TABLE 3.

Odds ratios by exposure to dust, smoke or vapors in relation to respiratory symptoms: stratification by smoking

	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†
never smoker	27719	1123	1.0		621	1.0		160	1.0		137	1.0		791	1.0
	5616	317	1.30#	1.14, 1.48	159	1.11	0.93, 1.33	52	1.57	1.13, 2.16	33	1.15	0.78, 1.70	171	1.11	0.93, 1.32
ever smoker	8248	799	1.0		461	1.0		111	1.0		159	1.0		319	1.0
	3521	413	1.08	0.95, 1.23	234	1.04	0.88, 1.22	41	0.82	0.57, 1.19	88	1.31	1.00, 1.72	145	1.20	0.97, 1.47
Smoke‡
never smoker	30309	1272	1.0		696	1.0		182	1.0		154	1.0		870	1.0
	3026	168	1.20	1.01, 1.42	84	0.97	0.77, 1.23	30	1.41	0.94, 2.12	16	0.86	0.51, 1.47	92	1.07	0.85, 1.34
ever smoker	9059	892	1.0		516	1.0		123	1.0		184	1.0		350	1.0
	2710	320	1.09	0.95, 1.25	179	1.02	0.85, 1.22	29	0.75	0.50, 1.14	63	1.15	0.85, 1.54	114	1.21	0.97, 1.51
Vapors§
never smoker	30186	1265	1.0		681	1.0		168	1.0		152	1.0		842	1.0
	3149	175	1.15	0.96, 1.36	99	1.09	0.87, 1.36	44	2.33	1.62, 3.35	18	0.94	0.56, 1.57	120	1.43	1.16, 1.76
ever smoker	8998	869	1.0		515	1.0		114	1.0		193	1.0		347	1.0
	2771	343	1.14	0.99, 1.31	180	0.98	0.82, 1.17	38	1.07	0.73, 1.57	54	0.92	0.67, 1.26	117	1.25	1.00, 1.57

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 solvent, dyes, cutting, cooling or lubricating oils, paints, formaldehyde, wood preservatives, pesticides

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