Table 1.
Means and distributions of 24-hour average PM2.5 and black carbon (BC) concentrations measured at study schools
| Schoola | Location | Pollutant | Monitoring Dates | Mean (SD) | Minimum | Median | Maximum |
|---|---|---|---|---|---|---|---|
| U1 | Urban, Medium-sized Highway | PM2.5 | 4/1/03–6/30/03 | 21.2 (11.8) | 2.1 | 18.4 | 75.0 |
| BC | 5/5/03–6/7/03 | 2.3 (1.1) | 0.68 | 2.4 | 5.5 | ||
| U2 | Urban, Large Highway | PM2.5 | 5/15/03–6/30/03, 3/11/04–6/21/04 | 24.7 (12.3) | 6.6 | 21.9 | 75.0 |
| BC | 2/23/04–3/28/04 | 2.4 (1.2) | 0.57 | 2.0 | 4.9 | ||
| U3 | Urban, Secondary Street | PM2.5 | 3/24/05–5/28/05 | 24.5 (8.4) | 11.5 | 23.1 | 49 |
| BC | 4/2/05–5/19/05 | 1.4 (0.48) | 0.33 | 1.5 | 2.3 | ||
| S1 | Suburban | PM2.5 | None | ||||
| BC | 5/6/03–6/7/03 | 0.66 (0.37) | 0.11 | 0.60 | 1.8 | ||
| S2 | Suburban | PM2.5 | 3/11/04–6/30/04 | 13.8 (9.2) | 1.0 | 12.0 | 41.3 |
| BC | 2/23/04–3/28/04 | 0.73 (0.61) | 0.10 | 0.49 | 2.7 |
a
U1 = Urban School 1, U2 = Urban School 2, U3 = Urban School 3, S1 = Suburban School 2003 measurements, S2 = Suburban School 2004 measurements