Table 1.
Temporally-adjusted winter pollutant concentrations across 24 distributed sites, by sampling interval. Concentrations which differed significantly between sampling schemes are shown in bold (p < 0.05).
| Pollutant | Rush-Hour Sampling | Work-Week Sampling | p-Value between Programs | ||
|---|---|---|---|---|---|
| Mean (SD) | Median | Mean (SD) | Median | ||
| PM2.5 (µg/m3) | 13.5 (1.63) | 13.4 | 13.2 (1.67) | 13.6 | 0.07 |
| BC (abs) | 1.39 (0.58) | 1.22 | 1.25 (0.47) | 1.10 | 0.0001 |
| Total EC (µg/m3) | 1.57 (0.74) | 1.48 | 1.43 (0.62) | 1.28 | 0.01 |
| Total OC (µg/m3) | 2.29 (0.62) | 2.03 | 2.45 (0.77) | 2.37 | 0.11 |
| Diesel Tracers (ng/m3): | |||||
| Al | 28.3 (14.4) | 23.8 | 27.8 (17.1) | 24.0 | 0.90 |
| Ca | 104.1 (77.85) | 86.08 | 86.3 (48.3) | 92.0 | 0.31 |
| Fe | 115.8 (49.47) | 104.9 | 109.2 (72.9) | 97.4 | 0.62 |
| Other Tracer Elements (ng/m3): | |||||
| As | 0.13 (0.10) | 0.10 | 0.30 (0.28) | 0.24 | 0.01 |
| Ba | 4.72 (2.16) | 3.98 | 4.30 (2.91) | 3.73 | 0.37 |
| Cr | 1.26 (0.42) | 1.22 | 1.09 (0.43) | 1.15 | 0.10 |
| Cu | 5.05 (2.04) | 4.36 | 4.30 (2.24) | 4.15 | 0.04 |
| K | 48.9 (12.19) | 49.6 | 42.7 (16.3) | 41.5 | 0.04 |
| Mg | 31.9 (69.20) | 14.9 | 16.9 (11.5) | 16.2 | 0.32 |
| Mn | 5.65 (2.30) | 5.37 | 4.55 (2.10) | 4.44 | 0.004 |
| Mo | 21.7 (97.61) | 1.77 | 32.3 (106.9) | 0.89 | 0.49 |
| Ni | 2.14 (4.21) | 0.37 | 0.69 (0.79) | 0.40 | 0.11 |
| P | 4.98 (1.31) | 4.92 | 4.43 (1.47) | 4.31 | 0.08 |
| Pb | 2.54 (0.52) | 2.54 | 2.44 (0.90) | 2.53 | 0.56 |
| S | 587.4 (110.60) | 593.9 | 568.4 (178.0) | 602.8 | 0.61 |
| Sb | 0.94 (0.30) | 0.85 | 0.82 (0.33) | 0.83 | 0.07 |
| Se | 0.41 (1.86) | 0.75 | 1.62 (1.50) | 1.28 | 0.03 |
| Sr | 0.56 (0.24) | 0.51 | 0.54 (0.28) | 0.54 | 0.66 |
| V | 0.22 (0.04) | 0.23 | 0.23 (0.07) | 0.23 | 0.73 |
| Zn | 26.9 (9.87) | 27.1 | 19.1 (9.17) | 17.8 | 0.001 |
| PAHs (ng/m3): | |||||
| Benz(a)anthracene | 0.08 (0.04) | 0.07 | 0.07 (0.03) | 0.06 | 0.003 |
| Benzo(a)pyrene | 0.03 (0.04) | 0.01 | 0.04 (0.03) | 0.03 | 0.77 |
| Benzo(e)pyrene | 0.08 (0.03) | 0.08 | 0.04 (0.01) | 0.04 | 0.01 |
| Benzo(ghi)fluoranthene | 0.04 (0.02) | 0.04 | 0.06 (0.02) | 0.06 | 0.14 |
| Benzo(ghi)perylene | 0.03 (0.01) | 0.03 | 0.04 (0.03) | 0.03 | 0.11 |
| Chrysene | 0.23 (0.07) | 0.19 | 0.19 (0.08) | 0.16 | <0.0001 |
| Fluoranthene | 0.20 (0.07) | 0.19 | 0.20 (0.08) | 0.17 | 0.53 |
| Indeno(1,2,3-cd)pyrene | 0.01 (0.002) | 0.01 | 0.01 (0.02) | 0 | 0.98 |
| Pyrene | 0.16 (0.05) | 0.15 | 0.17 (0.07) | 0.15 | 0.43 |
| Total PAHs | 0.71 (0.21) | 0.66 | 0.72 (0.18) | 0.64 | 0.74 |
| Hopanes (ng/m3): | |||||
| Total hopanes | 0.15 (0.11) | 0.12 | 0.19 (0.11) | 0.16 | 0.05 |
Total steranes samples were below LOD, using both sampling schemes.