TABLE III.
PM2.5 Summary Statistics (in μ/gm3)
| Smoking Status
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| Location
|
P & D
|
LH
|
Window Status
|
||||||
| P&D Drivers (N = 545) | LH Drivers (N = 334) | Terminal Background (N = 339) | Non-smoker (N = 348) | Smoker (N = 104) | Non-smoker (N = 160) | Smoker (N = 74) | Open (N = 168) | Shut (N = 180) | |
| Arithmetic | |||||||||
| Mean | 27.8 | 52.6 | 11.9 | 19.1 | 50.1 | 25.4 | 41.7 | 19.9 | 18.5 |
| SD | 39.0 | 327.7 | 8.7 | 11.5 | 51.1 | 19.1 | 45.3 | 11.5 | 11.5 |
| Geometric | |||||||||
| Mean | 20.1 | 23.1 | 8.9 | 16.2 | 36.5 | 19.3 | 32.8 | 17.2 | 15.3 |
| SD | 2.1 | 2.5 | 2.4 | 1.8 | 2.4 | 2.3 | 3.2 | 1.7 | 1.9 |
Notes: Using Wilcoxon rank sum tests, no significant differences were detected between driver types. Smoker exposures significantly higher than nonsmokers for all concentrations. Open windows significantly higher than closed windows for all concentrations. The geometric mean (GM) is an estimator of the median, and the geometric standard deviation (GSD) is a unitless multiplicative factor, e.g., one standard deviation above the GM is GM × GSD.