Related Subjects:
|Idiopathic Pulmonary Fibrosis
|Diffuse Parenchymal Lung disease
|Asbestos Related Lung disease
|Sarcoidosis
|Coal Worker's Pneumoconiosis
|Silicosis
|Farmer's Lung
|Cryptogenic Organising Pneumonia (COP-BOOP)
|Extrinsic Allergic alveolitis (Hypersensitivity)
|Pneumoconiosis
|Cor Pulmonale
π«οΈ Respirable crystalline silica (RCS) is found in stone, rocks, sands, and clays.
Long-term exposure β fibrosis (scarring) of lung tissue with progressive loss of function.
π In the UK, a Workplace Exposure Limit (WEL) regulates exposure to keep levels safe.
π About
- βοΈ Exposure to silica (SiOβ) occurs in stone cutting, glass/cement manufacturing, quarrying, foundries, and construction.
- β³ The disease can progress even after exposure stops.
π Epidemiology
- π Risk is dose-related (level Γ duration of exposure).
- β±οΈ Usually requires 10β20 years, but acute silicosis can occur with short-term high exposure.
- π¬π§ UK data: 14 deaths in 2006, 7 in 2007 from silicosis.
π· Occupations at Risk
- Quarrying, slate works, potteries, foundries, stonemasonry.
- Construction: cutting/breaking stone, concrete, or brick.
- Industries using silica flour.
πͺ¨ Silica Content of Stones
| Type of Stone | Silica % |
| Sandstone, gritstone, quartzite | > 70% |
| Concrete, mortar | 25β70% |
| Shale | 40β60% |
| China stone | β€ 50% |
| Slate | β€ 40% |
| Brick | β€ 30% |
| Granite | β€ 30% |
| Ironstone | β€ 15% |
| Basalt, dolerite | β€ 5% |
| Limestone, chalk, marble | β€ 2% (but may have silica layers) |
π©Ί Clinical Features
- π Progressive exertional breathlessness
- π« Persistent dry cough
- β‘ Chest pain or tightness
- π§© Progressive massive fibrosis (PMF) in severe cases
- π΄ Fatigue, weight loss in advanced disease
β οΈ Complications
- π§± PMF: Large fibrotic masses β severe restriction.
- π¦ TB: Increased risk from impaired macrophage function.
- π¬ COPD: Risk compounded by smoking.
- ποΈ Lung cancer: Recognised occupational carcinogen.
- π Cor pulmonale: Chronic PH β right heart failure.
π Investigations
- π©» CXR: Nodular opacities, upper/mid zones; "eggshell" hilar calcification (classic).
- π₯οΈ HRCT: Detects nodules, fibrosis, emphysema.
- π PFTs: Restrictive pattern, β lung volumes & gas transfer.
- π§ͺ BAL: Silica-laden macrophages, milky fluid.
- 𧬠Biopsy: Silica nodules + interstitial fibrosis.
π Management
- π« Prevention: Minimise exposure β water suppression, ventilation, dust control.
- π· PPE: N95 (or higher) respirators.
- π Smoking cessation: Reduces COPD and cancer risk.
- π©Ί Monitoring: Regular CXR + PFTs for exposed workers.
- π¨ Supportive care: Bronchodilators, Oβ therapy as needed.
- βοΈ Legal reporting & compensation: Silicosis is a prescribed occupational disease in the UK.
π References
3 Clinical Cases β Silicosis π¬οΈπͺ¨
- Case 1 β Chronic simple silicosis β³: A 62-year-old man, retired quarry worker with 30 yearsβ exposure to stone dust, presents with gradually worsening exertional breathlessness. Exam shows fine inspiratory crackles. Chest X-ray reveals multiple small, upper-lobe nodular opacities (<10 mm). Spirometry shows a restrictive pattern with mildly reduced DLCO. Teaching: Chronic simple silicosis typically presents after decades of exposure, with small nodules and slowly progressive fibrosis.
- Case 2 β Accelerated silicosis β‘: A 44-year-old sandblaster with only 7 years of high-intensity exposure reports breathlessness and chronic cough. CXR and HRCT show widespread nodularity and early conglomerate masses (progressive massive fibrosis). Teaching: Accelerated silicosis develops within 5β10 years of heavy exposure, more aggressive, and often mistaken for sarcoidosis or TB. Risk of complications such as massive fibrosis is high.
- Case 3 β Complicated silicosis with TB co-infection π¦ : A 55-year-old former miner with longstanding silicosis presents with night sweats, weight loss, and haemoptysis. Imaging shows upper-lobe fibrotic masses with cavitation. Sputum smear is positive for acid-fast bacilli. Teaching: Silicosis greatly increases the risk of pulmonary TB (βsilicotuberculosisβ), and TB must be excluded in any symptomatic patient. Lifelong surveillance for TB and lung cancer is essential.