Table 1.
Descriptive statistics of PM and elemental concentrations in the quasi-ultrafine, fine and coarse size fractions.
| Quasi-Ultrafine, PM0.2 | Fine, PM2.5 | Coarse, PM2.5–10 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Units: ng/m3 | N | Mean | Std Dev | N | Mean | Std Dev | N | Mean | Std Dev |
| PM Mass | 470 | 2,389.6 | 884.6 | 484 | 14,599.1 | 3,890.3 | 496 | 12,854.4 | 4,713.9 |
| Carbon Species | |||||||||
| EC | 461 | 364.7 | 192.5 | 470 | 873.6 | 483.0 | |||
| OC | 460 | 1,069.8 | 383.1 | 471 | 2,784.9 | 991.1 | |||
| Water-soluble OC | 460 | 426.6 | 136.3 | 473 | 975.6 | 305.8 | |||
| Water-insoluble OC | 458 | 641.6 | 293.0 | 470 | 1,798.9 | 864.6 | |||
| Ions* | |||||||||
| Ammonium | 94 | 101.9 | 87.1 | 93 | 362.8 | 182.5 | 93 | 89.9 | 57.7 |
| Chloride | 94 | 35.3 | 92.0 | 93 | 71.7 | 105.7 | 93 | 540.6 | 511.1 |
| Nitrate | 93 | 127.7 | 249.9 | 92 | 781.5 | 541.8 | 93 | 1,803.8 | 706.1 |
| Elements | |||||||||
| Al | 461 | 1.6 | 1.8 | 265 | 51.9 | 32.0 | 298 | 408.0 | 328.8 |
| Ba | 461 | 0.2 | 0.3 | 265 | 5.5 | 3.9 | 298 | 18.1 | 12.2 |
| Ca | 461 | 2.1 | 2.4 | 265 | 55.5 | 33.0 | 298 | 383.1 | 296.2 |
| Cr | 461 | 0.0 | 0.1 | 265 | 0.3 | 0.3 | 298 | 1.1 | 0.7 |
| Cu | 461 | 0.2 | 0.3 | 265 | 3.8 | 2.7 | 298 | 10.5 | 7.4 |
| Fe | 461 | 3.7 | 3.8 | 265 | 85.8 | 56.4 | 298 | 430.8 | 319.2 |
| K | 461 | 7.4 | 7.2 | 265 | 46.1 | 20.5 | 298 | 172.7 | 133.4 |
| Mg | 461 | 0.7 | 1.0 | 265 | 36.4 | 14.5 | 298 | 190.1 | 124.9 |
| Mn | 461 | 0.1 | 0.2 | 265 | 1.6 | 1.2 | 298 | 6.8 | 5.2 |
| Na | 461 | 3.9 | 3.8 | 265 | 194.1 | 116.8 | 298 | 821.5 | 699.4 |
| P | 461 | 0.5 | 0.5 | 265 | 4.7 | 3.7 | 298 | 20.4 | 23.6 |
| Pb | 461 | 0.5 | 0.5 | 265 | 1.5 | 0.9 | 298 | 1.2 | 0.8 |
| S | 461 | 54.0 | 37.6 | 265 | 328.3 | 137.6 | 298 | 167.9 | 107.3 |
| Sb | 461 | 0.2 | 0.1 | 265 | 1.0 | 0.7 | 298 | 1.7 | 1.3 |
| Sr | 461 | 0.1 | 0.1 | 265 | 0.8 | 0.4 | 298 | 3.6 | 2.3 |
| Ti | 461 | 0.3 | 0.6 | 265 | 5.6 | 3.6 | 298 | 34.5 | 26.0 |
| V | 461 | 0.5 | 0.5 | 265 | 1.7 | 1.0 | 298 | 1.0 | 0.7 |
| Zn | 461 | 1.3 | 2.8 | 265 | 6.4 | 7.4 | 298 | 9.5 | 8.2 |
| Units: pg/m3 | |||||||||
| Ag | 461 | 4.0 | 5.0 | 265 | 13.1 | 9.7 | 298 | 14.7 | 10.2 |
| As | 461 | 63.1 | 62.0 | 265 | 173.2 | 88.3 | 298 | 132.6 | 91.5 |
| B | 461 | 674.4 | 405.1 | 265 | 1,337.1 | 612.4 | 298 | 539.1 | 446.6 |
| Cd | 461 | 14.1 | 24.8 | 265 | 52.9 | 45.5 | 298 | 22.0 | 14.6 |
| Ce | 461 | 6.5 | 7.2 | 265 | 115.3 | 65.6 | 298 | 512.3 | 348.8 |
| Co | 461 | 4.2 | 7.9 | 265 | 38.7 | 35.7 | 298 | 163.9 | 123.0 |
| Cs | 461 | 0.5 | 0.6 | 265 | 5.7 | 3.1 | 298 | 29.1 | 22.0 |
| Dy | 461 | 0.1 | 0.1 | 265 | 2.8 | 1.7 | 298 | 22.0 | 16.9 |
| Ho | 461 | 0.0 | 0.0 | 265 | 0.6 | 0.3 | 298 | 4.4 | 3.4 |
| La | 461 | 4.6 | 4.8 | 265 | 115.6 | 77.8 | 298 | 314.3 | 215.1 |
| Li | 461 | 9.0 | 17.2 | 265 | 110.1 | 132.6 | 298 | 295.5 | 239.0 |
| Lu | 461 | 0.0 | 0.0 | 265 | 0.3 | 0.2 | 298 | 1.9 | 1.4 |
| Mo | 461 | 70.8 | 126.4 | 265 | 275.8 | 268.6 | 298 | 442.8 | 312.9 |
| Nb | 461 | 0.8 | 2.3 | 265 | 14.7 | 8.0 | 298 | 84.9 | 59.9 |
| Nd | 461 | 0.8 | 0.8 | 265 | 23.2 | 12.6 | 298 | 159.3 | 113.9 |
| Ni | 461 | 148.9 | 203.9 | 265 | 683.1 | 488.7 | 298 | 703.9 | 480.8 |
| Pd | 461 | 0.4 | 0.5 | 265 | 6.0 | 3.5 | 298 | 28.7 | 17.8 |
| Pr | 461 | 0.3 | 0.3 | 265 | 7.3 | 3.9 | 298 | 44.7 | 31.0 |
| Pt | 461 | 0.2 | 0.6 | 265 | 2.9 | 5.9 | 298 | 5.6 | 8.6 |
| Rb | 461 | 9.4 | 8.8 | 265 | 96.0 | 55.0 | 298 | 592.0 | 490.0 |
| Rh | 461 | 0.1 | 0.1 | 265 | 0.7 | 0.5 | 298 | 1.8 | 1.2 |
| Sc | 461 | 0.4 | 0.7 | 265 | 9.3 | 5.9 | 298 | 72.1 | 56.7 |
| Se | 45 | 80.0 | 29.2 | 47 | 235.9 | 70.7 | 54 | 84.8 | 50.3 |
| Sm | 461 | 0.1 | 0.1 | 265 | 4.6 | 2.5 | 298 | 29.7 | 21.8 |
| Th | 461 | 0.4 | 0.9 | 265 | 8.6 | 4.8 | 298 | 59.8 | 43.0 |
| Tl | 461 | 1.7 | 2.0 | 265 | 5.2 | 3.4 | 298 | 4.5 | 3.5 |
| U | 462 | 0.2 | 0.2 | 266 | 3.5 | 1.9 | 299 | 23.0 | 16.3 |
| W | 461 | 17.6 | 24.6 | 265 | 61.9 | 54.2 | 298 | 106.1 | 76.0 |
| Y | 461 | 0.5 | 1.2 | 265 | 18.3 | 11.3 | 298 | 141.2 | 98.1 |
| Yb | 461 | 0.0 | 0.1 | 265 | 1.7 | 1.1 | 298 | 12.7 | 9.7 |
*
Only measured ions concentrations collected at schools and central sites are summarized. Values at residences were imputed from community- and sampling period- specific measurements.