Infants aged 2 years or younger with bronchiolitis faced an increased risk for hospitalization due to air pollution, with a meta-analysis indicating a positive association between exposure to elevated levels of particulate matter (PM) and gaseous pollutants and the risk for hospitalization -- an association that was significant only for PM with a diameter ≤ 10 μm.
"Given that some of the air pollutants associated with hospitalization are well-established traffic-related compounds (eg, NO2), traffic mitigation strategies might play a relevant role in limiting the burden of bronchiolitis in infants," the authors wrote.
Gregorio Paolo Milani, MD, with the University of Milan, Milan, Italy, was the corresponding author of the study, which was published online on May 13 in Pediatric Allergy and Immunology.
Reliance on estimates rather than direct measurements of odds ratios may have overestimated associations, and significant variability in study designs, exposure assessment methods, and control for confounders complicated the comparisons. Additionally, fixed-site monitoring data may not have accurately captured individual-level exposures.
This study was partially supported by the Italian Ministry of Health. The authors reported having no conflicts of interest.