Abstract

In the last 20 years there have been a re-emergence of silicosis in many high-income countries due to the spread of artificial stone (with a high silica content) in manufacturing of domestic benchtops. The aim of our study was to assess the prognosis of a cluster of individuals with artificial stone silicosis (ASS) at least 2 years since diagnosis. Patients included in the study had a diagnosis of ASS confirmed by lung biopsy between 2017 and 2020. Follow-up visits were all performed in the same centre (Occupational Medicine Unit of Padova University Hospital, Italy) and consisted of respiratory function tests [i.e., spirometry,DLCO, and 6-minutes walking test (6MWT)] and high-resolution CT imaging. A total of 21 men were diagnosed with ASS. Their mean ± SD age at diagnosis was 43.6 ± 8 years; 8 were active smokers, 8 ex-smokers and 5 non-smokers. The mean duration of exposure before diagnosis was 17.3 ± 8.6 years. Six patients ceased their exposure to artificial stone following diagnosis. The mean duration of follow-up was 4.4 ± 1 years. At the last follow-up visit, FEV1% predicted and FVC% predicted were significantly lower than at diagnosis (p= 0.0014 and 0.0004 respectively);DLCO% predicted significantly decreased too (p= 0.0036). No changes were detected in the results of 6MWT. Regarding high-resolution CT studies, according to ICOERD criteria, at diagnosis all patients were diagnosed with simple silicosis (predominant ?p? opacities) and at follow-up 10 patients have progressed to massive fibrosis.To the best of our knowledge this is the first Italian follow-up study on the mid-term outcome of ASS and it shows a rapid and progressive worsening both of the functional and the radiological pattern.