Silicosis.

Abstract

I was pleased to see the emphasis on silicosis in your recent issue, but sad that the lessons my generation has learned over the past six decades have had so little impact worldwide on prevention. These lessons are: Silicosis presents a variety of radiological appearances, depending on the intensity and duration of exposure and the mineral content of the dust. There is only one useful test for surveillance—chest radiography. Symptoms and pulmonary impairment only come late in the evolution of the disease. In this context, ‘late’ does not mean duration of exposure, since very heavy exposure to freshly generated silica can cause death within a year. The International Labour Office (ILO) classification of radiographs was not intended for diagnosis but for epidemiological purposes, to reduce the inevitable variation between x-ray readers. Rather, it allows description of the changes seen in relation to standard ‘normal’ films. Diagnosis in individuals depends also on taking account of clinical factors, notably exposure to, and type of, dust.