Question

Explain how high levels of air pollution can influence the frequency of bacterial diseases such as pneumonia or bronchitis.

Answer 1

Ans:

Today, approximately 50% of the people in the world live in cities and urban areas and are exposed to progressively higher levels of air pollutants. Aggravation of the symptoms of disease, together with increases in the demand for emergency treatment, the number of hospitalizations, and the number of deaths is associated with particulate and gaseous pollutants, emitted by various sources. A long-term exposure to air pollutants causes exacerbate pre-existing diseases and in turn also increases the number of diseases like asthma, COPD, and lung cancer. The evidence strongly a link between air pollution and severity of illness associated with respiratory infection, and individuals with pre-existing lung disease may be at greater risk. Viruses are the causal pathogens in most upper respiratory tract infection cases, with fewer than 10% of the cases caused by bacteria. The viral pathogens primarily associated with upper respiratory tract infections include picornaviruses (notably, rhinoviruses and enteroviruses), coronaviruses, adenoviruses, parainfluenza viruses, influenza viruses, and respiratory syncytial viruses. The airway epithelium acts as the first defense against respiratory pathogens, as a physical barrier, with the mucociliary system and its immunological functions. It initiates multiple innate and adaptive immune mechanisms for efficient antiviral responses. The interaction between respiratory pathogens and airway epithelial cells results in production of substances, including type I and III interferons, lactoferrin, β-defensins, and nitric oxide, and also in the production of cytokines and chemokines, which recruit inflammatory cells and influence adaptive immunity. Viral infections can damage the barrier function leading to enhanced absorption of allergens and/or irritants across the airway wall promoting inflammation.