Table 3. Summary of summer inversion-focused and 24-h weeklong concentrations for 37 distributed sites per year, with percent above analytic LOD (=3 × standard deviation of the analytical blanks).
|
Inversion-focused |
24-h weeklong |
P-value between designs | |||||
|---|---|---|---|---|---|---|---|
| Mean (SD) | Median | %>LOD | Mean (SD) | Median | %>LOD | ||
| PM2.5 (μg/m3) | 14.35 (3.97) | 14.68 | 1.00 | 13.94 (2.01) | 13.34 | 1.00 | 0.57 |
| BC (abs) | 1.64 (0.91) | 1.59 | 1.00 | 1.06 (0.36) | 0.96 | 1.00 | 0.0007 |
| NO2 (p.p.b.) | 12.59 (6.63) | 10.59 | 1.00 | 10.37 (4.53) | 10.24 | 1.00 | 0.56 |
| Constituents measured by ICP-MS (ng/m3) | |||||||
| Al | 36.84 (30.03) | 32.93 | 0.81 | 34.34 (24.22) | 29.92 | 0.97 | 0.58 |
| As | 1.76 (0.95) | 1.75 | 0.97 | 1.28 (0.78) | 1.00 | 1.00 | 0.01 |
| Ba | 13.89 (20.82) | 7.47 | 0.49 | 4.14 (2.61) | 3.30 | 0.84 | 0.002 |
| Ca | 148.55 (270.76) | 84.49 | 0.78 | 156.42 (151.56) | 128.13 | 0.97 | 0.95 |
| Cd | 0.25 (0.21) | 0.23 | 0.95 | 0.14 (0.08) | 0.13 | 1.00 | 0.001 |
| Ce | 0.07 (0.05) | 0.05 | 0.92 | 0.07 (0.06) | 0.06 | 1.00 | 0.62 |
| Cr | 3.45 (3.54) | 2.12 | 0.95 | 1.06 (0.63) | 0.93 | 1.00 | <0.001 |
| Cs | 0.07 (0.20) | 0.02 | 1.00 | 0.03 (0.04) | 0.01 | 1.00 | 0.20 |
| Cu | 11.07 (9.94) | 9.43 | 0.95 | 5.71 (6.10) | 3.71 | 0.97 | 0.01 |
| Fe | 186.00 (158.27) | 128.49 | 0.97 | 110.83 (86.26) | 90.66 | 1.00 | 0.01 |
| K | 66.87 (68.99) | 57.27 | 0.97 | 93.05 (55.98) | 81.69 | 0.97 | 0.10 |
| La | 0.04 (0.04) | 0.03 | 0.92 | 0.04 (0.03) | 0.03 | 1.00 | 0.71 |
| Mg | 23.57 (30.19) | 12.45 | 0.76 | 18.42 (13.89) | 15.82 | 1.00 | 0.35 |
| Mn | 7.33 (7.00) | 5.42 | 0.97 | 4.90 (5.42) | 3.09 | 1.00 | 0.10 |
| Mo | 2.38 (2.45) | 1.53 | 0.97 | 1.44 (0.94) | 1.32 | 1.00 | 0.02 |
| Ni | 2.11 (2.01) | 1.41 | 0.95 | 1.38 (1.78) | 1.07 | 1.00 | 0.06 |
| P | 5.42 (3.83) | 4.48 | 0.84 | 4.45 (1.54) | 4.46 | 1.00 | 0.15 |
| Pb | 6.67 (6.14) | 5.78 | 1.00 | 3.87 (2.20) | 3.43 | 1.00 | 0.01 |
| S | 1013.00 (703.55) | 880.82 | 0.97 | 1032.00 (353.85) | 1016.22 | 1.00 | 0.95 |
| Sb | 1.37 (1.04) | 1.13 | 0.97 | 1.05 (0.43) | 0.96 | 1.00 | 0.09 |
| Se | 4.22 (4.95) | 2.87 | 0.68 | 1.86 (1.89) | 1.49 | 1.00 | 0.003 |
| Sr | 0.99 (1.09) | 0.70 | 0.81 | 1.05 (0.67) | 0.84 | 0.97 | 0.86 |
| Tl | 0.10 (0.17) | 0.04 | 1.00 | 0.07 (0.14) | 0.03 | 1.00 | 0.42 |
| V | 0.52 (0.25) | 0.52 | 0.97 | 0.49 (0.15) | 0.45 | 1.00 | 0.37 |
| Zn | 64.16 (103.26) | 36.37 | 0.95 | 23.79 (14.97) | 21.44 | 1.00 | 0.02 |
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 weeklong sample designs.