AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Assessment and Mitigation of Exhaled Electronic Cigarette Aerosols in a Multi-zone Indoor Environment
Li Zhang, Yan Lin, YIFANG ZHU, University of California Los Angeles
Abstract Number: 870 Working Group: Indoor Aerosols
Abstract Electronic cigarettes (E-cigs) are battery-operated devices gaining increasing popularity as an alternative to tobacco cigarettes. To better understand the transport of exhaled e-cig aerosols and to evaluate the efficiency of various mitigation strategies, experiments were conducted in two neighboring laboratory rooms (one as Vaping Room and the other as Non-Vaping Room) under various conditions, including door segregation, enhanced ventilation and air filtration. A recruited e-cig user vaped in Vaping Room and particle number concentration (PNC) and PM2.5 mass concentrations were measured concurrently in both rooms before, during and after the vaping activity. Secondhand exposure to exhaled e-cig aerosols was observed in this study. Transport of particle number from exhaled e-cig aerosols was observed from Vaping Room to Non-Vaping Room whereas almost no transport of PM2.5 was observed. The transport process could be effectively mitigated by controls, especially for door segregation, where particle levels were reduced from 48% to 6%. Other controls, including enhanced ventilation and air filtration, increased particle removal efficiency in the room. Particle decay due to room air exchange rate (AER) was the primary contributor compared with decay due to aerosol dynamics (including processes of particle evaporation, surface deposition and coagulation).