Spatiotemporal Contamination Characteristics, Bacterial Community Structure, and Airflow-Mediated Transport of Bacterial Aerosols in a Pediatric Emergency Consulting Room.

Pediatric emergency consulting rooms are characterized by high occupant density and frequent close-range interactions, creating potential hotspots for microbial aerosol exposure and cross-transmission in hospital built environments. However, microbial contamination and its spatial heterogeneity across different environmental media in pediatric emergency consulting rooms under routine clinical conditions remain insufficiently characterized. This study investigated a pediatric internal medicine emergency consulting room in a children's hospital to clarify bacterial contamination characteristics and airflow-driven transport mechanisms. Field sampling of culturable bacteria, high-throughput sequencing, and computational fluid dynamics simulations were combined to analyze airborne and surface contamination, culturable bacterial community structure, aerosol transport, deposition, and infection risk. The results showed limited differences in culturable airborne bacteria among sampling locations, likely reflecting ventilation-driven mixing within the small consulting room, whereas surface deposition exhibited pronounced spatial heterogeneity, with higher contamination on the floor and some wall surfaces. Bacterial aerosols smaller than 3.3 μm accounted for 73.47% of the total, indicating respirable fine particles as the dominant exposure fraction. Bacillota, Pseudomonadota, and Actinomycetota dominated the culturable bacterial communities, with Staphylococcus as the core genus. Numerical simulations indicated that airflow organization significantly affected aerosol dispersion and deposition, producing localized high-concentration and high-risk regions around the occupants and consultation desk. The consultation desk and floor accounted for 79.71% of the total deposited particles. These findings provide scenario-specific evidence for ventilation optimization, targeted disinfection, and exposure control in comparable pediatric emergency consulting environments.