SHELLFISH CONTAMINATION FROM SEWAGE-POLLUTED 

 WATERS AND FROM OTHER SOURCES. 



INTRODUCTION. 



The contamination of shellfish from sewage-polluted waters presents 

 sanitary problem of increasing importance to those interested in the 

 >roduction of pure-food supplies. Until comparatively recently there 

 las been but little apprehension in this country regarding the injury 

 ;o oysters and other shellfish from this source, but food officials and 

 anitarians are now awakening to the fact that either sewage must not 

 >e promiscuously emptied into our natural bodies of water or the shell- 

 ish industries must in many cases be removed to points far distant 

 Tom their present locations. Thorne 67 says: a "It is only within 

 ecent years that the need of protecting oyster fisheries against sewage 

 pollution has forced itself on the attention of those who have the 

 esponsibility for protecting the public health. " 

 When the great cities of to-day were mere villages, and what are 

 ow villages were green meadows, the wastes of man's activities were 

 omparatively insignificant, but conditions are now very different, 

 nd with the present rapid increase in population the situation will 

 >ecome more and more serious. In fact, cities and villages in the 

 )ast did not require complicated means of sewage disposal, yet this 

 roblem to-day has grown to such an extent that many city and 

 tate health officials are taking active steps to remedy the evils 

 Iready arising from present conditions. In the light of present 

 anitary knowledge and in consideration of the results obtained from 

 nvestigations made in this Department and elsewhere, it is known 

 hat sewage-polluted water is a menace to the shellfish industries. 

 Such insanitary conditions can not continue to exist without increas- 

 ng the probability of disease dissemination through the agency of 

 nfected oysters and other shellfish when used as food, especially when 

 oMsumed raw. 



The problem of sewage disposal is of national importance, and is 

 not confined to one locality nor to a single industry. The health 



a Reference numbers refer to bibliography, see p. 50. 



