampness. 

 The highest medical authorities all agree that the action of the sun's rays 

 upon air is prophylactic, rendering the environment more healthy. Good 

 natural light and ventilation alone are not enough, direct sunlight is also 

 important. 



Light and air are so important that their provision should be required 

 in every section of the city up to that point at which their benefits as to 

 that particular section tend to be outweighed by other needs and require- 

 ments of city life. Under New York City conditions the upper limit would 

 probably be the single detached house on a forty or fifty-foot lot with 

 ample open spaces about it. This the proposed E district regulations would 

 in large measure secure. At the other extreme the minimum provision of 

 light and air assuredly should not be less than that required by the present 

 Tenement House Law. For large areas in New York City neither of the 

 above extremes furnishes an appropriate standard. The one and one-half 

 and one times height districts and the C and D area districts will supply 

 the demand and need for light and air standards between these two extremes. 



From the point of view of public advantage the distribution of popula- 

 tion is very important. Most of the evils of city life come from congestion 

 of population. In precisely the measure that the city's population can be 

 distributed will those evils be mitigated. As the number of families housed 

 per 50-foot lot increases : 



(1) The provision of light and air, so essential to health, vitality and 

 comfort decreases. 



(2) The opportunities for personal contact and thus for the spread of 

 communicable disease increase. 



(3) Noise and confusion incident to increased street traffic increases. 



