Table 3.

Lung Cancer Odds Ratios Associated with Cumulative Occupational Silica Exposure in Subjects without Silicosis

Cumulative Silica Exposure (mg/m3-years)	Cases (n)	OR*	95% CI
Never	6,091	1.0	Referent
>0–0.39	665	1.22	1.07–1.40
0.4–1.09	720	1.50	1.31–1.71
1.1–2.39	757	1.48	1.30–1.69
≥2.4	740	1.42	1.25–1.63
Test for trend, P value		<0.01
P value excluding never exposed		<0.01

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

^*OR adjusted for study, age group, sex, smoking (pack-years, time since quitting smoking), and list A jobs.