Table 1.
Ventilation Rates (Air Change per Hour, ACH), Number of Occupants (Median [Interquartile Range, IQR]), Active E-cigarette Vapers (Median [IQR]), and Indoor Air Qualitiesa (Time-Weighted Average [TWA] ± Weighted Standard Deviation) for the Studied Vape-Shopsb
| Occupant (person) | Active vaper (person) | CO2 (ppm) | NO2 (ppb) | PM2.5 (mg/m3) | CMD (nm) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Vape-shop ID | Date | Open hours | Volume (m3) | ACH (h−1) | Median (IQR) | Total | Median (IQR) | Total | Open | Close | Open | Close | Open | Close | Open | Close |
| 1 | 8/25/16 | 12 pm to 10 pm | 118.7 | 0.146 | 4 (2) | 32 | 2 (2) | 24 | 663 ± 157 | 488 ± 164 | 16.6 ± 6.7 | 6.9 ± 9.7 | 3.49 ± 2.64 | 0.19 ± 3.27 | 286 ± 54 | 174 ± 106 |
| 2 | 9/23/16 | 10 am to 10 pm | 185.4 | 0.126 | 4 (2) | 42 | 2 (1) | 21 | 964 ± 226 | 696 ± 219 | 3.2 ± 0.9 | 1.5 ± 0.9 | 1.19 ± 1.58 | 0.12 ± 1.52 | 240 ± 58 | 185 ± 58 |
| 3 | 10/3/17 | 10 am to 10 pm | 471.4 | 0.152 | 5 (3) | 43 | 1 (1) | 13 | 550 ± 27 | 472 ± 78 | 15.5 ± 7.0 | 6.7 ± 9.1 | 1.09 ± 1.74 | 0.02 ± 1.07 | 230 ± 37 | 174 ± 55 |
| 4 | 11/22/17 | 11 am to 8 pm | 138.1 | 0.135 | 4 (2) | 27 | 1 (1) | 17 | 991 ± 109 | 586 ± 413 | 3.8 ± 1.7 | 3.9 ± 1.6 | 2.51 ± 2.10 | 0.05 ± 2.47 | 255 ± 38 | 173 ± 85 |
| 5 | 12/5/17 | 11 am to 8 pm | 163.1 | 0.151 | 2 (1) | 14 | 1 (0) | 12 | 591 ± 38 | 506 ± 28 | 11.7 ± 3.2 | 8.3 ± 2.0 | 0.03 ± 0.02 | 0.02 ± 0.01 | 180 ± 11 | 174 ± 6 |
| All | 752 ± 134 | 550 ± 225 | 10.2 ± 4.7 | 5.4 ± 6.1 | 1.66 ± 1.84 | 0.08 ± 2.01 | 238 ± 43 | 176 ± 70 | ||||||||
aCarbon dioxide (CO2), nitrogen dioxide (NO2), particulate matter (PM2.5), and median particle size (count median diameter, CMD) for opening and closing hours.
bOther indoor air contaminants (ie, aldehydes and nicotine) are shown in Figure 1.