Table 2.
Summary characteristics of particle component concentration, relative humidity, and temperature
| Variable | Median | Mean | IQR | S.D. | 75th | 95th | Max |
|---|---|---|---|---|---|---|---|
| PM 2.5 Major Components | |||||||
| SO42− (µg/m3) | 2.36 | 2.21 | 1.41 | 0.75 | 2.87 | 3.25 | 3.76 |
| NO3− (µg/m3) | 0.80 | 0.82 | 0.26 | 0.18 | 0.94 | 1.15 | 1.57 |
| NH4+ (µg/m3) | 0.75 | 0.76 | 0.45 | 0.25 | 0.96 | 1.17 | 1.49 |
| OC (µg/m3) | 1.64 | 1.72 | 0.47 | 0.39 | 1.92 | 2.51 | 3.56 |
| EC (µg/m3) | 0.45 | 0.48 | 0.16 | 0.14 | 0.55 | 0.76 | 1.23 |
| PM 2.5 Trace Elements | |||||||
| Zn (ng/m3) | 9.29 | 9.49 | 3.82 | 2.72 | 11.36 | 14.12 | 19.18 |
| V (ng/m3) | 1.43 | 1.70 | 2.00 | 1.29 | 2.54 | 4.15 | 6.84 |
| K (ng/m3) | 47.63 | 47.81 | 6.20 | 4.77 | 50.87 | 55.83 | 67.21 |
| Si (ng/m3) | 51.15 | 54.34 | 17.63 | 13.79 | 61.47 | 83.93 | 107.14 |
| Pb (ng/m3) | 1.96 | 2.39 | 1.77 | 1.07 | 3.30 | 4.33 | 5.52 |
| Ni (ng/m3) | 0.98 | 1.14 | 0.86 | 0.63 | 1.52 | 2.41 | 3.03 |
| Fe (ng/m3) | 49.72 | 50.80 | 22.12 | 17.20 | 61.01 | 82.70 | 124.43 |
| Cu (ng/m3) | 2.47 | 2.66 | 1.30 | 1.15 | 3.18 | 5.03 | 9.92 |
| Ca (ng/m3) | 22.68 | 23.30 | 6.94 | 5.59 | 26.36 | 34.00 | 50.17 |
| Br (ng/m3) | 2.63 | 2.63 | 0.41 | 0.32 | 2.83 | 3.15 | 3.68 |
| Total PM 2.5 Mass | |||||||
| PM2.5 (µg/m3) | 8.75 | 8.73 | 2.80 | 1.94 | 10.08 | 11.96 | 16.39 |
| Meteorological variables | |||||||
| Relative humidity (%) | 64.44 | 64.53 | 3.28 | 2.91 | 66.03 | 69.74 | 77.32 |
| Temperature (℃) | 10.09 | 10.09 | 1.36 | 1.05 | 10.83 | 11.72 | 12.86 |
Abbreviations: IQR for interquartile range; S.D. for standard deviation; 75th for 75th percentile; 95th for 95th percentile; Max for maximum value; SO42− for sulfate; NO3− for nitrate; NH4+ for ammonium; OC for organic carbon; EC for elemental carbon; Zn for zinc; V or vanadium; K for potassium; Si for silicon; Pb for lead; Ni for nickel; Fe for iron; Cu for copper; Ca for calcium; Br for bromine