Published By: National Library of Medicine
Contributors: Kari K. Dunning
Mesothelioma Associated with Commercial use of Vermiculite Containing Libby Amphibole
ABSTRACT
Objectives: To describe asbestos-related mortality among manufacturing workers who expanded and processed Libby vermiculite that contained amphibole fiber.
Methods: Standardized mortality ratio was calculated for 465 white male workers 31 years after last Libby vermiculite exposure.
Results: Two workers died from mesothelioma, resulting in a significantly increased standardized mortality ratio of 10.5 (95% confidence interval, 1.3 to 38.0). These workers were in the upper 10th percentile of cumulative fiber exposure, that is, 43.80 and 47.23 fiber-years/cm, respectively. One additional worker with cumulative fiber exposure of 5.73 fiber-years/cm developed mesothelioma but is not deceased. There were no other significantly increased standardized mortality ratios.
Conclusions: Workers expanding and processing Libby vermiculite in a manufacturing setting demonstrated an increased risk for the development of mesothelioma following exposure to the amphibole fiber contained within this vermiculite ore source.
AUTHORS
Kari K. Dunning
Stephen Adjei
Linda Levin
Amy M Rohs
Tim Hilbert
Eric Borton
Vikas Kapil
Carol Rice
Grace K Lemasters
James E Lockey