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Follow-Up of the Libby, Montana Screening Cohort: A 17-Year Mortality Study
Theodore C Larson1, Laura Williamson, Vinicius C Antao
1Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia (Mr Larson); Montana Department of Public Health and Human Services, Helena, Montana (Ms Williamson); Hospital for Special Surgery, New York, New York (Dr Antao).
Objective:
To evaluate mortality patterns among participants in a community-based screening program for asbestos-related disease.
Methods:
We calculated standardized mortality ratios (SMRs) and stratified results by exposure group (three occupational exposure groups, household contacts and residents without occupational asbestos exposure) and by radiographic abnormality presence.
Results:
All-cause mortality (15.8%; 1,429/8,043) was statistically lower than expected. Asbestosis was statistically elevated in all exposure groups. Lung cancer was moderately associated with vermiculite miner/miller employment. Mesothelioma was elevated in that same exposure group and among residents. Systemic autoimmune disease mortality was also elevated. Radiographic parenchymal abnormalities were associated with lung cancer mortality.
Conclusion:
In addition to asbestos-related mortality in occupational exposure groups, this initial follow-up of this cohort also shows elevated mortality for some asbestos-related causes in non-occupational exposure groups.
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