Jedsada Panthong¹, Naesinee Chaiear^1,, Narongpon Dumavibhat², Ponglada Subhannachart³

Objective: To describe the radiographic progression among sandstone workers exposed to respirable crystalline silica (RCS). Methods: The sample of 134 sandstone workers had at least 2 chest radiographs between January 2012 and April 2017. Their chest radiographs were assessed from the first through last visits to find two or more steps subcategory progression. All films were interpreted and classified by two physicians, who were qualified as NIOSH B readers according to International Labor Office System of Classification of Radiographs of Pneumoconiosis 2011 (ILO/ICRP). Results: Progressions were demonstrated among 30 (22.4%) workers as they had radiographic evidence of two or more step subcategory progression and 5 out of them had 2-times progression. The median duration of exposure was 10.0 years (IQR 8.0-15.0) (range 2.0-25.0). The median duration of follow-up was 31.0 months (IQR 20.0-38.0) (range 6.0-54.0) Conclusions: Our findings revealed that chest radiograph had progressed in 22.4% of patients over the median 10 years of exposure; nevertheless, the association between exposure duration and radiographic progression could not be described in this study.

chest radiograph, ILO classification, pneumoconiosis, progression, sandstone worker, silicosis