Lung disease after exposure to polyvinyl chloride dust.

A 41 year old man who worked at a PVC factory and had suffered from daily cough and gradually increasing dyspnoea since July 1981 has been followed since February 1982. He had smoked one package of cigarettes daily for 20 years. The patient had worked in a PVC factory from 1974 but had an accumulated exposure to PVC dust of only about 750 days. Total dust concentrations during packing of PVC ranged from 0.3 to 42mg/m3 (median of 38 measurements 2 mg/mi3). He had worked for a total of 60 days in the most dusty work phases. He had been exposed to relatively low concentrations (0-3 ppm) of vinyl chloride monomer (VCM). He had not been exposed to asbestos or other known fibrogenic agents. PVC had been considered harmless because of the large mean particle size given by the producer (20-200pm). When we examined dust samples from the workroom air by electron microscopy, however, most of the particles were smaller than I pm. Subjectively, the patient's performance capacity had declined but his clinical condition was normal. The chest radiograph was within normal limits. Spirometry yielded normal values but diffusing capacity transfer factor (TLco), was abnormal (TLCO 45%, Kco 36% of predicted normal values). An ergometer bicycle test (50 and 100 w for four minutes, 150 w for two minutes) resulted in moderate hypoxaemia (arterial oxygen tension 8.5 kPa (63.8 mm Hg), arterial carbon dioxide tension 3.6 kPa (27mm Hg), pH 7.36). The oxygen saturation was lowered from 94% to 89% during the test. The results of routine laboratory tests were normal, and so were the results of a large panel of immunological tests, including nuclear antibodies, DNA antibodies, number ofT and B lymphocytes in peripheral blood, immunoglobulin and complement (C3, C4) concentrations, and phytohaemagglutinin stimulation of lymphocytes. alantitrypsin concentration was 3.1 g/l (phenotype MM). The appearance of the bone marrow aspirate was normal. A thoracotomy was performed and histological examination of part of the lingula showed a profuse accumulation