Table 2.
Distribution of personal and regional fixed-site daily average and 30-min average exposures to air pollution, personal exposure to noise, and environmental variables.
| Exposure measure | n | Mean (sd) | 5% | 25% | Median | 75% | 95% | IQR* |
|---|---|---|---|---|---|---|---|---|
| Daily visit average (87 study visits) | ||||||||
| Personal exposures | ||||||||
| UFPs (particles/cm3) | 81 | 20,480 (18,338) | 2,918 | 7,742 | 16,560 | 22,631 | 57,501 | 14,890 |
| Black carbon (ng/m3) | 84 | 1,872 (1,435) | 537 | 947 | 1,233 | 2,411 | 4,560 | 1,464 |
| Noise (dBA) | 82 | 66.9 (3.9) | 60.7 | 64.2 | 67.3 | 69.4 | 73.8 | 5.2 |
| Fixed-site exposures | ||||||||
| PM2.5 (µg/m3) | 87 | 7.8 (3.2) | 3.0 | 5.2 | 7.8 | 10.7 | 12.8 | 5.5 |
| NO2 (ppb) | 87 | 11.8 (3.0) | 7.5 | 10.0 | 11.3 | 12.7 | 17.4 | 2.7 |
| O3 (ppb) | 87 | 27.6 (7.0) | 17.5 | 21.2 | 27.4 | 33.3 | 36.8 | 12.2 |
| Ox (ppb) ** | 87 | 22.2 (4.7) | 15.1 | 18.4 | 22.2 | 25.8 | 28.7 | 7.4 |
| Environmental variables | ||||||||
| Temperature (˚C) | 87 | 23.4 (3.3) | 16.6 | 21.8 | 24.1 | 25.7 | 26.9 | 3.9 |
| Relative humidity (%) | 87 | 51.5 (10.4) | 34.2 | 42.4 | 53.6 | 57.8 | 66.7 | 15.4 |
| 30-min average (46 study visits) | ||||||||
| Personal exposures | ||||||||
| UFPs (particles/cm3) | 420 | 19,733 (32,402) | 76.9 | 4,385 | 12,185 | 22,336 | 65,940 | 17,950 |
| Black carbon (ng/m3) | 448 | 1,821 (2,873) | 187 | 661 | 1,176 | 1,897 | 5,025 | 1,236 |
| Noise (dBA) | 360 | 66.9 (6.5) | 53.9 | 63.0 | 68.1 | 71.4 | 76.0 | 8.4 |
| Fixed-site exposures | ||||||||
| PM2.5 (µg/m3) | 462 | 7.7 (5.6) | 2.1 | 3.5 | 5.6 | 11.4 | 16.8 | 7.9 |
| NO2 (ppb) | 462 | 10.5 (3.5) | 5.1 | 8.2 | 10.5 | 12.3 | 15.7 | 4.0 |
| O3 (ppb) | 462 | 32.3 (11.6) | 16.3 | 23.6 | 31.1 | 38.6 | 56.4 | 15.1 |
| Ox (ppb) ** | 462 | 24.9 (7.3) | 14.3 | 19.8 | 24.3 | 28.5 | 39.3 | 8.7 |
| Environmental variables | ||||||||
| Temperature (˚C) | 462 | 25.0 (3.8) | 17.9 | 22.9 | 25.4 | 27.2 | 31.0 | 4.3 |
| Relative humidity (%) | 462 | 43.8 (13.9) | 25.9 | 33.1 | 42.2 | 51.7 | 73.5 | 18.6 |
*IQR = interquartile range. **Oxidant capacity of NO2 and O3 estimated as Ox = (1.07*NO2 + 2.075*O3)/3.145.