The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real- world conditions

The authors concluded that use of e-cigarettes resulted in substantial increases in PM2.5 and UFP, and represents a new source of indoor air environmental particulate matter exposure. CO2 concentrations before testing ranged from 590-1080 ppm, with averages of 702 ppm near the window and 711 ppm in the center; following testing, room CO2 was found to be 610-990 ppm, averaging 730 ppm near the window and 757 ppm in the center.
The maximum PM2.5 concentration was 174,160 μg/m3 (measured at 0.5 m, cigalike device) during exposure tests. The mean concentrations at 0.5m during exposure periods were 709 μg/m3 (cigalike), 1117 μg/m3 (tank), and 364 μg/m3 (adjustable). At 1m, the mean concentrations were 168, 1193, and 235 μg/m3 for cigalike, tank, and adjustable devices, respectively. At 0.5m, the cumulative mean (measured as the sum of all 1s values in a period divided by the number of minutes) of PM2.5 was calculated as 42533 μg/m3 for cigalike, 67028 μg/m3 for tank, and 21833 μg/m3 for adjustable e-cigarettes; at 1m, cumulative means were calculated as 10087, 71606, and 14111 μg/m3 for cigalike, tank, and adjustable devices, respectively.
UFP number concentrations (particle count/cm3) before exposure averaged 1,389.3 p/cc at 0.5m and 3491.3 p/cc at 1m, and averaged 7168.5 p/cc at 0.5m and 10,591.6 p/cc at 1m following exposure. During exposure, the UFP concentration peaked at 284,260 particles/cc (0.5 m, cigalike). Mean concentrations during exposure at 0.5m were 11,106 p/cc, 14,541 p/cc, and 8060 p/cc for cigalike, tank, and adjustable devices, respectively. At 1m, the mean concentrations were 10,366 p/cc for cigalike, 26,424 p/cc for tank, and 9,699 p/cc for the adjustable device. Cumulative mean concentrations for UFP were 666,334 p/cc for the cigalike device, 872,485 p/cc for the tank device, and 483,596 p/cc for the adjustable device. At 1m, means were 621,936 p/cc (cigalike), 1,585,464 p/cc (tank), and 581,925 p/cc (adjustable).

Volesky, K.D., et al. (2018). The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real- world conditions. Environmental pollution, 243, 882-889.