8.OCCUPATIONAL AND ENVIRONMENTAL LUNG DISEASES MBCHB 2019-2-1

8.OCCUPATIONAL AND ENVIRONMENTAL LUNG DISEASES MBCHB 2019-2-1 Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / IMED 4.1 / NGUGI -- Slide 1 OCCUPATIONAL AND ENVIRONMENTAL LUNG DISEASES PRESENTED BY: Juma Kimanzi, Raymond Mutinda, Jimmy Kesis, Emmanuel Kivandi, June Nderu, Husseina Hassan and Wanjiru Mwangi. Slide 2 What's in store for you! Inorganic dust-induced lung diseases/ pneumoconiosis.\nSilicosis Coal worker’s pneumoconiosis (CWP)/ Black lung disease Asbestosis Berylliosis Other specific pneumoconiosis e.g., talcosis, kaolin pneumoconiosis Organic dust-induced lung diseases. Byssinosis Grain dust-induced bronchitis Hypersensitivity pneumonitis(HP) Toxic and irritant gas induced lung diseases Slide 3 Definition As per International Labor Organization (ILO), the term “occupational disease” covers any disease contracted as a result of an exposure to risk factors arising from work activity.\nThe two main elements present in an occupational disease are; the casual relationship between exposure in a specific working environment or work activity and a specific disease. The fact that the disease occurs among a group of exposed persons with a frequency above the average morbidity of the rest of the population.\nOccupational lung disease is a broad group of diagnoses caused by the inhalation of dusts, chemicals or proteins leading to lung damage. Occupational lung disease is common in workers in certain specific occupations but even individuals who do not work in the industry can develop occupational lung diseases through indirect exposure. Slide 4 Pathogenesis of OCCUPATIONAL AND ENVIRONMENTAL LUNG DISEASES. Inhalation of the harmful inorganic or organic particles or gases. Attachment of the inhaled particles or gases into the respiratory epithelium. Engulfment of the particles by alveolar macrophages and release of inflammatory mediators. Continued activation of immune response and inflammation with repeated exposure to the particles or gases. Lung tissue injury and consequent healing by fibrosis and scarring. Long-term exposure results in chronic lung diseases. Slide 5 Pathogenesis of occupational and environmental lung diseases. Slide 6 Determinants of inhalation exposure Occupational environment. Factors e.g. type of industry, specific work process and presence of hazardous substances. Concentration and composition of hazardous substances. Particle size is important in dictating the site of lung tissue injury. Duration and frequency of exposure. Individuals with long work histories or exposure for long hours are at a higher risk. Work practices and control. Factors such as ventilation systems, use of PPEs, dust suppression techniques and adherence to safety protocols. Personal factors e.g. age, genetic predisposition, smoking status, pre-existing lung conditions and individual respiratory defense mechanisms. Compliance with safety regulations and technological advancements. Slide 7 Particle size in determination of inhalation exposure. Slide 8 Occupational and environmental Respiratory Diseases Slide 9 Diagnosis of occupational and environmental lung diseases. This requires meeting criteria of\n(1) evidence of structural pathology consistent with dust-related disease as documented by imaging,\n(2) evidence of causation by dust exposure as documented by the occupational and environmental history or markers of exposure\n(3) exclusion of confounders. Slide 10 Assessment for occupational and environmental lung diseases. Slide 11 History and exposure assessment The patient’s history is of paramount importance in assessing any potential occupational or environmental exposure.\nA useful and efficient construct for interviewing a patient about his or her occupational and environmental history is contained in the easy-to-remember mnemonic “WHACOS.” W: What do you do? - specific contaminants involved, the presence of visible dusts, chemical odors. H: How do you do it?- the size and ventilation of workspaces, the use of respiratory protective equipment A: Are the symptoms acute or chronic in nature?- The temporal association of exposure at work and symptoms may provide clues to occupation-related disease. C: Are any coworkers, family members, or friends sick with the same illness? O: Do you have any hobbies, pets, or travel outside of work? - alternative sources of exposure to potentially toxic agents, including hobbies, home characteristics, exposure to secondhand smoke, and proximity to traffic or industrial facilities S: Are you satisfied with your job? Slide 12 HISTORY AND EXPOSURE ASSESSMENT These simple questions can efficiently lead the patient into a useful dialog with the physician about occupational and environmental factors that can provide important clues about the etiology of an illness that may be related to a toxic exposure. Short-term and long-term exposures to potential toxic agents in the distant past also must be considered.\nHowever, the introduction of new processes and/or new c