J Lockey, G Lemasters, C Rice, K Hansen, L Levin, R Shipley, H Spitz and J Wiot
Department of Environmental Health, University of Cincinnati College of Medicine, Ohio, USA.

Refractory ceramic fibers (RCF) are manmade vitreous fibers (MMVF) manufactured for high-temperature applications. Between 1987 and 1992, a retrospective cohort and nested case-control study evaluated chest radiographs from 652 workers involved in the manufacture of these fibers for plausibility of a causal relationship between exposure to RCF and chest-radiographic changes. The exposure-response relationship was modeled with three variables: years since first fiber production job, years in fiber production, and cumulative fiber exposure to date of study X-ray. The case-control study used a comprehensive characterization of possible asbestos exposure to investigate asbestos as the potential causative agent of chest-radiographic changes. Chest radiographs of 20 workers (3.1%) demonstrated 19 pleural plaques and one diffuse pleural thickening. Nine of 72 workers (12.5%) with more than 20 yr since their first fiber-production job had plaques (odds ratio [OR] = 9.5; 95% confidence interval [CI] = 1.9 to 48.2). Five of 19 workers with more than 20 yr in fiber-production work (26.3%) had plaques (OR = 22.3; 95% CI = 3.6 to 137.0). Similarly, adjusted ORs demonstrated a progressive relationship between cumulative fiber-months per milliliter (fiber-mo/ml) exposure and plaques. The case-control study confirmed that asbestos exposure did not account for the observed association between fiber exposure and plaques. A validity review of historical films demonstrated biologic plausibility for the association, since sufficient latency existed from the time of first RCF exposure to the development of plaques. There was no significant increase in parenchymal changes consistent with interstitial fibrosis.

This article has been cited by other articles:

				B. G. MILLER, J. W. CHERRIE, S. GROAT, and E. KAUFFER Changes in Workplace Concentrations of Airborne Respirable Fibres in the European Ceramic Fibre Industry 1987 1996 Ann. Hyg., August 1, 2007; 51(6): 501 - 507. [Abstract] [Full Text] [PDF]

				R. C. BROWN, B. BELLMANN, H. MUHLE, J. M. G. DAVIS, and L. D. MAXIM Survey of the Biological Effects of Refractory Ceramic Fibres: Overload and Its Possible Consequences Ann. Hyg., June 1, 2005; 49(4): 295 - 307. [Abstract] [Full Text] [PDF]

				J. E. Lockey, G. K. LeMasters, L. Levin, C. Rice, J. Yiin, S. Reutman, and D. Papes A Longitudinal Study of Chest Radiographic Changes of Workers in the Refractory Ceramic Fiber Industry* Chest, June 1, 2002; 121(6): 2044 - 2051. [Abstract] [Full Text] [PDF]

				H A Cowie, P Wild, J Beck, G Auburtin, C Piekarski, N Massin, J W Cherrie, J F Hurley, B G Miller, S Groat, et al. An epidemiological study of the respiratory health of workers in the European refractory ceramic fibre industry Occup. Environ. Med., December 1, 2001; 58(12): 800 - 810. [Abstract] [Full Text] [PDF]

				P. DUMORTIER, I. BROUCKE, and P. DE VUYST Pseudoasbestos Bodies and Fibers in Bronchoalveolar Lavage of Refractory Ceramic Fiber Users Am. J. Respir. Crit. Care Med., August 1, 2001; 164(3): 499 - 503. [Abstract] [Full Text] [PDF]

				J. E. LOCKEY, L. S. LEVIN, G. K. LEMASTERS, R. T. MCKAY, C. H. RICE, K. R. HANSEN, D. M. PAPES, S. SIMPSON, and M. MEDVEDOVIC Longitudinal Estimates of Pulmonary Function in Refractory Ceramic Fiber Manufacturing Workers Am. J. Respir. Crit. Care Med., April 1, 1998; 157(4): 1226 - 1233. [Abstract] [Full Text] [PDF]

				J. A. Hoskins Pleural Plaques - Eliminating the Confusion Indoor and Built Environment, March 1, 1997; 6(2): 69 - 71. [PDF]

				A. Sood and J. B. L. Gee Asbestos-Related Pleural Plaques and Diffuse Pleural Thickening: Functional Consequences Indoor and Built Environment, March 1, 1997; 6(2): 114 - 118. [Abstract] [PDF]

				K. Browne Pathogenesis, Diagnosis and Clinical Relevance of Pleural Plaques Indoor and Built Environment, March 1, 1997; 6(2): 125 - 130. [PDF]