Air pollution has long been associated with respiratory infections, exacerbating chronic cardiopulmonary diseases and increasing susceptibility to these infections. Despite regulations aimed at reducing air pollution levels, ambient criteria air pollutants continue to rise, with 9 out of 10 individuals currently living in areas with air pollution that exceeds local regulations. This trend has significant health consequences, contributing to more than 7 million premature deaths globally every year.
The COVID-19 pandemic has further highlighted the association between air pollution and respiratory infections, with studies demonstrating a direct correlation between increased ambient particulate matter (PM) and the incidence of pneumonia. The earliest observation of this association dates back to 1937, with an autopsy study noting evidence of alveolar carbon pigmentation, consistent with air pollution exposure, in individuals who died from pneumonia.