SOURCES OF CONTAMINATION. 



33 



with which the oystermen have to contend. Regulations should be 

 enforced requiring better care of the hands and more personal clean- 

 liness in general on the part of oyster shuckers. To this end, the 

 necessary toilet facilities should be provided for their welfare and 

 comfort. 



Bacteriological tests made by exposing freshly prepared agar plates 

 4 inches in diameter where oysters were being shucked show the rela- 

 tive bacterial content of the air in such places. One set of such 

 experiments gave the following figures: 



A one-minute exposure resulted in the growth of 130 colonies; 

 two minutes, 180 colonies; three minutes, 220; four minutes, 350; 

 and five minutes, 430 colonies. The organisms consisted of molds, 

 yeasts, spore-bearing and various chromogenic and other colonies. 



FIG. 13. (/lam diggers' huts, 



hucking is (lone. Sanitary conditions on the interior generally very 

 unsatisfactory. 



Is it strange that under such conditions the oystermen have difficulty 

 in keeping opened oysters, especially when tubs and containers are 

 not covered? Contrast these results with a similar set of plates 

 exposed in the bottling room of a clean dairy where sanitary condi- 

 tions obtained: One-minute exposure, 9 colonies; two minutes, 15 

 colonies; three minutes, 20; four minutes, 2ft; and five minutes, 30 

 colonies. 



WASHING OYSTERS. 



It is essential that both the water and ice used in washing and 

 cooling shucked oysters should be free from pollution. Natural ice 

 harvested from polluted sources should not be used for this purpose, 

 and even artificial ice may become contaminated by careless handling. 

 A number of samples of water used for washing oysters were exam- 



