Elevated Lung Cancer Mortality Among Uranium Gaseous Diffusion Plant Workers: A Nested Case-Control Design

BACKGROUND. Several cancer mortality risk studies among uranium gaseous diffusion workers have failed to show elevated lung cancer risk.

OBJECTIVE: Assess lung cancer mortality risk among uranium gaseous diffusion workers at the Gaseous Diffusion Plant in Paducah, KY.

METHODS: Population: A cohort of 6,820 uranium gaseous diffusion workers was selected. Eligible workers worked more than six months from 1952 to 2002. There were 1,672 deaths, 696 cancer deaths, and 143 lung cancer deaths. Case/Control Definition: Lung cancer deaths were identified ICD codes 6 thru 10 appearing as the underlying cause of death on the death certificate. Controls were all other cohort members regardless of vital status. Exposure Assessment: External radiation exposure was assessed by external badge monitor data. Other toxic exposures (As, Be, Cr, Ni, U, & trichloroethyle) were assessed by a job-specific job-exposure-matrix. Tobacco smoking was assessed using sensitivity analysis. Data Analysis: STATA (Version 10.1) was used to compute descriptive and analytic statistics.

RESULTS: Lung cancer mortality risk among uranium gaseous diffusion workers was elevated approximately two fold (OR = 1.7; 95% CI 1.21, 2.31) and was primarly associated with nickel, uranium, and external radiation exposures as well as duration of employment. Tobacco smoking accounted for nearly twenty percent decrease in the cude mortality risk associated uranium,or nickel exposure.

CONCLUSION: Lung cancer mortality risk was elevated among uranium gaseous diffusion workers employed between 1952 and 2002 at the Paducah Gaseous Diffusion Plant.