<p>Respiratory health in urban populations is increasingly threatened by exposure to diverse and understudied non-industrial air pollutants. While the role of industrial emissions in air pollution has been well documented, growing evidence points to a significant contribution from urban sources such as vehicular traffic, construction activities, agriculture, and biomass burning. Motivated by the rising incidence of chronic respiratory conditions in cities, this review investigated how complex urban aerosols influence immune function and respiratory health. Drawing on recent epidemiological, immunological, and microbiome-based studies, the review identified key mechanisms linking aerosol exposure to microbial imbalances, immune dysregulation, and chronic inflammation. These disruptions are associated with increased risks of asthma, chronic obstructive pulmonary disease (COPD), and other respiratory infections, as well as broader systemic impacts such as neuroinflammation and metabolic disorders. The review concludes by proposing an integrated framework for urban air quality management that incorporates health-focused assessments, microbiome-targeted interventions, and policy strategies such as green infrastructure and pollution mitigation. These insights offer a foundation for future research and guide evidence-based policies aimed at improving respiratory health in urban settings.</p>