TABLE 4.

Odds ratios by exposure to sources of dust 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
Cotton dust	42330	2472	1.0		1383	1.0		342	1.0		392	1.0		1345	1.0
	2774	180	1.40§	1.19, 1.64	92	1.36	1.09, 1.69	22	1.39	0.89, 2.16	25	1.71	1.13, 2.60	81	1.05	0.84, 1.33
Wood dust	43004	2470	1.0		1373	1.0		339	1.0		381	1.0		1351	1.0
	2100	182	1.06	0.91, 1.25	102	1.01	0.82, 1.25	25	1.11	0.74, 1.69	36	1.25	0.88, 1.78	75	1.09	0.85, 1.38
Metal dust	42089	2379	1.0		1314	1.0		332	1.0		376	1.0		1317	1.0
	3015	273	1.09	0.95, 1.25	161	1.11	0.93, 1.32	32	1.03	0.71, 1.50	41	1.04	0.74, 1.45	109	1.15	0.94, 1.42
Mineral dust†	41969	2371	1.0		1307	1.0		330	1.0		375	1.0		1312	1.0
	3135	281	1.08	0.94, 1.23	168	1.11	0.93, 1.32	34	1.06	0.73, 1.53	42	1.02	0.73, 1.42	114	1.16	0.95, 1.43

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).

^†Mineral dust includes asbestos

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