Table 1 Characteristics of meteorological variables and air pollutants in Hefei, China, from 2014 to 2017
Indicator | Mean ± SD | Percentile | ||||
|---|---|---|---|---|---|---|
5 | 25 | 50 | 75 | 95 | ||
Mean temperature (°C) | 16.8 ± 9.0 | 2.4 | 8.8 | 17.8 | 24.5 | 30.1 |
Relative humidity (%) | 75.5 ± 12.9 | 52.0 | 67.0 | 76.0 | 85.0 | 95.0 |
Rainfall (mm) | 3.4 ± 10.1 | 0.0 | 0.0 | 0.0 | 0.9 | 19.8 |
Barometric pressure (hpa) | 1015 ± 60.0 | 1000.1 | 1005.5 | 1013.3 | 1021.1 | 1029.1 |
Wind velocity (m/s) | 1.9 ± 0.7 | 0.9 | 1.4 | 1.8 | 2.3 | 3.3 |
PM10 (ug/m3) | 95.0 ± 49.1 | 31.0 | 62.0 | 89.0 | 118.0 | 181.9 |
PM2.5 (ug/m3) | 64.6 ± 39.9 | 20.0 | 38.5 | 56.0 | 81.0 | 136.0 |
SO2 (ug/m3) | 15.7 ± 7.2 | 8.0 | 10.0 | 14.0 | 19.0 | 29.0 |
NO2 (ug/m3) | 39.5 ± 18.8 | 17.1 | 27.0 | 35.0 | 48.0 | 77.0 |
CO (mg/m3) | 1.0 ± 0.3 | 0.6 | 0.8 | 0.9 | 1.1 | 1.6 |
O3 (ug/m3) | 77.9 ± 41.9 | 25.0 | 46.0 | 68.0 | 103.0 | 160.0 |