Artificial Stone Silicosis: Rapid Progression Following Exposure Cessation

Background: Silicosis is rapidly emerging in high-income countries in relation to the replacement of natural stone with artificial stone, especially in the manufacturing and installation of kitchen and bathroom countertops. Progression of this form of silicosis following the cessation of exposure is unknown.

Research Question: The objective of this study was to determine the radiologic progression and lung function in individuals with artificial stone silicosis.

Study Design And Methods: Between 2009 and 2018, a total of 106 patients were diagnosed with artificial stone silicosis in the Bay of Cádiz area (southern Spain), 14.15% by using biopsy results and the remainder according to chest radiography and high-resolution CT imaging. Follow-up consisted of respiratory function tests and radiographic studies. All patients stopped working in the stone industry following diagnosis.

Results: All patients were men; their mean ± SD age at diagnosis was 36.2 ± 7.0 years, and the mean duration of exposure was 12.0 ± 4.3 years. At diagnosis, 99 patients were considered to have simple silicosis (93.4%) and seven to have progressive massive fibrosis (PMF) (6.6%). After a mean follow-up of 4.01 ± 2.1 years, disease in 56% of patients had progressed two or more International Labour Office subcategories, and the number of patients with PMF had increased to 40 (37.7%). Regarding lung function, there was a decrease in FVC and FEV, with an average decrease of 86.8 and 83.4 mL per year, respectively; in 25% of patients, the annual decrease was > 157 mL in FVC and > 133 mL in FEV. Multivariable analysis showed that lower FVC at diagnosis and longer duration of exposure to silica were associated with progression to PMF.

Interpretation: Artificial stone silicosis rapidly progresses to PMF even following exposure cessation, and a significant percentage of patients experience a very rapid decrease in lung function.