Table 1.
Statistical summary of air pollutants, meteorological factors and daily number of outpatient visits for RD.
| Variable | P 50 | IQR | P 25 | P 75 | Mean | SD | Max | Min |
| PM2.5 (µg/m3) | 36.0 | 39.4 | 21.6 | 61.0 | 47.6 | 37.7 | 276.2 | 3.4 |
| PM10 (µg/m3) | 61.6 | 53.4 | 39.4 | 92.8 | 72.5 | 45.3 | 339.2 | 7.2 |
| O3 (µg/m3) | 83.2 | 60.6 | 56.0 | 116.6 | 87.3 | 40.4 | 212.6 | 6.0 |
| NO2 (µg/m3) | 26.5 | 13.4 | 20.6 | 34.0 | 28.3 | 10.6 | 82.4 | 8.2 |
| SO2 (µg/m3) | 7.6 | 4.2 | 6.4 | 10.6 | 9.2 | 4.6 | 45.6 | 3.8 |
| CO (mg/m3) | 0.8 | 0.4 | 0.6 | 1.0 | 0.8 | 0.3 | 2.6 | 0.2 |
| TEMP (°C) | 17.5 | 14.7 | 9.7 | 24.4 | 17.0 | 8.4 | 32.9 | −3.8 |
| RH (%) | 76.0 | 21.9 | 65.3 | 87.2 | 75.6 | 14.5 | 100.0 | 30.3 |
| WS (m/s) | 1.8 | 0.7 | 1.4 | 2.1 | 1.8 | 0.5 | 4.2 | 0.4 |
| RD number | 24.0 | 21.0 | 15.0 | 36.0 | 26.7 | 16.9 | 149.0 | 0.0 |
| IRD number | 19.0 | 15.0 | 12.0 | 27.0 | 20.7 | 13.8 | 144.0 | 0.0 |
| CRD number | 4.0 | 6.0 | 2.0 | 8.0 | 5.8 | 5.1 | 45.0 | 0.0 |
PM2.5: particulate matter smaller than 2.5 µm, PM10: particulate matter smaller than 10 µm, O3: ozone, NO2: nitrogen dioxide, SO2: sulfur dioxide, CO: carbon monoxide, TEMP: average daily temperature, RH: average relative humidity, WS: daily average wind speed, RD: respiratory disease, IRD: infectious respiratory diseases, CRD: chronic respiratory disease, IQR: interquartile range, Max: maximal value, Min: minimal value.