ULTRAVIOLEl LIGHT — GERSHENFELD 217 



numbers of microorganisms in the air vary in different environments 

 and in the same environment at different periods, but certain forms are 

 generally present. Molds, yeasts, and spore-bearing bacteria, all of 

 which may be non-disease-producing, are rather common. Air laden 

 with excessive amounts of these organisms may be responsible for the 

 contamination and spoilage of foodstuffs and different products. Most 

 disease-producing bacteria are not found in the air under ordinary 

 conditions as in the home, or in the average working plant. How- 

 ever, under appropriate conditions, especially indoors or in enclosed 

 spaces, disease-producing bacteria may be found in the air of such 

 environments. They may remain viable for considerable periods 

 of time, even drift around in the air currents, and thus constitute 

 a hygienic or sanitary hazard. The elimination of such hazards 

 especially in hospitals and other institutions has been of great con- 

 cern to everyone. 



Workers in all branches of science have been constantly at war 

 with another kind of enemy — small invisible foes that are lurking 

 constantly in the atmosphere. The control of the sanitary quality of 

 the air in environments where foodstuffs and other products are proc- 

 essed or stored, by means of ultraviolet light, which are death rays to 

 these invisible foes, has reduced markedly spoilage losses. This same 

 weapon, made available easily and at all times, has supplied another 

 invaluable tool for the continued battle against those small invisible 

 and undesirable organisms which cause all kinds of scourges and are 

 ever ready to attack us from impenetrable ambuscades. 



PRACTICAL AIR SANITATION 



Hospitals. — Anyone who is familiar with the history of the be- 

 ginning of modern aseptic surgical methods will tell you about Lis- 

 ter's technique in which he attacked the problem of bacteria in the 

 air by using a carbolic acid spray before and during operations as a 

 means of killing all, or at least decreasing the content of, the disease- 

 producing bacteria in the atmosphere and thus reducing the number 

 of cases of postoperative infection. Sprays, because of the difficulty 

 of providing practical means of application, however, were not 

 found to be very effective. The introduction of air-filtration processes 

 and modern air-conditioning systems has not proved to be adequate in 

 all instances. These measures, however, aided by ultraviolet light 

 or the latter by itself, applied continuously in operating rooms have 

 resulted in an almost complete elimination of wound contamination 

 from air-borne bacteria. This changed condition has brought about 

 an improvement in clinical results that is agreeably surprising. 

 Wound healing has been more rapid and with less reactions. The 

 general postoperative condition of patients has shown marked im- 

 provement. The fatality rate has been cut in half through the elim- 



