Suggestions for Revision of the ILO Criteria for Abestosis Based on Screening 10,000 Workers.
NIOSH 1990 Nov:1261-1263
Revising International Labour Organization (ILO) criteria for asbestosis was discussed. The results of screening 4572 boiler makers and pipe fitters for asbestosis between 1986 and 1988 using the 1980 ILO classification system for radiographic profusions were discussed. Use of posterior/anterior and lateral chest X-rays indicated that approximately 21.5% of the subjects were classified as having 1/0 or 1/1 category profusions. Only 5.1% were categorized as 1/2 or higher and 73.4% were classified as normal. Repeat posterior/anterior films were required for 7% of the subjects because of confounding caused by over or under exposure and competing shadows contributed by breast, pectoral girdle muscle, and fat tissue. Underinflation of the lungs such that the diaphragms did not extend below the ninth intercostal space resulted in several spurious readings of 1/0. It was noted that underinflation typically occurred in 12% of posterior/anterior X-rays unless the technicians instructed the subjects to exhale and then inhale as deeply as possible. When these instructions were followed only about 2.1% of the X-ray films had diaphragms not below the ninth intercostal space. The authors state that instructions for readers should be improved and include adding lateral chest X-rays, adding boundary films especially to the 0/1 and 1/0 boundary which is the critical border for distinguishing between negative and positive films, and updating nonpneumoconiotic changes to include incremental emphysema, byssinosis, dialed aorta, and bronchiectasis.
Lung-lesions; Chest-X-rays; X-ray-analysis; Asbestos-workers; Respiratory-system-disorders; Occupational-medicine; Epidemiology; Medical-screening; Visual-images;
Asthma and Chronic Obstructive Pulmonary Disease; Disease and Injury; Respiratory-system-disorders;
Proceedings of the VIIth International Pneumoconioses Conference