AIr Contamination and AIr Sterilization

If secondary infections could be avoided in hospital wards, both the patients and the hospital would be greatly benefited. Until a few years ago, these infections were thought to be carried either by the attendants' hands or by droplets coughed out by the patients. Such droplets travel only a few feet, and sufficient space between the beds would control this mode of spread. However, the work of W. F. Wells and M. W. Wells1has shown that bacteria in very small particles, or "nuclei," can remain suspended in the air for two or three days, and this strongly suggests that air-borne bacteria may play a part in the spread of disease in the wards. That ultraviolet lamps can be used to kill air-borne bacteria has been demonstrated by several investigators. For example, Hart2reported that when he operated under a battery of eight tubular ultraviolet lamps, the wounds