Determination of the trend and spatial distribution of microbial levels based on space and occupant characteristics

For buildings to move beyond the conventional criteria of comfort, we require more metrics and tools to design spaces that enhance health and safety where microbes play a significant role. The knowledge gaps that exist with respect to the indoor environment and microbes mean we have not been able to monitor microbial health in real time or inform building design to create infection-resilient indoor spaces. This study determines the influence of occupant characteristics and built air exchange components on the presence and spatial distribution of particles, bacteria, and fungi. The analysis utilized microbial and particulate samples collected from educational institutions. Mann-Whitney-Wilcoxon, Spearman rank correlation, clustering, and standard regression analysis were applied. Tracking particle levels could provide reliable insight into microbial concentrations in indoor spaces. The number of occupants and age group played a significant role. The influence of vents on outdoor-related bacteria weakens as we move closer to the floor where the impact of occupants' presence starts to dominate. Significant transition of spatial distribution of indoor signature occurs at a distance of 80 % from the side of the door and halfway from the floor. Linear regression models captured these trends. The novel research findings point the way towards maintaining and understanding the microbial health of a space through real-time monitoring of particle level changes, and spatial analysis to assess the limitations of ventilation and building elements within the context of occupant characteristics. The results can provide building maintenance pathways for an immediate response to reduce transmission rates of respiratory disease.