The optimisation of UVGI air disinfection in a UK hospital building.

A number of studies have shown that approximately 1 in 10 hospital in-patients will acquire a nosocomial infection (NI) '*).These infections are associated with significant mortality rates, and have a large economic impact on health care systems. A Department of Health (DoH) study estimated that in acute care hospitals in England 950000 lost bed days and financial costs off 111 million (1986 rates) were associated with NI '3).Through the use of ultraviolet germicidal irradiation (UVGI) lamps it ii possible to achieve a high degree of pathogen disinfection. This paper presents a theoretical model for optimising the use of UVGI lamps in ventilation ducts. The paper also outlines a research project investigating the air disinfection effectiveness of UVGI in a Leeds teaching hospital.