Table 1. Summary statistics of indoor and outdoor VOCs and HCHO levels (μg/m3).
| Pollutant | Indoor | Outdoor | Indoor/Outdoor | Limit value2 | p-value3 | ||
|---|---|---|---|---|---|---|---|
| N | GM ± GSD1 | N | GM ± GSD | ||||
| TVOC | 634 | 230.7 ± 1.7 | 161 | 137.8 ± 1.9 | 1.67 | 400 | 0.002 |
| Benzene (MDL : 0.86) | 590 | 3.6 ± 2.4 | 150 | 3.0 ± 2.3 | 1.20 | 30 | 0.767 |
| Toluene (MDL : 1.92) | 634 | 22.8 ± 2.1 | 159 | 16.5 ± 2.6 | 1.38 | 1,000 | 0.107 |
| Ethylbenzene (MDL : 1.27) | 626 | 4.3 ± 1.9 | 149 | 3.2 ± 1.9 | 1.34 | 360 | 0.259 |
| m.p-Xylene (MDL : 1.78) | 624 | 7.2 ± 1.9 | 149 | 5.2 ± 1.9 | 1.38 | 700 | 0.512 |
| Styrene (MDL : 0.88) | 566 | 3.7 ± 1.8 | 116 | 2.9 ± 1.9 | 1.28 | 300 | 0.482 |
| o-Xylene (MDL : 0.93) | 557 | 2.8 ± 1.8 | 107 | 2.2 ± 1.7 | 1.27 | 700 | 0.620 |
| HCHO (MDL : 1.75) | 698 | 20.1 ± 1.6 | 195 | 8.1 ± 1.9 | 2.48 | 210 | 0.044 |
1 Geometric mean and geometric standard deviation
2 Limit values were recommended under Indoor Air Quality Control In Public Use Facilities, etc. Act (enacted by Ministry of Environment, 2016)
3 Statistical analysis by Student t-test