76 RADIATION BIOLOGY 



Institutions. Many institutions, through their isolation from sur- 

 rounding communities, have provided an opportunity to study the 

 possil)le vakie of a unixcrsal practice of air sanitation in large com- 

 munities. Schneiter et al. (1944) early reported a study in a training 

 school for delin(iuent boys started with such e(|uipment as was then 

 available. DuHuy ct al. (1948) have since reported no effect on the 

 incidence of disease among the boys, and that air sampling showed little 

 air disinfection. If there was no disinfection, no effect should have l)een 

 expected, but the more probable explanation is that the air-sampling 

 method did not properly detect the presence or absence of respiratory- 

 disease organisms, that the obsolete equipment did not pro\'ide an 

 effective use of the ultraviolet energy even though it was supplied in 

 excess, and that any possible effect on the spread of respiratory diseases 

 in the sleeping rooms was nullified by the lack of separation of the boys 

 in the irradiated dormitory from those in the control dormitory during 

 their class, intimate play, and eating periods. 



Navy Barracks. In contrast with these results, studies in Navy 

 barracks consistently indicated disinfection of the air and a significant 

 reduction in the spread of general respirator}^ diseases. Wheeler et al. 

 (1945) reported a 25 per cent reduction of respiratory illness and a 50 

 per cent reduction of the relatively highly resistant saprophytic organisms 

 dominating the air contamination. Miller et al. (1948) reported, in a 

 similar but theoretically more effective installation, a 19.2 per cent over- 

 all reduction in total respiratory disease and a 24 per cent reduction in the 

 unusually high streptococcus-disease rates. Willmon et al. (1948), 

 reviewing four years of Navy barracks study, are less certain of the 

 amount of reduction in disease, and Jarrett et al. (1948) reported about 

 50 per cent reductions in bacteria count but were dissatisfied with 

 the open-plate method which overemphasizes heavier dust-borne 

 contaminants. 



Conservatism as to Value. The universal appeal of air disinfection as a 

 general sanitary measure and the limited evidence of its specific health 

 value have led committees of the American Public Health Association 

 (1947) and of the National Research Council (1947) to issue warning 

 statements about air disinfection in general and about the ultraviolet 

 method in particular. Both committees point out that, at best, air dis- 

 infection can reduce only that limited part of the spread of respiratory 

 disease which may be air-borne, and they emphasize the difficulties in 

 obtaining effective ultraviolet air disinfection without face and skin 

 irritation of room occupants. 



There is need for further study of the extent to which air disinfection 

 might supplement the use of face masks, the smothering of the cough and 

 sneeze, and the physical isolation of patients suffering from respiratory 

 disease. 



