Table 4. Summary of winter inversion-focused and 24-h weeklong concentrations for 37 distributed sites per year, with percent above analytic LOD.
|
Inversion-focused |
24-h weeklong |
P-value between designs | |||||
|---|---|---|---|---|---|---|---|
| Mean (SD) | Median | %>LOD | Mean (SD) | Median | %>LOD | ||
| PM2.5 (μg/m3) | 12.76 (2.57) | 12.37 | 1.00 | 11.26 (2.01) | 11.12 | 1.00 | 0.01 |
| BC (abs) | 1.34 (0.53) | 1.24 | 1.00 | 0.93 (0.35) | 0.82 | 1.00 | 0.0002 |
| NO2 (p.p.b.) | 18.84 (6.19) | 16.77 | 1.00 | 15.61 (5.44) | 14.73 | 1.00 | 0.001 |
| Constituents measured by ICP-MS (ng/m3) | |||||||
| Al | 35.20 (44.16) | 24.18 | 0.89 | 15.62 (21.53) | 10.32 | 1.00 | 0.003 |
| As | 0.76 (0.39) | 0.62 | 1.00 | 0.77 (0.59) | 0.58 | 1.00 | 0.94 |
| Ba | 9.04 (11.17) | 3.42 | 0.65 | 11.95 (25.96) | 1.44 | 1.00 | 0.53 |
| Ca | 110.00 (113.57) | 64.44 | 0.89 | 278.50 (772.58) | 100.9 | 1.00 | 0.29 |
| Cd | 0.21 (0.29) | 0.13 | 1.00 | 0.41 (0.95) | 0.17 | 1.00 | 0.22 |
| Ce | 0.11 (0.28) | 0.06 | 1.00 | 0.24 (0.95) | 0.03 | 1.00 | 0.45 |
| Cr | 1.69 (1.70) | 1.41 | 0.97 | 1.08 (2.27) | 0.43 | 0.97 | 0.25 |
| Cs | 0.06 (0.13) | 0.01 | 1.00 | 0.04 (0.10) | 0.01 | 1.00 | 0.49 |
| Cu | 4.24 (2.83) | 3.50 | 1.00 | 3.96 (4.34) | 2.77 | 1.00 | 0.74 |
| Fe | 158.71 (202.91) | 87.49 | 1.00 | 259.97 (675.82) | 53.38 | 1.00 | 0.39 |
| K | 99.22 (189.72) | 39.12 | 1.00 | 55.79 (46.44) | 40.70 | 1.00 | 0.18 |
| La | 0.06 (0.17) | 0.02 | 0.95 | 0.03 (0.04) | 0.02 | 1.00 | 0.14 |
| Mg | 10.48 (9.03) | 8.13 | 0.97 | 16.21 (26.90) | 6.40 | 0.97 | 0.06 |
| Mn | 6.94 (9.77) | 3.11 | 1.00 | 9.08 (21.96) | 2.14 | 1.00 | 0.59 |
| Mo | 3.58 (4.57) | 2.04 | 1.00 | 1.07 (0.74) | 0.87 | 1.00 | 0.002 |
| Ni | 1.15 (1.35) | 0.65 | 0.97 | 0.54 (0.95) | 0.30 | 1.00 | 0.03 |
| P | 5.60 (5.98) | 3.76 | 1.00 | 4.06 (3.69) | 2.84 | 1.00 | 0.10 |
| Pb | 4.36 (3.64) | 3.15 | 0.97 | 4.21 (5.43) | 2.57 | 1.00 | 0.89 |
| S | 554.95 (259.56) | 487.54 | 1.00 | 485.39 (272.89) | 415.27 | 1.00 | 0.27 |
| Sb | 0.87 (0.58) | 0.68 | 1.00 | 0.65 (0.51) | 0.53 | 1.00 | 0.09 |
| Se | 0.63 (3.98) | 1.13 | 0.97 | 1.14 (1.13) | 0.92 | 0.86 | 0.05 |
| Sr | 0.56 (0.60) | 0.30 | 1.00 | 0.43 (0.55) | 0.23 | 1.00 | 0.27 |
| Tl | 0.04 (0.05) | 0.03 | 1.00 | 0.08 (0.17) | 0.02 | 1.00 | 0.24 |
| V | 0.35 (0.14) | 0.30 | 1.00 | 0.33 (0.41) | 0.25 | 1.00 | 0.79 |
| Zn | 47.12 (64.13) | 23.02 | 0.95 | 38.99 (84.12) | 10.47 | 1.00 | 0.64 |
The P-value is from a paired t-test comparing inversion-focused and 24-h weeklong concentrations. Bolded P-values indicate a significant difference (P<0.05) between inversion-focused and 24-h week long sample designs.