Short-term personal exposure to multiple air pollutants affects nasal microbiota in school-age children

Air pollution has significant harmful effects on human health, particularly on children living in urban environments. Disruption of upper respiratory microbiota can represent a key factor in the development of diseases and symptoms. This panel study analyze how personal exposure to air pollutants on the nasal microbiota of school-age children in Milan, Italy, across two seasons. We monitored short-term (~16 h) personal exposure to Volatile Organic Compounds (VOC) and equivalent Black Carbon (eBC) in 95 children during winter and 74 during spring, with 68 children monitored both seasons. Our analysis of nasal microbiota reveals that both types of pollutants influenced microbiota diversity, and the relative abundance of key genera, such as Corynebacterium, Moraxella, and Streptococcus. Notably, seasonality played a significant role in modulating the relationship between exposure and microbiota, with distinct effects observed in winter compared to spring. Our findings show that air pollution, particularly short-term exposure, alters the nasal microbiota in children. However, further research is needed to determine whether and how these changes influence respiratory health.