Table 1 Demographic characteristics and lung function outcomes among participants (N = 1594)
| Â | Year | |
|---|---|---|
Participant characteristics | 2020 | 2021 |
Demographic characteristic | Â | Â |
 Age (years) | 19.2 ± 0.7 | 20.2 ± 0.7 |
 Female | 894(56.1) | 894(56.1) |
 Urban | 841(52.8) | 879(55.1) |
 BMI (kg/m2) | 21.9 ± 3.8 | 21.3 ± 3.7 |
Cigarette smoke exposure | Â | Â |
 Smoking status | 20(1.3) | 26(1.6) |
 Passive smoking | 107(6.7) | 130(8.2) |
Alcohol consumption (Yes) | 70(4.4) | 81(5.1) |
Physical activity at least once a week (Yes) | 1285(80.6) | 982(61.6) |
Lung disease history (Yes) | 142(8.9) | 160(10.0) |
Socioeconomic status | Â | Â |
 Socioeconomic-disadvantage | 581(36.4) | 533(33.4) |
 Socioeconomic-advantage | 1013(63.6) | 1061(66.6) |
Lung function index | Â | Â |
 FVC (ml) | 3158.8 ± 815.4 | 3420.5 ± 770.6 |
 FEV1.0 (ml) | 3005.3 ± 729.9 | 3182.9 ± 667.7 |
 FEF25 (ml/s) | 5716.7 ± 1846.1 | 5924.9 ± 1759.9 |
 FEF50 (ml/s) | 4685.9 ± 1370.6 | 4581.2 ± 1312.5 |
 FEF75 (ml/s) | 3043.9 ± 1010.3 | 2745.1 ± 937.6 |
 FEF25-75 (ml/s) | 4374.5 ± 1256.1 | 4219.6 ± 1177.8 |
Ozone (µg/m3) | 110.7 | 102.0 |