74 



RADIATION BIOLOGY 



Hospitals. When new low-pressure sources of 2537 A ultraviolet, with 

 a germicidal ellicieucy fivefold greater than that of previously available 

 sources revived the interest in practical applications, they were first 

 found by Hart (193G) and Overholt and Betts (1940) to improve the air 



(10" 100° 90° 80° 70° 60 



4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 

 DISTANCE FROM FIXTURE, ft 



(6) 



Fig 2-15 (a) Spatial distribution of ultraviolet from typical bactericidal tubes and 

 louvered reflectors with a downward barrier reflector, (h) Isointen.s.ty lines ni milli- 

 watts per square foot in a plane perpendicular to the center of the G30T8 tube ot 

 Fig. 2-9. 



sanitation in operating rooms. This success led to trials by Sauer et al. 

 (1942), Del Mundo and McKhann (1941), and Robertson et al. (1939; 

 1943) in infant nurseries where an even more definite improvement was 

 found by air sampling as w(^ll as by records of the spread of contagion 

 among infants. On the basis of these tests the use of germicidal lamps 



