Engineering Approaches to Characterize the Effectiveness of Upper-room UVC Lights for Controlling Aerosol Transmission of Influenza

Abstract

S-29B8-2 Background/Aims: The inactivating effect of UVC (200–280 nm) light on influenza virus, to be reviewed, provides an opportunity for engineering controls to prevent airborne influenza transmission. In this presentation, some engineering approaches to predict the effectiveness of upper-room UVC systems by characterizing the air movement in buildings and accounting for susceptibility of influenza would be introduced. Methods: Numerical methods were used for simulating the air movement considered to convey the aerosolized influenza virus and they referred to the experimental data demonstrating susceptibility of aerosolized influenza virus to UVC light and UVC intensity distribution data in upper area of rooms. A simplified ward including a source point was modeled and the inactivation performance of upper-room UVC light were predicted in several cases changing the position of UVC light and ventilation openings, which might eventually change the airflow distribution in the ward. Results: The experimental results indicated reasonable susceptibility of the aerosolized influenza virus to UVC light. In many simulated cases with the data, the position of UVC light and some factors affecting air movement in the ward such as the position of ventilation openings affected the entire inactivation efficiency of upper-room UVC systems. Specifically speaking, the residence time of air containing influenza virus at high UVC intensity area needs to be increased for better performance of the systems. Conclusion: Considering the possibility of aerosol transmission of influenza, air movement is a critical factor not only for the dispersion of influenza virus but also for the inactivating effect of upper-room UVC systems.