Abstract

A 70 mm. radiographic survey in 914 workmen exposed to china-clay dust was made in 1959 in an industrial plant in which kaolin deposits are processed for the earthenware industry in Ayyat, United Arab Republic. All were ex-agricultural workers and thus not exposed to any industrial dust hazards.

The purpose of the survey was to study the prevalence of pneumoconiosis and active tuberculosis. Fifty subjects were considered to require further investigation and large films were therefore taken which showed the following results: five cases of pneumoconiosis; one case of pneumoconiosis and tuberculosis; and 13 cases of active tuberculosis. Of the five pneumoconiosis cases, two were classified as progressive massive fibrosis (P.M.F.), two as category 3 and one as category 1 simple pneumoconiosis. All had been heavily exposed for 15 years or more.

Case records of the pneumoconiosis group are given with follow-up observations for two and a half years. There were no important clinical or radiographic changes except that one of the two patients with P.M.F. died of cor pulmonale. Correlation of the clinical features and radiographic abnormalities was poor. The low prevalence of pneumoconiosis, in spite of the heavy and prolonged exposure, is emphasized. A sample of the airborne dust contained about 2% of SiO₂.