SHELLFISH CONTAMINATION FROM SEWAGE-POLLUTED 
WATERS AND FROM OTHER SOURCES. 
INTRODUCTION. 
The contamination of shellfish from sewage-polluted waters presents 
a sanitary problem of increasing importance to those interested in the 
production of pure-food supplies. Until comparatively recently there 
has been but little apprehension in this country regarding the injury 
to oysters and other shellfish from this source, but food officials and 
sanitarians are now awakening to the fact that either sewage must not 
be promiscuously emptied into our natural bodies of water or the shell- 
fish industries must in many cases be removed to points far distant 
from their present locations. Thorne” says:*% ‘‘It is only within 
recent years that the need of protecting oyster fisheries against sewage 
pollution has forced itself on the attention of those who have the 
responsibility for protecting the public health.”’ 
When the great cities of to-day were mere villages, and what are 
now villages were green meadows, the wastes of man’s activities were 
comparatively insignificant, but conditions are now very different, 
and with the present rapid increase in population the situation mal 
become more and more serious. In fact, cities and villages in the 
past did not require complicated means of sewage disposal, yet this 
problem to-day has grown to such an extent that many city and 
State health officials are taking active steps to remedy the evils 
already arising from present conditions. In the lght of present 
sanitary knowledge and in consideration of the results obtained from 
investigations made in this Department and elsewhere, it is known 
that sewage-polluted water is a menace to the shellfish industries. 
Such insanitary conditions can not continue to exist without increas- 
ing the probability of disease dissemination through the agency of 
infected oysters and other shellfish when used as food, Bacay when 
consumed raw. 
The problem of sewage disposal is of national importance, and is 
not confined to one locality nor to a single industry. The health 
« Reference numbers refer to bibliography, see p. 50. 
