title: Mesothelioma associated with commercial use of vermiculite containing Libby amphibole.
abstract: OBJECTIVE
  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.affiliation: Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.
authors.forename: Kari K
authors.initials: KK
authors.lastname: Dunning
authors.forename: Stephen
authors.initials: S
authors.lastname: Adjei
authors.forename: Linda
authors.initials: L
authors.lastname: Levin
authors.forename: Amy M
authors.initials: AM
authors.lastname: Rohs
authors.forename: Tim
authors.initials: T
authors.lastname: Hilbert
authors.forename: Eric
authors.initials: E
authors.lastname: Borton
authors.forename: Vikas
authors.initials: V
authors.lastname: Kapil
authors.forename: Carol
authors.initials: C
authors.lastname: Rice
authors.forename: Grace K
authors.initials: GK
authors.lastname: Lemasters
authors.forename: James E
authors.initials: JE
authors.lastname: Lockey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000538:Aluminum Silicates / Q000009:adverse effects*; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D019652:Extraction and Processing Industry; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D008175:Lung Neoplasms / Q000139:chemically induced / Q000401:mortality*; D008297:Male; D008654:Mesothelioma / Q000139:chemically induced / Q000401:mortality*; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000401:mortality; D055815:Young Adult
chemical_list: D000538:Aluminum Silicates; C003760:vermiculite