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Descriptive statistics for air pollutants during 2003–2011.
| Variable | No. of days | Means (SD) of AP concentration (ppm) |
|---|---|---|
| Spring (Apr–May) | ||
| PM10 | 2,809 | 62.792 (44.276) |
| NO2 | 2,871 | 0.023 (0.011) |
| SO2 | 2,825 | 0.004 (0.002) |
| O3 | 2,898 | 0.049 (0.013) |
| CO | 2,915 | 0.450 (0.274) |
| Fall (Sep–Oct) | ||
| PM10 | 2,680 | 41.044 (21.406) |
| NO2 | 2,775 | 0.020 (0.010) |
| SO2 | 2,765 | 0.004 (0.001) |
| O3 | 2,864 | 0.036 (0.013) |
| CO | 2,827 | 0.420 (0.277) |
AP = air pollutant; SD = standard deviation.
