Recommended
More Related Content
Similar to THE PNEUMOCONIOSES - Copy (2).pptx
Similar to THE PNEUMOCONIOSES - Copy (2).pptx (20)
More from JAMESNYIRENDA5
Recently uploaded
Recently uploaded (20)
THE PNEUMOCONIOSES - Copy (2).pptx
- 1. THE PNEUMOCONIOSES DR STEPHEN SILUMESII , GENERAL MEDICAL OFFICER , OHSI KITWE
- 2. Pneumoconioses are a group of chronic lung diseases caused by long term exposure to respirable (< 5 micrometer diameter) of mineral dust. Many different mineral and metal dusts. Silica asbestos and coal mining dust are the most important in Southern Africa.
- 3. DISEASE EXPOSURE Coal workers pneumoconiosis Coal dust Asbestosis Asbestos fibres Silicosis Quartz (crystalline silica) Kaolin pneumoconiosis Kaolin (china clay) Berylliosis Beryllium Stannosis Tin ore Siderosis Iron oxide Baritosis Barium sulphate Bauxite worker’s lung shaver’s disease Aluminium
- 4. EPIDEMIOLOGY There is a long latent period between exposure to silica and onset of disease The risk of disease varies according to level of exposure In the UK an average of 167 cases of pneumoconiosis per year (2005 -2010) In South Africa pneumoconiosis 58% of all occupational lung diseases About 20% prevalence among black gold miners (2000)
- 8. PATHOPHYSIOLOGY The classical features of pneumoconiosis are as follows ; - Deposition of mineral dust in the alveoli - Mineral particles are phagocytosed by alveolar macrophages - Localized inflammatory reaction leads to long term changes in the histology of the lung : - Fibrotic reaction in the surrounding lung parenchyma, with reticulin formation and collagen deposition
- 9. - Necrosis and cavitation of the fibrotic nodules can occur in the later stages of the disease - Progressive disease leads to coalescence of fibrotic areas into large parenchymal masses (progressive massive fibrosis (PMF) - Gas diffusion is affected , leading to↓ transfer factor - Lung volumes ↓ (FEV¹ and FVC ) , classically a restrictive pattern
- 10. NATURAL HISTORY Natural history , clinical features , and radiology appearance vary according to the specific mineral exposure Silicosis - progressive and aggressive pattern Asbestosis and CWP can follow either a benign or progressive pattern Stannosis and siderosis follow a benign course
- 11. SILICOSIS This is a pneumoconiosis associated with exposure to respirable crystalline silica. Silica is encountered mainly as crystalline quartz, a component of igneous rocks.
- 13. Sources of respirable particles of silica Mining - ore of Cu, Coal, Fe, Pb, Zn, Au Gold mine drilling team NB: absence of PPE.
- 14. Sources of silica cont’d Quarries
- 15. Sources of silica dust Rock and concrete works
- 16. Sources of silica Construction – tunnels, roads and train tracks [blasting, H&D of quarry stones/rock, mixing of concrete, dry sweeping with compressed air]
- 17. Sources of silica Foundries & glass prod
- 18. Sources of silica Stone crushing
- 20. CLINICAL FEATURES There are three recognized types of silicosis : Acute Subacute Chronic
- 21. Acute Early onset of dyspnoea and dry cough within a few months of heavy exposure to fine dusts (e.g sand-blasting ) CXR shows patchy small airway consolidation (appearance similar to pulmonary oedema) Progression over 1-2 years , with respiratory failure
- 22. Subacute Gradual onset of dyspnoea and dry cough over the years moderate exposure CXR shows upper-and mid-zone nodular fibrosis , with classical feature of ‘egg-shell’ calcification of the hilar lymph nodes PMF can occur , with coalescence of the fibrotic nodules Restrictive pattern of impaired lung function
- 23. Chronic Slow development of nodules on CXR over many years after low level exposure Silicosis is associated with lager nodules on CXR and more rapid progression than coal worker’s pneumoconiosis with which it may co-exist However with the exception of egg shell calcification , silicosis can be difficult to distinguish from CWP clinically and radiologically in dual exposed cases
- 24. RADIOLOGICAL FEAUTRES CXR shows small nodular opacities in the lung parenchyma. Distribution depends on the specific disease , but tends to affect the upper lobes first PMF associated is associated with large areas of confluent shadowing , usually starting in the upper zones The international Labour Organization (ILO) has devised a classification system for the CXR features of all pneumoconioses This classification is used to determine severity of disease for compensation purposes and is based on size , shape and distribution of the opacities
- 25. Size ;small round opacities versus small irregular opacities
- 28. Large opacities
- 30. MANAGEMENT There is usually no specific treatment No specific intervention halts progression Management is to remove from the exposure Treatment of advanced disease is supportive Regular examination of sputum for tubercle bacilli; confirmed infection is treated with standard anti- tuberculous chemotherapy 10 – 30% of silicosis cases progress after removal from exposure
- 31. Silicosis and Coal workers’ pneumoconiosis (CWP) or ‘‘Black lung disease’’ (pathology) Silicosis vs CW pneumoconiosis
- 32. HEALTH SURVEILLANCE Health surveillance(clinical examination, lung function tests and CXR) is required for all those who are exposed Annual periodical examinations are recommended for all workers in the mining industry
- 33. PREVENTION Exposure controls in the mining industry including; ventilation dust reduction measures use of PPE
- 34. COMPENSATION Pneumoconiosis is a notifiable and compensable disease in Zambia
- 35. THE END
- 36. References An Overview of Sillica-associated lung disease ILO- NEAPAD ZAMBIA, Professor Shahieda Adams Oxford Handbook of Occupational Health Preventive and Social Medicine , K.Park 25th edition Davidsons Principles and Practice of Medicine Overview of Occupational Diseases , Dr Kingsley Ngosa , OHSI Kitwe OHSI Briefing on TB and Pneumoconioisis to Chamber of Mines SHE Committee , March 2022
- 37. THANK YOU
Editor's Notes
- In prodn of Mining of