VENTILATION 357 



403. Dust. In the emery, corundum, sandpaper, and 

 allied industries, great attention is given to keeping the dust 

 away from the mouth and nostrils of the workmen by means 

 of hoods and exhaust fans. Oftentimes workmen remove 

 their hoods recklessly and thereby expose their lives to dan- 

 ger. There are two or three times as many deaths among 

 grinders, polishers, and cutters due to disease of the lungs 

 brought on by breathing these particles, as among adults 

 following other occupations. Proper working conditions and 

 a due amount of precaution on the part of the workman, 

 however, render a comparatively good protection against 

 these dangers. 



In the rag-dusting, sorting, and cutting rooms of some 

 paper mills, objectionable amounts of dust are often present. 

 Workmen exposed to dusty atmospheres are especially sus- 

 ceptible to diseases of the lungs, such as tuberculosis, because 

 of the constant irritation of the respiratory tract. Constant 

 coughing causes the mucous membrane of the throat to 

 become inflamed and this condition allows germs to thrive. 

 In a healthy individual the normal mucous membrane would 

 not allow the germs to penetrate the membrane. 



404. Cause of Tuberculosis. It is a well-known fact that 

 a large percentage of deaths among factory operatives is due 

 to consumption. While perhaps some of this may be traced 

 to the environment of the home, many cases are contracted 

 in the factory from people who are in the early stages of the 

 disease. The reason lies in the fact that in every act of 

 spitting, coughing, sneezing, and speaking, minute droplets 

 of saliva, which may contain tuberculosis germs (specific 

 bacilli), are sent forth into the air, in which they remain sus- 

 pended for some time. The spitting consumptive is usually a 



