Complicated silicosis resulting from occupational exposure to engineered stone products
A 54-year-old man, formerly a smoker, presented with a 6-year history of chronic cough and exertional breathlessness without previous respiratory illnesses. Born in Vietnam, he came to Australia as a refugee at the age of 20 years. A screening chest x-ray was performed on his arrival in Australia; as the patient was not informed about any abnormality, this was assumed to be normal. He commenced work as a labourer; he denied exposure to silica-containing materials and did not participate in activities typically associated with silica exposure (such as jack-hammering) during this period. About 15 years later, the patient started a job manufacturing stone benchtops. He cut, ground, finished and installed the benchtops, using a popular brand of engineered stone comprising > 85% crystalline silica. Occasionally, he made benchtops from granite and marble. During the first 7 years of this work, the patient did not use any respiratory protective equipment, but later used a simple paper mask. Despite some dust extraction facilities in the factory, he reported that the environment was visibly dusty and that dust suppression with water was hardly ever used.
At presentation, chest examination showed scattered fine crackles and bronchial breath sounds bilaterally in the upper zones. Spirometry showed restriction (forced expiratory volume in 1 second [FEV1]/forced vital…