Table 2.
Summary of meteorologic and air pollution levels.
| Percentile
|
||||||||
|---|---|---|---|---|---|---|---|---|
| Parametera | No. | Mean | 10th | 25th | 50th | 75th | 90th | 24 hrb |
| Meteorology (24 hr) | ||||||||
| Temperature (°C) | 265 | 17.8 | 12.2 | 16.1 | 18.0 | 20.3 | 23.6 | — |
| Relative humidity (%) | 265 | 70.3 | 52.5 | 57.4 | 70.1 | 82.6 | 92.6 | — |
| Pollution (4 hr) | ||||||||
| PM2.5 (μ g/m3) | 264 | 17.8 | 7.0 | 11.6 | 16.5 | 22.2 | 30.9 | 17.2 |
| EC (μ g/m3) | 260 | 2.3 | 0.9 | 1.2 | 1.6 | 2.9 | 4.4 | 2.0 |
| O3 (ppb) | 251 | 18.5 | 9.0 | 12.7 | 17.0 | 22.5 | 30.3 | 29.4 |
| CO (ppb) | 236 | 362.0 | 169.7 | 221.5 | 304.3 | 398.1 | 682.1 | 332.1 |
| SO2 (ppb) | 240 | 1.9 | 0.7 | 0.9 | 1.5 | 2.4 | 3.6 | 2.5 |
| NO2 (ppb) | 222 | 17.8 | 7.1 | 12.0 | 17.0 | 22.8 | 29.8 | 17.1 |
a
Values correspond to the mean for the 24-hr or 4-hr periods before the HRV measurements.
b
Corresponding 24-hr mean values for time period before the health measurements.