Table 5.
Lung Cancer Risks Associated with Cumulative Occupational Silica Exposure by Smoking Status
| Cumulative exposure (mg/m3-years) | Never-Smokers |
Former Smokers |
Current Smokers |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Cases (n) | OR* | 95% CI | Cases (n) | OR† | 95% CI | Cases (n) | OR‡ | 95% CI | |
| Never | 1,121 | 1.0 | Referent | 3,696 | 1.0 | Referent | 7,161 | 1.0 | Referent |
| >0–0.39 | 60 | 1.17 | 0.85–1.57 | 366 | 1.07 | 0.92–1.25 | 687 | 1.19 | 1.03–1.39 |
| 0.4–1.09 | 59 | 1.07 | 0.78–1.43 | 433 | 1.37 | 1.18–1.59 | 729 | 1.33 | 1.15–1.55 |
| 1.1–2.39 | 60 | 1.02 | 0.75–1.36 | 441 | 1.35 | 1.16–1.57 | 730 | 1.29 | 1.11–1.50 |
| ≥2.4 | 69 | 1.40 | 1.03–1.86 | 496 | 1.47 | 1.27–1.70 | 793 | 1.39 | 1.20–1.62 |
| Test for trend, P value | <0.01 | <0.01 | <0.01 | ||||||
| P value excluding never exposed | 0.02 | <0.01 | 0.07 | ||||||
Definition of abbreviations: CI = confidence interval; OR = odds ratio.
*
OR adjusted for sex, study, age group, and list A jobs.
†
OR adjusted for sex, study, age group, list A jobs, pack-years, and time since quitting smoking.
‡
OR adjusted for sex, study, age group, list A jobs, and pack-years.