364. HUMAN BIOLOGY 



meet the strong economic argument Jor soft coal by the 

 less definite and oft-questioned statements of possible 

 health hazards against. When economic gain meets economic 

 loss on even terms, health and comfort and civic pride may 

 ultimately determine the issue. 



Atmospheric pollution with smoke and dust, and the fog, 

 which is increased by the presence of both of these in the 

 air, is greater over cities than in the country, with a resulting 

 reduction of the permeabihty of the air by those valuable 

 short rays of fight which are known to be preventive and 

 curative for rickets. While rickets may occur in any latitude 

 if there is interference with the metabofic processes which 

 determine normal development, particularly of the soft 

 growing ends of the long bones of the body, it is found most 

 abundantly, and indeed almost universally, among babies 

 in their first year of fife in the large northern cities of Europe 

 and America. Here, in addition to the fimitations of the 

 sun's rays by low incfination and cloud, children are housed 

 unsuitably as to fight and fed unsuitably as to antirachitic 

 elements of diet. 



Rickets is but rarely found as a direct cause of death, 

 but its harmfulness if reflected in increased susceptibifity 

 of children to bronchitis and pneumonia, and in the difficulty 

 of childbearing in women whose pelves have been deformed 

 by rickets in childhood. Even with the widespread use of 

 cod liver oil and artificial sunlight to correct and prevent 

 the rickets of infants in the cities of the United States 

 there was even as late as 1920 a ratio of 1.75 cases per child 

 population in cities to every one among country children. 



While many elements go to make up the causes of death 

 from bronchitis and pneumonia, it is worth noting that 

 in the registration area of the United States the city 

 rates were far above those of the country as shown in 

 Table vi. 



In those areas of our cities where rickets prevails among 

 children, for example where Negroes and Italians live in 

 crowded tenements, the death rates of children from pneu- 

 monia and bronchitis are found to be from two to three 

 times as high as in the rural areas of the same latitude. 

 The same races that exhibit rickets most abundantly in 



