Occupational exposure to wood dust and risk of lung cancer in two population-based case–control studies in Montreal, Canada

Table 3 Odds ratio for lung cancer associated with occupational exposure wood dust in two case–control studies

	Controls	Cases	OR₁*	OR₂**	95% CI (OR₂)
Study I	Population Controls
No exposure	389	630	1.0	1.0	(ref)
Any level of exposure	144	227	0.8	0.7	0.5	1.0
Any level ≤ 20 years	88	141	0.8	0.7	0.5	1.0
Any level > 20 years	56	86	0.7	0.7	0.4	1.1
Non-substantial level	74	113	0.8	0.7	0.5	1.0
Substantial level	70	114	0.7	0.7	0.5	1.0
Study I	Cancer Controls
No exposure	1072	630	1.0	1.0	(ref)
Any level of exposure	277	227	1.2	1.1	0.9	1.5
Any level ≤ 20 years	179	141	1.2	1.1	0.8	1.5
Any level > 20 years	98	86	1.2	1.2	0.8	1.7
Non-substantial level	161	113	1.0	1.0	0.7	1.3
Substantial level	116	114	1.5	1.4	1.0	2.0
Study II	Population Controls
No exposure	640	501	1.0	1.0	(ref)
Any level of exposure	254	235	1.2	1.1	0.9	1.5
Any level ≤ 20 years	165	139	1.1	1.0	0.8	1.4
Any level > 20 years	89	96	1.4	1.3	0.9	1.9
Non-substantial level	201	167	1.1	1.0	0.7	1.3
Substantial level	53	68	1.9	1.7	1.1	2.7

*adjusted for age, ethnolinguistic group, years of education, median family income, respondent status and cigarette index.
**adjusted for the same covariates as above, as well as IARC Group 1 occupational carcinogens (asbestos, diesel exhaust, formaldehyde, cadmium, chromium VI, nickel and silica).

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