Respiratory Diseases in Agate Grinding Workers in Iran

BACKGROUND: Agate is a hard silica stone with bands of various colors, which is used in jewelry. The agate grinding workers are exposed to silica dust. OBJECTIVE: To determine the prevalence of respiratory diseases in agate grinding workers and the associated factors. METHODS: In this cross-sectional study, 170 agate grinding workers from Mashhad, northeastern Iran, were examined. Medical and occupational history for respiratory illnesses was taken using respiratory questionnaire of the national program of silicosis control, lung examination, spirometry and chest radiography. Chest x-rays were interpreted according to the International Labor Office (ILO) classification system, 2000. RESULTS: The mean±SD of age and work duration of the participants were 31.2±10.1 and 13±8.2 years, respectively. The prevalence of silicosis among agate workers was 12.9% (95% CI: 7.9%–18.0%); 18 workers had simple and 4 had complicated silicosis. There was a significant (p<0.05) relationship between contracting silicosis and exposure duration. 20 (11.7%) workers had symptoms consistent with chronic bronchitis and 8 (4.7%) showed asthma and asthma-like symptoms. The most frequent disorder observed in spirometry was the restrictive pattern (n=43, 30%). In the agate grinders, clinical and spirometry findings did not match with radiological findings. CONCLUSION: Agate grinding workers are at increased risk for respiratory diseases, specifically for silicosis and chronic bronchitis. The disease is related to silica dust exposure, poor ventilation and inappropriate personal protection.