Transport and Mitigation of Exhaled Electronic Cigarette Aerosols in a Multizone Indoor Environment

Using an electronic cigarette (e-cig) has been shown to emit a substantial amount of particles and degrade indoor air quality. Here, we tested the effectiveness of different mitigation strategies to reduce indoor particulate pollution due to e-cigs. We simultaneously measured concentrations of particle number (PNC) and fine particle (PM2.5) mass in a vaping room and an adjacent non-vaping room, both of which were well controlled, during e-cig use under six different experimental conditions: (1) the baseline scenario, in which the connecting door between the two rooms was open, the ventilation in both rooms was low, and no air purifier was operated; (2) the connecting door between the two rooms was closed; (3) the ventilation was enhanced in the vaping room; (4) the ventilation was enhanced in the non-vaping room; (5) an air purifier was operated in the vaping room; and (6) an air purifier was operated in the non-vaping room. We found that the particle concentrations significantly decreased in both of the rooms when either the ventilation was enhanced or the air purifier was operated. Closing the connecting door between the two rooms produced the largest reduction (42%) of PNC in the non-vaping room; however, it also led to a 26% increase of PNC in the vaping room. Previous studies have demonstrated that vape shops contain high concentrations of particles when no mitigation strategies are implemented. Our results provide a basis for assessing and reducing exposure to e-cig aerosols and its associated health effects in future studies.