Effects of Power and E-Liquid Constituents on Secondhand Electronic Cigarette Emissions
SARAH FRESQUEZ, Gabriela Gabriela, Emma Piner, Talia Chavis, Sinan Sousan, Department of Public Health, East Carolina University
Abstract Number: 45
Working Group: Health-Related Aerosols
Abstract
Electronic cigarette (ECIG) aerosol emissions contain PM2.5 particles with diameters of 2.5 micrometers or less that can pose significant health risks upon inhalation. Users can increase aerosol emissions, or “clouds,” by adjusting the power output of their devices. Additionally, they can tailor the vaping experience by modifying e-liquid characteristics such as flavor, nicotine type (freebase or salt), nicotine concentration, and the ratio of propylene glycol (PG) to vegetable glycerin (VG). Measuring particulate matter (PM) mass concentrations using “gold standard” air monitoring techniques involves expensive and time-consuming processes. These include calculating time-weighted averages from discrete filter samples, which are used to develop filter correction factors for commercially available real-time monitors. These correction factors are essential to address the overestimations and underestimations of PM concentrations commonly observed in real-time data. This study investigates how varying ECIG device power settings and e-liquid features affect PM2.5 filter correction factors, mass concentrations, and aerosol size distributions. Experiments were conducted in a controlled laboratory chamber during 30-minute sessions. Two sets of conditions were tested: the first involved four e-liquid flavors at five different wattage settings, and the second compared freebase and salt nicotine e-liquids across the same wattages. Filter correction factors ranged from 9.08 to 15.25 for the combined Scanning Mobility Particle Spectrometer and Aerodynamic Particle Sizer monitors, and from 0.36 to 0.53 for the personal DataRam (pDR-1500). These values revealed both over- and underestimations in real-time PM2.5 measurements. Mass concentrations reached up to 60,000 µg/m³, and particle sizes ranged from 0.10 to 2.52 µm. The elevated PM2.5 levels in secondhand ECIG emissions suggest an even greater risk for firsthand users. These findings emphasize the importance of accurate monitoring and regulation of ECIG aerosol emissions to protect public health.