Radiographic abnormalities in Vermont granite workers exposed to low levels of granite dust.
Graham-WG; Ashikaga-T; Hemenway-D; Weaver-S; O'Grady-RV
Chest 1991 Dec; 100(6):1507-1514
A study of radiographic abnormalities in Vermont granite workers only exposed to low concentrations of granite dust was conducted. The study material consisted of chest X-ray films of 972 quarry and stone shed workers, 941 males, in the Vermont granite industry. The films were read for opacities using the International Labor Organization system by three B-readers. Occupational and medical histories were reviewed. Breathing zone samples were collected in a random selection of quarries and stone sheds and analyzed for total dust. Twenty eight films (3%) were interpreted by at least two readers as showing abnormalities indicative of pneumoconiosis. Only seven films showed evidence of silicosis. Pack years of smoking, years of employment in the granite industry, and the interaction between them were significantly correlated with the presence of X- ray abnormalities. The opacities on the remaining films, primarily irregular opacities in the lower lung regions, were of doubtful clinical significance. Breathing zone total dust concentrations ranged from 153 to 2320 micrograms per cubic meter (microg/m3), mean 601microg/m3. This was equivalent to an average quartz (14808607) concentration of 60microg/m3. The quartz content of 48 samples (11.5%) exceeded the OSHA standard for quartz, 100microg/m3. The authors conclude that quartz exposures in the Vermont granite industry have been controlled to the point where radiographic evidence of silicosis has been eliminated.
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Quarry-workers; Quartz-dust; Occupational-exposure; Chest-X-rays; Lung-lesions; Respiratory-system-disorders; Air-sampling; Mineral-dusts
Medicine Med Ctr Hospital of Vermont Chest Unit Burlington, VT 05401
University of Vermont & St Agric College, Burlington, Vermont