262 Microbes and You 



AIR CONDITIONING 

 Temperature, humidity, and movement of air are intimately re- 

 lated in any consideration of human comfort. Even when the 

 temperature and the humidity are high, the mere circulation of 

 air by use of a fan can make a person more comfortable. Im- 

 proper air conditioning, such as maintaining too low a temperature, 

 too low a humidity, or too rapid circulation of air, can be detri- 

 mental to health by chilling persons, and some believe this induces 

 the onset of common colds. 



AIR TREATMENT DEVICES 



We might consider Lister's work in introducing carbolic acid 

 spravs into the air surrounding patients during surgery to be the 

 earliest attempt to "purify" the air. Little progress was made in 

 expanding research in this direction until quite recently when 

 aerosol mists were introduced. Glycol vapors, particularly pro- 

 pvlene and triethylene glycol, are employed as air disinfectants, 

 and they exhibit many characteristics ideal for the killing of micro- 

 organisms. As little as 0.5 mg. of propylene glycol vapor per liter 

 of air can virtually sterilize heavily contaminated air in fifteen 

 seconds, according to some investigators, and triethylene glycol 

 is apparently even more effective than propylene glycol. Chemical 

 treatment of the air with aerosols, however, bears a relationship to 

 temperature and humidity. 



While most studies on the treatment of the atmosphere with 

 aerosols have been aimed at reducing the count of viable organ- 

 isms, a great deal more information is needed before it can be 

 stated conclusively that these mists have a direct effect on reducing 

 disease. 



ODORS AND HEALTH 



The role played by bad odors in human health has been a mat- 

 ter of pure speculation for decades. It was commonly believed 

 that bad air was the direct cause of certain fevers. A disease 

 still masquerading under a false name is malaria, which literally 

 means bad air. Since persons engaged in work around sewers 



