Table 2.
Average concentrations (ng/m3) and associated standard deviations of elements in PM2.5 at our study site during the three selected periods.
| Element | P1 | P2 | P3 |
|---|---|---|---|
| K | 3400 ± 8100 | 3100 ± 4200 | 1310 ± 710 |
| Ca | 164 ± 174 | 23 ± 51 | 870 ± 500 |
| V | 0.2 ± 0.7 | 0.5 ± 1.7 | 0.1 ± 0.6 |
| Cr | 2.8 ± 8.0 | 1.0 ± 2.1 | 4.0 ± 4.4 |
| Mn | 32 ± 30 | 12.4 ± 17.4 | 76 ± 57 |
| Fe | 460 ± 400 | 260 ± 280 | 2400 ± 1450 |
| Ni | 2.7 ± 6.3 | 3.2 ± 3.6 | 3.5 ± 3.5 |
| Cu | 81 ± 200 | 81 ± 109 | 21 ± 11 |
| Zn | 125 ± 105 | 68 ± 87 | 166 ± 150 |
| As | 2.5 ± 5.0 | 1.2 ± 5.0 | 3.1 ± 6.4 |
| Se | 4.4 ± 5.9 | 2.5 ± 3.3 | 2.8 ± 3.2 |
| Ba | 240 ± 740 | 210 ± 410 | 152 ± 70 |
| Pb | 71 ± 65 | 52 ± 71 | 39 ± 36 |