Radiographic abnormalities in Vermont granite workers exposed to low levels of quartz.
Graham-WB; Weaver-S; Ashikaga-T; Hemenway-D; O'Grady-R
NIOSH 1990 Sep; :686-687
A study was made in granite workers to determine if exposure to low levels of quartz (14808607) dust could produce abnormalities on chest x-rays. Chest x-rays taken for 972 workers in 1953 were evaluated by three B-readers using the International Labour Office format. Films were defined as abnormal if at least two readers assigned profusion scores of 1/0 or greater, for rounded or irregular opacities. Personal breathing zone samples operating at 6 liters per minute were used for gravimetric sampling of respirable dust particles. X-rays were judged abnormal in 6.9% of workers. Abnormalities consistent with pneumoconiosis were noted in 2.88% (28 workers), and only seven workers had films judged abnormal by all three readers. Irregular opacities were the primary abnormalities on 21 x-rays. Rounded opacities typical of early silicosis were noted in 0.7%; none had profusion scores of 2/1 or higher. Four x- rays had irregular opacities with profusion scores of 2/1 or higher. This type of opacity tended to occur in lower lung zones, and no egg shell calcifications or large opacities were observed. Age, years spent in granite work and years as smokers were significantly higher in workers with abnormal films. Several workers with abnormal x-rays had notably low dust exposures. Mean dust levels for 417 samples were 601+/-365 micrograms per cubic meter (microg/m3). Using a quartz level of 10%, it was determined that 11% of samples exceeded the OSHA standard of 100microg/m3. The authors conclude that current dust controls conforming to OSHA standards have essentially eliminated radiographic silicosis.
NIOSH-Grant; Pulmonary-system-disorders; Humans; Occupational-exposure; Quartz-dust; Quarry-workers; Stone-processing; Lung-disorders; Respiratory-system-disorders; Exposure-levels; Chest-X-rays
Medicine Med Ctr Hospital of Vermont Chest Unit Burlington, VT 05401
(NIOSH) 90-108; Grant-Number-R01-OH-001035
Proceedings of the VIIth International Pneumoconioses Conference, Part I. Pittsburgh, Pennsylvania, August 23-26, 1988. NIOSH, U.S. Department of Health and Human Services, DHHS (NIOSH) Publication No. 90-108 Part I
University of Vermont and St Agric College, Burlington, Vermont