Regression models on the log value of indoor PM2.5 level and its related influential factors
| Model 1 | Model 2 | Model 3 | |||||||
| Coeff* | t | p | Coeff* | t | p | Coeff* | t | p | |
| Log (outdoor PM2.5 level) | 0.52 | 4.43 | 0.000 | 0.54 | 15.06 | 0.000 | 0.57 | 14.84 | 0.000 |
| ASD | 0.41 | 6.45 | 0.000 | 0.41 | 7.30 | 0.000 | – | – | – |
| OD | −0.03 | −0.57 | 0.568 | – | – | – | – | – | – |
| Restaurants or bars† | 0.29 | 6.67 | 0.000 | 0.29 | 6.68 | 0.000 | 0.30 | 7.91 | 0.000 |
| Interaction item 1‡ | −0.20 | −3.05 | 0.002 | −2.0 | −3.13 | 0.002 | – | – | – |
| Wuhan | −0.31 | −0.90 | 0.371 | – | – | – | – | – | – |
| Xi'an | 0.13 | 0.24 | 0.814 | – | – | – | – | – | – |
| Kunming | −0.25 | −0.67 | 0.502 | – | – | – | – | – | – |
| Guiyang | 0.41 | 1.04 | 0.299 | – | – | – | – | – | – |
| Interaction item 2§ | 0.39 | 1.28 | 0.202 | – | – | – | – | – | – |
| Interaction item 3¶ | −0.11 | −0.20 | 0.845 | – | – | – | – | – | – |
| Interaction item 4** | 0.20 | 0.63 | 0.531 | – | – | – | – | – | – |
| Interaction item 5†† | −0.43 | −1.13 | 0.258 | – | – | – | – | – | – |
| R2 | 0.51 | 0.49 | 0.41 | ||||||
↵* Here are all standardised coefficients.
↵† Restaurants were coded as ‘0’ (referent group) and bars were code as ‘1’.
↵‡ Interaction item of type of venues (restaurants or bars) with ASD.
↵§ Interaction items of Wuhan and outdoor PM2.5 levels.
↵¶ Interaction items of Xi'an and outdoor PM2.5 levels.
↵** Interaction items of Kunming and outdoor PM2.5 levels.
↵†† Interaction items of Guiyang and outdoor PM2.5 levels.
ASD, active smokers density, number of smokers per 100 m3; OD, occupants density, number of occupants per 100 m3.