A longitudinal study of chest radiographic changes of workers in the refractory ceramic fiber industry.
OBJECTIVE
This industry-wide longitudinal study examines chest radiographic changes of workers manufacturing refractory ceramic fibers (RCF).


METHODS
Chest radiographs were obtained every 3 years and were interpreted using the 1980 International Labour Organization classification for pneumoconiosis. Three exposure metrics were calculated: duration and latency in a production job, and cumulative exposure (fiber-months per cubic centimeter).


METHODS
The radiographic survey included 625 current workers at five manufacturing sites and 383 former workers at two of the five sites.


RESULTS
Pleural changes were seen in 27 workers (2.7%). Of workers with > 20 years of latency from initial production job or 20 years of duration in a production job, 16 workers (8.0%) and 5 workers (8.1%) demonstrated pleural changes, respectively. Results from the cumulative exposure analysis (> 135 fiber-months per cubic centimeter) demonstrated a significant elevated odds ratio (OR) of 6.0 (95% confidence interval [CI], 1.4 to 31.0). The incidence of irregular opacities at profusion categories > or = 1/0 was similar to other nonspecified dust-exposed worker populations at 1.0%, and showed a nonsignificant elevated OR in regard to cumulative fiber exposure of 4.7 (95% CI, 0.97 to 23.5).


CONCLUSIONS
RCF are significantly associated with pleural changes that were predominantly pleural plaques, but have not resulted in a statistically significant increase in interstitial changes.
Lockey
James E
JE
Division of Occupational and Environmental Medicine, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0056, USA.
LeMasters
Grace K
GK
Levin
Linda
L
Rice
Carol
C
Yiin
James
J
Reutman
Susan
S
Papes
Diane
D
D000328:Adult; D002516:Ceramics / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019016:Mineral Fibers / Q000009:adverse effects*; D009784:Occupational Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D011446:Prospective Studies; D011859:Radiography
D019016:Mineral Fibers