Riley R L, Knight M, Middlebrook G
Am Rev Respir Dis. 1976 Apr;113(4):413-8. doi: 10.1164/arrd.1976.113.4.413.
To test the effectiveness of irradiating the upper air of a room with ultraviolet light at reducing the concentration of airborne tubercle bacilli, the susceptibility to the germicidal effects of ultraviolet light, Z, was determined for various mycobacteria. Virulent tubercle bacilli and bacille Calmette-Guérin (BCG) were equally susceptible to ultraviolet radiation, whereas Mycobacterium phlei had 10 times their resistance (Z, approximately one-tenth that for M. tuberculosis). The effectiveness against BCG of upper air ultraviolet irradiation in a room was tested directly by nebulizing BCG into the air of the room and monitoring its rate of disappearance. With one 17-watt fixture operating, the rate of disappearance increased 6-fold; with 2 fixtures operating (46 watts total), the rate of disappearance increased 9-fold. This implies that under steady-state conditions, the concentrations of airborne organisms with ultraviolet light(s) on would have been one-sixth and one-ninth, respectively. The increase in rate of decay of the airborne organisms using 1 fixture was equivalent to 10 air changes per hour, whereas that using 2 fixtures was approximately 25 air changes per hour (range: 18 to 33 air changes per hour). These increments are less than those reported previously for Serratia marcescens, because the Z value for BCG is approximately one-seventh that for serratia. These findings with BCG are believed to be directly applicable to virulent tubercle bacilli.
为了测试用紫外线照射房间上层空气以降低空气中结核杆菌浓度的效果，测定了各种分枝杆菌对紫外线杀菌作用的敏感性Z。有毒力的结核杆菌和卡介苗（BCG）对紫外线辐射的敏感性相同，而草分枝杆菌的抵抗力是它们的10倍（Z值约为结核分枝杆菌的十分之一）。通过将卡介苗雾化到房间空气中并监测其消失速率，直接测试了房间上层空气紫外线照射对卡介苗的效果。使用一个17瓦的灯具时，消失速率增加了6倍；使用2个灯具（总共46瓦）时，消失速率增加了9倍。这意味着在稳态条件下，开启紫外线时空气中微生物的浓度分别为原来的六分之一和九分之一。使用1个灯具时空气中微生物衰减速率的增加相当于每小时换气10次，而使用2个灯具时约为每小时换气25次（范围：每小时换气18至33次）。这些增加量小于先前报道的粘质沙雷氏菌的增加量，因为卡介苗的Z值约为沙雷氏菌的七分之一。关于卡介苗的这些发现被认为可直接应用于有毒力的结核杆菌。
