Long-term health experience of jet engine manufacturing workers: VI: incidence of malignant central nervous system neoplasms in relation to estimated workplace exposures.

Objective: To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with specific chemical or physical exposures.
Methods: Subjects were 210,784 workers employed from 1952 to 2001. We conducted a cohort incidence study and two nested case-control studies with focus on the North Haven facility where we previously observed a not statistically significant overall elevation in GB rates. We estimated individual-level exposure metrics for 11 agents.
Results: In the total cohort, none of the agent metrics considered was associated with increased GB risk. The GB incidence rates in North Haven were also not related to workplace exposures, including the "blue haze" exposure unique to North Haven.
Conclusions: If not due to chance alone, GB rates in North Haven may reflect external occupational factors, nonoccupational factors, or workplace factors unique to North Haven unmeasured in the current evaluation.