Air Pollution in Infancy Linked to Higher Rates of Respiratory Infections

by Erica Marchand
Boston, United States (SPX) May 01, 2026
Ambient air pollution in the first year of life is associated with a greater burden of respiratory infections, according to preliminary findings from the Immune Development in Early Life (IDEaL) Rome Cohort, to be presented at the Pediatric Academic Societies (PAS) 2026 Meeting in Boston.

The research draws on clinical assessments conducted at 2, 5, 9, and 12 months of age, supplemented by structured phone follow-ups. Physician-diagnosed respiratory infections and wheezing episodes were logged in a dedicated electronic case report form. Residential postal codes were matched to the nearest government air quality monitoring station to estimate individual exposure to particulate matter (PM10), nitrogen oxides (NOx), and nitrogen dioxide (NO2). Cumulative pollutant exposure was computed up to each assessment visit, and pairwise Spearman correlations were evaluated between exposure metrics and infection outcomes.

Higher cumulative exposure to ambient air pollutants was associated with an increased number of respiratory infections during infancy. Significant positive correlations were observed for PM10 (r=0.47, p<0.001), NOx (r=0.39, p<0.001), and NO2 (r=0.39, p<0.001) with total recurrent respiratory infections. Similar associations were identified with wheezing episodes, with PM10 showing a correlation of r=0.25 and NOx and NO2 each at r=0.24 and r=0.23 respectively (all p<0.001).

Individual infection types including bronchiolitis, bronchitis, acute otitis media, SARS-CoV-2 infection, and tonsillitis also demonstrated significant, though more modest, associations with pollutant exposure, averaging approximately r=0.20.

The findings support an association and potential role for ambient air pollution in increasing respiratory infection burden during early childhood. Researchers note that integration of high-resolution environmental monitoring data will be needed to refine exposure estimates and clarify the mechanisms through which pollutants may impair infant immune defenses.

The work raises the possibility that early environmental health protections could reduce infection vulnerability in infancy. Lead author Donato Amodio, MD, PhD, Assistant Professor at Ospedale Pediatrico Bambino Gesu (OPBG), is among the presenting authors at the PAS 2026 Meeting, which takes place April 24-27 in Boston.