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HUMAN BIOLOGY 



disease. The city child suffers more from diarrhea and 

 enteritis probably because the environment of brick, stone, 

 concrete and asphalt prevents his adjusting to temperature, 

 humidity and air motion, as favorably as he does where 

 fohage is present. Carelessness in the city household in many 

 of the minor details of cleanhness and care of children may 

 result from the general demoralization which commonly 

 accompanies spells of hot weather. Even among cities there 

 are differences in the unfavorableness of environment. For 

 instance, in Washington, where the expectancy of hfe is 

 the highest of all the cities of 500,000 and over in the regis- 

 tration area, and in Pittsburgh, where it is lowest, we have the 

 extremes of abundant foliage, parks and spacious streets 

 in one place and an almost treeless, parkless city of bare 

 streets in the other. Pittsburgh's death rate from diarrhea 

 and enteritis under two years of age has for many years 

 ranged from two and a half to four times as high as that 

 of Washington, for the white population, although much 

 of this difference is doubtless due to differences in age, 

 sex and social elements. In view of all these facts, it seems 

 not improbable that the atmospheric environment of 

 Washington is responsible in considerable measure for the 

 advantages which its children enjoy in a low death rate 

 from this chief cause of infant mortahty. 



