Miller-SL; Hernandez-M; Fennelly-K; Martyny-J; Macher-J; Kujundzic; Xu-P; Fabian-P; Peccia-J; Howard-C
NIOSH 2002 Oct; :1-80
Airborne transmission of Mycobacterium tuberculosis and other infectious agents within indoor environments has been a recognized hazard for decades. Engineering controls such as ventilation and negative pressure have been helpful for control of tuberculosis (TB) transmission in high-risk settings such as hospital isolation rooms. Increasing costs associated with providing ventilation has prompted renewed interest in other means to remove airborne infectious agents from room air, such as the application of ultraviolet germicidal irradiation (UVGI). One application of UVGI is to irradiate the upper part of a room while minimizing radiation exposure to persons in the lower part of the room. Data has been available showing that UVGI has the potential to be a useful engineering control for TB. The 1994 CDC TB Guidelines (Centers for Disease Control and Prevention, 1994) relied primarily on upper-room air UVGI studies over 30 years old when guidelines were written for its use as an engineering control measure to mitigate the transmission of airborne M. tuberculosis. Knowledge gaps still remained in regard to the impacts of environmental factors such as air mixing, relative humidity and various other parameters on the efficacy of upper-room air UVGI. In addition, no room studies had been conducted using modem UVGI fixtures and bulbs. Thus questions still remain on the best approach to install UVGI in real settings. The aim of our study was to systematically investigate the conditions under which UVGI can be expected to mitigate the spread of tuberculosis. Completion of this work has significantly improved our fundamental understanding of the efficacy of upper-room air UVGI systems and will facilitate their design, optimization and implementation on a practical scale.
Microorganisms; Air-contamination; Airborne-particles; Infection-control; Infectious-diseases; Engineering-controls; Ventilation-systems; Ultraviolet-radiation; Indoor-air-pollution; Health-care-personnel; Health-care-facilities; Respiratory-system-disorders; Pulmonary-system-disorders; Indoor-environmental-quality
Final Contract Report
NTIS Accession No.
National Institute for Occupational Safety and Health
Department of Mechanical Engineering, 427 UCB, University of Colorado, Boulder, Colorado 80309