In germany we have this allready but it doesnt work. It reduce the problem. But the real problem is ER. In a life death situation it doesnt work. ER are very hard to keep clean. But yes you are absolutly right
EDIT:// I am no doctor but did work in Hospitals. Doctor friends working in ER are telling me about those dangers. And also bigger Hospitals have less control about it.
220nm light is under investigation since it's germicidal but so far appears far less harmful to humans than other UV ranges. If those findings are validated we might see some permanent narrow-band, low-power UV lights in hospitals.