TABLE 2.

Odds ratios by exposure to dust, smoke or vapors in relation to respiratory symptoms: The Singapore Chinese Health Study

	No Symptoms	Non-Chronic Cough or Phlegm			Chronic Phlegm			Chronic Dry Cough			Chronic Bronchitis			Adult-Onset Asthma
	n	n	OR*	95% CI	n	OR*	95% CI	n	OR*	95% CI	n	OR*	95% CI	n	OR*	95% CI
Dust†	35967	1922	1.0		1082	1.0		271	1.0		296	1.0		1110	1.0
	9137	730	1.19#	1.08, 1.30	393	1.08	0.95, 1.22	93	1.15	0.90, 1.46	121	1.26	1.01, 1.57	316	1.14	1.00, 1.30
Smoke‡	39368	2164	1.0		1212	1.0		305	1.0		338	1.0		1220	1.0
	5736	488	1.12	1.01, 1.25	263	1.01	0.87, 1.16	59	1.00	0.75, 1.34	79	1.07	0.83, 1.38	206	1.13	0.97, 1.33
Vapors§	39184	2134	1.0		1196	1.0		282	1.0		345	1.0		1189	1.0
	5920	518	1.15	1.03, 1.27	279	1.03	0.89, 1.18	82	1.55	1.19, 2.01	72	0.93	0.71, 1.22	237	1.34	1.15, 1.56

Definition of abbreviations: CI = confidence interval; OR = odds ratio.

^*Models are adjusted for age, gender, dialect, smoking status (never, former, current), age at starting to smoke (≥ 20, 15–19, ≤ 14 years), and cigarettes per day (≤ 12, 13–22, ≥ 23).

^†Dust = cotton, wood, metal, mineral, asbestos

^‡Smoke = welding, coal burning, wood burning, other

^§Vapors = chemical solvents, dyes, cutting, cooling or lubricating oils, paints, formaldehyde, wood preservatives, pesticides

^#Odds ratio relative to the reference category equal to OR 1.0 for unexposed individuals