The Role of Airborne Bacterial and Fungal Bioaerosols in Respiratory Diseases

Airborne particulate matter (PM) is a major environmental hazard worldwide, responsible for millions of early deaths each year. Short-term contact with outdoor PM frequently results in lower respiratory infections (LRI). Among these pollutants, bioaerosols which include bacteria, fungi, viruses, and allergens are increasingly acknowledged as key players in respiratory diseases like asthma and tuberculosis. Pulmonary Tuberculosis (PTB), an infection caused by Mycobacterium tuberculosis , remains a significant health concern, especially in developing nations, causing approximately one million deaths annually. The fungi Cladosporium and Fusarium are commonly found in air, both indoors and outdoors, while bacteria such as Bacillus and Pseudomonas dominate many environmental air samples. Various infections including pneumonia, tuberculosis, brucellosis, anthrax, and Q fever are linked to bacterial bioaerosols, with fungal and viral particles playing roles in chronic respiratory illnesses. Long-term exposure to these biological particles can lead to immune system alterations, including inflammation and tissue remodeling that contribute to steroid-resistant asthma. Gaining insights into the dynamics and effects of pathogenic bioaerosols alongside particulate pollution is critical for developing health policies aimed at reducing their impact. This review compiles the latest findings on the mechanisms by which bioaerosols affect airway tissues, trigger immune responses, and worsen chronic respiratory conditions, underscoring the importance of integrative environmental and medical strategies.