TABLE 1.

Exclusion criteria for the selection of healthy, nonsmoker Caucasians in the Lung Health and Canadian Environment study (age range 20 to 44 years)

Criteria	Men (n=1163)		Women (n=1408)		Total (n=2571)
	Excluded	Remaining	Excluded	Remaining	Excluded	Remaining
FEV1 or FVC data missing	33	1130	65	1343	98	2473
Smoker or exsmoker	576	558	689	654	1261	1212
History of asthma	60	498	88	566	148	1064
Lung problem before 16 years of age	33	465	47	519	80	984
Cough for >3 months	21	444	42	477	63	921
Sputum production for >3 months	12	432	13	464	25	896
Wheeze apart from colds	26	406	30	434	56	840
Woken by shortness of breath	11	395	17	417	28	812

Data presented as n. FEV₁ Forced expiratory volume in 1 s; FVC Forced vital capacity