Spatial Distribution of Microbes in the Apartment Transition Spaces and Exposure Risks Along Resident Flow Paths

The microbial contamination levels in the apartment transition spaces, frequently traversed by pedestrians, are closely related to resident health. This study analyzed the microbial distribution in these spaces and modeled and assessed the microbial exposure risk faced by residents following different flow paths. The results showed that the dominant genera of airborne microbes, settling microbes, wall microbes, and ground microbes were Staphylococcus, Bacillus, and Micrococcus, collectively accounting for over 70% of the total microbial population. The concentration of settling microbes in noncorridor spaces was 9.7 times higher than in corridor spaces, necessitating targeted disinfection of settling microbes in noncorridor spaces. The analysis of biodiversity indices elucidates the extent to which the biodiversity of different types of microbes is affected by variations in pedestrian flow, with airborne microbes being the most affected and ground microbes the least affected. This study also constructed a microbial exposure risk assessment model during residents’ mobility in the apartment transitional spaces. Based on this model, it was confirmed that nonfirst-floor residents using the elevator to enter and exit their homes face the highest exposure risk to airborne microbes and wall microbes, while those using the stairwell face the highest exposure risk to settling microbes and ground microbes. First-floor residents face the lowest microbial exposure risk when entering and exiting their homes. The research results not only establish a microbial exposure risk assessment system but also provide important theoretical reference for evaluating and improving the environmental quality of other similar scenarios.