Table 3.
Cohort studies of benzene exposure and non-Hodgkin’s lymphoma (NHL)
| Author, year (Reference) |
RR | CIlow | CIup | N | Location/ industry |
Exposure | Exposure category |
Self- report |
Outcome | All cause SMR |
Adj RR |
Adj CIlow |
Adj CIup |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bloemen et al 20049 | 2.15 | 0.44 | 6.28 | 3 | Michigan/ Chemical |
Any exposure >10 yrs, 15 yr lag |
High | No | NHL SMR | 0.90 | 2.39 | 0.45 | 5.87 |
| Collins et al 200325 | 1.80 | 0.40 | 5.10 | 3 | Illinois/Chemical | >40 days exposed >100 ppm |
High | No | NHL SMR | 1.00 | 1.81 | 0.34 | 4.44 |
| Hayes et al 19971 | 4.70 | 1.20 | 18.10 | 7 | China/Multiple | Average exposure ≥25 ppm |
High | No | NHL incidence | na* | na | na | na |
| Rinsky et al 20028 | 0.96 | 0.31 | 2.25 | 5 | Ohio/Rubber | ≥1 ppm-day | All | No | NHL SMR | 0.98 | 0.98 | 0.31 | 2.03 |
| Sorahan et al 20052 | 1.00 | 0.64 | 1.49 | 24 | UK/Multiple | Identified by companies as being exposed to benzene |
All | Yes | NHL incidence | 1.07 | 0.93 | 0.60 | 1.34 |
| Wong 198726 | 1.51 | 0.02 | 8.40 | 1 | Multiple/Chemical | Continuous exposure, cumulative exposure >720 ppm-mo |
High | No | LR SMR | 0.63 | 2.39 | 0.00 | 9.38 |
Adj, adjusted for the healthy worker effect; CIlow, lower 95% CI; CIup, upper 95% CI; exposure, the exposure category selected for this meta-analysis; exposure category, described as “High” if results for a high exposure category were used; LR, lymphosarcoma and reticulosarcoma; N, number of cases in the selected exposure category; SMR, standardised mortality ratio; Self-report, “Yes” means exposure history based primarily on self-reported work history.
*
Internal comparison group used in Hayes et al 1997 so the healthy worker effect adjustment was not done.