Table 2: Respiratory complaints of subjects.

Exposed subjects Controls

Wheezing56 (60.2%)24 (45.3%)>0.05
Dyspnea last year41 (44.1%)15 (28.3%)0.043
Chest tightness last year35 (37.6%)8 (15.2%)0.003
Exercise dyspnea last year40 (43.0%)12 (22.6%)0.010
Dyspnea on level ground59 (63.4%)17 (32.1%)0.0002
Winter morning cough30 (32.3%)7 (13.2%)0.008
Winter daily cough36 (38.7%)12 (22.6%)0.034
Cough for 3 months25 (26.9%)8 (15.1%)>0.05
Winter morning phlegm26 (28.0%)6 (11.3%)0.014
Winter daily phlegm39 (41.9%)11 (20.8%)0.007
Phlegm for 3 months24 (25.8%)6 (11.3%)0.028