PHGY 216 Independent Assignment - Omar Habashy 20300157 (2)

What is “Asbestosis”? Asbestosis is a chronic lung condition caused by long exposure to asbestos. Asbestos is a mineral commonly used in the construction of buildings or houses due to its heat resistance and durability. Microscopic fibres of asbestos can be inhaled through the nose and eventually reach the lungs. These fibres then become stuck in the lungs and lead to inflammation and scarring of the tissue, making it difficult for the lungs to expand and contract like they normally do. 1 What does Asbestosis affect? Asbestosis primarily affects the respiratory system, particularly the lungs. Lungs under healthy conditions facilitate the exchange of oxygen and carbon dioxide between the inhaled air and the bloodstream. 2 In tiny sacs called alveoli surrounded by capillaries, oxygen binds to hemoglobin in red blood cells. Oxygen is then transported to tissues throughout the body. Simultaneously, carbon dioxide, the waste product of our cellular metabolism is diffused from the blood into the alveoli and is exhaled. 3 Illustrated in Figure 1, oxygen gas is exchanged for carbon dioxide in the bloodstream in the adjacent capillary. 4 The lungs are also protected by systems of defense including mucus production, the immune system, and cilia which are tiny hair-like structures on the surface of cells that move mucus and foreign particles up toward the mouth where they can be sneezed or caught out of the body. 5 Fibres of asbestos can become lodged in both the airway and the alveolar sac itself, triggering an immune response that results in chronic inflammation and fibrosis (scar tissue) in the lungs. 6 As per Figure 1, fibres would likely obstruct the alveoli sac from the air in/out region, inhibiting oxygen-containing inhaled air to complete the process of gas exchange. Furthermore, as scarring progresses, the lungs become stiff and rigid, complicating their ability to expand and contract during breathing. Figure 1. Schematic Arrangement of Alveolar-Capillary Membrane 4 What changes are caused by Asbestosis? The activation of immune cells and release of inflammatory mediators, inflammation attempts to repair the damaged lung tissue by forming scar tissue in the lung parenchyma. 7 The composition of the scar tissue mainly consists of collagen fibres, which are significantly less flexible and functional than normal lung tissue. As depicted in Figure 2, different proteins called interleukins are shown to affect various cells in the lungs, either promoting or inhibiting processes that take part in the formation of scar tissue (pulmonary fibrosis). 8 The combination of stiffness and now compromised alveoli subsequently has the potential to result in hypoxemia (abnormally low concentration of oxygen in the blood) and hypercapnia (excessive carbon dioxide in the bloodstream). Thus, individuals with asbestosis generally experience dyspnea (difficulty breathing). Common symptoms include 9 : ➢ Shortness of breath ➢ Fatigue ➢ Wheezing ➢ Persistent cough ➢ Chest tightness or pain ➢ Enlarged and more rounded fingertips and toes compared to the typical size

Figure 2. Interleukins Influence the Morphology and Functions of Various Cells in Pulmonary Fibrosis. 8 Asbestos’s ability to impair the gas exchange and reduced lung function can also impact other organ systems. For instance, downstream consequences of hypoxemia may lead to pulmonary hypertension, which is high blood pressure affecting both arteries in the lungs and the right side of the heart. This can lead to cor pulmonale, which is when the right side of the heart gets too large and starts to fail. 10 Moreover, pulmonary hypertension caused by asbestosis could exacerbate negative health implications for those already suffering from similar medical conditions. These pathophysiological changes disrupt the body’s equilibrium and highlight the complexity of respiratory function and its fragility. What can I do about asbestosis? First, avoid further exposure to asbestos and other possible irritants such as tobacco smoke and other pollutants. This will help mitigate the progression of the disease into more severe, irreversible stages. Next, you should seek medical consultation for evaluation immediately. Consulting a healthcare professional, preferably a physician who specializes in respiratory diseases can evaluate your health status and assess any symptoms you may have. Based on the evaluation and any test results, you will be provided guidance or recommendations on any next steps including continued personal monitoring of health, additional testing, and options for treatments of symptoms. One major treatment for asbestosis is oxygen therapy, involving oxygen supplementation for those who have difficulties breathing. By increasing the oxygen concentration of inhaled air, oxygen content in the blood helps compensate for the impaired gas exchange on the alveoli level caused by asbestos. This can alleviate symptoms such as shortness of breath and improve the oxygen saturation of arterial blood, improving the workload on the heart. Action Plan ➔ Avoid Exposure: Steer clear of asbestos and any other lung irritants to protect your health. ➔ Consult Specialists: Seek medical guidance from healthcare professionals specializing in respiratory diseases and infections. Develop and cater a personalized management approach. ➔ Mintor Symptoms: Stay careful and aware of any differences in breathing, coughing, discomfort, or chest pain and report them immediately. ➔ Stay Informed: Stay up-to-date with trusted organizations to better advocate for your health. Patient Resources ● Asbestos Disease Awareness Organization (ADAO) ○ www.asbestosdiseaseawareness.org ● The Mesothelioma Center ○ www.asbestos.com References Haddad, M. (2023, July 20). Physiology, lung. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK545177/ She, Y. X., Yu, Q., & Tang, X. X. (2021). Role of interleukins in the pathogenesis of pulmonary fibrosis. Cell Death Discovery, 7(1). https://doi.org/10.1038/s41420-021-00437-9