Silicosis

• Most abundant mineral in the world.
• Silicosis is pulmonary fibrosis which occurs as a result of breathing in fine crystalline silica (from quartz) 
• After 10-20 years exposure
• Now uncommon in developed countries (good occupational health and safety)
• Simple nodular silicosis is like simple coalworker’s pneumoconiosis (no symptoms but visible on CXR)
• Complicated silicosis → progressive fibrosis → loss of lung function and dyspnoea
• Histologically – concentric layers of collagen surrounding a central core of dust and dying macrophages 

↑ Risk of developing lung cancer