Table 3.
Concentration and size of airborne particles released from ultrasonic humidifier for each type of water
| Used water | Mass concentration (mg/m 3 ) | Number concentration (#/cm 3 ) | Peak of size distribution (nm) |
|---|---|---|---|
| Tap water |
0.46 ± 0.03 |
(5.0 ± 1.1) × 104 |
183 ± 9 |
| High-silica water |
0.58 ± 0.04 |
(3.6 ± 0.0) × 104 |
180 ± 3 |
| CaCl2 (400 mg/L Ca) |
1.66 ± 0.16 |
(6.3 ± 0.5) × 104 |
>410 |
| CaCl2 (200 mg/L Ca) |
1.26 ± 0.19 |
(4.2 ± 0.3) × 104 |
356 ± 11 |
| CaCl2 (80 mg/L Ca) |
0.46 ± 0.11 |
(5.0 ± 0.1) × 104 |
283 ± 9 |
| CaCl2 (40 mg/L Ca) |
0.12 ± 0.03 |
(4.5 ± 0.0) × 104 |
222 ± 4 |
| CaCl2 (10 mg/L Ca) |
0.08 ± 0.01 |
(3.4 ± 0.1) × 104 |
123 ± 4 |
| CaCl2 (4 mg/L Ca) |
0.02 ± 0.01 |
(2.7 ± 0.3) × 104 |
108 ± 2 |
| RO water |
<0.01 |
(4.4 ± 0.6) × 104 |
90 ± 2 |
| Ultrapure water | <0.01 | (0.7 ± 0.0) × 104 | Not determined |
Data are shown as mean ± SD, calculated from 5 repeats of 2 min analyses.