Lung cancer mortality and carbon black exposure: Cox regression analysis of a cohort from a German carbon black production plant.

Abstract

We undertook a lung cancer mortality analysis of 1528 German carbon black workers, followed between the years of 1976-1998, who produced furnace black, lamp black, and gas black. We used Cox modeling across age with time-dependent covariates, ie, cumulative and mean carbon black exposure, duration of work in departments, adjusting for calendar time, a smoking indicator, and age at hire. Exposures were lagged up to 20 years. Analyses were performed with the full cohort and after restriction to an inception cohort. A total of 50 lung cancer deaths occurred. No positive association was found with carbon black exposure indices. Some models indicated an increasing risk across duration of work in the lamp black producing department. Our results do not suggest that carbon black exposure is a human lung carcinogen. The lamp black results, if no artifact, may point at historical exposures to gaseous polycyclic aromatic hydrocarbons.