Air Pollution and Respiratory Health: A Longitudinal Study of Urban Populations in High-Density Cities

Lucía Martín¹, Peter Walsh², Carla Mendes³, Javier Torres⁴, Anna Nelson⁵

Abstract

Background:
Urbanization and industrialization have significantly increased air pollution levels, raising concerns over long-term respiratory health impacts. This study examines the correlation between air pollution exposure and respiratory illnesses in high-density cities.

Methods:
A longitudinal cohort of 2,500 adults living in urban areas with high pollution indices was followed over five years. Particulate matter (PM2.5, PM10) and nitrogen dioxide (NO₂) concentrations were measured continuously. Spirometry tests and health surveys were conducted annually to assess respiratory function and symptom prevalence.

Results:
Prolonged exposure to PM2.5 above WHO guidelines was associated with a 24% increase in chronic obstructive pulmonary disease (COPD) risk (p < 0.001) and a 16% increase in asthma incidence (p < 0.01). Spirometry results showed a mean annual decline in FEV1 of 3.1% among high-exposure participants, compared to 1.8% in low-exposure groups.

Conclusion:
Long-term exposure to urban air pollution significantly exacerbates respiratory health risks. Mitigation strategies focusing on emission reductions are essential to improve health outcomes in densely populated regions.