Table 2.
Six environmental factors included in the prediction model.
| Variables | Correlation with measured PM2.5 | Prediction model | |||
|---|---|---|---|---|---|
| coefficient | P value | Slope | p-value | R2 | |
| Constant | 90.65 | <0.0001 | 0.6568 | ||
| Pack-year | 0.47 | 0.0093 | 0.42 | 0.0148 | |
| Passive smoking | 0.40 | 0.0289 | 24.40 | 0.0013 | |
| Use of solid fuels for cooking | 0.28 | 0.1285 | 21.55 | 0.0100 | |
| Time length of air conditioner in summer | −0.37 | 0.0423 | −2.53 | 0.0195 | |
| Ventilation condition in bedrooms | −0.26 | 0.1667 | −22.64 | 0.0379 | |
| Distance to major road | 0.07 | 0.7162 | −10.77 | 0.0347 | |
| Use of air conditioner | −0.29 | 0.1189 | — | — | |
| Good ventilation condition in kitchen | −0.11 | 0.5775 | — | — | |
| Outdoor PM2.5 | 0.62 | 0.0002 | — | — | |
The prediction model equation with final prediction variables are the following: PM2.5 exposure = f(pack-years, passive smoking, use of solid fuels for cooking, time length of air conditioner in summer, ventilation condition in bedrooms, distance to major road).