AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Temporal and Spatial Variations of Ultrafine Particles and PM2.5 of Secondhand Electronic Cigarette Aerosols
Tongke Zhao, Che-Husan (Sherry) Lin, Qiuju Guo, YIFANG ZHU, University of California Los Angeles
Abstract Number: 225 Working Group: Electronic Cigarettes - Particle Generation
Abstract Electronic cigarettes (ECs), as an increasingly popular alternative to tobacco cigarettes, are a new source of indoor airborne particles. Although there is no sidestream of EC, the exhaled EC aerosols are recognized as secondhand EC aerosols. However, there were limited studies that characterized these particles. To study the characteristics of secondhand EC aerosols, real-time measurements of particle size distribution, particle number concentration (PNC), PM2.5, CO2, CO, and formaldehyde concentrations were conducted before, during, and after EC-use among 29 volunteers in an 80-m3 room. To assess the transport of particles, two sampling locations were set up at 0.8 and 1.5 m away from the volunteers, respectively. Results showed that the average PNC and PM2.5 mass concentrations during puffing were 2.14e4 and 52.6 µg/m3 at the 0.8 m location. Owing to fast evaporation, the measured concentration of secondhand EC particles negatively correlated with the distances to EC users. The average PNC and PM2.5 mass concentrations were 9.55e3 /m3 and 9.89 µg/m3 at the 1.5 m location. Both PNC and PM2.5 measured in this study were either comparable with or less than other indoor emission sources. Two modes of secondhand EC particles were observed at about 19 nm and 95 nm, respectively. Furthermore, experienced EC users produced higher level of secondhand EC particles than naïve users. This study can be used for secondhand EC particle exposure assessment in indoor environments.