Objective: The biopersistence of refractory ceramic fiber (RCF) in human lung tissue is unknown and may contribute to an association between cumulative fiber exposure and radiographic changes.
Methods: Lung tissue fiber was analyzed for a case series of 10 RCF workers and a 20-year longitudinal chest radiograph study of 1323 workers was conducted.
Results: Within lung tissue, RCF comprised 14% to 100% of fibers 5 μm or more in length and was identified up to 20 years after RCF employment. Among workers with no reported asbestos exposure, cumulative exposure of more than 63 to 110 and more than 110 fiber-months/cm3 was associated with radiographic pleural changes of 8.5% (odds ratio, 7.2; 95% confidence interval, 1.4 to 36.8) and 11.6% (odds ratio, 10.3; 95% confidence interval, 2.1 to 49.9), respectively.
Conclusions: Refractory ceramic fiber can persist in human lung tissue for up to 20 years and may contribute to the significant association between cumulative fiber exposure and radiographic pleural changes.
From the Departments of Environmental Health (Drs Lockey, Rice, Levin, and LeMasters, and Mr Hilbert and Mr Borton) and Internal Medicine (Pulmonary Division) (Dr Lockey), University of Cincinnati College of Medicine, Cincinnati, Ohio; Pathology Department (Dr Roggli), Duke University Medical Center, Durham, NC; and Pathology Department (Dr Biddinger), Georgia Health Sciences University, Augusta, Ga.
Address correspondence to: James E. Lockey, MD, MS, Departments of Environmental Health and Internal Medicine (Pulmonary Division), University of Cincinnati College of Medicine, 3223 Eden Ave, ML 0056, Cincinnati, OH 45267 (email@example.com).
This study was funded by the High Temperature Insulation Wool Coalition (HTIWC).
Authors JL, TH, CR, LL, EB, PB, and GL have been partially funded by a grant from HTIWC; VR and JL report serving as expert witnesses in asbestos litigation; TH and EB were paid by HTIWC to conduct data management on one occasion outside the scope of this grant; and JL and GL report their spouse is partially funded by a grant from HTIWC.
The JOEM Editorial Board and planners have no financial interest related to this research.