Table 2. Comparisons of the air quality and meteorological data in the forest and urban environments.
| Forest | Urban | P1 value | P2 value | ||
|---|---|---|---|---|---|
| aN = 96 | Indoor N = 94 | outdoor N = 96 | |||
| SO2 (ppb) | 0.45 ± 0.46 | 0.17 ± 0.18 | 3.04 ± 1.43 | < .001 | < .001 |
| NO (ppb) | 0.27 ± 0.24 | 39.22 ± 22.97 | 12.45 ± 11.6 | < .001 | < .001 |
| NO2 (ppb) | 2.61 ± 2.19 | 4.45 ± 1.61 | 30.34 ± 9.02 | < .001 | < .001 |
| NOx (ppb) | 2.44 ± 2.17 | 43.67 ± 22.14 | 42.79 ± 18.4 | < .001 | < .001 |
| CO (ppm) | 0.37 ± 0.19 | 1.09 ± 0.51 | 0.87 ± 0.31 | < .001 | < .001 |
| O3 (ppb) | 27.48 ± 16.15 | 6.65 ± 0.73 | 13.56 ± 10.4 | < .001 | < .001 |
| Temperature (°C) | 13.05 ± 1.91 | 17.94 ± 1.03 | 17.35 ± 1.69 | < .001 | < .001 |
| Relative humidity | 91.36 ± 5.60 | 67.86 ± 2.86 | 82.33 ± 6.45 | < .001 | < .001 |
P1 value corresponds to t-test comparisons of the Xitou and urban sites (indoor). P2 value corresponds to t-test comparisons of the Xitou and Wanhua sites (outdoor) of the Environmental Protection Agency, Taipei, Taiwan. aN corresponds to the sample size for the hourly average data.